Oximes electrical effects

B. Electrical Effects of Oxime, Hydroxamic Acid, Hydroxylamino... 

Values of electrical effect substituent constants for oxime and hydroxylamino groups have been reported ° their values are set forth in Tables la-c. No value for the acid group, CO(NHOH), was available. We have estimated values for it they are given in Tables la-c. Also in Tables la-c are values for some other types of substituents either for purposes of comparison or because they were used in correlations in this work. 

On the condition that two subsets have a structural feature whose parameterization is essentially the same, they can be combined into a single data set. As an example consider set 0X13, anfi-Ak—iyw-X—C=NOH, where Ak is either Me or Et. The electrical effects of these groups for Me and Et, respectively, are a , —.01, —,Q ad, —.14, —.12 ae, —.030, —. 036 the values of the steric parameter v are. 52 and. 56. A significant difference is found only in the polarizability parameter a, where the values for Me and Et are. 046 and. 093, respectively. Combination of oxime pXa values for Ak = Me or Et results in set 0X13 the best correlation was with the LDR equation. As only three substituent types are present in this data set and is 0.33, this data set cannot be considered as proof of anything. The only acceptable conclusion is that it is in accord with the combination of the two subsets. 

Further evidence for the above chemical shift rule was collected subsequently for systems such as oximes, oxime hydrochlorides, hydrazones, hydrazonium iodides, and imines 287, as well as for A -(2-cyclohexen-l-ylidene)amines (enimines) 288. Similar to enol ethers267, electric-field effects are held responsible287. 

The neurotropic activity of five new oximes 8-11 and 13 has been studied (Table 4). Carbon derivative 8 was the most toxic compound (LD50 355 mg/kg). The stimulating effect of phenamine strengthened under the influence of germanium derivative 11 by 266%, but silicon derivative 9 decreased it by 55%. 5-Trimethylgermyl-2-furyltrifluoroacetyloxime (9) in comparatively small doses (50 mg/kg) completely prevented retrogradal amnesia caused by electric shock (RA 100%). 

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