Bis(thiophosphinoyl)methane, CH 2 (PPh 2 dS) 2 , and its monolithium salt [Li{(SdPPh 2 ) 2 CH}-(THF)(Et 2 O)] (1) have been used to prepare a series of low-valent group 14 metal complexes. The reaction of lithium salt [Li{(SdPPh 2 ) 2 CH}(THF)(Et 2 O)] (1) with 1 equiv of MCl 2 (M=Ge, Sn) in diethyl ether afforded monomeric organometal(II) chlorides [MCl{CH(PPh 2 dS) 2 }] (M=Ge (2), Sn (3)). Treatment of CH 2 (PPh 2 dS) 2 with equimolar M{N(SiMe 3 ) 2 } 2 (M = Sn, Pb) afforded 1,3dimetallacyclobutanes [M{μ 2 -C(Ph 2 PdS) 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(PPh 2 dS) 2 }(μ-S)] 2 (6) and lead(II) chalcogenates [PbE{C(PPh 2 dS) 2 }] (E = S (7), Se (8)), respectively. Compounds 2-8 have been determined by X-ray crystallography.

The reaction of [Ge{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] (1) with LiBut or LiC⋮CPh in Et2O afforded substituted products [Ge(R){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}] [R = But (2) or C⋮CPh (3)], respectively. However, the one-pot reaction of 1 with PhC⋮CH and BunLi in Et2O afforded lithium germinate [{(PhC⋮C)3Ge}3GeLi(Et2O)3] (4). Compound 1 can also undergo ligand transfer reaction with LiAlH4 to give [AlH{N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}2] (5). Treatment of 1 with excess NaBH4 in THF afforded germanium(II) hydride-borane adduct [Ge(BH3){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}H] (6). The reaction of 1 with MI (M = Cu and Au) gave the first examples of Ge(II)−M(I) adducts [Ge(CuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl]4 (7) and [Ge(AuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] (8). Compounds 2−8 have been characterized by X-ray analysis.

The bisgermavinylidene [(Me3SiNPPh2)2CGe→GeC(PPh2NSiMe3)2] (1) has been used as the source of unstable germavinylidene for the synthesis of a series of metal−germavinylidene complexes. Treatment of 1 with M(PPh3)4 (M = Ni, Pd) afforded the metal−germavinylidene complexes [{(Me3SiNPPh2)2CGe}2Ni(PPh3)2] (2) and [{(Me3SiNPPh2)2CGe-μ2}Pd(PPh3)]2 (3), respectively. The germavinylidene moiety from 1 acts as a two-electron terminal and bridging ligand, respectively. Similar reaction of 1 with AgCl or AuI gave [(Me3SiNPPh2)2CGe(Ag)(Cl)]2 (5) and [(Me3SiNPPh2)2CGe(Au)(I)]2 (6), respectively. The result has shown that the germavinylidene moiety from 1 behaves as a Lewis base and undergoes an insertion reaction into the metal−halogen bond. X-ray structures of 2, 3, 5, and 6 have been determined.

The synthesis and characterization of various novel group 14 metal compounds derived from 2,6lutidylbisphosphoranosulfide, [(SdPPr i 2 CH 2 ) 2 C 5 H 3 N-2,6] (1), are reported. The monoanionic bis-(thiophosphinoyl) lithium complex [Li{(SdPPr i 2 CH)(SdPPr i 2 CH 2 )C 5 H 3 N-2,6}(Et 2 O)] (2) has been prepared from the reaction of 1 with an equimolar amount of n BuLi in THF. Treatment of 1 with 1 equiv of M{N(SiMe 3 ) 2 } 2 (M = Sn, Pb) afforded the 1,3-distannacyclobutane [{2-{Sn{C(Pr i 2 Pd S)}}-6-{CH 2 (Pr i 2 PdS)}}C 5 H 3 N] 2 (3) and 1,3-diplumbacyclobutane [{2-{Pb{C(Pr i 2 PdS)}}-6-{CH 2 -(Pr i 2 PdS)}}-C 5 H 3 N] 2 (4), respectively. The metathesis reaction of 2 with GeCl 2 3 (dioxane) and SnCl 2 gave the unexpected digermylgermylene Ge[GeCl 2 {(SdPPr i 2 CH)(SdPPr i 2 CH 2 )C 5 H 3 N-2,6}] 2 (5) and ionic [2,6-lutidylbis(thiophosphinoyl)methanide]tin(II) trichlorostannate [{C 5 H 3 N-2,6-(CH 2 PPr 6), respectively. The X-ray structures of 2-6 have been determined by X-ray crystallography.

The reaction of bis(germavinylidene) [(Me3SiN=PPh2)2C=Ge-->Ge=C(PPh2=NSiMe3)2] (1) with CpMn(CO)2(THF) (Cp = eta5-C5H5) in THF afforded [(Me3SiN=PPh2)2C=Ge-->Mn(CO)2Cp] (2). Similar reaction of 1 with (cod)RhCl (cod = 1,5-cyclooctadiene) in THF gave [(Me3SiN=NPPh2)2{(cod)Rh}C-GeCl] (3). The results suggested that reactive germavinylidene may exist in solution. The X-ray structures of 2 and 3 have been determined.