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, R 1 = 0.0297, and wR 2 = 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.

Impact of Isonicotinic Acid Blending in Chitosan/Polyvinyl Alcohol on Ripening-Dependent Changes of Green Stage Tomato

“…The absorption peaks at 763 cm −1 and 696 cm −1 were related to the deformation vibration of the aromatic ring in INA [ 37 ]. The peaks of INA detected at 1616, 1562, 1478, 1411, and 1337 cm −1 ( Figure 2 ) are closely parallel to those of picolinic acid observed by Świderski et al [ 38 ].…”

“…The band at 3052 cm −1 was related to νs (CH) vibration of ring protons in the molecule. It is well known that broad absorption bands between 2607 and 2152 cm −1 indicate the existence of an O–H⋅⋅⋅N type of intermolecular hydrogen bonding [ 37 , 39 ]. Hence, the peak found at 2412 cm −1 could be related to the presence of this type of intermolecular hydrogen bonding between INA molecules.…”

A Co-Crystallised Cobalt(II) Cluster of Pyridinedicarboxylic Acid (PDC) as a Luminescent Material for Selective Sensing of Methanol

“…Dipicolinic acid or 2,6-pyridinedicarboxylic acid has been widely used as a ligand binding to metal transition ions and may present various modes of coordination such as bidentate, tridentate, or chelate bridging via O, N, O atoms. Moreover, depending on the groups being deprotonated, dipicolinic acid can serve as either proton acceptor or proton donor [1]. Because of its low toxicity, the ligand has recently gained so much interest, making it useful in applications involving biological studies, chemical sensing and environmental remediation [2,3].…”

Theoretical Investigation on Growth Kinetics and Thermodynamic Properties of Pyridine-2-Carboxylic Acid Crystals

“…[1] It is not only a potential proton acceptor but also a proton donor depending on the deprotonated groups. [2] The growth aspects of pyridine-2-carboxylic crystals have been studied in the past, but there are no reports on the nucleation kinetics and DFT study of this organic material. In the present work, the nucleation parameters such as interfacial energy (σ), volume free energy (∆Gv), critical energy barrier for nucleation (∆G * ), radius of the critical nucleus (r * ) and nucleation rate (J) were evaluated.…”