Complexes of Fe(III), Co(III), and Cu(II) with Acylhydrazones Containing a Triphenylphosphonium Fragment: Synthesis, Crystal Structure, and Antibacterial Activity

New acylhydrazones based on para- and meta-nitrobenzohydrazides and a substituted salicylaldehyde containing a triphenylphosphonium fragment were synthesized and characterized by spectral methods. A series of new mononuclear coordination compounds of Fe(III), Co(III), and Cu(II) were obtained from these acylhydrazones, and their molecular structures were 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. The transition from the organic compound to the complex was found to markedly enhance the activity against Escherichia coli.