Preparation and structural organisation of heteroleptic tetraphenylantimony(V) complexes comprising unidentately and bidentately coordinated O,O′-dialkyldithiophosphate groups: Multinuclear (13C, 31P) CP/MAS NMR and single-crystal X-ray diffraction stu

Crystalline heteroleptic dialkyldithiophosphate tetraphenylantimony(V) complexes of the general formula [Sb(C6H5)4{S2P(OR)2}] (R = C3H7, i-C4H9) have been prepared and studied by 13C and 31P CP/MAS NMR spectroscopy and single-crystal X-ray diffraction. Unexpected structural distinctions were discovered on these chemically related compounds, which are defined by the principally different coordination modes of O,O′-dipropyldithiophosphate and O,O′-di-iso-butyldithiophosphate ligands in their molecular structures (i.e., S,S′-bidentate chelating and S-unidentately coordinated, respectively). 31P Chemical shift anisotropy parameters (δaniso and η) calculated from spinning sideband manifolds in MAS NMR spectra are remarkably different for phosphorus sites in both species of dithiophosphate ligands of these tetraphenylantimony(V) compounds.