Cu(II) and Zn(II) crystal complexes based on pyrazolone: Synthesis and application as antibacterial agents

Abstract

4-Benzoyl-3-methyl-1-phenyl-5-pyrazolone (HPMBP) was synthesized via the Friedel–Crafts reaction and characterized through 1H NMR spectroscopy, Infrared spectroscopy and Electrospray ionization time-of-flight(ESI-TOF). The Cu(II) and Zn(II) coordination complexes, namely, [Cu(HPMBP)(2,2′-bpy)(Cl)]·H2O(1) and [Zn(HPMBP)(2,2′-bpy)(Cl)]·H2O(2), were synthesized in CH3OH(HPMBP:2,2′-bipyridine:M = 1:1:1, M = Cu, Zn). Single crystal X-ray diffraction(SCXRD) studies show that Cu(II) and Zn(II) exhibit a distorted square pyramidal configuration through two oxygen atoms of HPMBP, two cis-nitrogen atoms of 2,2′-bipyridine and monodentate chloride ion. Moreover, the Hirshfeld surface analysis of the in complexes was performed using crystallographic calculations. Furthermore, the antibacterial activities of 1 and 2 are more potent than HPMBP, in particular, the antimicrobial properties of 2 are better than those of 1. Scanning electron microscopy (SEM) indicated that 1 had a regular strip shape, while 2 had an irregular circular shape. Our work provides a theoretical basis for studying the antibacterial activity of transition metal ion complexes.