Synthesis, structure and biological activity of zinc(II) pincer complexes with 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine

Abstract

The reaction of 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPT) pincer ligand with Zn(NO3)2 and Zn(ClO4)2·6H2O/HCl yielded, [Zn(BPT)(NO3)2] (2), and [Zn(BPT)(H2O)Cl]ClO4 (3) complexes, respectively. However, zinc(II) chloride with BPT involved CN rupture and formed instead [Zn(DMP)2Cl2] (1) complex (DMP = 3,5-dimethylpyrazole). The structures of all complexes were confirmed by single crystal X-ray structure and NMR analyses. The intermolecular interactions included in the molecular packing of the complex units were analyzed using Hirshfeld analysis. Bond topological parameters were utilized to investigate the nature and strength of the Zn-N, Zn-Cl and Zn-O coordination interactions. The antimicrobial profile of the Zn(II) complexes were examined against Gram-positive and Gram-negative bacteria as well as the fungus C. albicans. The two pincer complexes (2 and 3) were found to be good antibacterial and antifungal agents while the ligand (BPT) was not active at the applied concentration. Also, the nitrato (2) and perchlorate (3) Zn(II) complexes are more potent antimicrobial agents than complex 1.