Isomerization modification

The title compounds exist in isomeric modifications similar to those of the oxa analogues. Review material has appeared on the 1,2,3-isomers (84MI20 86CHE8U), 1,2,4-isomers [65AHC(5)119 82AHC(32)285],... 

The number of acids possessing the same atomic weight, and belonging to this division, is determined, first, by the comple mentary variation of the two alcohol radios, and, secondly, by the number of possible isomers of these radicals. The two lowest terms of the series are alone incapable of isomeric modification by either of the causes mentioned. 

An inspection of this formula shows thaf glycoUio add admits of no isomeric modification, except with a total change cf type. The part of the formula below the dotted line repre> sents oxatyl, which cannot be altered without sacrificing the add character of the compound there remains therefore only the part of the formula above the dotted lino, which admits of the following modification —... 

We had only one remaining possibility. The neutral compound exists in two isomeric modifications the trans- [PtIV(NH3)2Cl4] and the cis-[PtIV(NH3)2Cl4]. The former was the more thermodynamically stable and was the one we first prepared. We now synthesized the ds-configuration, and finally, achieved complete success. 

Camphidone occurs in two isomeric modifications, separable in the form of the picrates, a-camphidone and /3-camphidone ... 

Chromium Chlorsulphates may be prepared either by the action of sulphuric acid on chromic chloride, or by the interaction of hydrochloric acid -with chromium sulphate. Isomeric modifications of these salts exist, for it has been shown that in certain cases the — SO4, and in others the —Cl, is ionised. 

This body as we perceive, offers but little interest in its properties but it is the more remarkable in its relation to hydrobenzdyl, from the fact, as analysk proves, that it has a perfectly similar composition, and is therefore an isomeric modification of the same, as is apparently shewn by its unintelligible origin from the oil, through the equally inexplicable action of potassa when air is excluded. 

The technical product is a mixture of two isomeric modifications. Its purification is difficult. 

These can exist in t-alkaline solution it unites with phenols to form azo dyes while the second modification obtained by a longer action of the alkali, at higher temperature if necessary, does not possess this property at all, or only in a slight degree. If they (the latter) be treated with adds, they are converted back into the diazonium salts, and now have the property of combining with phenols to form azo dyes. In spite of numerous experiments the constitution of these substances is not wholly clear. 

Cyanogen derivatives arc numerous and capable of great complexity. Platinous cyanide Pt(CN)3, is obtained as a yellow precipitate when mercuric cyanide is added to a solution of alkali chlorplatinite. Double cyanides of the general formula M 2Pt(CN)4 are formed by such reactions as 6 KCN + PtCL = K2Pt(CN) + 4 KC1 + (CN),. These platino-cyanides do not respond to the ordinary tests for platinum. These compounds yield beautifully colored hydrates, and the barium and calcium hydrates have optical isomeric modifications.2 Certain of these hydrates become remarkably fluorescent under excitation from ultraviolet light or radium. 

There are three isomeric modifications of aldehyde — Metaldehyde, crystalline, subliming at 1320°. Paraldehyde, liquid, boiling at 126°,... 

The number of isomers in this division trill obviously depend, Hist upon the complementary variations of and (CHJ secondly, upon the isomeric modifications of which is susceptible and thurify, upon tho iBomoric modifications of (CH,).. 

Sulfur trioxid exists in two isomeric (see isomerism) modifications, being one of the few instances of isomerism among mineral substances. The a modification, liquid at summer temperature, solidifies in colorless prisms at 16° (60°.8 F.) and boils at 46° (114°.8 F.). The isomere is a white, crystalline solid which gradually fuses and passes into the a form at about 50° (1S3° F.). 

Sulfurous Acid—HaSOs—83.—Although sulfurous acid has not been isolated, it, in all probability, exists in the acid solution, formed when sulfur dioxid is dissolved in water SOa -t- HaO = SOjHa. Its salts, the sulfites, are well defined. From the existence of certain organic derivatives (see sulfonic acids) it would seem that two isomeric modifications of the acid may exist. They are distinguished as the symmetrical, in which the S atom is quadrivalent,... 

The discovery of isomerism, however unexpected, is thus entirely consistent with the atomic theory, of which it is merely a special case. Isomerism is of very frequent occurrence among organic compounds, owing, no doubt, to their usually large atomic weights, since the numerous atoms of the elements afford much scope for isomeric modifications and doubtless this principle plays an important part in the processes of organic life and growth, as well as in decay. 

Needles. M. 101-2°. Sol. AcOH, OS, OgHg, hot EtOH. An isomeric modification has m.p. 88-0°, and is more sol. than higher-melting form. 

Analyses of two isomeric modifications of l,3-diphenyl-2(phenylazo> propene (115) prove that they are the cis- and trans-isomers with respect to the C=C double bond. The dimensions of both isomers are very similar... 

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