77 Se, 13 C and 1 H NMR investigations on ortho ‐carbonyl benzeneselenenyl derivatives

o ‐Carbonyl benzeneselenenyl compounds with COCH 3 , CHO and COOCH 3 as carbonyl functions and SeCl, SeBr, SeSCN, SeSeCN, SeCN and SeCH 3 as selenium‐containing groups, have been studied by 1 H, 13 C and 77 Se NMR spectroscopy. The IR CO stretching frequencies of these compounds are also reported. If the SeCH 3 derivatives are excluded, the compounds mainly adopt a planar ‘ cis ’ conformation, due to an interaction between the CO group and the selenium atom. The range of over 800 ppm for the observed 77 Se chemical shifts makes 77 Se NMR spectroscopy a powerful tool for physical organic chemists.