Confirmation and characterization of the hypervalent Sb•••N bonding recognized in triarylstibanes bearing an amino side chain by X-ray, NMR and theoretical calculations

Hypervalent Sb . . .N bonding observed in triarylstibanes was investigated by single-crystal X-ray diffraction study, comparison of the N-15 chemical shifts, and HMBC NMR spectroscopic detection of the H-1-C-13 long-range coupling. This bonding is strongly dependent on the Lewis acidity of the central antimony atom. A good correlation was observed between N-15 chemical shift and the charge distribution obtained from semi-empirical molecular orbital calculations. (C) 2000 Elsevier Science Ltd. Ail rights reserved.