Synthesis, structure, computational, antimicrobial and <i>in vitro</i> anticancer studies of copper(II) complexes with N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine and tris(2-hydroxyethyl)amine

<div><p>The present work consists of synthesis, structural characterization, spectral, density functional theory (DFT), antimicrobial, and anticancer studies of two copper(II) complexes, [Cu(THEEN)(DNB)](DNB) (<b>1</b>) and [Cu(TEAH₃)₂](DNB)₂ (<b>2</b>). In these complexes, THEEN is N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine, a tetrapodal ligand, and TEAH₃ is tris(2-hydroxyethyl)amine, a tripodal ligand, and the counter-anion is 3,5-dinitrobenzoate (DNB⁻). X-ray crystallography studies reveal that both complexes have distorted octahedron geometries. DFT studies have been performed to calculate structural parameters, vibrational bands, and energy gaps of frontier orbital (HOMO-LUMO) with B3LYP/6–31G*/LANL2DZ level of theory using DMSO as solvent. The theoretical and crystallographic analyses are consistent. Antimicrobial studies have been performed with new copper(II) complexes against Gram(+) bacteria (<i>Staphylococcus aureus</i>), Gram(−) bacteria (<i>Serratia marcescens</i>, <i>Sphingobium japonicum,</i> and <i>Stenotrophomonas maltophilia</i>) and fungal species (<i>Candida albicans</i>, <i>Aspergillus niger,</i> and <i>Saccharomyces cerevisiae</i>). The copper(II) complexes have also shown <i>in vitro</i> cytotoxicity on MCF-7, HCT-116, and HL-60 human cell lines. This study demonstrates that <b>2</b> was active against MCF-7 cell lines with IC₅₀ of 23 μg/mL.</p>