# Tailoring, spectroscopic, DFT, solvatochromic, antitumor, and molecular docking studies of new polynuclear Cu(II)-hydrazone complexes

## TL;DR

This paper explores new copper(II)-hydrazone complexes, their structures, and their potential as antitumor agents, particularly against hepatocellular carcinoma.

## Contribution

The study introduces new polynuclear Cu(II)-hydrazone complexes and demonstrates their enhanced antitumor activity compared to cisPt.

## Key findings

- Cu-NBHD complexes have distorted octahedral geometries confirmed by magnetic and spectral data.
- The bromo complex 2 showed higher anticancer activity than cisPt against hepatocellular carcinoma.
- DFT calculations aligned with experimental results, supporting the complexes' structural and biological properties.

## Abstract

Hydrazones and their metal complexes have acquired a lot of interest because of their various biological and catalytic applications. The reaction of the symmetrical hydrazone (NBHD) with Cu(II) salts, including Cl−, Br−, and SO42−, has been investigated. The structures of Cu-NBHD complexes were explored by using various spectroscopic and analytical tools. Fluorescence spectra for NBHD and Cu(II)-NBHD complexes were recorded in a large number of solvents to probe their solvatochromic manners. Theoretical calculations for NBHD and Cu-NBHD complexes were conducted, and the results were correlated with the experimental data. The anticancer action of Cu-NBHD complexes was investigated towards Hepatocellular carcinoma and the results were supported by molecular docking studies. The Cu-NBHD complexes have distorted octahedral geometrical structures as evidenced from magnetic moment, electronic and ESR spectral data. NBHD acts as a bis(monoanionic bidentate) in case of Cl− and Br− ions and bis(neutral bidentate) in case of SO42− ion. The coordinating sites are phenolic oxygen and azomethine nitrogen atoms. In case of bromo and sulfato complexes, binuclear complexes were obtained. However, a tetranuclear complex was obtained in case of the chloro complex. DFT calculations for NBHD and Cu-NBHD complexes were performed, and the results were correlated with the practical results. All Cu-NBHD complexes exhibited anticancer activity towards Hepatocellular carcinoma. The bromo complex 2 showed an enhanced activity than that of cisPt. Using different copper(II) salts gives different bi- and tetra-nuclear complexes. Al complexes exhibited anticancer activity towards Hepatocellular carcinoma and the bromo complex 2 showed enhanced activity than that of cisPt. The encouraging activity prompts further studies about the complex as an antitumor agent.

The online version contains supplementary material available at 10.1038/s41598-025-32666-8.