Synthesis, Crystal Structures, Thermal, and Spectroscopic Properties of Four New Metal(II) (M = Co, Ni, Cu, Hg) Complexes of 2-Benzoylbenzoate With 3-Picoline

Abstract

Four 2-benzoylbenzoate (bba) complexes, [Co(bba)<inf>2</inf>(H <inf>2</inf>O)<inf>2</inf>(3-pic)<inf>2</inf>] (1), [Ni(bba)<inf>2</inf>(H <inf>2</inf>O)<inf>2</inf>(3-pic)<inf>2</inf>] (2), [Cu(bba)<inf>2</inf>(3-pic) <inf>2</inf>] (3), and [Hg(bba)<inf>2</inf>(3-pic)<inf>2</inf>] (4), have been synthesized and characterized by IR spectra, thermal (TG, DTG, and DTA) analysis, and single crystal X-ray diffraction. All the complexes consist of neutral monomeric units with 1 and 2 crystallizing in the orthorhombic (P n a 2<inf>1</inf>), 3 in triclinic (P<inf>1</inf>), and 4 in monoclinic (P2 <inf>1</inf>/c) crystal systems. The metal(II) ions exhibit distorted octahedral coordination for 1, 2, and 3 and mercury(II) exhibits distorted trigonal prism coordination. In 1 and 2, bba is monodentate, whereas in 3 and 4 bba is bidentate. 3-Picoline (3-pic) is a classical N-monodentate ligand. Bba are coordinated to metal(II) with carboxylates and IR spectra of all complexes display characteristic absorptions of carboxylate {υ(OCO)<inf>asym</inf> and υ(OCO)<inf>sym</inf>}. Thermogravimetric (TG) analyses show that 1 and 2 are thermally stable (T<inf>decomp.</inf>>60°C) and 3 and 4 are thermally stable (T<inf>decomp.</inf>>120°C). © 2011 Taylor & Francis.