Synthesis and Characterization of a New Neodymium Complex: DFT Insights and Potential Anticancer Applications

Abstract

A new complex of type [Nd (HL) (NO₃)₂] has been synthesized with a Schiff base ligand H₂L derived from 2-hydroxy-3-methoxybenzaldehyde and L-histidine. The structure of the synthesized complex was established using elemental analysis, molar conductivities, FT-IR, ¹HNMR, SEM, and x-ray diffraction (XRD) spectroscopy. FT-IR data revealed that H₂L acts as a tetradentate ligand through the carboxylic acid, azomethine nitrogen, methoxy oxygen, and hydroxyl groups. Based on the electronic spectra, an octahedral configuration was hypothesized for the complex. The TGA method was employed to study the thermal behavior of ligand and its complex, and thermodynamic parameters were determined using Coats–Redfern equations. The XRD analysis revealed that the synthesized compounds possess nanoscale dimensions, with their crystallinity significantly enhanced by the coordination of the Nd(III) ion with H₂L. DFT calculations were performed to optimize the geometry of the proposed structures, indicating improved thermodynamic and electronic stabilities. The reduced HOMO–LUMO gap in the Nd(III) complex further highlights its remarkable conductive and electronic properties. The surface morphology of the Nd(III) complex was analyzed using SEM to investigate its structural characteristics. The SEM images reveal a variety of particle shapes, including elongated, prismatic, and irregular blocky particles with sharp edges, suggesting a crystalline nature. The ligand and its Nd(III) complex were evaluated for their anticancer activity against prostate carcinoma, breast carcinoma, and lung carcinoma cell lines. The inhibition rate of Nd(III) complex was 92.81%, 93.25%, and 94.58%, respectively. The results demonstrated that the Nd(III) complex exhibited significantly enhanced anticancer activity compared to the ligand alone, likely due to its improved structural and electronic properties. These findings suggest that the Nd(III) complex holds promise as a potent anticancer agent.