Synthesis, Characterization, and Biological Studies of Novel Salicylatocopper(II) Complexes Containing 1,10‐Phenanthroline

The presented study reports the synthesis, structural characterization, and biological evaluation of four novel dinuclear copper(II) complexes with salicylate derivatives, such as 4‐bromsalicylate ((4‐Br‐Sal) 2− ), 4‐(trifluoromethyl)salicylate ((4(CF 3 )‐Sal) 2− ), 6‐fluorosalicylate ((6‐F‐Sal) 2− ), and 5‐(2´,4´‐difluorophenyl)‐salicylate/diflunisal (dflu 2− ) and 1,10‐phenanthroline (phen) as neutral N,N′‐ donor ligand: [Cu 2 (4‐Br‐Sal) 2 (phen) 2 ] ( 1 ), [Cu 2 (4‐CF 3 ‐Sal) 2 (phen) 2 ] ( 2 ), [Cu 2 (6‐F‐Sal) 2 (phen) 2 ] ( 3 ), [Cu 2 (diflu) 2 (phen) 2 ] ( 4 ). The complexes are structurally confirmed via X‐ray crystallography, revealing distorted square‐pyramidal geometries and dimeric arrangements stabilized by hydrogen bonding, and containing various amount of solvent molecules in their secondary structure (1.2 H 2 O for complex 1 , 1.36 H 2 O for 2 , 3.2 H 2 O·EtOH for 3 , 1.6 H 2 O and/or 4·H 2 O for 4 ). UV–vis spectroscopic studies demonstrate their significant interactions with calf thymus DNA (ct‐DNA), suggesting intercalation as the most possible mode of binding. Ethidium bromide displacement and viscosity assays support these findings, highlighting their potential as DNA‐targeting agents. Furthermore, the complexes exhibit moderate superoxide dismutase mimetic activity, and catechol oxidase mimetic studies reveal complex‐specific variations in catalytic turnover rates, with complex 3 achieving the highest efficiency due to its optimal Cu···Cu distance and geometry. The study advances the understanding of copper(II)‐based coordination compounds, emphasizing their structural, biological, and catalytic potentials for applications in bioinorganic chemistry and therapeutics.