Synthesis and Spectroscopic Studies of Triorganotin(IV) Complexes Involving Diorganophosphino and Diorganophosphino-N-Phenyl(Thioformamido) Ligands - the Crystal and Molecular-Structure of Dicyclohexylphosphino-N-Phenyl(Thioformamido)-Triphenyltin, Ph₃Sn[(c-C₆H₁₁)₂PC(S)NPh]

Abstract

Phosphorus-31 and tin-119 n.m.r . data imply that the tin complexes R₃Sn[R1,PC(S) NPh ] (where R = Ph, Me, Bu; R′ = Ph) exist in solution as both sulfur-bonded and nitrogen-bonded isomers. When R′ = c-C₆H₁₁, only one isomer is observed. n.m.r . data are also reported for the series R₃SnPR′₂. Both series of complexes contain four-coordinate tin in dichloromethane solution. The crystal and molecular structure of the tin(IV) complex Ph₃Sn[(c-C₆H₁₁)₂PC(S) NPh ] has been determined by single-crystal X-ray diffraction techniques. The crystals are triclinic, space group Pī , a 10.689(2), b 11.066(1), c 16.315(3) Ǻ, α 101.94(1), β 104.85(1) and γ 105.72(1)° with Z 2; R and R_w were 0.032 and 0.030 respectively for 5169 unique reflections with I ≥ 2σ(I). The structure has two independent centrosymmetrically related mononuclear molecules within the unit cell. The tin atom is in a tetrahedral environment formed by three phenylic carbon atoms and a sulfur atom from the [(c- C₆H₁₁)₂PC(S) NPh ]^- ligand.