Synthesis and Investigation of Mixed‐Ligand Transition Metal Complexes of Alkyl Dithiocarbonate and Benzoylhydrazine or Benzoylhydrazone Derivatives

Abstract Mixed‐ligand complexes of the types [Ni(Etdtcn)(BH)], [Ni(Budtcn) (BeBH)], and [M(Rdtcn)(salBH)], where M = Co(II), Ni(II), or Cu(II); R = methyl (Me), ethyl (Et), propyl (Prop) or butyl of the dithiocarbonate (Bu); dtcn = dithiocarbonate group; BH = benzoyl‐hydrazine anion, BeBH = benzaldehyde benzoylhydrazone anion, and salBH = salicylaldehyde benzoylhydrazone anion have been synthesised. Elemental analyses, molar conductivities, and spectral (IR, UV, and mass) studies have been used to elucidate the structure of the metal complexes. HBH and HBeBH coordinate in the enol form as bidentate ligands forming a square‐planar structure around Ni(II). Moreover, the HsalBH ligand behaves as tridentate anion with all metal ions and an octahedral structure for these complexes is proposed. The three ligands and some of their complexes were screened against three species of bacteria, namely B. cereus (G +ve), P. aeruginosa (G −ve), and S. aureus (G +ve) and five types of fungi, A. flavus, A. fumigatus var. albus, A. niger, F. oxysporum or C. tropicum. The HsalBH ligand has shown high activity against bacteria and fungi, probably due to the presence of a hydroxyl group in this ligand.