Coordination Adducts of Niobium(V) and Tantalum(V) Azide M(N 3 ) 5 (M=Nb, Ta) with Nitrogen Donor Ligands and their Self‐Ionization

Several new donor–acceptor adducts of niobium and tantalum pentaazide with N‐donor ligands have been prepared from the pentafluorides by fluoride–azide exchange with Me 3 SiN 3 in the presence of the corresponding donor ligand. With 2,2′‐bipyridine and 1,10‐phenanthroline, the self‐ionization products [MF 4 (2,2′‐bipy) 2 ] + [M(N 3 ) 6 ] − , [M(N 3 ) 4 (2,2′‐bipy) 2 ] + [M(N 3 ) 6 ] − and [M(N 3 ) 4 (1,10‐phen) 2 ] + [M(N 3 ) 6 ] − were obtained. With the donor ligands 3,3′‐bipyridine and 4,4′‐bipyridine the neutral pentaazide adducts (M(N 3 ) 5 ) 2 ⋅L (M=Nb, Ta; L=3,3′‐bipy, 4,4′‐bipy) were formed.