Complexes of rhenium(V) with aminoacetophenones and their reactions with some bidentate ligands

Complexes of rhenium(V) with 2-, 3- and 4-aminoacetophenone (H2aap) have been synthesized. The reaction of trans-ReOCl3(PPh3)(2) with 2-H-2aap in benzene yielded the imido complex [Re(2-aap)Cl-3(PPh3)], in which the oxo oxygen and one of the PPh3 groups were substituted by the dianionic imido nitrogen and the neutral ketonic oxygen, respectively. With 3-and 4-H-2aap the imido complexes trans-[Re(aap)Cl-3(PPh3)(2)] were isolated. The monodentate coordination mode of these latter two ligands was authenticated by the X-ray crystal structure of trans-[Re(3-aap)Cl-3(PPh3)(2)]; crystals are triclinic, P1, with a = 10.567(5), b = 11.989(6), c = 18.739(8) Angstrom, alpha = 74.82(4)degrees, beta = 75.27(4)degrees, gamma = 73.15(4)degrees, U = 2152(2) Angstrom(3), Z = 2, R = 0.0469. The further reaction of [Re(3-aap)Cl-3(PPh3)(2)] with the, bidentate ligands 2-aminophenol and 8-hydroxyquinoline (HL) led to the isolation of complexes of the type [Re(3-aap)Cl-2(PPh3)(L)]. However, with 1,2-diaminobenzene (H(2)dab), the 3-aap imido moiety was displaced by the imido group (N(C6H4)NH2),to give the complex trans-[Re(dab)Cl-3(PPh3)(2)].