Synthesis, structure and theoretical simulation of a zinc(II) coordination complex with 2,3-pyridinedicarboxylate

Abstract

Hydrolytic opening reaction of 2,3-pyridine dicarboxylic anhydride with the zinc dichloride led to form the chelate complex of mono deprotonated 2,3-pyridine dicarboxylic acid, [Zn(2,3-pdcH)2(H2O)2], (2,3-pdcH = 2,3-pyridinedicarboxylic acid). The coordinated compound crystallizes in the monoclinic space group P21/n. The crystal structure of the title compound exhibits a homoleptic complex with distorted octahedral geometry and ligand coordinated via pyridine nitrogen and oxygen atoms from one deprotonated dicarboxylic acid. Intermolecular interactions were analysed by Hirshfeld surfaces. After formation of the metal complex, the crystal packing is stabilized by O–H⋯O and C–H⋯O hydrogen bonds. There are moreover hydrophobic interactions, which consist in stacking between the pyridine cycle and the carboxylic/carboxylate groups. NBO and QTAIM analyses have been performed to evaluate the charge delocalization interactions that occur between the Zn(II) central ion and the surrounding ligand donor atoms. The HOMO and LUMO energies and Molecular Electrostatic Potential surface were derived from DFT theoretical calculations.