Abstract
The versatility of aniline derivatives as ligands for Re (V) and Tc (V) has been investigated. The reaction of (n-Bu4N) [MOCl4] (M=Re, Tc) with 1, 2-diaminobenzene (H2dab) and 2, 3-diaminopyridine (H2dap) gave the products (Bu4N) [MO (dab) 2] (1) and [MO (dapH) 2]Cl (2) respectively. Both chelates in 1 and 2 are coordinated as diamides; however, in 2 the pyridine nitrogens of dapH are protonated. With trans-[ReOCl3 (PPh3) 2] as a starting complex, a number of products were isolated, depending on the reaction conditions. For example, with 3-hydroxy-1, 2-diaminobenzene (H2dab-OH) under N2, [Re (dab-OH) Cl3 (PPh3) 2] (3) was produced, in which dab-OH substituted the oxo group and is coordinated as a monodentate imide. With 3-nitro-1, 2-diaminobenzene (H2dab-NO2), the oxo-free complex [ReCl (PPh3) (dab-NO2) 2] (4) was obtained, with bidentate diamido coordination of each chelate. Using trans-[ReO2 (py) 4]Cl as a starting complex, complexes of the type [Re (sbqdi-OH) 3]Cl (5) and cis-[ReO2 (Hdab) (py) 2] (6) were isolated, where sbqdi-OH coordinates as the monoanionic semibenzoquinonediimine and Hdab as a bidentate monoamide. The crystal structures of these complexes are discussed in this account.
