Schiff Bases and their Copper(II) Complexes Derived from Cinnamaldehyde and Different Hydrazides: Synthesis and Antibacterial Properties

Abstract

New hydrazone Schiff base ligands were synthesized from the condensation of cinnamaldehyde and three different hydrazides (benzhydrazide, isoniazid, and 4-phenylsemicarbazide), and these compounds were further reacted with copper(II) ion affording three different Schiff base metal complexes. All hydrazone Schiff base ligands and their respective metal complexes were chemically characterised using NMR, FTIR, CHN analyses, and UV-visible spectrophotometry and these chemical analyses showed successful coordination of hydrazone Schiff base ligands to copper(II) ion. All synthesized Schiff base ligands and metal complexes were screened against Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, and Pseudomonas aeruginosa. Interestingly, all Schiff base metal complexes showed a higher antibacterial activity than their parent hydrazone Schiff base ligands; as shown by an increase of up to 60% of inhibition observed for one of the metal complexes.

Synthesis, Characterization and Biological Evaluation of New Enamide Fluorinated‐Schiff Base Derivatives as Potential Cytotoxic and Apoptosis‐Inducing Agents

“…Reacting the main intermediate, hydrazide 2 , with cinnamaldehyde in methanol yielded the corresponding cinnamaldehyde Schiff base 6 [29] . The 1 H‐NMR spectrum revealed two broad singlet signals at δ 11.62 and 10.03 ppm, characteristic for 2NH protons, as well as characteristic azomethine (CH=N) proton as doublet signal appeared at δ 8.20 ppm, in addition to the other protons which integrated for 23 protons.…”

Synthesis, Spectroscopic, Molecular Modeling and Anti-Fungal Studies of Some Divalent Metal Complexes of 4-Hydroxyacetophenone Isonicotinoyl Hydrazone

“…The biological activities of many of these compounds have been shown to be related to their metal-chelating abilities [16] [17] [18]. Therefore this class of compounds could be a good starting point to develop new led compounds in the treatment of multidrug-resistant bacteria.…”