Main group compounds as amphoteric ligands to transition metals. Synthesis and molecular structure of Cr(CO)(5)[PPh(2)CH(2)Ga(CH(2)CMe(3))(2)center dot NM(3)]

The reactivities of the group 13 compounds, R(2)MCH(2)PPh(2) and R(2)MPPh(2), as amphoteric ligands to transition metals have been investigated. The ligands R(2)MCH(2)PPh(2) (R = CH(2)CMe(3), CH(2)SiMe(3); M = Ga, In) reacted readily with Cr(CO)(5)NMe(3) in benzene solution to form Cr(CO)(5)[PPh(2)CH(2)MR(2) . NMe(3)], whereas for ligands of the type R(2)MPPh(2) (R = CH(2)CMe(3), CH(2)SiMe(3); M = Al, Ga, In), only the two aluminum compounds and (Me(3)CCH(2))(2)GaPPh(2) formed isolable products of the type Cr(CO)(5)[PPh(2)MR(2) . NMe(3)]. However, the gallium and indium ligands with (trimethylsilyl)methyl substituents (Me(3)SiCH(2))(2)MPPh(2) reacted with NEt(4)M(T)(CO)(5)Cl (M(T) = Cr, Mo, W) to form products of the type NEt(4)M(T)(CO)(5)[PPh(2)MR(2)Cl]. All new compounds were characterized by their physical properties, C and H analyses, and H-1 and P-31 NMR and IR spectral properties. The identity of NEt(4)Cr(CO)(5)[PPh(2)In(CH(2)SiMe(3))(2) . Cl] was further confirmed by the subsequent identification of products from reactions with anhydrous HCl and with MeI. In addition, Cr(CO)(5)[PPh(2)CH(2)Ga(CH(2)CMe(3))(2) . NMe(3)] was characterized by an X-ray structural study.