Mixed tri- and bi-dentate Schiff-base complexes of technetium(V) and rhenium(V). The crystal structure of N-(2-oxidophenyl)salicylideneiminato-NOO?)oxo(8-quinolinolato-NO) technetium(V)

Six-co-ordinate complexes of technetium(V) and rhenium(V) containing the MO3+ core with triand bi-dentate Schiff-base ligands were synthesized and characterized. The complexes with general formula [MO(L1)L] [M = Tc or Re; L1 = N-(2-oxidophenyl)salicylideneiminate; L = salicylideneiminate, N-methyl- and N-phenyl-salicylideneiminate, or 8-quinolinolato (quin)] were characterized by elemental analysis, i.r.,1H n.m.r., and mass spectroscopy. The structure of [TcO(L1)(quin)] was also determined by X-ray analysis. The co-ordination around the metal is approximately octahedral. The phenolic oxygen of the quip ligand is trans to the Tc=O group. The tridentate Schiff-base ligand lies on the equatorial plane with respect to Tc=O. The complex crystallizes in monoclinic space group P21/n with a = 15.496(8), b = 10.355(4), c = 12.122(5) Å, ? = 109.03(6)°, and Z = 4. The structure has been refined to R = 0.054 for 2 025 observed reflections.