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)

Abstract

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 TcO group. The tridentate Schiff-base ligand lies on the equatorial plane with respect to TcO. The complex crystallizes in monoclinic space group P2₁/n with a= 15.496(8), b= 10.355(4), c= 12.122(5)Å, β= 109.03(6)°, and Z= 4. The structure has been refined to R= 0.054 for 2 025 observed reflections.