# Synthesis, computational, biological activity and molecular docking study of Co2+, Ni2+ and Cu2+ chelates of a new indolbenzohydrazone NO donor

## TL;DR

This study synthesizes and characterizes new metal chelates of an indolbenzohydrazone compound, testing their antioxidant and antibacterial properties and exploring their potential in solar cells and cancer treatment.

## Contribution

The paper introduces new Co2+, Ni2+, and Cu2+ chelates of an indolbenzohydrazone NO donor and evaluates their structural, thermal, and biological properties.

## Key findings

- The compounds showed promising antioxidant and antibacterial activity against Bacillus cereus and Escherichia coli.
- Molecular docking studies indicated effective binding to bacterial proteins and breast cancer cell receptors.
- The compounds have semiconductor-like properties, suggesting potential use in solar cells.

## Abstract

A novel Schiff base namely, (Z)-4-((3-cyano-4,6-dimethylpyridin-2-yl)amino)-N′-(2-oxoindolin-3-ylidene)benzohydrazide (H2BISH) (C1) and its corresponding metal acetate chelates; [Co2(HBISH)(CH3COO)3(H2O)2]·H2O (C2), [Ni(HBISH)(CH3COO)]·2.5H2O (C3) and [Cu(HBISH)(CH3COO)(H2O)] (C4) were prepared and characterized using elemental and spectroscopic (IR, UV–vis., nuclear magnetic resonance (1H&13C), electron paramagnetic resonance (ESR), mass and XRD measurements. IR spectral data revealed that H2BISH acts as monobasic in all metal complexes. The 1HNMR chemical shifts of the ligand protons are relatively well reproduced at the HF/6-31G(d) level of theory. Ni2+ complex (C1) adopted a tetrahedral structure while Co2+ (C2) and Cu2+ complexes assigned an octahedral one. The structure of C2 was further investigated by XRD technique orthorhombic C30 Co3 N22O5 geometry with lattice constants a = 6.5688 Å, b = 31.7110 Å and c = 18.1864 Å and Cm c m space group. Kinetic parameters of thermal degradation of studied compounds were evaluated by Coats–Redfern and Horowitz–Metzger equations. Density function theory was utilized to draw the structures and evaluate the correlated parameters. All title compounds have small negative Eg of order: C2 < C3 < C4 < C1 (H2BISH) revealing the ease of CT in turn the higher polarizability, increased reactivity and softness as well as the values lie in the range of semiconductor suggesting the possibility of utilization of present compounds in solar cells. The compounds were tested for antioxidant power (DPPH free radical scavenger assay) and bacterial inhibition against Bacillus cereus as Gram + ve and Escherichia coli as Gram − ve bacteria. A molecular docking mechanism between the ligand and its M2+ chelating was evaluated against bacterial proteins and Breast cancer cells sites receptors to explain how these compounds attach the protein’s active sites. The findings showed promising binding.

The online version contains supplementary material available at 10.1038/s41598-025-20172-w.