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.

Key Words:

• 2-thioxo-1,3,2 -dithiaphospholanes; NMR
• chemical shift anisotropy
• IGLO calculation
• crystal structure