The hindered inversion of the seven-membered ring inN-(chlorodimethylgermylmethyl)- andN-(chlorodimethylstannylmethyl)hexahydroazepin-2-ones

The stereochemical flexibility ofN-(chlorodimethylgermylmethyl)- andN-(chlorodimethylstannylmethyl)hexahydroazepin-2-ones was studied by dynamic NMR spectroscopy. Protons of the NCH₂M and MMe₂ groups (M=Ge, Sn) were shown to be anisochronic at low temperatures (<−70°C). The free activation energy of the process resulting in chemical equivalence of the protons indicated was determined. The anisochronicity of signals observed is due to the restricted inversion of the seven-membered cycle. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2379–2381, November, 1998.