Kekule, in 1858, concluded that it was nitroacetonitrile, NO 2 CH 2 CN, a view opposed by Steiner (1883), E.
The formulae of Kekule, Divers and Armstrong have been discarded, and it remains to be shown whether Nef's carbonyloxime formula (or the bimolecular formula of Steiner) or Scholl's glyoxime peroxide formula is correct.
See Kekule, Das Leben F.
Kekule was the forerunner of his celebrated benzene theory in particular, and of the universal application of structural formulae to the representation of the most complex organic compounds equally lucidly as the representation of the simplest salts.
A further generalization was effected by August Kekule, who rejected the hydrochloric acid type as unnecessary, and introduced the methane type and condensed mixed types.
The " structure theory " (or the mode of linking of the atoms) of carbon compounds, founded by Butlerow, Kekule and Couper and, at a later date, marvellously enhanced by the doctrine of stereo-isomerism, due to J.
The ringed structure of benzene, C 6 H 61 was first suggested in 1865 by August Kekule, who represented the molecule by six CH groups placed at the six angles of a regular hexagon, the sides of which denoted the valencies saturated by adjacent carbon atoms, the fourth valencies of each carbon atom being represented as saturated along alternate sides.
This formula, notwithstanding many attempts at both disproving and modifying it, has well stood the test of time; the subject has been the basis of constant discussion, many variations have been proposed, but the original conception of Kekule remains quite as convenient as any of the newer forms, especially when considering the syntheses and decompositions of the benzene complex.
Although Kekule founded his famous benzene formula in 1865 on the assumptions that the six hydrogen atoms in benzene are equivalent and that the molecule is symmetrical, i.e.
Carius showed that potassium chlorate and sulphuric acid oxidized benzene to trichlorphenomalic acid, a substance afterwards investigated by Kekule and 0.
The pioneer in this field was August Kekule, who, in 1865 (Ann., 137, p. 129; see also his Lehrbuch der organischen Chemie), submitted his well-known formula for benzene, so founding the " benzene theory " and opening up a problem which, notwithstanding the immense amount of labour since bestowed upon it, still remains imperfectly solved.
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.'
Kekule answered Ladenburg by formulating a dynamic interpretation of valency.
Therefore, according to Kekule, the double linkages are in a state of continual oscillation, and if his dynamical notion of valency, or a similar hypothesis, be correct, then the difference between the 1.2 and 1.6 di-derivatives rests on the insufficiency of his formula, which represents the configuration during one set of oscillations only.
The explanation thus attempted by Kekule was adversely criticized, more especially by A.
Kekule (Ann., 1883, 221, p. 230), however, reinvestigated this acid; he showed that it was dibasic and not tribasic; that it gave tartaric acid on reduction; and, finally, that it was dioxytartaric acid, HOOC C(OH) 2 C(OH) 2 COOH.
Kekule also urged that the formation of trichlorphenomalic acid, shown by him and O.
He admitted the possibility of the formulae of Kekule, Claus, Dewar and Ladenburg, although as to the last di-trimethylene derivatives should be possible reduction products, being formed by severing two of the prism edges; and he attempted to solve the problem by a systematic investigation of the reduced phthalic acids.
The relative merits of the formulae of Kekule, Claus and Dewar were next investigated by means of the reduction products of benzene, it being Baeyer's intention to detect whether double linkages were or were not present in the benzene complex.
It was found that the results were capable of expression by the empirical relation CaH2b= 104.3b+49'09m+105.47n, where C a H 2b denotes the formula of the hydrocarbon, m the number of single carbon linkings and n the number of double linkings, m and n being calculated on the Kekule formulae.
Simultaneously with the discussions of Kekule, Ladenburg, Claus, Baeyer and others as to the merits of various plane formulae of the benzene complex, there were published many suggestions with regard to the arrangement of the atoms in space, all of which attempted to explain the number of isomers and the equivalence of the hydrogen atoms. The development of stereo-isomerism at the hands of ' Victor Meyer and G.
Two acids corresponding to the formula of Kekule and Claus are triphenyl acrylic acid, (C6H5)2C: C([[Cooh) C 6 H]],, and triphenyl acetic acid, (C,H,),C 000H.
Soc. Trans., p. 1013) considered in detail an octahedral form, and showed how by means of certain simple rotations of his system the formulae of Kekule and Claus could be obtained as projections.
One of the most important applications of these values is found in the case of the constitution of benzene, where Thomsen decides in favour of the Claus formula, involving nine single carbon linkages, and rejects the Kekule formula, which has three single and three double bonds (see section IV.).
Virchow's conjecture as to the starchy nature of the substance was disproved by Friedrich and Kekule, who confirmed Professor Miller's previous finding as to its albuminous or protein nature.
Kekule, De fabula meleagrea dissertatio (1861); Surber, Die Meleagersage (Zurich, 1880); articles on "Meleager" and "Meleagrides" in Roscher's Lexikon der Mythologie; L.
Kekule at Ghent, then visited England, studied in Paris and with Ch.
He was educated at Dollar Academy and Edinburgh University, being at the latter first a pupil, and afterwards the assistant, of Lord Playfair, then professor of chemistry; he also studied under Kekule at Ghent.
To Kekule is due the credit of taking the decisive step in introducing the notion of tetravalent carbon in a clear way, i.e.
KEKULE, FRIEDRICH AUGUST (1829-1896), German chemist, was born at Darmstadt on the 7th of September 1829.
Frankland, when in 1858 Kekule published a paper in which, after giving reasons for regarding carbon as a tetravalent element, he set forth the essential features of his famous doctrine of the linking of atoms. He explained that in substances containing several carbon atoms it must be assumed that some of the affinities of each carbon atom are bound by the affinities of the atoms of other elements contained in the substance, and some by an equal number of the affinities of the other carbon atoms. The simplest case is when two carbon atoms are combined so that one affinity of the one is tied to one affinity of the other; two, therefore, of the affinities of the two atoms are occupied in keeping the two atoms together, and only the remaining six are available for atoms of other elements.
This conception led Kekule to his "closed-chain" or "ring" theory of the constitution of benzene which has been called the "most brilliant piece of prediction to be found in the whole range of organic chemistry," and this in turn led in particular to the elucidation of the constitution of the "aromatic compounds," and in general to new methods of chemical synthesis and decomposition, and to a deeper insight into the composition of numberless organic bodies and their mutual relations.
Japp, in the Kekule memorial lecture he delivered before the London Chemical Society on the 15th of December 1897, declared that three-fourths of modern organic chemistry is directly or indirectly the product of Kekule's benzene theory, and that without its guidance and inspiration the industries of the coal-tar colours and artificial therapeutic agents in their present form and extension would have been inconceivable.
It is obtained by condensing benzal chloride with mercury diphenyl (Kekule and Franchimont, Ber., 1872, 5, p. 907); from benzal chloride or benzotrichloride and zinc dust or aluminium chloride; from chloroform or carbon tetrachloride and benzene in the presence of aluminium chloride; and deamidating diand tri-aminotriphenylmethane with nitrous acid and alcohol (0.
Kekule and R.
Kekule, and in 1858 took his degree as Ph.D.