STRUCTURE AND DYNAMICS OF BIS(ORGANOTHIOPHOSPHORYL) DISULFIDES IN THESOLID-STATE - X-RAY-DIFFRACTION AND CROSS-POLARIZATION MAGIC-ANGLE-SPINNING NUCLEAR-MAGNETIC-RESONANCE STUDIES

The structure and dynamics of selected bis(organothiophosphoryl) disul fides have been studied by single-crystal X-ray diffraction and high-r esolution solid-state NMR spectroscopy. The crystal and molecular stru ctures of bis[tert-butyl(phenyl)thiophosphoryl] disulfide 1, bis-(diph enoxythiophosphoryl) disulfide 2 and bis[tert-butyl(methoxy)thiophosph oryl] disulfide 3 were determined, giving space groups of C2/c, P2(1)2 (1)2(1) and P1BAR for 1, 2 and 3, respectively. Both phosphorus centre s of the disulfide 1 have the same absolute configuration, as have tho se of the disulfide 3, although their environments were significantly different. It has been unambiguously proved that the S-S disulfide bon d length varies as a function of the PSSP torsional angle. Moreover th e influence the S-S-P=S conformation has on the P-S bond length is dis cussed. Carbon-13 NMR dipolar-dephasing experiments, using powdered sa mples, indicated that both the tert-butyl and methoxy groups attached to the phosphorus atom were in a fast regime exchange.