The first crystal structures of mixed chalcogen derivatives SnR(2)[(OPPh(2))(SPPh(2))N](2) (R=Me or Ph)

The compounds SnR(2)[(OPPh(2))(SPPh(2))N](2) (R = Me, Bu(n), CH(2)Ph or Ph) were prepared by metathesis reactions between SnR(2)Cl(2) and K[(OPPh(2))(SPPh(2))N] in toluene. Reactions between SnR(3)Cl (R = Me or Ph) and K[(OPPh(2))(SPPh(2))N] (1:1 molar ratio) in boiling toluene also produced the dimethyl- and diphenyl-tin(IV) derivatives as redistribution products. The same reactions in chloroform at room temperature afford the corresponding triorganotin(IV) compounds. The compounds were characterized by means of IR and multinuclear NMR spectroscopy. The crystal and molecular structures of SnR(2)[(OPPh(2))(SPPh(2))N](2) (R = Me 1 or Ph 2) derivatives were determined by X-ray diffractometry. Both compounds exhibit very similar spiro-bicyclic structures, with the tin atom as spiro atom. The ligand moieties are monometallic biconnective (bidentate) through both oxygen and sulfur atoms [Sn-S 2.758(1) in 1 and 2.680(4) in 2, Sn-O 2.199(2) in 1 and 2.189(5) Angstrom in 2]. The co-ordination geometry around the central metal atom is octahedral, with C-Sn-C, O-Sn-O (trans) and S-Sn-S (trans) angles of 180 degrees. The conformation of the six-membered SnOSP2N inorganic rings is twisted boat.