Phosphoramidic difluoride complexes of tin(IV) chloride: A multinuclear (119Sn, 31P, 19F and 1H) NMR characterisation in solution

Abstract: Two octahedral complexes of the general formula SnCl4 ·2(O)PF2NR2 (R=Me (1) or Et (2)) have been synthesised from SnCl4 and the ligand R2NP(O)F2 in anhydrous CHCl3. The new adducts have been characterised by multinuclear (119Sn, 31P, 19F and 1H) NMR, IR spectroscopy and elemental analysis. When compared with previously described hexamethylphosphoramide (HMPA) and trimethylphosphate (TMPA) analogues, the NMR data of the two complexes prepared suggest the presence of only the cis isomer in solution. Steric factors and the Lewis basicity of the ligand may explain the stereochemistry observed. Low temperature 31P and 119Sn NMR spectra show that the compounds partially dissociate in dichloromethane. Additionally, DFT/B3LYP calculations on complex 1 and its ligand have been carried out to support the interpretations of NMR data. [Copyright &y& Elsevier]