FULMINIC ACID, Hcno or H 2 C 2 N 2 0 2, an organic acid isomeric with cyanic and cyanuric acids; its salts, termed fulminates, are very explosive and are much employed as detonators.
The researches of Liebig (1823), Liebig and Gay-Lussac (1824), and of Liebig again in 1838 showed the acid to be isomeric with cyanic acid, and probably (Hcno) 2, since it gave mixed and acid salts.
By passing the vapour of this compound through a red-hot tube, it yields the isomeric a0- pyridylpyrrol, the potassium salt of which with methyl iodide gives a substance methylated both in the pyridine and pyrrol nuclei.
Pasteur proved that the inactivity of the one acid depended upon the fact that it was composed of two isomeric constituents: one the ordinary or dextrorotary acid, and the other a new acid, which possessed an equally powerful left-handed action.
The principal elements are found in various combinations, the hydrocarbons of the Pennsylvania oils being mainly paraffins (q.v.), while those of Caucasian petroleum belong for the most part to the naphthenes, isomeric with the olefines (q.v.).
The isomeric I.
Faraday's discovery of butylene, isomeric with ethylene, in 1825.
These three hydrocarbons are isomeric, i.e.
In comparison with the isomeric propylene, CH 3 HC:CH 2, it is remarkably inert, being only very slowly attacked by bromine, which readily combines with propylene.
Starting with the three isomeric compounds, he found that one gave two tribrombenzenes, another gave three, while the third gave only one.
Thus salicylic acid yields n-pimelic acid, [[Hooc (Ch 2) 5 Cooh]], while o-, m-, and p-cresotinic acids, C 6 H 3 (CH 3)(OH)(000H), yield isomeric methylpimelic acids.
CH CH HC, N CH HC CH HC HC HC Hcch Hc Ch Ch Kekule t i Dewar Ladenburg One of the earliest and strongest objections urged against Kekule's formula was that it demanded two isomeric ortho-di-substitution derivatives; for if we number the carbon atoms in cyclical order from i to 6, then the derivatives 1.2 and 1.6 should be different.'
He assumed that if we have one atom 1 It is now established that ortho compounds do exist in isomeric forms, instances being provided by chlor-, brom-, and amino-toluene, chlorphenol, and chloraniline; but arguments, e.g.
These isomeric hydrocarbons, of the formula C14H10, are to be regarded as formed by the fusion of three.
Obviously, isomeric ring-systems are possible, since the carbon atoms in the original rings are not all of equal value.
In general, isomers boil at about the same temperature, as is shown by the isomeric esters CH1802: Methyl octoate..
The isomeric pentanes also exhibit a similar relationCH 3 (CH 2)4CH3 =38°,(CH3)2CHC2Hb =30°,(CH 3) 4 C =9.5°.
He has also shown that the nitrophenols yield, in addition to the colourless true nitrophenol ethers, an isomeric series of coloured unstable quinonoid aci-ethers, which have practically the same colour and yield the same absorption spectra as the coloured metallic salts.
It is to be noted in the Kolbe method of synthesis that potassium phenolate may be used in place of the sodium salt, provided that the temperature be kept low (about 150° C.), for at the higher temperature (220° C.) the isomeric para-oxybenzoic acid is produced.
When boiled with calcium chloride and ammonia, salicylic acid gives a precipitate of insoluble basic calcium salicylate, C 6 H 4 ‹ 0 2 i Ca, a reaction which serves to distinguish it from the isomeric metaand para-hydroxybenzoic acids.
Its sodium salt is transformed into the isomeric C6H4(0C6H5) CO 2 Na when heated to 300°.
Beckmann, Ber., 1886, 1 9, p. 9 8 9; 188 7, 20, p. 2580), yielding as final products an acid-amide or anilide, thus: RC(:N OH)R'-RC(OH) :NR' ---> As regards the constitution of the oximes, two possibilities exist, namely >C: NOH, or > C' ?, and the first of these is presumably correct, since on alkylation and subsequent hydrolysis an alkyl hydroxylamine of the type NH 2 OR is obtained, and consequently it is to be presumed that in the alkylated oxime, the alkyl group is attached to oxygen, and the oxime itself therefore contains the hydroxyl group. It is to be noted that the oximes of aromatic aldehydes and of unsymmetrical aromatic ketones frequently exist in isomeric forms. This isomerism is explained by the HantzschWerner hypothesis (Ber., 1890, 23, p. II) in which the assumption is made that the three valencies of the nitrogen atom do not lie in the same plane.
It behaves as a powerful reducing agent, and on hydrolysis with dilute mineral acids is decomposed into formaldehyde and hydroxylamine, together with some formic acid and ammonia, the amount of each product formed varying with temperature, time of reaction, amount of water present, &c. This latter reaction is probably due to some of the oxime existing in the form of the isomeric formamide HCO NH 2.
The aldehyde group reacts with hydrocyanic acid to produce two stereo-isomeric cyanhydrins; this isomerism is due to the conversion of an originally non-asymmetric carbon atom into an asymmetric one.
PHENANTHRENE, C14H10, a hydrocarbon isomeric with anthracene, with which it occurs in the fraction of the coal tar distillate boiling between 270°-400° C. It may be separated from the anthracene oil by repeated fractional distillation, followed by fractional crystallization from alcohol (anthracene being the less soluble), and finally purified by oxidizing any residual anthracene with potassium bichromate and sulphuric acid (R.
When methyl iodide is used, nitromethane is the sole product, but the higher homologues give more or less of the isomeric nitrous esters.
The nitro compounds are colourless, somewhat pleasant smelling liquids, which distil without decomposition and possess boiling points much higher than those of the isomeric nitrous esters.
Hantzsch (Ber., 18 99, 3 2, pp. 577 et seq.) are probably derived from the isomeric iso-nitro compounds R: NO(OH), and thus the nitro derivatives are to be looked upon as pseudo-acids.
Phenylnitromethane, C 6 H 5 CH 2 NO 2, isomeric with the nitrotoluenes, is prepared by the action of benzyl chloride on silver nitrite.
It readily forms a sodium salt, from the aqueous solution of which on the addition of a mineral acid an isomeric solid form of the nitro compound (melting at 84° C.) is precipitated.
These compounds may be considered as 5-triazolones, a series of isomeric 3-triazolones resulting from the condensation of phenylsemicarbazide with aromatic aldehydes in the presence of an oxidant.
It may be distinguished from the isomeric ethylene succinic acid by the fact that its sodium salt does not give a precipitate with ferric chloride.
Nutmeg butter yields on distillation with water a volatile oil to the extent of about 6%, consisting almost entirely of a hydrocarbon called myristicene, CioHis, boiling at 165° C. It is accompanied by a small quantity of an oxygenated oil, myristicol, isomeric with carvol, but differing from it in not forming a crystalline compound with hydrosulphuric acid.
Ordinary fusel oil yields also an isomeric amyl alcohol (active amyl alcohol) boiling at about 128°.
VALERIC ACID, or [[Valerianic Acid, C4h9 C02h]], an organic acid belonging to the fatty acid series, which exists in four isomeric forms, one of which contains an asymmetric carbon atom and consequently occurs in two optically active modifications and one optically inactive modification.
Consequently, of each pair of isomers we may establish beforehand which is the more stable; either in particular circumstances, a direct change taking place, as, for instance, with maleic acid, which when exposed to sunlight in presence of a trace of bromine, yields the isomeric fumaric acid almost at once, or, indirectly, one may conclude that the isomer which forms under greater heat-development is the more stable, at least at lower temperatures.
Similarly, pentane, C 5 H 12, and hexane, C6H14, may exist in three and five theoretically isomeric forms respectively; confirmation of this theory is supplied by the fact that all these compounds have been obtained, but no more.
And so, as a rule, from isomeric alcohols, those containing a group - CH 2.0H, yield by oxidation aldehydes and are distinguished by the name primary; whereas those containing CH OH, called secondary, produce ketones.
In this equation a relates to molecular attraction; and it is not improbable that in isomeric molecules, containing in sum the same amount of the same atoms, those mutual attractions are approximately the same, whereas the chief difference lies in the value of b, that is, the volume occupied by the molecule itself.
Hantzsch (Ber., 18 9 6, 2 9, p. 947 1898, 31, p. 1253) has shown that the chlorand bromdiazoniumthiocyanates, when dissolved in alcohol containing a trace of hydrochloric acid, become converted into the isomeric thiocyanbenzene diazonium chlorides and bromides.
This hydroxide, although possessing powerful basic properties, is unstable in the presence of alkalis and neutralizes them, being converted first into the isomeric benzene-diazotic acid, the potassium salt of which is obtained when the diazonium chloride is added to an excess of cold concentrated potash (A.
The same oxygen ether is formed by the methylation of the silver salt of the normal diazo hydroxide; this points to the conclusion that the isomeric hydroxides, corresponding with the silver derivatives, have the same structural formulae, namely, R N: N OH.