✍ Scribed by R. F. Rekker; W. Th. Nauta
No coin nor oath required. For personal study only.
This article gives the experimental results of UV measurements made on a number of benzophenones with ethyl, __iso__propyl and __tert.__butyl groups as substituents. The results are compared with the previously published data on the corresponding methyl‐substituted benzophenones^1,2,3,4^. Our investigation showed that there is no significant difference between the effects of introduction of ortho‐methyl, ortho‐ethyl or ortho‐isopropyl groups into a benzophenone. With a tert.‐butyl group, however, the result is somewhat different: in this case a steric effect is observed on the electronic spectra, which is only slightly smaller than that encountered in 2,6‐dimethylbenzophenone. When plotting the λ~C~ differences between meta/para‐substituted derivatives and the unsubstituted benzophenone against the Hammett σ‐values the result is a straight line, the Hammett σ‐constant being −0.061 for ethanol and −0.050 for __iso__octane solutions.
📜 SIMILAR VOLUMES
## Abstract This article gives the experimental results of UV measurements made on an extensive series of __unsymmetrically__ substituted methylbenzophenones in solution (ethanol and __iso__‐octane). The results obtained are compared with our previously published UV measurements on symmetrically su
A study has been made of the oxidation of a number of substituted benzhydrols by chromic acid in aqueous acetic acid. The reaction rate constants are linearly proportional to the KR+ values of the alcohols. ortho-Substitution increases the rate of reaction and reduces the magnitude of the primary ki