Synthesis, crystal structures, thermal, and spectroscopic properties of four new metal(II) (M = Co, Ni, Cu, Hg) complexes of 2-benzoylbenzoate with 3-picoline

Four 2-benzoylbenzoate (bba) complexes, [Co(bba)2(H 2O)2(3-pic)2] (1), [Ni(bba)2(H 2O)2(3-pic)2] (2), [Cu(bba)2(3-pic) 2] (3), and [Hg(bba)2(3-pic)2] (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 21), 3 in triclinic (P1), and 4 in monoclinic (P2 1/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)asym and υ(OCO)sym}. Thermogravimetric (TG) analyses show that 1 and 2 are thermally stable (Tdecomp.>60°C) and 3 and 4 are thermally stable (Tdecomp.>120°C). © 2011 Taylor & Francis.