¹³C and ⁷⁷Se NMR of some selenium and thiophene derivatives. ¹<i>J</i>, ²<i>J</i> and ³<i>J</i> SeSe coupling constants

Abstract

Abstract The results of 13 C and (when pertinent) 77 Se NMR spectra of thiopene and selenophene derivatives containing exocyclic selenium atoms are presented. The 77 Se spectra show an interaction between nitro or carbonyl groups and selenium when they are ortho to each other. The measurement of 1 J (SeSe), 2 J (SeSe) and 3 J (SeSe) has been attempted on disymmetric diselenides; only 1 J (SeSe) can be measured and values are very low, generally below 20 Hz. Other coupling cannot be observed and are smaller than the line width, which is 2 Hz. No theoretical interpretation can be advanced at present.