title: Synthesis, crystal structure, and thermal decomposition of the cobalt(II) complex with 2-picolinic acid.
abstract: The cobalt(II) complex of 2-picolinic acid (Hpic), namely, [Co(pic)₂(H₂O)₂] · 2H₂O, was synthesized with the reaction of cobalt acetate and 2-picolinic acid as the reactants by solid-solid reaction at room temperature. The composition and structure of the complex were characterized by elemental analysis, infrared spectroscopy, single crystal X-ray diffraction, and thermogravimetry-differential scanning calorimetry (TG-DSC). The crystal structure of the complex belongs to monoclinic system and space group P2(1)/n, with cell parameters of a = 9.8468(7) Å, b = 5.2013(4) Å, c = 14.6041(15) Å, β = 111.745(6)°, V = 747.96(11) Å³, Z = 2, D(c) = 1.666 g cm⁻³, R₁ = 0.0297, and wR₂ = 0.0831. In the title complex, the Co(II) ion is six-coordinated by two pyridine N atoms and two carboxyl O atoms from two 2-picolinic acid anions, and two O atoms from two H2O molecules, and forming a slightly distorted octahedral geometry. The thermal decomposition processes of the complex under nitrogen include dehydration and pyrolysis of the ligand, and the final residue is cobalt oxalate at about 450°C.
authors.affiliation: State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
authors.forename: Di
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
authors.forename: Guo-Qing
authors.identifier: 0000-0002-1242-5327
authors.initials: GQ
authors.lastname: Zhong
mesh_terms: D002152:Calorimetry, Differential Scanning; D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000138:chemical synthesis* / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010848:Picolinic Acids / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D046911:Macromolecular Substances; D010848:Picolinic Acids; D003035:Cobalt; C030614:picolinic acid