I. Symbol for iodine. Properties: Brownish-black, syrupy liquid. Burning

taste. Tarry odor. Incompatible with acids, alka-

loids, carbonate, hydroxides, mercuric chloride; sol-

131

I. See iodine-131.

uble in water, alcohol-ether, or alcohol-ether-water

mixture; partially soluble in alcohol and ether; mis-

IAA. Abbreviation for 3-indoleacetic acid.

cible with glycerol.

Derivation: Aqueous solution of sulfonated ammo-

IATA. Abbreviation for International Air Trans-

nium compounds derived from the action of sulfuric

port Association (Geneva), which publishes annual

acid on distillates from bituminous shales.

regulations for air shipment of hazardous materials.

Grade: NF.

Use: Pharmaceutical products such as skin oint-

IBIB. Abbreviation for isobutyl isobutyrate.

ments, cosmetic preparations, special dermatologi-

cal soaps.

ibuprofen. (p-isobutyl-hydratropic acid; 2-(4-

isobutylphenyl)propionic acid).

“Ichthymall” [Mallinckrodt]. TM for

CAS: 15687-27-1. C

ichthammol.

Properties: Mw 206.31.

Use: Ingredient in over-the-counter pain relievers.

“Ichthyol.” [Mallinckrodt]. TM for

-ic. A suffix, used in naming inorganic com-

ichthammol.

pounds, that indicates that the central element is

present in its highest oxidation state. Thus in ferric

ICP. See inductively coupled plasma emission

chloride (FeCl

) the iron has an oxidation number of

spectroscopy.

+3, equivalent to its valence: in an ionized state it

would have three positive charges (Fe

). (A recom-

-ide. A suffix used in naming compounds com-

mended change in this system of nomenclature is to

posed of two elements; in such names the first (elec-

use the common name of the element (iron) together

tropositive) element retains its name without

with a Roman numeral showing the oxidation num-

change, while the second (electronegative) bears the

ber; thus, ferric chloride would be iron (III) chlo-

suffix -ide as a modification of the elemental name.

ride.)

Examples: sodium hydroxide, magnesium chloride,

hydrogen sulfide, etc. Similarly, oxygen is modified

ICC. Abbreviation for ignition control com-

to oxide, fluorine to fluoride, phosphorus to phos-

pound; also Interstate Commerce Commission.

phide, and carbon to carbide.

ice. (H

O).

ideal gas. (perfect gas). A gas in which there is

Properties: An allotropic, crystalline form of water.

complete absence of cohesive forces between the

Mp 0C (32F), latent heat of melting 80 calories/g, d

component molecules; the behavior of such a gas

0.91. Its property of melting under pressure accounts

can be predicted accurately by the ideal gas equation

for slipperiness. Occurs in nature as ice I, but several

through all ranges of temperature and pressure. The

other forms are known.

concept is theoretical, since no actual gas meets the

Use: Preservation of fish at sea, medicine (reduction

ideal requirement; carbon dioxide especially lacks

of swelling).

conformity. The generalized ideal gas law is derived

See water.

from a combination of the laws of Boyle and

Charles, namely pv

RT, where p is pressure, v is

Iceland moss.

volume, T is absolute temperature and R is the gas

Properties: A water-soluble gum that gels on

constant (p0v0/273.2C).

cooling.

Derivation: A lichen growing in Scandinavia and

ideal solution. A solution that exhibits no

Iceland.

change of internal energy on mixing and complete

Use: Flavoring for alcoholic beverages, food addi-

uniformity of cohesive forces. Its behavior is de-

tive, cosmetics.

scribed by Raoult’s law over all ranges of tempera-

ture and concentration.

Iceland spar. A form of calcite having unique

optical properties.

Use: Polarizing light (Nicol prism).

identification limit. Minimum quantity of a

material that can be revealed by a given reaction or

ichthammol. (ammonium ichthosulfonate). test.

681

682IDENTITY PERIOD

identity period. The repeating unit or monomer example, gadolinium fixed to a targeting antibody is

that occurs n times in a natural or synthetic polymer used in MRI.

molecule; for example, the anhydroglucose unit in

cellulose is enclosed in brackets:

imazaquin.

CAS: 81335-37-7. mf: C

Hazard: Moderately toxic by ingestion and skin con-

tact. Low toxicity by inhalation.

Use: Agricultural chemical.

Imhoff tank. A reinforced concrete structure of

considerable size (approximately 35 ft high) de-

signed especially for sewage clarification. Its princi-

pal features are (1) an upper or sedimentation com-

IFT. Abbreviation for the Institute of Food Tech-

partment in which in-flowing sewage deposits its

nologists.

suspended solids by gravity (residence time 2–3

hours), the free water being drawn off through an

Ig. Abbreviation for immunoglobulin.

outlet, and (2) a separate lower compartment in

which digestion of the accumulated sediment

“Igenal” [BASF]. TM for a series of dyestuffs

(sludge) takes place. The sludge is passed from the

for chrome-tanned leather. Characterized by unusu-

upper compartment to the digestion chamber

al tinctorial power.

through an inclined slot or channel. The gases gener-

ated by digestion are released through suitably locat-

ignition control compound. A substance,

ed vents. The digested sludge is removed through

such as methyl diphenyl phosphate or trimethyl

outlet pipes at intervals of about 6 months. The dried

phosphate, added to gasoline to control spark plug

sludge contains 2–3% ammonia and 1% phosphoric

fouling, surface ignition, and engine rumble.

acid, which make it suitable as a soil conditioner.

See sewage sludge.

ignition point. See autoignition temperature.

imidazo(2,1-a)isoquinoline, 5,6-dihydro-2-

ignotine. See carnosine.

(m-methoxyphenyl)-.

CAS: 61001-21-6. mf: C

IILE. Ion-induced light emission.

Hazard: A reproductive hazard.

“Illium” [Stainless Foundry]. TM for a se-

imidazole. (glyoxalin).

ries of stainless–steel and nickel-base alloys with a

CAS: 288-32-4.

high corrosion resistance.

illoxan.

❘

CHNCH

❘

CH. A dinitrogen ring compound. An an-

CAS: 51338-27-3. mf: C

timetabolite and inhibitor of histamine. Colorless crys-

Hazard: Moderately toxic by ingestion and skin con-

tals; mp 90C; bp 257C; soluble in water, alcohol, and

tact. Low toxicity by inhalation.

ether.

Use: Agricultural chemical.

Use: Biological control of pests, especially fabric-

feeding insects, often in combination with dl-p-fluo-

rophenylalanine, an amino-acid inhibitor; also as a

ilmenite. (titanic iron ore). FeO•TiO

. Iron-

contact insecticide in an oil spray. The mechanism is

black mineral, black to brownish-red streak, subme-

that of structural antagonism rather than active tox-

tallic luster, resembles magnetite in appearance but

icity.

is readily distinguished by feeble magnetic charac-

See antihistamine; antagonist, structural.

ter, d 4.5–5, Mohs hardness 5–6.

Occurrence: Widely in U.S., Canada, Sweden, the

former U.S.S.R., India; also made synthetically.

4,5-imidazoledicarboxamide. See glycarby-

Use: Titanium paints and enamel, source of titanium

lamide.

metal, welding rods, titanium alloys, ceramics.

4-imidazole ethylamine. See histamine.

“Imag” [Mallinckrodt]. TM for a potassium

iodide mixture containing 90% potassium iodide

and made free-flowing with 8% magnesium carbon-

2-imidazolidinone. See ethylene urea.

ate and 2% potassium hydroxide.

2-imidazolidone. See ethylene urea.

imaging contrast agent. Added to a sample to

increases the intensity of the signal detected by an

imaging technique such as MRI and ultrasound. For

imidazo(4,5-d)pyrimidine. See purine.

683 IMP

2-(1h-imidazol-4-ylmethyl)-8h-indeno(1,2- “Immedial” [BASF]. TM for a series of sulfur

d)thiazole monofumarate.

dyestuffs. Characterized by very good fastness to

CAS: 159081-23-9. mf: C

S•C

light and good fastness to washing and perspiration.

Hazard: A poison by ingestion.

Use: Dyeing of cotton and rayon.

immiscible. Descriptive of substances of the

(1-imidazolyl)tributylplumbane.

same phase or state of matter that cannot be uniform-

CAS: 16128-42-0. mf: C

Pb.

ly mixed or blended. Though usually applied to

Hazard: A poison.

liquids such as oil and water, the term also may refer

to powders that differ widely in some physical prop-

imide. A nitrogen-containing acid having two

erty, e.g., specific gravity, such as magnesium car-

double bonds.

bonate and barium sulfate.

See succinimide; phthalimide.

See miscibility.

imidine. Derivative of an acid amide.

immune endoglobulin.

R−C:NH−NH

CAS: 9007-83-4.

Hazard: Low toxicity by ingestion. Human systemic

imine. A nitrogen-containing organic substance

effects

having a carbon-to-nitrogen double bond.

Source: Human natural product.

immune response. The generation of antibod-

ies to an antigen by a vertebrate organism.

Such compounds are highly reactive, even more so

than the carbon-nitrogen triple bond characteristic of

immune serum globulin. A sterile solution of

nitriles.

globulins that contains those antibodies normally

present in adult blood. Over 90% of the total protein

is globulin. It is a transparent, nearly colorless, near-

3,3

′

-iminobispropylamine. (dipropylene tria-

ly odorless liquid. Must be kept refrigerated.

mine; 3,3

′

-diaminodipropylamine).

Derivation: From a plasma or serum pool of venous

CAS: 56-18-8. H

NHC

or placental blood from 1000 or more individuals.

Properties: Colorless liquid. D 0.9307 (20/20C), bp

Grade: USP.

240.6C, fp −6.1C, flash p 175F (79.4C) (CC). Solu-

Use: Medicine (immunology).

ble in water and polar organic solvents. Combus-

See antigen; globulin.

tible.

Hazard: Toxic by ingestion and inhalation; irritant.

immune system. The complex group of cells

Use: Intermediate for soaps, dyestuffs, rubber chemi-

and organs that defends the body against infection

cals, emulsifying agents, petroleum specialties, in-

and disease.

secticides, and pharmaceuticals.

immunochemistry. That branch of chemistry

iminodiacetic acid disodium salt hydrate.

concerned with the various defense mechanisms of

(iminodiethanoic acid disodium salt hydrate).

the animal organism against infective agents, partic-

CAS: 142-73-4. HN(CH

NA)

•xH

ularly the response between the body and foreign

Properties: Crystalline solid.

macromolecules (antigens) and the interaction be-

Hazard: Irritant.

tween the products of the response (antibodies) and

Use: Intermediate for surface-active agents, complex

the agents that have elicited them. This involves

salts, chelating agents, and aminocarboxylic acid

study of the many proteins (serum globulins, en-

synthesis.

zymes, bacteria, and viruses) involved in these re-

sponses. It developed from the original work of

iminodiacetonitrile. HN(CH

CN)

Jenner (1775) and Pasteur (1880).

Properties: Light-tan, crystalline solid. Mp 77–78C.

See antigen-antibody; complement.

Soluble in water and acetone.

Use: Chemical intermediate.

immunoglobulin. See globulin; immune se-

rum globulin.

l-N

)-(1-iminoethyl)lysine hydrochloride.

CAS: 150403-89-7. mf: C

•ClH.

immunotherapy. Using the immune system to

Hazard: A poison.

treat disease, for example, in the development of

vaccines. May also refer to the therapy of diseases

iminourea. See guanidine.

caused by the immune system.

See cancer.

“Imlar” [Du Pont]. TM for vinyl resin−base

finish used where extreme resistance to abnormal

IMP. (1) Abbreviation for inosine monophos-

chemical exposure is required. phate.

684IMPACT STRENGTH

See inosinic acid; sodium inosinate. (2) Abbreviation arsenic atoms are present in germanium crystals in

this percentage; this fact is largely responsible for

for insoluble metaphosphate (Maddrell salt).

the semiconducting properties of germanium. Here

See sodium metaphosphate.

the impurity is beneficial, but often it is detrimental,

for example, in graphite used as a moderator in

impact strength. The ability of a material to

nuclear reactors, and in many metallic catalysts. In

accept a sudden blow or shock without fracture or

the air, trace amounts of sulfur dioxide and carbon

other substantial damage, measured by standard im-

monoxide are potentially dangerous impurities in

pact-testing equipment (Izod, Charpy). It is a prop-

concentration of 5 ppm of sulfur dioxide and 50 ppm

erty of hard, friable materials such as metals, hard

of carbon monoxide.

rubber, engineering plastics, Portland cement, glass,

See purity; chemical; trace element; air pollution;

etc.

semiconductor; purification.

impalpable. Descriptive of a state of subdividion

inborn errors of metabolism. Inherited dis-

of particles so fine that the individual particles can-

eases resulting from alterations in genes that code

not be distinguished as such by pressing a powder

for enzymes.

between the thumb and index finger.

incendiary gel. (1) Mixture of thermite sus-

impeller. A type of agitator used in mixing or

pended in oil set to a jelly with a small amount of

blending fluids of low viscosity, usually in a cylin-

soap; it undergoes spontaneous ignition on contact

drical chamber, either open or closed. The motion

with air. Another type may contain magnesium in

induced by an impeller is a combination of flow and

jellied oil. (2) Jellied gasoline combined with thick-

turbulence, the proportion of each depending on the

ening agents such as napalm or finely divided mag-

size, speed, and position of the impeller. In common

nesium.

use are the marine propeller, the turbine, and the

helical ribbon types. Propeller and turbine impellers

incineration. Disposal of solid and liquid organ-

are attached to a power-driven rotating shaft that

ic waste materials by burning at temperatures from

enters the container either vertically (top entering)

1200 to 1500C. This method is approved by the EPA

or at an angle (side entering), they may be centered

for use on very toxic organic chemicals and chemi-

in a liquid or placed off center, depending on the

cal wastes. Use of specially equipped incinerator

flow pattern desired. The propeller type has from

ships for burning chemical wastes at sea has become

two to four elliptical blades, whereas the turbine has

a common practice.

a number of rectangular blades set vertically or at an

See waste control.

angle. A wide range of flow-turbulence patterns can

be obtained with either type. Helical ribbon impel-

inclusion complex. (adduct). An unbonded as-

lers are used for viscous liquids and dry powders.

sociation of two molecules in which a molecule of

Many variations of impellers are available for liq-

one component is either wholly or partly locked

uids up to medium viscosity for a multitude of spe-

within the crystal lattice of the other. There are

cial mixing techniques.

several types of such complexes, the most familiar

See agitator; mixing.

being the so-called clathrates (from Latin, “cross-

bars of a grating”). The clathrate compound

imperial green. See copper acetoarsenite.

(OH)

•SO

may be depicted as

“Implex” [Rohm & Haas]. TM for thermo-

plastic, high-impact acrylic molding powder, sup-

plied in natural and colored forms. Maximum

toughness, gloss, stain-, and heat-resistant grades.

Use: Shoe heels, business-machine and musical in-

strument keys, housings, automotive parts, knobs,

metalized parts, etc.

where the interlocked rings denote mutual enclosure

imprinting. A biochemical phenomenon that de-

of two identical cages. The formula for any clathrate

termines, for certain genes, which one of the pair of

compound is determined by the ratio of available cavi-

alleles, the mother’s or the father’s, will be active in

ties to the amount of cage material. Inclusion com-

that individual.

pounds can be used to separate molecules of different

shapes, e.g., straight-chain hydrocarbons from those

impurity. The presence of one substance in an-

containing side chains, as well as structural isomers.

other, often in such low concentration that it cannot

They can also be used as templates for directing chem-

be measured quantitatively by ordinary analytical

ical reactions.

methods. It is impossible to prepare an ideally pure

See clathrate compound; gas hydrate.

substance. In certain metal crystal lattices, foreign

substances can exist in as low a concentration as

“Incoloy” [Inco]. TM for a series of corrosion-

one-millionth of an atomic percent. For example, resistant alloys of nickel, iron, and chromium.

685 INDICATOR

incomplete penetrance. The gene for a condi- polymers on exposure to air and sunlight. Combus-

tion is present, but not obviously expressed in all tible.

individuals in a family with the gene. Derivation: Contained in the fraction of crude coal

tar distillates that boils from 176–182C.

Hazard: Toxic by inhalation. TLV: 10 ppm.

“Inconel” [Inco]. TM for a series of corrosion-

Use: Preparation of coumarone-indene resins, inter-

resistant alloys of nickel and chromium.

mediate.

See coumarone.

IND. Abbreviation for investigational new drug.

indenolol hydrochloride.

“Indalone” [FMC]. TM for n-butyl mesityl

CAS: 68906-88-7. mf: C

•ClH.

oxide oxalate.

Hazard: Moderately toxic by ingestion.

Use: Insect repellents that can be applied directly on

the skin.

indeno(1,2,3-cd)pyrene.

See butopyronoxyl.

CAS: 193-39-5. mf: C

Properties: Yellow crystals from cyclohexane;

indan. (hydrindene; 2,3-dihydroindene).

bright-yellow plates from pet ether

CAS: 496-11-7.

Hazard: Confirmed carcinogen.

❘

HCHCHCHC

❘

independent assortment. During meiosis

each of the two copies of a gene is distributed to the

Bicyclic.

germ cells independently of the distribution of other

Properties: Colorless liquid. Bp 176.5C, fp −51.4C,

genes.

refr index 1.5388 (16.4C), d 0.965 (20/4C). Insolu-

See linkage.

ble in water; soluble in alcohol and ether. Combus-

tible.

indeterminate error. An error that cannot be

Derivation: From coal tar.

identified.

Hazard: Irritant to skin and eyes.

Use: Organic synthesis.

indinavir sulfate.

CAS: 157810-81-6. mf: C

•H

indanthren blue 3g. See 6,15-dihydrohy-

Hazard: Moderately toxic by ingestion.

droxy-5,9,14,18-anthrazinetetrone.

Indian red. (iron saffron). A red (maroon)

indanthrene. See indanthrone.

pigment made by calcining copperas to obtain red

ferric oxide. Fine particle size.

indanthrene yellow. See flavanthrene.

Use: Pigment in paint, rubber, and plastics; polishing

agent.

indanthrone. (Indanthrene Blue R; 6,15-dihy-

See iron oxide red; rouge.

dro-5,14,18-anthrazinetetrone).

CAS: 81-77-6. C

. A blue vat dye or pig-

Indian yellow. (1) (Aureolin) A yellow pigment

ment. The molecule consists of two anthraquinone

distinguished by being unaffected by hydrogen sul-

nuclei linked through two −NH groups.

fide. It is durable, without action on other pigments,

Properties: Heat- and light-stable blue powder. De-

and is permanent in oils and water-color. It consists

composes at 470C. Soluble in concentrated sulfuric

of a double nitrite of cobalt and potassium and is

acid and dilute alkaline solutions.

prepared by adding excess of potassium nitrite solu-

Derivation: By fusion of ␤-aminoanthroquinone

tion to a solution of cobalt nitrate acidified with

with caustic potash in the presence of potassium

acetic acid. (2) Also sometimes used for the yellow

nitrate.

synthetic dye primuline.

Use: Dyeing unmordanted cotton, pigment in quality

See cobalt potassium nitrite.

paints and enamels.

indicator. An organic substance (usually a dye or

indazol blue r. See C.I. basic blue 16.

intermediate) that indicates by a change in its color

the presence, absence, or concentration of some

indene.

other substance, or the degree of reaction between

CAS: 95-13-6.

two or more other substances. The most common

example is the use of acid-base indicators such as

❘

HCHCHCHC

❘

CHCH

❘

. litmus, phenolphthalein, and methyl orange to indi-

cate the presence or absence of acids and bases, or

Properties: Colorless liquid. D 0.996 (20/4C), fp the approximate concentration of hydrogen ion in a

−3.5C, bp 182C, refr index 1.5726 (25C), flash p solution.

173F (78.3C). Insoluble in water; soluble in most Use: Analytical chemistry. The pH ranges of several

organic solvents; oxidizes readily in air. Forms typical indicators are as follows:

686INDIGO

on silver-plated steel aircraft bearings that are tar-

alizarin yellow R 10.1–12.0 yellow to red

nish resistant, radiation detector.

methyl orange 3.1– 4.4 red to yellow

phenolphthalein 8.3–10.0 colorless to red

indium acetylacetonate. In(C

)

phenol red 6.8– 8.4 yellow to red

Properties: Mp 186C.

litmus 4.4– 8.3 red to blue

Hazard: See indium.

Congo red 3.0– 5.2 blue to red

Use: Catalyst.

bromthymol blue 6.0– 7.6 yellow to blue

chlorphenol red 5.2– 6.8 yellow to red

indium antimonide. InSb.

cresol purple 7.4– 9.0 yellow to

Properties: Crystalline solid. Mp 535C.

purple

Hazard: See indium; antimony.

See titration; pH.

Use: Electronic grade used for semiconductor de-

vices and infrared detector, computer technology

(Hall effect).

indigo. (indigotin; synthetic indigo blue; CI

73000).

indium arsenide. InAs.

CAS: 482-89-3. C

. A double indole deriva-

Properties: Crystals. Mp 943C. Insoluble in acids.

tive.

Hazard: See indium; arsenic.

Use: Electronic grade for semiconductor devices, in

injection lasers.

indium chloride. (indium trichloride).

CAS: 10025-82-8. InCl

Properties: White powder. Deliquescent. D 3.46

(25C), mp 586C, sublimes at 300C. Soluble in alco-

Properties: Dark blue, crystalline powder; bronze

hol and water.

luster. D 1.35, sublimes at 300C (decomposes). Sol-

Derivation: Direct union of the elements or by the

uble in aniline, nitrobenzene, chloroform, glacial

action of hydrochloric acid on the metal.

acetic acid, and concentrated sulfuric acid; insoluble

Hazard: See indium.

in water, ether, and alcohol.

Derivation: From aniline and chloroacetic acid, and

indium oxide. (indium sesquioxide; indium

fusing the resulting phenylglycine with alkali and

trioxide).

sodium amide. Formerly from plants of genus Indi-

CAS: 1312-43-2. In

gofera.

Properties: White to light-yellow powder in both

Grade: Technical, pure.

amorphous and crystalline forms, depending on

Use: Textile dyeing and printing inks, manufacture of

temperature. D 7.179. Soluble in hot acid (amor-

indigo derivatives, paints, analytical reagents.

phous); insoluble (crystals).

Derivation: By burning the metal in air or heating the

indirect dye. A mordant dye.

hydroxide, nitrate, or carbonate.

Hazard: See indium.

Use: Manufacture of special glasses.

indium.

CAS: 7440-74-6. In. Metallic element atomic num-

indium phosphide. InP. A brittle metallic

ber 49, of group IIIA of the periodic table, aw

mass, mp 1070C, slightly soluble in mineral acids.

114.82, valences of 1, 3; 2 stable isotopes.

Hazard: See indium.

Properties: Ductile shiny silver-white metal. D 7.31

Use: Electronic grade in semiconductor devices, in-

(20C), mp 156C, bp 2075C, Mohs hardness 1.2.

jection lasers, and experimental solar cells.

Softer than lead. Soluble in acids; insoluble in alka-

lies. Corrosion-resistant at room temperature. Oxi-

indium sulfate.

dizes readily at higher temperatures.

CAS: 13464-82-9. In

(SO

)

Occurrence: Not found native but in a variety of zinc

Properties: Grayish powder. Deliquescent. D 3.438.

and other ores. The indium content is generally very

Soluble in water. Decomposed by heat.

low, rarely exceeding 0.001%. Indium-bearing ores

Hazard: See indium; tellurium.

occur in the western U.S., Canada, Peru, Japan,

Europe, the former U.S.S.R.

indium telluride. In

Available forms: Small ingots or bars, shot, pencils,

Properties: Black, friable crystals; D 5.8, mp 665C.

wire, sheets, powder, single crystals. Purity: Techni-

Hazard: See indium.

cal, high purity (below 10 ppm impurities).

Use: Semiconductor technology.

Hazard: Metal and its compounds toxic by inhala-

tion. TLV: 0.1 (In) mg/m

Use: Automobile bearings, electronic and semicon-

indium trichloride.

ductor devices, low-melting brazing and soldering CAS: 10025-82-8. InCl

alloys, reactor control rods, electroplated coatings Properties: Tan to yellow deliquescent crystals. D

687 “INDUSTRENE”

4.0, mp 585C (sublimes). Soluble in water. Keep in Use: Medicine for treatment of arthritis.

closed containers.

Hazard: See indium.

indomethacin sodium trihydrate.

Use: Electroplating baths.

CAS: 74252-25-8. mf: C

ClNO

•3H

O•Na.

Hazard: A poison by ingestion.

“Indo Carbon” [BASF]. TM for sulfur dye-

indophenine reaction. Intense blue coloration

stuffs.

given by thiophene or its derivatives when treated

Use: Dyeing and printing of cotton and rayon.

with concentrated sulfuric acid with a trace of isatin.

“Indocin.” TM for the antiinflammatory drug

“Indopol” [BP Amoco]. TM for viscous poly-

indomethacin.

butenes.

Use: Treatment of arthritis.

Available forms: Liquid.

Grade: 10 viscosity.

indole. (2,3-benzopyrrole).

Use: In lubricating-oil additives for ashless disper-

CAS: 120-72-9.

sant; processing, rolling, and compressor oils;

caulks, sealants, adhesives; as an elastomeric pro-

cess aid; and cling improver in cling films.

indospicine monohydrochloride

monohydrate.

Properties: White to yellowish scales, turning red on

CAS: 16377-01-8. mf: C

•ClH•H

exposure to light and air; unpleasant odor in high

Hazard: A reproductive hazard.

concentration but pleasant in dilute solutions. Mp

Source: Natural product.

52C, bp 254C. Soluble in alcohol, ether, hot water,

and fixed oils; insoluble in mineral oil and glycerol.

indoxacarb.

Derivation: From indigo and by numerous synthe-

CAS: 173584-44-6. mf: C

ClF

ses. Also can be produced from the 220–260C frac-

Hazard: A poison by ingestion. Low toxicity by

tion of coal tar.

inhalation and skin contact.

Grade: Technical, CP, FCC.

Use: Agricultural chemical.

Hazard: A carcinogen.

Use: Chemical reagent, perfumery.

induced fit. A change in the conformation of an

enzyme in response to substrate binding that renders

3-indoleacetic acid. (IA; IAA; ␤-indoleacetic

the enzyme catalytically active. It is one of the mod-

acid).

els used to explain substrate specificity.

CAS: 87-51-4. C

NCH

COOH. A plant hormone.

Properties: Crystals. Mp 168–170C. The natural

inducer. A signal molecule that, when bound to a

material is levorotatory, specific rotation −3.8 de-

regulatory protein, produces an increase in the ex-

grees in alcohol (20C). Insoluble in water and chlo-

pression of a given gene.

roform; soluble in alcohol and ether.

Use: Agriculture and horticulture, growth-promoting

induction. An increase in the expression of a

hormone, plant cell enlarger.

gene in response to a change in the activity of a

See auxin; plant growth regulator.

regulatory protein.

indole-␣-aminopropionic acid. See trypto-

inductively coupled plasma emission

phan.

spectroscopy. (ICP). An analysis system in

which the energy of a plasma excites the atoms of an

3-indolebutyric acid. (hormodin).

injected sample causing the excited atoms to emit

CAS: 133-32-4. C

N(CH

)

COOH.

light at signature wavelengths. Three-dimensional

Properties: White or off-white powder; essentially

computer-generated images are used to interpret the

odorless. Mp 123C. Insoluble in water; soluble in

results.

alcohols and ketones.

Use: Plant hormone, especially used in rooting

indulines. Blue azine dyestuffs obtained by the

plants.

interaction of amino-azo benzene and aniline hydro-

See auxin; plant growth regulator.

chloride.

indole-2,3-dione. See isatin.

indurite. Explosive containing 40% guncotton

and 60% nitrobenzene.

indomethacin. (USAN name for 1-(p-chloro-

benzoyl)-5-methoxy-2-methylindole-3-acetic

“Industrene” [Crompton & Knowles]. TM

acid). for fatty acids.

CAS: 53-86-1. C

ClNO

. Use: Rubber compounding, foam dispersants, lubri-

688INDUSTRIAL ALCOHOL

cants, water repellents, polishes, metallic soaps, enamels, drying, photography.

crayons, alkyd resins, mineral flotation adjuvants, See radiation.

and emulsifiers.

infrared spectroscopy. An analytical tech-

nique that may measure either (1) the range of wave-

industrial alcohol. See alcohol, industrial.

lengths in the infrared that are absorbed by a speci-

men, which characterize its molecular constitution

industrial carbon. See carbon, industrial.

(absorption spectroscopy), or (2) the infrared waves

emitted by excited atoms or molecules (emission

industrial chemistry. See chemical technol-

spectroscopy). Extremely hot bodies (stars) emit

ogy; chemical process industry.

spectra in which the atomic composition can be

determined by characteristic lines such as the sodi-

industrial diamonds. See diamonds, indus-

um D line in the sun’s spectrum. Infrared absorption

trial.

bands identify molecular components and struc-

tures, some of which are:

industrial dust. See dust, industrial.

Absorption Band (␮) Structure Indicated

industrial waste. See waste control; chemi-

2.3–3.2 OH and NH groups; H

cal waste.

3.2–3.3 aromatics, olefins

3.33–3.55 aliphatics

inert. A term used to indicate chemical inactivity

5.7–6.1 aldehydes, ketones, acids,

in an element or compound. Helium, neon, and ar-

amides

gon are practically inert gaseous elements; carbon

See microwave spectroscopy; absorption (2).

dioxide is a gaseous compound of low activity. In-

gredients added to mixtures chiefly for bulk and

“Infrax” [Carborundum]. TM for a refractory

weight purposes are said to be inert.

insulation used as primary linings of fuel-fired and

See noble; extender.

electric furnaces only when protected by a cement

facing. Available in brick form.

inert gas. Gaseous element of group 18 of the

periodic table, such as helium or argon, which is

infusion. An aqueous solution obtained by treat-

nonreactive under ordinary conditions. These gases

ing drugs with hot or cold water, without boiling.

are not completely unreactive and inert gas com-

Generally prepared by pouring boiling water upon

pounds have been synthesized.

the vegetable substance and macerating the mixture

in a tightly closed vessel until the liquid cools. When

infinite dilution. Point of maximum dissocia-

not otherwise specified, they are of 5% strength by

tion of an electrolyte at which point the greatest

weight.

amount of conductivity has been reached.

infusorial earth. See diatomaceous earth.

informatics. The study of the application of com-

puter and statistical techniques to the management

ingot iron. Highly refined steel with a maximum

of information. In genome projects, informatics in-

of 0.15% impurity. Due to high purity it has excel-

cludes the development of methods to search data-

lent ductility and resistance to rusting.

bases quickly, to analyze DNA sequence informa-

tion, and to predict protein sequence and structure

ingrain dye. An insoluble dye developed by

from DNA sequence data.

impregnating a fabric with one or more intermedi-

See bioinformatics.

ates and then producing the dye by reaction with a

different intermediate.

informational macromolecules. Biomolec-

ules containing information in the form of specific

inherit. In genetics, to receive genetic material

sequences of different monomers; for example,

from parents through biological processes.

many proteins, lipids, polysaccharides, and nucleic

acids.

inherited. See inherit.

informed consent. An individual willingly

“Inhibisil” [PPG]. TM for a non-toxic corro-

agrees to participate in an activity after first being

sion inhibiting silica pigment for metal finishes.

advised of the risks and benefits.

Use: Paints and coatings.

See privacy.

infrared. The region of the electromagnetic spec- inhibitor. (1) A compound (usually organic) that

trum including wavelengths from 0.78 micron to retards or stops an undesired chemical reaction, such

approximately 300 microns (i.e., longer than visible as corrosion, oxidation or polymerization. Exam-

light and shorter than microwave). ples are acetanilide which retards decomposition of

Use: Spectroscopic analysis, medicine, baking of hydrogen peroxide and salicylic acid, used to pre-

689 INOSINE

vent prevulcanization of rubber. Such substances part semiliquid resin blend is flowed through a noz-

zle into the mold cavity, where it polymerizes as a

are sometimes called negative catalysts. (2) A bio-

result of chemical reaction. One of the components

logical antagonist used to retard growth of pests and

contains the activating agent or curative; the two

insects and in medicine.

parts must be mixed with the greatest care for satis-

See antagonist, structural; antioxidant.

factory results. Isocyanate resins (urethanes) and

epoxy resins are well adapted to this fast, low-ener-

“Inhibitor NPH” [Mallinckrodt]. TM for a

gy process.

synthetic organic chemical that provides an effec-

tive means of controlling hard polymer formation in

ink. See printing ink; writing ink.

synthetic rubber production.

Properties: Fine white to yellow-white platelets;

ammoniacal odor. Bulk d 5 lb/gal, mp 160–164C

“Inoc” [Nalco]. TM for bioaugmentation

(with decomposition).

products.

Use: In the treatment of wastewater for removal of

initiating explosive. See explosive, initiating. organics.

initiation codon. (AUG). Codes for the first

“Inol k65” [Degussa].

amino acid in all polypeptide sequences, which is N-

CAS: 188364-50-3.

formyl-methionine in prokaryotes and methionine

Hazard: Moderately toxic by ingestion and skin con-

in eukaryotes.

tact. A severe skin irritant.

TM for an antioxidant.

Use: In a wide range of petroleum products including

initiation complex. A complex of all ribosomal

lubricants, industrial oils, and refinery streams.

components, a mRNA, and the initiating Met-

tRNAMet (eukaryotes) or fMet-tRNAMet (proka-

ryotes).

inorganic chemistry. A major branch of chem-

istry that is generally considered to embrace all

substances except hydrocarbons and their deriva-

initiator. An agent used to start the polymeriza-

tives, or all substances that are not compounds of

tion of a monomer. Its action is similar to that of a

carbon, with the exception of carbon oxides and

catalyst, except that it is usually consumed in the

carbon disulfide. It covers a broad range of subjects,

reaction. Organic peroxides and similar compounds

among which are atomic structure, crystallography,

are often used and shortwave radiation has a similar

chemical bonding, coordination compounds, acid-

initiating effect. Free radicals usually play a part.

base reactions, ceramics, and the various subdivi-

See activator; free radical.

sions of electrochemistry (electrolysis, battery sci-

ence, corrosion, semiconduction, etc.). It is

injection molding. A plastic-molding opera-

important to state that inorganic and organic chemis-

tion, introduced about 1935, performed in a single

try often overlap. For example, chemical bonding

machine capable of producing both small articles of

applies to both disciplines, electrochemistry and

complex geometry (combs), and large units that

acid-base reactions have their organic counterparts;

could not be made economically in any other way

catalysts and coordination compounds may be either

(auto body parts, tubs, etc.). Though used primarily

organic or inorganic. Regarding the importance of

for thermoplastics, the injection method can be

inorganic chemistry, R. T. Sanderson has written:

modified to handle thermosets. A simplified de-

“All chemistry is the science of atoms, involving an

scription is as follows: (1) A molding powder is fed

understanding of why they possess certain charac-

into the heating chamber of the machine, which

teristic qualities and why these qualities dictate the

holds several times as much material as is necessary

behavior of atoms when they come together. All

to fill the mold. The powder is heated to a viscous

properties of material substances are the inevitable

liquid. (2) An amount of molding powder that is just

result of the kind of atoms and the manner in which

sufficient to fill the mold cavity is then forced into

they are attached and assembled. All chemical

the rear of the heating chamber by a plunger, thus

change involves a rearrangement of atoms. Inorgan-

injecting an equal amount of liquid plastic from the

ic chemistry [is] the only discipline within chemistry

front of the heating chamber into the mold. (3) The

that....examines specifically the differences

material remains in the mold under high pressure

among all the different kinds of atoms.”

until it cools, and is then ejected. The rheological

properties of the fluid plastic are of critical impor-

tance, as it must flow readily through the sprue and

inosine. (hypoxanthine riboside).

mold gate and fill the mold uniformly. The amount CAS: 58-63-9. C

. An important intermedi-

of material injected into a mold can range from less ate in animal purine metabolism. Also available as

than 1 ounce to 25 pounds or more. Modern injec- its barium salt.

tion-molding machines have many specialized me- Properties: (Dihydrate.) Crystallizes in needles from

chanical features and are of impressive dimensions. water. Mp 90C (anhydrous), 218C (decomposes).

Of comparatively recent development is the tech- Levorotatory in solution. Slightly soluble in water;

nique of reaction injection molding, in which a two- soluble in alcohol.

690INOSINE DIALDEHYDE

Derivation: By deamination of adenosine. harmless to humans since they quickly decompose

Use: Biochemical research. to nontoxic compounds), nicotine, copper naphthe-

nate, and petroleum derivatives. (3) Synthetic or-

ganic compounds: (a) chlorinated hydrocarbons

inosine dialdehyde.

such as DDT, dieldrin, endrin, chlordane, lindane, p-

CAS: 23590-99-0. mf: C

dichlorobenzene; (b) the organic esters of phospho-

Hazard: Moderately toxic.

rus (the parathions and related substances). (4) Of

comparatively recent development are pyrethroids,

inosinic acid. (IMP; hypoxanthine riboside-5-

or insect growth regulators, which act as neurotox-

phosphoric acid).

ins, preventing larvae from becoming adult forms

CAS: 131-99-7. C

P. An important inter-

(juvenile hormones); and metabolic inhibitors, e.g.,

mediate in the synthesis and metabolism of animal

imidazole, which function as structural antagonists.

purines.

Hazard: Insecticides are toxic to humans in varying

Properties: Syrup; agreeable sour taste. Freely solu-

degrees. Among the safest are the pyrethrins, roten-

ble in water and formic acid; very sparingly soluble

one, and methoxychlor. Most of the organophos-

in alcohol and ether.

phorus types (parathion and related compounds) are

Derivation: From meat extract or by enzymatic

highly toxic but are reasonably biodegradable. The

deamination of muscle adenylic acid.

chlorinated hydrocarbons resist biodegradation;

Use: Biochemical research, flavor enhancer.

their use has been restricted and in some cases

See sodium inosinate.

(DDT) banned for agricultural application, due to

their harmful ecological effects. EPA is constantly

inositol. (hexahydroxycyclohexane).

monitoring new insecticides and issues warnings or

CAS: 87-89-8. C

(OH)

•2H

O. A constituent of

restrictions on their use; its approval is required

body tissue. There are nine isomeric forms of inosi-

before they can be registered.

tol (myo-inositol or meso-inositol or specifically the

See pesticide; fumigant; herbicide; rodenticide; re-

cis-1,2,3,5-trans-4,6-hexahydroxycyclohexane has

pellent.

vitamin activity).

Properties: (I-inositol.) White crystals; odorless;

insect wax. See shellac; Chinese insect wax.

sweet taste. Mp 224–227C, d 1.524 (dihydrate),

1.752 when anhydrous, dihydrate melts at

insert. In a complete plasmid clone, there are two

215–216C. Soluble in water; insoluble in absolute

types of DNA—the “vector” sequences and the “in-

alcohol and ether. Stable to heat, strong acid, and

sert”. The vector sequences are those regions neces-

alkali. Amounts are expressed in milligrams of ino-

sary for propagation, antibiotic resistance, and all

sitol.

those functions necessary for useful cloning. The

Source: Food source: vegetables, citrus fruits, cereal

insert is the piece of DNA of interest.

grains, liver, kidney, heart, and other meats. Com-

mercial source: corn steep liquor by precipitation

and hydrolysis of crude phytate.

insertion. A chromosome abnormality in which a

Grade: NF, FCC. piece of DNA is incorporated into a gene and there-

Use: Medicine, nutrition, intermediate. by disrupts the gene’s normal function.

See chromosome; DNA; gene; mutation.

inositol hexaphosphoric acid. See phytic

acid.

insertion mutation. A mutation caused by in-

sertion of one or more extra bases between bases in

DNA, or a mutagen which itself is inserted between

inositol hexaphosphoric acid ester, sodium

bases.

salt. See sodium phytate.

See insertion.

INPC. Abbreviation for isopropyl-N-phenylcar-

insertion sequence. The specific base se-

bamate.

quences at either end of a transposon which allow

See IPC.

for insertion into DNA.

INS. Ion neutralization spectroscopy.

in situ hybridization. Use of a DNA or RNA

probe to detect the presence of the complementary

insecticide. A type of pesticide designed to con-

DNA sequence in cloned bacterial or cultured eu-

trol insect life that is harmful to humans, either

karyotic cells.

directly as disease vectors or indirectly as destroyers

of crops, food products, or textile fabrics. General

instantizing. See agglomeration (2).

types are as follows: (1) Inorganic: arsenic, lead, and

copper (inorganic compounds and mixtures); the

use of these has diminished sharply in recent years

Institute of Food Technologists. (IFT)

because of the development of more effective types Founded in 1939, the Institute of Food Technolo-

less toxic to humans. (2) Natural organic com- gists is a nonprofit scientific society with 28,000

pounds, such as rotenone and pyrethrins (relatively members working in food science, food technology,

691 INTERCALATION

and related professions in industry, academia and e.g., polystyrene, PVC, cellulose, glass, magnesia,

government. The Institute advances the science and and aluminum silicate.

technology of food through the exchange of knowl- Air is a unique case, as it is the only gaseous material

edge. Itsa world headquarters are at 221 N. LaSalle in actual use as an insulator. Its dielectric constant is

St., Ste. 300, Chicago, IL 60601-1291. Website: 1.0058, far less than that of any other dielectric

HTTP://www.ift.org. material, and it has low thermal conductivity as well.

It is particularly effective when trapped within a

solid network, as in wool, cellular plastics, or glass

instrument. Any of a wide variety of devices

fibers, or as an interlayer between wall panels.

used for one of the following purposes: (1) observa-

tion (microscope); (2) measurement (thermometer,

thermocouple, flowmeter, balance); (3) chemical

insulin. A polypeptide hormone having a molecu-

analysis (spectrometer). lar weight of 5733. It is formed in the isles of Lan-

See analytical chemistry; instrumentation. gerhans located in the pancreas and was so named

for this reason. Insulin is composed of 16 amino

acids arranged in a coiled chain and cross-linked in

instrumentation. (1) Plant. An inclusive term

several places by the disulfide bonds of cystine resi-

for sensing devices that measure, record, and control

dues. The sequence of amino acids has been eluci-

temperature, flow rate, thickness, pH, liquid level,

dated. The insulin molecule was synthesized in

and other process variables on a continuous basis.

1963. In 1977, rat insulin was produced in the bacte-

Some types, e.g., thickness gauges, utilize radioiso-

rium E. coli by recombinant DNA techniques. A

topes. Particularly sophisticated computerized in-

year later human insulin was generated after chemi-

strumentation is required in petroleum refining and

cally synthesized genes were added to E. coli. This

nuclear reactor control. (2) Laboratory. A broad

synthetic insulin is now in commercial production

range of analytical techniques and devices utilized

and has been approved by FDA. Insulin regulates

in the many types of chromatography and spectros-

carbohydrate metabolism in the body by decreasing

copy. Significant advances in analytical instrumen-

the blood glucose level. A systemic deficiency leads

tation have been made in recent years, e.g., in liquid

to diabetes.

chromatography (HPLC). A notable event in this

Properties: White powder or hexagonal crystals.

field is the annual Pittsburgh Conference on Analyt-

Readily soluble in dilute acids; soluble in water.

ical Chemistry and Applied Spectroscopy. (3) Gen-

Derivation: Extraction of minced pancreas with

eral. Of special significance for both laboratory and

acidified dilute alcohol, followed by precipitation

process control is the introduction of fiber optical

with absolute alcohol; also by gene-splicing

devices that can transmit signals from many remote

methods.

locations. They are particularly useful in analyzing

Grade: USP, in various solutions or suspensions that

samples of radioactive chemicals and other hazard-

include insulin injection; isophane insulin suspen-

ous materials. They are also used in high-tempera-

sion; protamine zinc insulin suspension; NF, as glo-

ture thermometry and dosimetry.

bin zinc insulin injection.

See fiber, optical.

Hazard: Overdosage can be fatal.

Use: Medicine (for diabetes control).

insulating oil. See transformer oil.

See Banting; recombinant DNA.

insulator. Any substance or mixture that has an

integral membrane proteins. Proteins in-

extremely low dielectric constant, low thermal con-

serted into a membrane by hydrophobic interac-

ductivity, or both. Electrical insulators are either

tions. Contrast with peripheral proteins.

solid or liquid, the latter being used in transformers

(askarel, mineral oils, silicone oils). A wide variety

intercalating mutagen. A mutagen that inserts

of solid types includes porcelains, glass, mica, alu-

itself between two successive bases in a nucleic acid

mina, various high polymers (epoxies, polyethyl-

causing a frame-shift mutation.

ene, polystyrene, phenolics), cellulosic materials,

nylon, and silicone resins. All these may be used

alone or combined with other insulators as compos-

intercalation compound. A compound com-

ites. posed of a crystalline lattice that acts as an electron

See dielectric; transformer oil. donor, and “foreign” electron acceptor atoms inter-

Thermal insulators comprise an equally broad range spersed or diffused between the planes of the lattice.

of materials. Such inorganics as mineral fibers, An important group of intercalated compounds are

magnesia, aluminum silicate, cellulose, and glass composed of graphite, where bromine, for example,

fibers are widely used for steam and hot-water pipes, can act as electron acceptor. Graphite is particularly

furnaces, and blown-in home insulation. Organic susceptible to this phenomenon because of its order-

products that are effective include plastic foams ly stacked layers of crystals. Anhydrous metal ni-

(polyurethane, polyvinyl chloride, polystyrene) and trates such as copper and zinc nitrates also form

cellular rubber. There are a number of materials that intercalated compounds with graphite. A further ex-

may be called double insulators, since they have ample is trilithium nitride, whose structure consists

both electrical and thermal insulating properties, of a series of layers of dilithium nitride, between

692“INTERCAR”

which is a layer of lithium atoms. This markedly

interferon. An antiviral protein produced by ver-

tebrate cells in response to virus infection. Discov-

increases the conductivity, so that the material be-

ered in 1957, it is a product of the infected cell, rather

comes an effective solid electrolyte in batteries.

than of the disease-inducing virus. It can be formed

Other substances having this property are sodium ␤-

by any type of infected cell and is effective against

alumina, titanium disulfide. and some metal diox-

many viruses, but only in the cells of the organism

ides. The phenomenon does not impair the crystal-

that produced it. It is quite different from an anti-

line structure and is reversible. Intercalated

body which is produced only by specialized cells

compounds are used for superconductors, synthetic

and acts by combining directly with a specific virus.

lubricants, catalysts, and storage batteries. They are

Interferon does not inactivate viruses directly, but

used in biochemical research; an acridine-based

reacts with susceptible cells which then resist virus

compound that can intercalate between stacked

multiplication. Prostaglandins are believed to be

pairs of bases in a DNA helix is used in cancer

effective in maintaining normal interferon produc-

research.

tion in the body. Four types of interferon are present-

ly known. As a result of advanced recombinant

“Intercar” [AKZO]. TM for a series of water-

DNA techniques, a biologically active protein al-

dispersible paint driers.

most identical with interferon has been made outside

Available forms: Supplied in high metal concentra-

the body by exposing to virus action bacteria into

tion (calcium 4%, cobalt 6%, lead 24%, manganese

which the genetic code controlling interferon forma-

6%).

tion in the body has been introduced. The “synthet-

ic” interferon is available in quantities large enough

“Intercide” [AKZO]. TM for a series of fungi-

to permit its use in treatment of various virus dis-

cides and mildewcides.

eases. The interferon molecule itself has not yet

Use: Wood and fabric preservatives.

been synthesized.

See recombinant DNA.

interface. The area of contact between two im-

miscible phases of a dispersion which may involve

intergenic. Between two genes, e.g., intergenic

either the same or different states of matter. Five

DNA is the DNA found between two genes. The

types are possible: (1) solid-solid (carbon

term is often used to mean non-functional DNA (or

black−rubber), (2) liquid-liquid (water-oil), (3) sol-

at least DNA with no known importance to the two

id-gas (smoke-air), (4) solid-liquid (clay-water), (5)

genes flanking it). Alternatively, one might speak of

liquid-gas (water-air). At a fresh surface of either

the “intergenic distance” between two genes as the

liquid or solid the molecular attraction exerts a net

number of base pairs from the polyA site of the first

inward pull. Hence the characteristic property of a

gene to the cap site of the second. This usage might

liquid is surface tension and that of a solid surface is

therefore include the promoter region of the second

adsorption. Both have the same cause, namely, the

gene.

inward cohesive forces acting on the molecules at

the surface. These phenomena provide to some de-

interification. See ester interchange.

gree the fundamental mechanism for many industri-

ally important processes (catalysis, emulsification,

mixing, alloying) and products (detergents, adhe-

interleukin-2. A type of biological response

sives, lubricants, paints). Such properties as wetta-

modifier (a substance that can improve the body’s

bility of solid powders, spreading coefficients of

natural response to disease). It stimulates the growth

liquids, and protective action of colloidal substances

of certain disease-fighting blood cells in the immune

are intimately associated with interfacial behavior.

system. Also called IL-2.

See surface; surface tension; catalysis; emulsion; de-

tergent; wetting agent.

intermediary metabolism. The enzyme-cata-

lyzed reactions that extract chemical energy from

interfacial film. Skinlike structure that devel-

nutrient molecules and utilize it to synthesize mole-

ops at the interface between the two emulsion

cules and perform cell functions.

phases, consisting of adsorbed and oriented mole-

cules of the emulsifying agent in a state of loose

intermediate. An organic compound, either

aggregation. It surrounds the droplets of the internal

cyclic (derived from coal tar or petroleum products

phase and keeps them from flowing together.

such as benzene, toluene, naphthalene, etc.) or acy-

clic (e.g., ethyl and methyl alcohol). These com-

interfacial surface energy. The tension mea-

pounds may be considered as chemical stepping

sured in dynes per centimeter.

stones between the parent substance and the final

product. The cyclic type (e.g., aniline, ␤-naphthol,

interference. One crossover event inhibits the and benzoylbenzoic acid) still predominate as inter-

chances of another crossover event. Also known as mediates for synthetic dyes and have few other uses;

positive interference. Negative interference in- the acyclic type in general have many independent

creases the chance of a second crossover. uses. Exceptions are hexamethylenetetramine, an

See crossing over. acyclic intermediate for phenolformaldehyde resin

693 INTUMESCENCE

and butadiene for synthetic elastomers. Intermedi-

interstitial. (1) Descriptive of a nonstoichiomet-

ates are the foundation of the modern approach to ric compound of a metal and a nonmetal whose

organic technology. The distinction between an in- structure conforms to a simple chemical formula,

termediate and an end product is not always precise.

but exists over a limited range of chemical composi-

See azo dye intermediate.

tion. Interstitial compounds are represented by bor-

ides, nitrides, and carbides of the transition metals.

(2) Descriptive of an atom of an impurity that causes

intermetallic compound. (1) A compound or

a defect or dislocation in a crystalline lattice, e.g., an

alloy formed by two metals that have been placed in

atom of carbon or nitrogen in an iron crystal, or of

intimate contact during the process of brazing or

arsenic in a semiconductor. (3) In a biological sense,

coating, the compound occurring at the interface

the term describes cells located between or within

between the metal surfaces. In some cases, as in

layers of tissue.

galvanizing, the metals form bimetallic compounds;

in others they form alloys or solid solutions of vary-

“Interwax” [AKZO]. TM for a series of wax

ing composition. (2) A two- or three-component

modifiers.

metal system prepared with special metals having

“P”

High molecular weight polybutene and paraf-

semiconducting properties, e.g., gallium, for use in

fin wax.

lasers, diodes, transistors, etc.

“M”

High molecular weight polybutene and am-

See galvanizing; semiconductor.

ber-colored, microcrystalline wax.

“280”

A hard, high-melting-point synthetic wax.

intermolecular. Describes an interaction (e.g., a

Use: In lacquers and varnishes, as a plastic lubricant

chemical reaction) between different molecules.

and antiblocking agent, as an extender or substitute

for carnauba wax.

internal compensation. (intramolecular

compensation; meso form). The optical neutral-

“Interwet” [AKZO]. TM for a series of wetting

ization produced in a molecule when two asymmet-

agents for emulsion paints, latex paints, and vinyl

ric centers in the molecule produce equal, opposite

plastisols.

amount of rotation of the plane of polarization.

See meso-.

“Intracron” [Crompton]. TM for a group of

fiber-reactive dyes.

internal conversion. The effect of an atom

Available forms: Liquid and powder.

produced by a ␥-ray photon emerging from the nu-

Use: For cellulosic fibers and blends.

cleus, and giving up its energy on meeting with an

extra nuclear electron.

intramolecular compensation. See internal

compensation; meso-.

internal energy. The sum of the kinetic and

potential energies (including electromagnetic field

intramolecular reaction. Change in position

energies) of the particles that make up a system.

of an atom or group of atoms in a molecule giving

rise to a different, though isomeric compound.

International Union of Pure and Applied

Chemistry. (IUPAC). A voluntary nonprofit

“Intrasil.” [Crompton] TM for a group of dis-

association of national organizations representing

perse dyes.

chemists in 45 member countries. It was formed in

Available forms: Liquid and powder.

1919 with the object of facilitating international

Use: Acetate and polyester apparel and polyester

agreement and uniform practice in both academic

automotive fabrics.

and industrial aspects of chemistry. Examples are

nomenclature, atomic weights, symbols and termi-

introfier. Substance used to lower interfacial ten-

nology, physicochemical constants, and certain

sion between two phases, usually a liquid soluble in

methods of analysis and assay. In addition to stan-

both phases; a wetting accelerator.

dardization, IUPAC carries on several hundred re-

search projects relating to food technology, water

introns. The DNA base sequences interrupting

and air quality, single-cell proteins, etc. Its Secretar-

the protein-coding sequences of a gene; these se-

iat can be reached at PO Box 13757, Research Trian-

quences are transcribed into RNA but are cut out of

gle Park, NC 27709-3757, USA.

the message before it is translated into protein.

Website: www.iupac.org.

See: Exons.

interphase. The period in the cell cycle when

intumescence. The foaming and swelling of a

DNA is replicated in the nucleus. It is followed by

plastic or other material when exposed to high sur-

mitosis.

face temperatures or flames.

Use: Polyurethane base coating materials for rocket

interstellar space. See astrochemistry. reentry.

694INULIN

inulin. (alantin; alant atarch). sculptured pieces (lost wax process) and adapted to

Properties: Spherical crystals. Mp 158–165C. Hy- industry for manufacture of precision metal parts. It

groscopic in moist air. Soluble in hot water. is generally known as precision investment casting.

Source: From chicory root.

The sequence of operations is (1) a wax prototype is

Use: Diagnostic aid for kidney function.

made in a metal mold; (2) several of these are at-

tached to a central member, also made of wax to

“Invar.” TM for an iron-nickel alloy containing

form a “tree”; (3) the tree is dipped and dried eight

40–50% nickel and characterized by an extremely

times in a ceramic glaze, thus building up a coating

low coefficient of thermal expansion.

or “investment”; (4) the assembly is baked in an

Use: Precision instruments, measuring tapes,

oven, thus melting out the wax, leaving a cavity

weights, etc.

which is then used as a mold for liquid metal. Great

accuracy can be obtained with this method. The

invariant point. State of system where the exact nature of the waxes and coatings is not dis-

number of degrees of freedom is zero. closed.

invention. The chief requirement of an invention in vitro. A condition in which a reaction is car-

is that it be unobvious to a person having ordinary ried out in a laboratory experiment (i.e., a glass

skill in the art to which the claim pertains and know- container, test tube, or beaker), as opposed to a

ing everything that has gone before, as shown by reaction occurring in a living organism (in vivo).

publication anywhere or public use in the U.S. When

reliance for patentability is placed on a new mixture

iocetamic acid.

of components that have been used separately, it

CAS: 16034-77-8. mf: C

must be shown that there is some unexpected coac-

Hazard: Low toxicity by ingestion.

tion between the ingredients and not just the additive

effects of the several materials. The inventor is the

iodeosin. (tetraiodofluorescein). C

one who contributes the inventive concept in work-

Properties: Red powder. Soluble in dilute alkalies;

able detail, not the one who demonstrates it or tests

slightly soluble in alcohol and ether; insoluble in

it.

water.

Derivation: Interaction of fluorescein and iodine in

inversion. Splitting up of higher sugars into mol-

presence of iodic acid.

ecules of a lower sugar.

Use: Indicator in analytical chemistry.

inversion point. Temperature at which one po-

iodic acid.

lymorphic form of a substance changes into another

CAS: 7782-68-5. HIO

under variant conditions.

Properties: Colorless, rhombic crystals or white,

crystalline powder. D 4.629, mp 110C (decom-

invertase. (sucrase; invertin). Enzyme pro- poses). A moderately strong acid. Soluble in cold

duced by yeast and by the lining of the intestines. It and hot water.

is a white powder, soluble in water. It catalyzes the Derivation: By adding sulfuric acid to a solution of

conversion of sucrose (ordinary sugar) to glucose barium iodate and subsequent filtration and crystal-

and levulose (fructose) during fermentation of lization.

sugars. Hazard: Toxic by ingestion, strong irritant to eyes

Use: Production of invert sugar for syrups and candy; and skin.

analytical reagent for sucrose. Use: Analytical chemistry, medicine (1–3% solu-

tion).

invert soaps. Cationic detergents with disinfec-

tant properties.

iodic acid anhydride. (iodine pentoxide).

Properties: White, crystalline powder. D 4.799, mp

invert sugar. A mixture of 50% glucose and

300C (decomposes). Soluble in water and nitric

50% fructose obtained by the hydrolysis of sucrose.

acid; insoluble in absolute alcohol, chloroform,

It absorbs water readily and is usually handled only

ether, carbon disulfide.

as a syrup. Because of its fructose content, invert

Hazard: Toxic by ingestion, strong irritant to eyes

sugar is levorotatory in solution and sweeter than

and skin, strong oxidizing agent.

sucrose. Invert sugar is often incorporated in prod-

Use: Oxidizing agent, organic synthesis.

ucts where loss of water must be avoided. Commer-

cially it is obtained from the inversion of a 96% cane

sugar solution.

iodinated casein.

Use: Food industry, brewing industry, confectionery, Use: Drug (veterinary); food additive.

humectant.

iodine.

investment casting.

A ceramic or metal casting CAS: 7553-56-2. I. Nonmetallic halogen element of

method originally used to make reproductions of atomic number 53; group VIIA of the periodic table;

695 IODINE TRICHLORIDE

the least reactive of the halogens, aw 126.9045; Derivation: By the interaction of iodine and bro-

valences

1,3,5,7; no stable isotopes but many

mine.

artificial radioactive isotopes.

Hazard: Toxic by ingestion and inhalation, vapors

Properties: Heavy, grayish-black plates or granules

corrosive to tissue.

having a metallic luster; characteristic odor. Readily

Use: Organic synthesis.

sublimed having a violet vapor. D 4.98, mp 113.5C,

bp 184C. Soluble in alcohol, carbon disulfide, chlo-

iodine monochloride.

roform, ether, carbon tetrachloride, glycerol, and

CAS: 7790-99-0. ICl.

alkaline iodide solutions; insoluble in water. A

Properties: Black crystals (␣ and ␤ forms) or redd-

semiconductor.

ish-brown, oily liquid. Mp (␣) 27C, (␤) 14C, bp

Derivation: (a) From brine wells in Michigan, Okla-

101C (decomposes), d (␣) 3.18 (0C), (␤) 3.24 (liq-

homa, Japan, Indonesia; (b) from mother liquors of

uid at 34C). Soluble in alcohol, water (with decom-

Chilean nitrate. It can also be extracted from kelp.

position), and dilute hydrochloric acid.

Method of purification: Sublimation.

Derivation: By the action of dry chlorine on iodine.

Grade: Crude, CP, USP.

Hazard: Toxic by ingestion and inhalation, strong

irritant to eyes and skin.

irritant to eyes and skin. TLV: ceiling 0.1 ppm.

Use: Analytical chemistry, organic synthesis.

Use: Dyes (aniline dyes, phthalein dyes), alkylation

and condensation catalyst, iodides, iodates, antisep-

iodine number. (iodine value). The percent-

tics and germicides, X-ray contrast media, food and

age of iodine that will be absorbed by a chemically

feed additive, stabilizers, photographic film, water

unsaturated substance (vegetable oils, rubber, etc.)

treatment, pharmaceuticals, medicinal soaps, unsa-

in a given time under arbitrary conditions. A mea-

turation indicator.

sure of unsaturation.

iodine pentafluoride.

iodine 131. (

131

I). Radioactive iodine of mass

CAS: 7783-66-6. IF

number 131.

Properties: Fuming liquid. Bp 98C, mp 9.4C, d

Properties: Half-life 8 days. Radiation: ␤ and ␥.

3.189 (25C). Attacks glass.

Derivation: By pile irradiation of tellurium and from

Derivation: Passing fluorine over iodine. Available

the fission products of nuclear reactor fuels.

in cylinders at 98.0% min purity.

Available forms: As elemental iodine and in a weak-

Hazard: Dangerous fire risk, reacts violently with

ly basic solution of sodium iodide in sodium sulfite;

water. Toxic by ingestion and inhalation, corrosive

iodine 131 is also available in tagged compounds

to skin and mucous membranes. TLV: 2.5 mg(F)/

such as dithymol diiodide, potassium iodate, diiodo-

fluorescein, insulin, ACTH, etc.

Use: Fluorinating and incendiary agent.

Grade: USP lists iodinated

131

I serum albumin, rose

bengal sodium

131

I injection, sodium iodide

131

I cap-

iodine pentoxide. See iodic acid anhydride.

sules and solution, sodium iodohippurate

131

I injec-

tion.

iodine test. Placing a few drops of potassium

Use: Diagnosis and treatment of goiter, hyperthy-

iodide solution on a sample to detect the presence of

roidism, and other thyroid disorders; internal radia-

starch. The test is positive if sample turns blue.

tion therapy; in film gauges to measure film thick-

nesses of the order of one micron; for detecting leaks

iodine tincture. A solution of iodine and potas-

in water lines; as a source of radiation in oil field

sium iodide or sodium iodide in alcohol, a reddish-

tests; as a tracer in chemical analysis; as a tracer in

brown liquid having the odors of iodine and alcohol,

studying diet iodine for cattle, the functions of the

contains 44–50% by volume alcohol, 2 g of iodine

thyroid gland, the efficiency of mixing pulp fibers,

and 2.4 g sodium iodide per 100 cc.

the thermal stability of potassium iodate in bread

Grade: USP

dough, chemical reaction mechanisms, etc.

Hazard: Toxic by ingestion, avoid using on open

cuts.

iodine bromide. See iodine monobromide.

Use: Antiseptic (use on skin surface only).

iodine chloride. See iodine monochloride;

iodine trichloride. ICl

iodine trichloride.

Properties: Orange-yellow, deliquescent, crystal-

line powder; pungent irritating odor. Mp 33C, d

iodine cyanide. See cyanogen iodide.

3.11. Soluble in water (with decomposition), alco-

hol, and benzene.

iodine monobromide. (bromine iodide). Derivation: By interaction of iodine and chlorine.

CAS: 7789-33-5. IBr. Hazard: Toxic by ingestion and inhalation, corrosive

Properties: Crystals, purplish-black mass. Mp 42C, to tissue.

bp 116C (decomposes), d 4.41. Soluble in water Use: Agent for introducing iodine and chlorine in

with decomposition, alcohol, and ether. organic synthesis; topical antiseptic.

696IODINE VALUE

iodine value. See iodine number. iodoform. (triiodomethane).

CAS: 75-47-8. CHI

Properties: Small greenish yellow or lustrous crys-

iodipamide. (CH

)

(CONHC

COOH)

tals or powder; penetrating odor. D 4.08, mp 115C.

Properties: White,, crystalline powder; nearly

Soluble in benzene and acetone; partially soluble in

odorless. Very slightly soluble in alcohol, chloro-

alcohol, glycerol, chloroform, carbon disulfide, and

form, ether; insoluble in water; pH of saturated solu-

ether; insoluble in water.

tion is 3.5–3.9.

Derivation: (a) By heating acetone or methanol with

Hazard: Toxic by ingestion.

iodine in presence of an alkali or alkaline carbon-

Use: Medicine (X-ray contrast medium).

ates. (b) Electrolytically, by passing a current

through a solution containing potassium iodide, al-

iodisan. See propiodal.

cohol, and sodium carbonate.

Grade: Technical, NF.

iodized oil. An iodine addition product of vege-

Hazard: Irritant. Decomposes violently at 400F

table oil or oils containing 38–42% organically com-

(204C). TLV: 0.6 ppm.

bined iodine.

Use: Medicine (antiseptic for external use only).

Properties: Thick, viscous, oily liquid; affected by

air and light. Soluble in solvent naphtha.

iodomethane. See methyl iodide.

Hazard: Toxic by ingestion.

Use: Medicine (radiopaque medium).

1-iodooctadecane. (octadecyl iodide).

(CH

)

iodoacetic acid, sodium salt. (sodium io-

Properties: Solid. Mw 380.40, mp 33-35C, bp

doacetate).

194–197C (2 mm Hg), fp 110C. Light sensitive.

CAS: 305-53-3. ICH

Na.

Hazard: Irritant.

Properties: Colorless or white crystals. Mw 207.93,

Use: Reagent for introduction of C

chain.

mp 210C. Soluble in water, alcohol, and very slight-

ly soluble in ether. Hygroscopic in moist air.

iodopanoic acid. See iopanoic acid.

Hazard: Toxic.

Use: Analytical reagent.

iodophenazone.

CAS: 129-81-7. mf: C

(iodoacetoxy)tributylstannane. See tributyl-

Hazard: Moderately toxic by ingestion.

tin iodoacetate.

iodophor. (“tamed iodine”). (1) A complex of

(iodoacetoxy)tripropylstannane. See tripro-

iodine with certain types of surface-active agents

pyltin iodoacetate.

that have detergent properties. (2) More generally,

any carrier of iodine.

o-iodobenzoic acid tributylstannyl ester.

See tributyltin-o-iodobenzoate.

iodophosphonium. See phosphonium iodide.

(o-iodobenzoyloxy)tripropylstannane.

2-iodopropane. See isopropyl iodide.

CAS: 73927-94-3. mf: C

Sn.

Hazard: A poison. TWA 0.1 mg(Sn)/m

; STEL 0.2

(iodopropionyloxy)tributylstannane. See

mg(Sn)/m

(skin).

tributyltin-␤-iodopropionate.

4-iodo-3,5-dimethyl-n-(2-methylphenyl)-1h-

iodopyracet meglumine.

pyrazole-1-acetamide.

CAS: 3736-90-1. mf: C

•C

CAS: 302542-42-3. mf: C

Hazard: Low toxicity.

Hazard: Moderately toxic by ingestion.

N-iodosuccinimide. (succiniodimide).

4-iodo-3,5-dimethyl-n-(3-methylphenyl)-1h-

(−CH

CO)

NI).

pyrazole-1-acetamide.

Properties: Colorless crystals. Mp 200–201C. Solu-

CAS: 302542-51-4. mf: C

ble in acetone and methanol; insoluble in carbon

Hazard: Moderately toxic by ingestion.

tetrachloride and ether; decomposes in water.

Hazard: Skin irritant.

4-iodo-3,5-dimethyl-n-(4-methylphenyl)-1h-

Use: Iodinizing agent in synthetic organic chemistry.

pyrazole-1-acetamide.

CAS: 302542-63-8. mf: C

iodotributylstannane.

Hazard: Moderately toxic by ingestion.

CAS: 7342-47-4. mf: C

ISn.

Hazard: A poison by ingestion and skin contact.

iodoethane. See ethyl iodide.

Moderately toxic by inhalation. Tributyl tin com-

pounds are extremely toxic to marine life. TWA 0.1

iodoethylene. See tetraiodoethylene. mg(Sn)/m

; STEL 0.2 mg(Sn)/m

(skin).

697 IONIZATION

iodotrimethyltin. Ion exchange occurs extensively in soils. Ion ex-

CAS: 811-73-4. mf: C

ISn. change resins are synthetic resins containing active

Properties: White powder, insol in water and org groups (usually sulfonic, carboxylic, phenol, or sub-

stituted amino groups) that give the resin the proper-

solvs.

ty of combining with or exchanging ions between

Hazard: A poison. TWA 0.1 mg(Sn)/m

; STEL 0.2

the resin and a solution. Thus, a resin with active

mg(Sn)/m

(skin).

sulfonic groups can be converted to the sodium form

and will then exchange its sodium ions with the

iodotriphenylstannane.

calcium ions present in hard water. Some specific

CAS: 894-09-7. mf: C

ISn.

applications of ion exchange: water softening, milk

Hazard: A poison. TWA 0.1 mg(Sn)/m

; STEL 0.2

softening (substitution of sodium ions for calcium

mg(Sn)/m

(skin).

ions in milk), removal of iron from wine (substitu-

tion of hydrogen ions), recovery of chromate from

iodotripropylstannane. See tripropyltin io-

plating solutions uranium from acid solutions, strep-

dide.

tomycin from broths, removal of formic acid from

formaldehyde solutions, demineralization of sugar

iomeprol.

solutions, recovery of valuable metals from wastes,

CAS: 78649-41-9. mf: C

recovery of nicotine from tobacco-dryer gases, ca-

Hazard: Low toxicity.

talysis of reaction between butyl alcohol and fatty

acids, recovery and separation of radioactive iso-

ion. An atom or radical that has lost or gained one

topes from atomic fission, chromatography, estab-

or more electrons and has thus acquired an electric

lishment of mass micro standards, in cigarette filters

charge. Positively charged ions are cations and those

to remove polonium from smoke.

having a negative charge are anions. An ion often

See zeolite.

has entirely different properties from the element

(atom) from which it was formed. In sodium chlo-

ion-exchange chromatography. A chroma-

ride solution, sodium exists as sodium ion (Na

), i.e.,

tographic method based on the ability of polymers to

sodium atoms that have lost one electron. The chlo-

sorb ionized solutes reversibly, e.g., cross-linked

rine is present as chloride ion (Cl

−

), i.e., chlorine

resins with exchangeable hydrogen or hydroxyl

atoms that have gained one electron. Copper sulfate

ions. It can be carried out both in columns and on

solution contains copper ion (Cu

), i.e., copper

sheets.

atoms that have lost two electrons, and sulfate ion

(SO

2−

), i.e., sulfate radicals that have gained two

ion-exchange resin. See ion exchange.

electrons. Ions occur in water solution or in the fused

state (except in the case of gases). Compounds that

ion exclusion. The process in which a synthetic

form ions are called electrolytes because they enable

resin of the ion exchange type absorbs nonionized

the solution to conduct electricity. Ion formation

solutes such as glycerine or sugar while it does not

causes an abnormal increase in the boiling point of

absorb ionized solutes that are also present in a

water and also lowers the freezing point, the extent

solution in contact with the resin. Thus, sodium

depending on the concentration of the solution. Ions

chloride and glycerine can be separated by passage

are also formed in gases as a result of electrical

of their aqueous solution through a bed of particles

discharge.

of an ion exclusion resin.

See ionization; electrolysis; ion exchange.

ionic bond. (electrovalent bond). Refers to the

ion channel. An integral membrane protein that

formation of ions by transfer of one or more elec-

provides for the regulated transport of specific a ion

trons from one atom to another.

or ions across a membrane.

See bond, chemical.

ion electrode. Electrode that develops and mea-

ionic detergent. See detergent.

sures an electrical potential in response to the activi-

ty of an ion in solution to which it is selective.

ionization. A chemical change by which ions are

ion exchange. A reversible chemical reaction formed from a neutral molecule of an inorganic

between a solid (ion exchanger) and a fluid (usually solid, liquid, or gas. The most common type of

a water solution) by means of which ions may be ionization occurs when an ionically bonded inor-

interchanged from one substance to another. The ganic compound such as sodium chloride or sulfuric

superficial physical structure of the solid is not af- acid is dissolved in water (or other solvent); the

fected. The customary procedure is to pass the fluid molecule separates or dissociates into two ions, the

through a bed of the solid, which is granular and metallic ion being positively charged by loss of an

porous and has only a limited capacity for exchange. electron and the nonmetallic ion being negatively

The process is essentially a batch type in which the charged by gaining an electron. The degree of disso-

ion exchanger, upon nearing depletion, is regenerat- ciation varies with the type of compound, the sol-

ed by inexpensive brines, carbonate solutions, etc. vent, and the temperature. Molecules or atoms of

698IONIZING RADIATION

gases are ionized by passage of an electric current both anion and cation adsorption sites. These sites

through the gas; this removes electrons and leaves a

will associate with mobile anions and cations in

positive charge. Compounds that ionize in solution

solution and thus remove both kinds of ions from

greatly increase the conductivity of the solvent. Ion-

solutions. These ions may be eluted by rinsing with

ization is most effective in water because its high

water. Process can make clean separations of ionic-

dielectric constant lowers the ionic bonding forces

nonionic mixtures. Has also been suggested for de-

in the solute molecules enough to cause separation

mineralization of salt solutions.

of their constituent atoms. Ion formation produces a

See ion.

notable rise in the boiling point and a depression of

the freezing point of water. An electric current

iopanoic acid. (iodopanoic acid; 3-amino-␣-

passed through a solution containing ions causes

ethyl-2,4,6-triiodohydrocinnamic acid).

them to move to the oppositely charged electrode;

CAS: 96-83-3. C

CH(COOH)C

this effect is the basis of many industrial electro-

Properties: Cream-colored powder; tasteless; faintly

chemical operations, such as electroplating and the

aromatic odor. Mp 152–158C (decomposes), dark-

manufacture of sodium hydroxide and chlorine.

ens on exposure to light. Soluble in acetone, ether,

See ion; electroplating; electrolysis; electrolyte; dis-

alcohol, chloroform, and dilute alkalies; insoluble in

sociation.

water.

Grade: USP.

ionizing radiation. See radiation, ionizing.

Use: Medicine (radiopaque medium).

ionomer resin. A copolymer of ethylene and a

IPA. (1) Abbreviation for isophthalic acid. (2)

vinyl monomer with an acid group, such as meth-

Abbreviation for isopropyl alcohol.

acrylic acid. They are cross-linked polymers in that

the linkages are ionic as well as covalent bonds.

IPAE. See isopropylaminoethanol.

There are positively and negatively charged groups

which are not associated with each other and this

Ipatieff, Vladimir N. (1890–1952). Born in

polar character makes these resins unique.

Russia, Ipatieff was an army officer as well as a

Properties: Transparent, electrically conductive, re-

chemist. He was a member of the Academy of Sci-

silient, and thermoplastic. Cannot be completely

ence and carried out organic research at the Institute

dissolved in any commercial solvents. High resis-

of Chemistry in Leningrad. He left the the former

tance to abrasion, cracking, corona attack; high ten-

U.S.S.R. under the Stalin regime and at the invita-

sile strength. Working temperature approximately

tion of Gustav Egloff joined the Universal Oil Prod-

−108 to +65.5C.

ucts Co. He and his close associate, Herman Pines,

Use: Break-resistant transparent bottles, packaging

did basic development on catalytic alkylation and

films, mercury flasks, protective equipment, pipe

isomerization of hydrocarbons of the greatest im-

and tubing, electric distribution elements. As foam,

portance for high-octane aviation gasoline.

insulation of fresh concrete.

See bond, chemical.

IPC. (INPC; isopropyl-N-phenylcarbamate).

CAS: 122-42-9. C

NHCOOCH(CH

)

ionone. (␣-or␤-cyclocitrylidenacetone).

Properties: White to gray crystalline needles;

CAS: 8013-90-9. C

odorless when pure. Mp 84C (technical grade). Sol-

Properties: Light-yellow to colorless liquid; violet

uble in alcohol, acetone, isopropyl alcohol; insolu-

odor. D 0.927–0.933 (25C), bp 126–128C (12 mm

ble in water.

Hg), refr index 1.4970–1.5020 (20C). Soluble in

Hazard: Toxic by ingestion.

alcohol, ether, mineral oil, and propylene glycol;

Use: Herbicide.

insoluble in water and glycerol.

Grade: 95%, 99%, mixed isomers, FCC.

IPC, chloro-. See chloro-IPC.

Derivation: (1) Condensing citral with acetone fol-

lowed by ring closure with an acid, (2) reaction of

ipecac. Dried root of Cephaelis ipecacuanha.

acetylene with acetone followed by hydrogenation,

Occurrence: Brazil and Bolivia, cultivated in India.

condensation with diketone, and further reaction

Grade: Technical, USP.

with acetylene.

Hazard: Contains emetine, a toxic alkaloid.

Use: Perfumery, chemical synthesis, flavoring, vita-

Use: Medicine (emetic), production of emetine.

min A production (␤ isomer).

IPM. See m-phthalodinitrile.

ionophore. A compound that binds metal ions

and diffuses across membranes carrying the bound

Ir. Symbol for iridium

ion. An example is valinomycin, which transports

potassium.

“Ircogel” [Lubrizol]. TM for a variety of calci-

ion retardation. A process based on amphoter- um sulfonates, thixotropic.

ic (bifunctional) ion-exchange resins containing Grade: 900 (paste), 903, 904, 905, 906, 907 (gel),

699 IRIDOSMINE

2064 (pourable liquid), 2050B (polymeric organic Use: Radiography of light castings, treatment of

phosphate).

cancer.

Available forms: Gel, pourable liquids.

Use: A thixotrope for PVC plastisols, organosol, and

iridium bromide. See iridium tribromide.

high- solids solvent-based paints; 2064: corrosion

inhibitor for latex paint and other water-based coat-

iridium chloride. See iridic chloride; iridium

ings; 2085B: rust-preventative coatings.

trichloride.

“Irganox” [Novartis]. TM for a series of com-

iridium potassium chloride. (potassium

plex, high molecular weight stabilizers that inhibit

chloroiridate; potassium iridium chloride).

oxidation and thermal degradation of many organic

IrCl

materials. They contain multifunctional chemical

Properties: Dark-red crystals. D 3.549. Soluble in

groupings. Several are hindered polyphenols. All

water (hot).

are white, crystalline, free-flowing powders; nons-

Use: Black pigment (porcelain decoration). The iridi-

taining, nonvolatile, and odorless.

um (III) salt is also known: K

IrCl

, greenish-yellow.

“Irgasan” [Novartis]. TM for broad-spectrum

iridium sesquioxide. Ir

antibacterial agent.

Properties: Black powder. Slightly soluble in hydro-

Use: Deodorant soaps and underarm deodorants.

chloric acid (concentrated); insoluble in water. De-

composes at 400C.

iridic chloride. (iridium chloride; iridium tet-

Derivation: By heating the chloroiridate K

IrCl

with

rachloride). IrCl

sodium carbonate.

Properties: Brownish-black mass, hygroscopic. Sol-

Use: Ceramics (porcelain decoration).

uble in water, alcohol, and dilute hydrochloric acid.

Derivation: Action of chlorine or aqua regia on the

iridium tetrachloride. See iridic chloride.

ammonium salt (NH

)

IrCl

Use: Analysis (testing for nitric acid in the presence

iridium tribromide. (iridium bromide).

of nitrous acid), microscopy, plating solution.

IrBr

•4H

Properties: Olive-green, brown, or black crystals.

iridium.

Soluble in water; insoluble in alcohol. Prepared by

CAS: 7439-88-5. Ir. Metallic element of atomic

action of hydrobromic acid on iridium trihydroxide.

number 77, one of the platinum metals, group VIII

of the periodic table, aw 192.22, valences

iridium trichloride. (iridium chloride).

1,2,3,4,6, two stable isotopes.

CAS: 12645-45-3. IrCl

Properties: Silver-white, low ductility. Does not tar-

Properties: Dull green to blue-black particles. Mp

nish in air. On heating strongly, a slightly volatile

763C (decomposes). Insoluble in water and alcohol.

oxide is formed. Bulk d 22.65 (20C calculated) The

Prepared by action of chlorine on iridium powder at

most dense element known. Mp 2443C, bp approxi-

600C.

mately 4500C, most corrosion-resistant element,

modulus of elasticity is one of highest (75,000,000

iridomyrmecin. C

psi), Brinell hardness (cast) 218, highly resistant to

Properties: Colorless crystals. Mp 60C, bp 104C

chemical attack. Insoluble in acids; slowly soluble

(1.5 mm Hg), characteristic odor, refr index 1.46,

in aqua regia and in fused alkalies.

optically active. Soluble in ether and fatty alcohols;

Occurrence: Canada, South Africa, the former

almost insoluble in water.

U.S.S.R., Alaska.

Use: Insecticide, biocide.

Derivation: Occurs with platinum, remains insoluble

when the crude platinum is treated with aqua regia,

occurs as iridosmine. The powder is obtained by

iridosmine. (osmiridium). A natural alloy of

hydrogen reduction of ammonium chloroiridate.

iridium and osmium containing some platinum, rhe-

Available forms: Powder, single crystals.

nium, ruthenium, iron, copper, palladium.

Use: Alloy with platinum for ammonia fuel-cell cata-

Properties: Tin-white to light steel gray in color;

lyst, electric contacts and thermocouples, commer-

streak, same; metallic luster. D l8.8–21.12, Mohs

cial electrodes and resistance wires, laboratory

hardness 6–7. Composition is variable ranging from

ware, extrusion dies for glass fibers, jewelry. Pri-

10.0–77.2% iridium, 17.2–80.0% osmium,

mary standards of weight and length.

0–10.1% platinum, 0–17.2% rhenium, 0–8.9% ru-

thenium, 0–1.5% iron, 0.0.9% copper, trace, palladi-

192

iridium. Radioactive iridium of mass number um. Unattacked by aqua regia.

192. Occurrence: Alaska, South Africa.

Properties: Half-life, 74 days. Radiation: ␤ and ␥. Use: Fountain-pen point tips, surgical needles, watch

Derivation: Pile irradiation of iridium. pivots, compass bearings, hardening platinum (stan-

Available forms: Iridium metal or potassium or sodi- dard weights, jewelry), source of iridium and os-

um chloroiridate in hydrochloric acid solution. mium.

700IRINOTECTAN HYDROCHLORIDE

irinotectan hydrochloride hydrate. oxalate; (d) by electrolytic deposition from solu-

CAS: 136572-09-3. mf: C

•ClH•3H

tions of a ferrous salt (99.9% pure).

Hazard: Moderately toxic by ingestion.

Use: Powder metallurgy products, magnets, high-fre-

quency cores, auto parts, catalyst in ammonia syn-

Irish moss. See carrageenan. thesis.

Available forms: (3) Cast iron and wrought iron are

mixtures of iron and other materials.

“Irish Moss” [Home Brewery]. TM for a

Available forms: (4) Single crystals and whiskers

beer clarifier.

are also available.

Use: Clarifier added in last 15 minutes of boil.

Available forms: (5) Iron sponge.

Hazard: Dust and fine particles suspended in air are

irloxacin. See 6-fluoro-7-(1-pyrrolyl)-1-ethyl-

flammable and an explosion risk. TLV: (as oxide

1,4-dihydro-4-oxo-3.

fume) 5 mg/m

; for soluble salts (as iron) 1 mg/m

Biochemistry: Iron is a constituent of hemoglobin

“IRN” [Pfizer]. TM for a group of magnetic

and is essential to plant and animal life, an important

iron oxides, black ferroso-ferric oxides (Fe

) and

factor in cellular oxidation mechanism.

brown ␥-ferric oxides (Fe

), with application in

Use: Medicine and dietary supplements.

ferric cores and electronic parts, magnetic inks,

data-handling accounting systems, recording and

iron. Radioactive iron, mass number 55.

instrumentation tapes.

Properties: Half life 2.91 years, decays through K

capture.

iron.

See iron 59.

CAS: 7439-89-6. Fe. Metallic element of atomic

Hazard: Toxic material.

number 26, group VIII of the periodic table, aw

55.847, valences

2,3; 4 stable isotopes, 4 artificial-

iron. Radioactive iron of mass number 59.

ly radioactive isotopes.

Properties: Half-life 46.3 days. Radiation: ␤ and ␥.

Properties: Silver-white malleable metal. Tensile

Derivation: Pile irradiation of iron metal, giving a

strength 30,000 psi, Brinell hardness 60, mp 1536C,

product that contains iron 55 impurity. Both iron 55

bp 3000C, d 7.87 (20C), magnetic permeability

and iron 59 are produced pure in the cyclotron.

88,400 gauss (25C). The only metal that can be

Enriched samples of each are also available.

tempered. Mechanical properties are altered by im-

Hazard: Toxic material.

purities, especially carbon. Iron is highly reactive

Use: Medicine, tracer element in biochemical and

chemically, a strong reducing agent, oxidizes readi-

metallurgical research.

ly in moist air, reacts with steam when hot, to yield

hydrogen and iron oxides. Dissolves in nonoxidiz-

iron acetate liquor. (iron liquor; black li-

ing acids (sulfuric and hydrochloric acid) and in cold

quor; black mordant; iron pyrolignite).

dilute nitric acid. For biochemical properties, see

Properties: Intensely black liquor, sometimes con-

below.

taining copperas or tannin. Absorbs oxygen from the

Source: Hematite, limonite, magnetite, siderite, also

air. D 1.09–1.115, containing 5–5.5% iron.

taconite (low-grade 25–30% iron).

Derivation: (1) By the action of pyroligneous acid on

Occurrence: Minnesota (Mesabi), Alabama, Labra-

iron filings, (2) double decomposition of ferrous

dor, Yukon, Europe, South America.

sulfate with calcium pyrolignite (calcium acetate).

Available forms: (1) Molten (or pig) iron. Derived

Use: Mordant, especially for alizarine and nitroso

(a) by smelting ore with limestone and coke in blast

dyes.

furnaces (purity 91–92%), (b) by continuous direct

reduction in which iron ore and limestone are pre-

iron alum. See ferric potassium sulfate.

heated in a fluidized bed, followed by heating to

926C, by melting at 1926C, and reduction to iron at

iron(II) ascorbate. See ferrous ascorbate.

1648C with powdered coal (purity 99%—propri-

etary process).

iron black. (contains no iron).

Use: Steels of various types, other alloys (cast and

Properties: Fine black powder.

wrought iron), source of hydrogen by reaction with

Derivation: Action of zinc upon an acid solution of

steam.

an antimony salt, a black antimony being precipitat-

See steel.

ed as a fine powder.

Available forms: (2) Powdered iron. Derived (a) by

Use: Imparting the appearance of polished steel to

treatment of ore or scrap with hydrochloric acid to

papier mache and plaster of Paris.

give ferrous chloride solution, which is then purified

by filtration, vacuum crystallized, and dehydrated to

ferrous chloride dehydrate powder; this is reduced at

iron blue. A pigment (of which there are several

800C to metallic iron (briquettes or powder) of varieties) prepared by precipitating ferrous ferrocy-

99.5% purity; (b) by thermal decomposition of iron anide from a solution of ferrocyanide and ferrous

carbonyl [Fe(CO

)] at 250C (99.6–99.9% pure); (c) sulfate. Subsequent oxidation produces a complex

by hydrogen reduction of high-purity ferric oxide or ferriferrocyanide whose shade and pigment proper-

701 IRON OXIDE PROCESS

ties are dependent upon the oxidizing agent, reactant

iron octoate.

concentrations, pH, temperature, size of batch, and Use: Catalyst for curing silicone resins and rubbers.

other conditions of manufacture. Common oxidants See soap (2).

are nitric acid, sulfuric acid, potassium dichromate

with sulfuric acid, perchlorates, and peroxides.

iron-ore cement. Cements in which ferric ox-

Properties: Insoluble in water, oils, alcohol, hot par-

ide replaces a large part of the alumina. There must

affin, organic solvents; unaffected by dilute acids.

be some alumina present, however. Iron-ore cement

Unstable to alkalies of all concentrations or reducing

is rather slow setting and hardening, but is more

media. Resistant to light and ordinary baking tem-

resistant to seawater than is Portland cement. It is

peratures.

light to chocolate brown in color, d about 3.31,

Use: Paints, printing inks, plastics, cosmetics (eye

higher than Portland cement.

shadow), artist colors, laundry blue, paper dyeing,

fertilizer ingredient, baked enamel finishes for autos

iron ore, chrome. See chromite.

and appliances, industrial finishes.

iron ore, magnetic. See magnetite.

iron caprylate.

iron ore, red. See hematite, red.

Use: Food additive.

iron oxide, black. (ferrosoferric oxide; fer-

iron(II) carbonate. See ferrous carbonate.

roferric oxide; iron oxide, magnetic; black

rouge).

iron carbonate, precipitated. See iron ox-

CAS: 1309-37-1. FeO•Fe

or Fe

ide, brown.

See magnetite.

Properties: Reddish or bluish-black amorphous

iron carbonyl. See iron pentacarbonyl.

powder. D 5.18, mp 1538C (decomposes). Soluble

in acids; insoluble in water, alcohol, and ether.

iron, cast. See cast iron.

Derivation: (1) Action of air, steam, or carbon diox-

ide on iron; (2) specially pure grade by precipitating

iron(II) citrate. See ferrous citrate.

hydrated ferric oxide from a solution of iron salts,

dehydrating, and reducing with hydrogen, (3) oc-

iron compounds. See ferric-; ferrous-.

curs in nature as the mineral magnetite.

Grade: Technical, pure (96% min).

iron(III) diethyldithiocarbamate.

Use: Pigment, polishing compound, metallurgy,

CAS: 13963-59-2. mf: C

FeN

magnetic inks, and in ferrites for electronic industry,

Hazard: Moderately toxic.

coatings for magnetic tape, catalyst.

irone. (6-methylionone).

iron oxide, brown. (iron subcarbonate; iron

CAS: (␣) 79-69-6; (␤) 79-70-9; (␥) 79-68-5.

carbonate, precipitated).

Properties: Reddish-brown powder containing fer-

Properties: Yellowish liquid; Mw 206.32, mp

ric carbonate with ferric hydroxide Fe(OH)

and

89–90C, refractive index 1.5017 (20C), d 0.9434

ferrous hydroxide Fe(OH)

in varying quantities; not

(21/4C). Soluble in alcohol. A mixture of three iso-

a true oxide. Soluble in acids; insoluble in water and

mers (␣-, ␤- and ␥-irone).

alcohol.

Use: Perfumery, violet odor. The ␣ isomer is also

Derivation: By the interaction of solution of ferrous

used as a flavoring agent.

sulfate and sodium carbonate.

Grade: Technical.

iron(III)-edta complex.

Use: Paint pigment.

CAS: 15275-07-7. mf: C

FeN

Hazard: A poison.

iron oxide, hydrated. See ferric hydroxide.

iron formation. Complex sedimentary or

iron oxide, metallic brown. A naturally oc-

weakly metamorphosed rock that usually consists of

curring earth, principally ferric oxide to which ex-

oxides, sulfides, or carbonates of iron, often in asso-

tenders have been added.

ciation with chert.

Use: Paint pigment.

iron linoleate.

iron oxide process. A process for the removal

Use: Food additive.

of sulfides from a gas by passing the gas through a

mixture of iron oxide, Fe

(called iron sponge or

iron mass. See iron sponge.

iron mass), and wood shavings. The iron oxide is

converted to iron sulfide and can be regenerated by

iron naphthenate. allowing the iron sulfide to contact air.

Use: Food additive. See iron sponge, spent.

702IRON OXIDE RED

iron oxide red. (burnt sienna; Indian red; slurry of the hydrated ferric oxide produced in puri-

red iron oxide; red oxide; rouge (1); Turkey fying alum and then dried. The iron sponge or iron

red). mass is used for removing sulfur from coal gas or

CAS: 1332-37-2. Pigments composed mainly of fer- similar materials.

ric oxide (Fe

). Use: For precipitating copper or lead from solutions

Use: Marine paints, metal primers, polishing com- of their salts, and in electric furnace steel operations.

pounds, pigment in rubber and plastic products, the- See iron oxide process; iron sponge, spent.

atrical rouge, grease paints.

See ferric oxide.

iron, sponge. See Sponge iron.

iron oxide yellow. (hydrated ferric oxide).

iron sponge, spent. (iron mass, spent; spent

•H

O. A precipitated pigment of finer particle

oxide). Iron sponge after saturation with sulfur. It is

size and greater tinctorial strength than the naturally

liable to spontaneous heating.

occurring oxides such as ocher; excellent light-

See iron oxide process.

fastness and resistance to alkali.

Use: Paints, rubber products, plastics.

iron, stainless. Alloys containing 3–38% chro-

mium, with or without traces of nickel, essentially

iron pentacarbonyl. (iron carbonyl).

magnetic and ferritic in character. High chromium

CAS: 13463-40-6. Fe(CO)

irons are brittle after welding. Most popular compo-

Properties: Mobile, yellow liquid. D 1.466 (18C), bp

sition for fabrication is 15–18% chromium, 0.1% C

102.8C (749 mm Hg), decomposes at 200C, mp

(max).

−21C, flash p 5F (−15C). Evolves carbon monoxide

See steel, stainless.

on exposure to air or to light. Soluble in nickel

tetracarbonyl and most organic solvents; soluble

iron-sulfur center. A prosthetic group of some

with decomposition in acids and alkalies; insoluble

redox proteins involved in respiration and other

in water.

electron transfers. Fe

or Fe

is with Cys groups in

Derivation: Finely divided iron is treated with car-

the protein.

bon monoxide, in the presence of a catalyst such as

ammonia.

iron tallate.

Hazard: Flammable, dangerous fire risk. Toxic by

Use: Food additive.

ingestion, inhalation, and skin absorption. TLV:

TWA 0.1 ppm (Fe); STEL 0.2 ppm.

irradiation. Exposure to radiation of wave-

Use: Catalyst in organic reactions, carbonyl iron for

lengths shorter than those of visible light (␥, x-ray,

high-frequency coils.

or UV) either for medical purposes (cancer therapy,

removal of skin blemishes), for destruction of bacte-

iron powder. See iron.

ria in milk and other foodstuffs or for inducing

polymerization of monomers or vulcanization of

iron protochloride. See ferrous chloride.

rubber. UV irradiation was formerly used to induce

activation of vitamin D in milk and has been used for

iron protoiodide. See ferrous iodide.

some time to sterilize the air in operating rooms, etc.

iron protosulfide. See ferrous sulfide.

irreversible. A permanent chemical or physico-

chemical change. Examples are (1) a chemical reac-

iron pyrite. See pyrite.

tion that can proceed only to the right, giving a

product that is stable and that cannot revert to the

iron pyrolignite. See iron acetate liquor.

original constituents; most reactions are of this type;

(2) a colloidal system that cannot be restored to its

iron pyrophosphate. See ferric pyrophos-

original form after coagulation or precipitation, for

phate.

example, the hardening of egg white or milk protein

by heat, the formation of butter from milk (mechani-

iron red. Red varieties of ferric oxide that are

cal action), and the coagulation of rubber latex by

used as pigments.

acid (chemical action).

See iron oxide red.

See reversible.

iron sponge. (iron mass, iron oxide). Finely

irreversible colloid. A colloidal substance that

divided iron oxide, distributed on a support so as to

when coagulated cannot be brought back to the col-

give a large surface area. One form is a mixture of

loidal state.

wood shavings covered with a hydrated iron oxide.

This may be made by mixing wet wood shavings

with iron borings or similar material and allowing

“Irron.” [LaMotte] TM for 8-quinolinol-7-

rusting to occur to produce finely divided iron oxide. iodo-5-sulfonic acid.

In another method, wood shavings are mixed with a Use: Colorimetric determination of iron.