Fe(III), Co(III), and Cu(II) complexes with acylhydrazones containing a triphenylphosphonium moiety: synthesis, crystal structure, and antibacterial activity

New acylhydrazones based on para- and meta-nitrobenzhydrazides and substituted salicylic aldehyde containing a triphenylphosphonium fragment were synthesized and spectrally characterized. With these acylhydrazones, a series of new mononuclear coordination compounds of Fe(III), Co(III), and Cu(II) were obtained, the molecular structure of which was determined by single-crystal X-ray diffraction. The antibacterial activity of the isolated acylhydrazones and copper(II) complexes against Staphylococcus aureus and Escherichia coli was studied. It was shown that the transition from an organic compound to a complex one contributes to a significant increase in activity against E. coli.