Conformational study of 2-arylazo-1-vinylpyrroles.
Conformational study of 2-phenylazo-1-vinylpyrrole and 2-(4-bromophenyl)azo-5-methyl-1-vinylpyrrole was performed on the basis of the experimental measurements and high-level ab initio calculations of their 13C--13C and 13C--1H spin-spin coupling constants, showing marked stereochemical behaviour upon the internal rotation of the vinyl group and the pyrrolyl moiety. In liquid phase, both compounds were found to adopt predominant s-trans-s-trans conformation with the noticeable population (ca. 30%) of the higher-energy s-cis-s-trans conformation in the latter compound. As follows from the X-ray data, 2-phenylazo-1-vinylpyrrole crystallizes in s-trans-s-trans conformation while the crystalline molecular structure of 2-(4-bromophenyl)azo-5-methyl-1-vinylpyrrole is s-cis-s-trans.
Rusakov
Yury Yu
YY
A. E. Favorsky Institute of Chemistry, Irkutsk, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033 Irkutsk, Russia.
Krivdin
Leonid B
LB
Senotrusova
Elena Yu
EY
Schmidt
Elena Yu
EY
Vasiltsov
Alexander M
AM
Mikhaleva
Albina I
AI
Trofimov
Boris A
BA
Dyachenko
Oleg A
OA
Chekhlov
Anatolii N
AN
Kazheva
Olga N
ON