Organoimidotantalum(V) complexes containing halide, dialkylamide, monoalkylamide, alkoxide, aryloxide, trialkylphosphine and tetrahydrofuran ligands. Crystal structures of [{Ta(µ-Cl)Cl(NSiMe3)[N(SiMe3)2]}2] and [{Ta(µ-OMe)(OMe)(NSiMe3)[N(SiMe3)2]}2]

By means of various reactions the compound [TaCl3{N(SiMe3)2}2]1 has been converted into the following organoimido complexes: [{Ta(µ-Cl)Cl(NSiMe3)[N(SiMe3)2]}2]2, [{Ta(µ-I)I(NSiMe3)[N(SiMe3)2]}]4, [TaCl2(NSiMe3){N(SiMe3)2}(thf)]5(thf = tetrahydrofuran), [Ta(NEt)(NHEt){N(SiMe3)2}2]6 and [Ta(NBut)(NHEt){N(SiMe3)2}2]7. From 2 the compounds [Ta(NSiMe3){N(SiMe3)2}(NHBut)2]8, [Ta(NSiMe3){N(SiMe3)2}(OBut)2]9 and [{Ta(µ-OMe)(OMe)(NSiMe3)[N(SiMe3)2]}2]10 were obtained, and from [TaCl3(OC6H2MeBut2)2], [Ta(NEt)(NHEt)(OC6H2MeBut2)2]11, [Ta(NCH2But)(NHCH2But)(OC6H2MeBut2)2]12 and [Ta(NBut)(NHBut)(OC6H2MeBut2)2]13 were prepared. The compounds [TaCl3(NPh)(PEt3)2]14 and [TaCl3(NPh)(PEt2Ph)2]15 were prepared from reactions involving NHPh(SiMe3) and TaCl5 in the presence of the trialkylphosphine ligand. All of these new compounds have been characterized by NMR, IR and mass spectra and two of them, 2 and 10, have been structurally characterized by single-crystal X-ray crystallography.