Mononuclear and binuclear rhenium(I) carbonyl complexes of 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPT), [{ReCl(CO)3}n(TPT)] (n=1, 2), and the formation of mixed-metal compounds with Re-TPT-M (M=MnII, CoII, CuII) bonds

The novel mononuclear complex [ReCl(CO)3(TPT)] has been isolated where the triazine ligand is acting in a didentate chelate mode. The metalloligand properties of this Re(I) complex were demonstrated when it reacts didentally either with the {ReCl(CO)3} fragment or with the [M(hfac)2] (M=Mn, Co, Cu; hfac=hexafluoroacetylacetonate ion) complexes, producing the homobinuclear [{ReCl(CO)3}2(TPT)] and the heterobimetallic [(CO)3ClRe(TPT)M(hfac)2] substances, respectively. In methanol solution the binuclear Re-TPT-Re complex forms the [{ReCl(CO)3}2(TPT)]·MeOH complex, where a methoxide group seems to be interacting with the acidic triazine ring and the nitrogen atom of the uncoordinated pyridyl group is protonated. In general, the studies in solution of the dirhenium Re-TPT-Re complex show evidence of its interaction with the solvent molecules apparently in an acid-base fashion. On the other hand, the mixed-metal Re-TPT-M derivatives show dissociation reactions in solution generating the parent mononuclear [ReCl(CO)3(TPT)] compound and the [M(hfac)2] complexes. The systems under study were characterized through IR, 1H NMR and electronic spectroscopy, electrochemical and magnetic moment measurements.