The tendency of the charge transfer system, derived from chloranilic acid and 2-amino-2-(hydroxymethyl)-1,3-propanediol towards copper(II) complex-formation: characterization, anion impact, and biological studies

Abstract

Six new copper (II) complexes from the reaction of Cu X2, X = NO3−, Cl− or OAc− with the charge transfer complex [(CLA)2(THAM)2(H2O)] (CT) derived from 1:1 reaction between chloranilic acid (CLA) and 2-amino-2-(hydroxymethyl)-1,3-propanediol (THAM) were isolated and characterized. The nature of products was found to be anion and mole ratio-dependent. The physicochemical characterization of the products showed the formation of two sets of complexes, 2:1 and 1:1 of Cu(II): CT -mole ratios, giving binuclear and mononuclear copper(II) complexes, respectively. The different spectral results showed that complexes, [Cu2(CLA)(THAM)2(H2O)4], 1, [Cu2(CLA)(THAM)2(H2O)4]·H2O, 2 and [Cu2(CLA)(THAM)2(CH3COO)2(H2O)2], 3, are of elongated, distorted octahedral structures, complexes [Cu(CLA)(THAM)(NO3)], 4, and [Cu(CLA)(THAM)Cl], 5, are distorted square planner, while [Cu(CLA)(THAM)(CH3COO)(H2O)], 6, is compressed distorted octahedral structure. Applying thermal analysis techniques (TG and DTA), Cu(II) complexes exhibited high thermal stability, with high activation energy, Ea = (89.3–659.7) JK−1mol−1. The thermal decomposition showed exothermic behavior, ∆Ho = [(-75.9)-(-230.4)] kJmol−1, and more ordered transition states, ∆So = [(-0.20)-(-0.22)] kJK−1mol−1. The CT-complex and its Cu(II) complexes have been tested versus some pathogenic bacterial and fungal species, showing considerable activity, in the order; [(CLA)2(THAM)2(H2O)], (CT) > [Cu(CLA)(THAM)(NO3)], 4 > [Cu2(CLA)(THAM)2(H2O)4],1 ≈ [Cu(CLA)(THAM)(CH3COO)(H2O)], 6 ≈ [Cu2(CLA)(THAM)2(CH3COO)2(H2O)2], 3 ≈ [Cu(CLA)(THAM)Cl], 5 ≈ [Cu2(CLA)(THAM)2(H2O)4]·H2O, 2. Moreover, the in vitro cytotoxic activity test versus the breast cancer cell (MCF7), showing promising results.