2-THIOXO-1,3,2-DITHIAPHOSPHOLANES -SOLID-STATE MAS NMR AND CRYSTAL STRUCTURE INVESTIGATIONS AS WELL AS IGLO CALCULATIONS OF 31P SHIELDING TENSORS

Abstract

2-Thioxo-1,3,2-dithiaphospholanes with P-substituents R = Me, Et, i-Pr, t-Bu, Ph, 3,5-Me2C6H3, and 4-MeOC6H4 were prepared and characterized by solution and high resolution solid-state 31P and 13C NMR spectroscopy. The influence of different alkyl and aryl substituents at the phosphorus atom on the anisotropy of 31P chemical shift and on the molecular structure is discussed. The orientation of the principal axes with respect to the molecular frame is predicted from the solid-state 31P NMR results. Quantum chemical calculations of the 31P shielding tensors by the IGLO method confirm these results. The crystal structures of 2-tert-butyl-2-thioxo-1,3,2-dithiaphospholane and 2-(3,5-dimethylphenyl)-2-thioxo-1,3,2-dithiaphospholane are presented and discussed.