Structure, 31P and 13C chemical shift anisotrophy of (CH 3) 3P, (CH 3) 3PO, (CH 3) 3PS and (CH 3) 3PSe as determined by liquid crystal NMR spectroscopy

Abstract

The 13P and 13C spectra of the triply 13C labelled molecules (CH 3) 3P, (CH 3) 3PO, (CH 3) 3PS and (CH 3) 3PSe oriented in a nematic phase are reported. The CPC bond angles have been measured. The 13P chemical shift tensor shows a large anisotropy except in the case of (CH 3) 3P. The abnormal large value observed for the PSe bond length suggests a large anisotropy of the 1 J(PSe) spin coupling.