Synthesis, characterization and structural analysis of complexes from 2,2′:6′,2′′-terpyridine derivatives with transition metals

Abstract

The synthesis and structural characterization of three families of coordination complexes synthesized from 4′-phenyl-2,2′:6′,2′′-terpyridine (8, Ph-TPY), 4′-(4-chlorophenyl)-2,2′:6′,2′′-terpyridine (9, ClPh-TPY) and 4′-(4-methoxyphenyl)-2,2′:6′,2′′-terpyridine (10, MeOPh-TPY) ligands with the divalent metals Co2+, Fe2+, Mn2+ and Ni2+ are reported. The compounds were synthesized from a 1:2 mixture of the metal and ligand, resulting in a series of complexes with the general formula [M(R-TPY)2](ClO4)2 (where M = Co2+, Fe2+, Mn2+ and Ni2+, and R-TPY = Ph-TPY, ClPh-TPY and MeOPh-TPY). The general formula and structural and supramolecular features were determinated by single-crystal X-ray diffraction for bis(4′-phenyl-2,2′:6′,2′′-terpyridine)nickel(II) bis(perchlorate), [Ni(C21H15N3)2](ClO4)2 or [Ni(Ph-TPY)2](ClO4)2, bis[4′-(4-methoxyphenyl)-2,2′:6′,2′′-terpyridine]manganese(II) bis(perchlorate), [Mn(C22H17N3O)2](ClO4)2 or [Mn(MeOPh-TPY)2](ClO4)2, and bis(4′-phenyl-2,2′:6′,2′′-terpyridine)manganese(II) bis(perchlorate), [Mn(C21H15N3)2](ClO4)2 or [Mn(Ph-TPY)2](ClO4)2. In all three cases, the complexes present distorted octahedral coordination polyhedra and the crystal packing is determined mainly by weak C—H...π interactions. All the compounds (except for the Ni derivatives, for which FT–IR, UV–Vis and thermal analysis are reported) were fully characterized by spectroscopic (FT–IR, UV–Vis and NMR spectroscopy) and thermal (TGA–DSC, thermogravimetric analysis–differential scanning calorimetry) methods.