Synthesis, X-ray crystal structure and BVS calculation of Co(II) complex of pyrimidine derived Schiff base ligand: Approached by Hirshfeld surface analysis and TDDFT calculation

Abstract

A new Co(II) complex [Co(L)(Cl)2]•(MeOH)2 (1) has been synthesized using a symmetrical Pyrimidine derived Schiff base ligand 2,2′-((2E,2′E)-2,2′-(butane-2,3-diylidene)bis(hydrazin-1-yl-2-ylidene))bis(4,6-dimethylpyrimidine) (L) and characterized by single crystal X-ray crystallography analysis. The solid-state structure of 1 is pseudooctahedral with two methanol molecules outside the coordination sphere. The said complex is stabilized through various intermolecular H-bonding incorporating non coordinated solvent methanol molecules. Bond Valence Sum (BVS) calculation confirms that the central cobalt atom in 1 exists as ‘+2′ oxidation state instead of ‘+3′. Hirshfeld surface analysis is performed to determine the intermolecular interactions and the crystal packing of the title complex. The 2D fingerprint plots associated with the Hirshfeld surface clearly present each significant interaction involved in the structure, by quantifying them in an effective visual manner. The electronic transition of complex 1 was recorded in methanol solvent and the electronic distribution of HOMO−LUMO can be rationalized theoretically (through time-dependent density functional theory (TDDFT)).