Synthesis, structure, and reactivity of group 14 bid (thiophosphinoyl) metal complexes

Article abstract of DOI:10.1021/om9008923

Bis(thiophosphinoyl)methane, CH₂(PPh₂=S)₂, and its monolithium salt [Li{(S=PPh₂)₂CH}-(THF)(Et ₂O)] (1) have been used to prepare a series of low-valent group 14 metal complexes. The reaction of lithium salt [Li{(S=PPh₂) ₂CH}(THF)(Et₂O)] (1) with 1 equiv of MCl₂ (M = Ge, Sn) in diethyl ether afforded monomeric organometal(II) chlorides [MCl{CH(PPh₂=S)₂}] (M = Ge (2), Sn (3)). Treatment of CH₂(PPh₂=S)₂ with equimolar M(N(SiMe ₃)₂}₂ (M = Sn, Pb) afforded 1,3-dimetallacyclobutanes [M(μ²-C(Ph₂P=S) ₂}]₂ (M = Sn (4), Pb (5)), which are believed to be formed by the dimerization of the metallavinylidene intermediate. Compounds 2 and 5 further reacted with elemental chalcogens (S and Se) to give trans-dithiadigermetane [GeCl(CH(PPh₂=S)₂}(μ-S)] ₂ (6) and lead(II) chalcogenates [PbE{C(PPh₂=S) ₂}] (E = S (7), Se (8)), respectively. Compounds 2-8 have been determined by X-ray crystallography.