solid–solid synthesis, crystal structure and thermal decomposition of copper(ii) complex of 2-picolinic acid

The copper(ii) complex [cu(pic)2]·2h2o was synthesized with 2-picolinic acid (hpic) and copper acetate as reactants by room temperature solid-solid reaction. the composition and structure of the complex was characterized by elemental analyses, single crystal x-ray diffraction, x-ray powder diffraction, ft-ir spectroscopy and thermogravimetry-differential scanning calorimetry. the crystal structure of the copper(ii) complex belongs to triclinic system and space group , with cell parameters of a = 5.1274(16) å, b = 7.641(2) å, c = 9.209(2) å,α = 74.91(2)°, β = 84.56(2)°, γ = 71.58(3)°, v = 338.48(15) å3, z = 1, f(000) = 175, r1 = 0.0530, and wr2 = 0.1141. the cu(ii) ion is six-coordinated through two nitrogen atoms from two pyridine rings and four carboxyl oxygen atoms from four different 2-picolinic acid anions, forming an elongated octahedral geometry. the interaction of carboxylate o and cu(ii) forms an one-dimensional chain structure, and the complex exhibits a twodimensional layered structure by hydrogen bonds. the thermal decomposition processes of the complex under air include dehydration and pyrolysis of the ligand, and the final residue at about 400 °c is copper oxide.