Rhenium(I) compounds bound by tripodal ligands of pyridine and N-methylimidazole

摘要

The reaction of Re(CO)(5)Br with tris(2-pyridyl) methanol (tpmOH) leads to unexpectedly complex chemistry with three new compounds forming instead of a single product. In compound 1, the tpmOH ligand binds to the metal in the N, N', N"-mode; 2 has tpmO(-) bound in the N, N', O-mode; while 3 is a dimer with the tpmO(-) ligand utilizing each of the four donor atoms to bridge the two metal centers. The analogous methyl ether ligands, tris(2-pyridyl) methoxymethane (tpmOMe) or tris[2-(1-methylimidazolyl)]methoxymethane (timmOMe), each yielded a single product, 4 and 5, respectively, bound in the N, N', N"-mode, and are new leads for potential radiotherapeutic agents. All compounds have been structurally characterized.