Metal Complexes of trans-2,2,4,4-Tetrafluoro-1,3-di-tert-butyl-1,3-diphosphetane

The title ligand, L, forms metal complexes LW(CO)₅ {pentacarbonyl(trans-1,3-di-tert-butyl-2,2,4,4-tetrafluoro-1,3-diphosphetane-P)tungsten, [W(C₁₀H₁₈F₄P₂)(CO)₅], (1)} and L(AuCl)₂.2CH₂Cl₂ {μ-(trans-1,3-di-tert-butyl-2,2,4,4-tetrafluoro-1,3-diphosphetane-P:P′)-bis(chlorogold) dichloromethane solvate, [Au₂Cl₂(C₁₀H₁₈F₄P₂)].2CH₂Cl₂, (2)}. Complex (1) crystallizes with two independent but closely similar molecules; the P—W bond is short [2.482, 2.488 (2) Å] and the P—C_Bu bonds are lengthened by ca 0.03 Å compared with those in the ligand disulfide, LS₂ [Fild, Jones, Ruhnau & Thöne (1994), Z. Naturforsch. Teil B, 49, 1361–1367; the structure of L is not available for comparison]. The diphosphetane ring is folded by angle of 21.4 (3)/22.0 (1)° about the C...C axis, in contrast with its exact planarity in both LS₂ and complex (2), which crystallizes with imposed 2/m symmetry (m for the solvent); the Au—P bond is slightly shorter than the normal range at 2.212 (2) Å. Short contacts of 3.604 (2) Å are observed between the Au and solvent Cl atoms.

-1