ON DYNAMIC ISOMERISM. 209 
taking advantage of their slight solubility, Titherley has recently prepared 
the labile silver salts of benzamide and acetamide, 
C;H;.CO.NHAg2C,H;.C(OAg) : NH, 
CH;.CO.NHAg?CH;.C(OAg) : NH, 
and Hantzsch has isolated the isodynamic forms of mercuric cyanurate.? 
But whilst it is possible to prepare N and O salts from the amides, the 
ketones appear to yield only enolic salts, and it is doubtful if metals 
ever become directly linked to carbon except in the carbides and perhaps 
the cyanides. Ethyl phenylformylacetate appears at first sight to be an 
exception, since it yields two series of salts: the enolic sodium salt, 
NaO.CH : CPh.CO,Et, prepared by the action of sodium on an ethereal 
solution of the ester, is converted almost instantly when dissolved in 
water, into an aldehydic isomeride, which gives no coloration with ferric 
chloride ; on the other hand, the solid aldehydic copper salt, when 
precipitated from aqueous solution, soon passes into an enolic isomeride, 
The aldehydic salt has always been formulated as Na.CO.CHPh.CO,Et, 
but there does not appear to be any precedent for the direct displacement 
of aldehydic hydrogen by metals, and the difficulty entirely disappears if 
the salt be regarded as derived from an enolised ester (see p, 206) ; 
NaO.CH : CPh.CO,Et2H.CO.CPh : C(OEt).ONa, 
(enolic salt) (aldehydic salt) 
Dynamic isomerism is also possible, though not yet proved, amongst 
simple inorganic salts like the sulphites 
Na0.S0.0NaZNa.SO,.ONa., 
10, Transference of an Anion.—In the majority of organic compounds the 
OH group is devoid of basic properties, and it is only in cases like the 
ammonium, the sulphur, and the iodine bases that it is capable of functioning 
as ananion. Occasionally, however, the necessary conditions are fulfilled, 
and a state of equilibrium may be observed between an ammonium base and 
an isomeric carbinol, the transference of the hydroxyl- group being exactly 
comparable with that of the mobile hydrogen atom in the ketones and nitro- 
compounds.* Thus Hantzsch has shown that phenylmethylacridinium 
hydroxide, when liberated from its salts, is rapidly converted into the 
neutral isomeric phenylmethylacridol, 4 
+ 1 t 
C,H. © PACA Pat 
n¢ CoH Me | OH <..HO.CPh (OsHs . 
Becrer ne 2 (GH, Ne 
The case that has been most fully studied is that of the alkaloid 
cotarnine,°® 
+ a 
CH : NMe|OH CH(OH), NM 
Gree AOL ahaa of MELON Me 
pp eas a | . 
CH,. CH, CH, lor, 
! Trans. 1901, 79, 409. ? Ber. 1902, 35, 2717. 
* Hantzsch describes as pseudo- acids all those substances which, like the nitro- 
paraflins, are themselves neutral, but yield salts derived from an isomeric acid. 
Similarly psewdo- bases are neutral substances which combine with acids to form salts 
of an isomeric base. Occasionally the cyano- derivatives (nitrils) of the pseudo- 
bases (carbinols) can be converted into salt-like isomerides (substituted ammonium 
cyanides), and these are therefore called pseudo- salts. ‘To these three cases Hantzsch 
applies the term ‘ionie isomerism,’ * Hantzsch, Ber., 1899, 32, 575-600. 
® Dobbie, Lauder, and Tinkler, Zrans. 1903, 83, 598. 
1904, P 
