A dynamic nuclear magnetic resonance study of ring inversion occurring in 1,4-oxa-thian, -selenan, and -telluran

Abstract

The low temperature ¹H n.m.r. spectra of 1,4-oxachalcenans have been observed and for 1,4-oxathian and 1,4-oxaselenan consist of ABCD multiplets which have been analysed and for which spectral parameters are reported. Coalescence phenomena observed in the spectra were interpreted in terms of ring inversion occurring in the molecules and thermodynamic parameters obtained by means of total line-shape fitting techniques are reported for this process.