New Zinc Coordination Compound with Simple Salicylato and Pyridine Ligands: Synthesis, Crystal Structure and Hirshfeld Surface Analysis

Abstract

A novel mononuclear zinc coordination compound with formula [Zn(Hsal)2(Py)2] (H2sal = salicylic acid, Py = pyridine) was prepared by mixing aqueous solutions of sodium salicylate and zinc sulfate in 1:1 molar ratio, and to the resulting solution pyridine was added dropwise. The obtained compound was characterized by elemental analysis, IR spectroscopy, and its crystal structure was determined by single-crystal X-ray diffraction method. X-ray structure analysis has shown that the central zinc ion is four-coordinated by two monodentate salicylato ligands and two pyridine molecules, forming a distorted tetrahedron. Since the asymmetric unit consists of two halves of coordination molecules, orthorhombic Ibca space group symmetry leads to two coordination molecules with slightly different geometry. The comparison between the two is given in terms of interatomic distances and angles, and also in terms of differences in intermolecular interactions obtained as a result of Hirshfeld surface analysis. With the assistance of C−H…O interactions, the adjacent molecules are linked into chains and further connected into three-dimensional network.