2,2′-bipyridyl and N,N,N′,N′-tetramethylethylenediamine derivatives of molybdenum(V), niobium(V) and tantalum(V) t-butylimido complexes

Abstract

Abstract MoCl5 reacts with two equivalents of Me3SiNHCMe3 in benzene to give [Mo(NCMe3)Cl3(NH2CMe3)]2 · 1 6 C6H6 (1) and with six equivalents of t-butylamine to give [Mo(NCMe3)(NHCMe3)Cl2(NH2CMe3)]2 · 1 6 C6H6 (2). Complex (1) reacts with PMe3 to give [Mo(NCMe3)Cl3(PMe3]2] (3), with 2,2′-bipyridyl (bipy) to give [Mo(NCMe3)Cl3(bipy)] (4) and with N,N,N′,N′-tetramethylethylenediamine (tmed) to give [Mo(NCMe3)Cl3(tmed)] · 1 3 C6H6 (5). The IR spectra suggest mer-trichloro ligands. Complex (2) reacts with bipy in benzene to give [Mo(NCMe3)(NHCMe3)Cl2(bipy)] (6) for which the IR spectrum suggests trans-chloro ligands. In benzene, [Nb(NCMe3)Cl3(NH2CMe3)]2 reacts with 4-picoline (pic) to give [Nb(NCMe3)Cl3(pic)2] (7), with bipy to give [Nb(NCMe3)Cl3(bipy)] · 1 12 C6H6 (8) and with tmed to give [Nb(NCMe3)Cl3(tmed)] (9). The tantalum complexes [Ta(NCMe3) Cl3(bipy)] · 1 3 C6H6 (10), [Ta(NCMe3)Cl3(tmed)] · 1 6 C6H6 (11), [Ta(NCMe3)(NCHMe3)Cl2 (bipy)] · 1 2 C6H6 (12) were also prepared. [Ta(NEt)Cl3(NH2Et)]2 (13) and [Ta(NCHMe2) (NHCHMe2)Cl2(bipy)] (15) were characterized by NMR spectroscopy. The NMR spectra of complexes (7), (9), (11) (12) and (15) show different coordination environments for the two nitrogen donor atoms of the bipy or tmed ligands.