Metal-oxygen versus metal-sulfur bonding of the ambident monothiophosphinato ligand in some triphenylmetal(IV) derivatives, Ph3M[OSPR2] (M = Ge, Sn, Pb). Crystal structures of Ph3Ge[O(S)PPh2] and [Ph2Sn{O(S)PPh2} (μ-OH)]2

Article abstract of DOI:10.1016/S0277-5387(96)00354-3

Diorganomonothiophosphinato-triphenylmetal(IV) derivatives, Ph₃M(OSPR₂) (M = Ge, Sn, Pb; R = Me, Et, Ph), were prepared and investigated. The IR and multinuclear (¹H, ¹³C, ³¹P) NMR spectra are discussed in relation to the M - O and/or M - S bonding of the ambident OSPR^-₂ ligand. The crystal and molecular structures of Ph₃Ge[O(S)PPh₂] (1) and [Ph₂Sn{O(S)PPh₂} (μ-OH)]₂ (2) were determined by X-ray diffractometry. The asymmetric unit for Ph₃Ge[O(S)PPh₂] contains two independent molecules. The monothiophosphinato group is bonded to germanium only through oxygen (av. Ge - O 1.826, Ge ? S 3.892 A?), leading to a tetrahedral coordination around the germanium atom. The crystal of [Ph₂Sn{O(S)PPh₂}(μ-OH)]₂ consists of dimeric units built up through Sn - O - Sn bridges involving the oxygen atom of the hydroxy groups. The monothiophosphinato group is again monodentate [Sn(1) - O(1) 2.089(3), Sn(1) ? S(1) (non-bonding) 4.164 A?] and the coordination geometry around tin is trigonal bipyramidal, with the O(1) atom of the phosphorous ligand and the O(2′) atom of a bridging hydroxy group in axial positions. Copyright