Design, synthesis and structure of a trinuclear copper(ii) complex having a Cu3OH core with regard to aspects of antiproliferative activity and magnetic properties

Abstract

We report a novel triangular trinuclear copper(II) complex with a central μ₃-OH bridge, [(CuL)₃(μ₃-OH)(ClO₄)₂]·CH₃OH·H₂O (1), stabilised by the oxime-based Schiff base ligand, 3-(((5-bromothiophen-2-yl)methylene)hydrazineylidene)butan-2-one oxime (HL). Comprehensive characterization of 1 has been realised through different analytical and physical methods coupled with spectroscopic techniques. 1 has been structurally characterised by single crystal X-ray diffraction. The antiproliferative capacity of HL and 1 has been evaluated against human lung cancer cell line A549. Compound 1 shows promising efficacy in contrast to HL, which shows a limited cytotoxicity. Contrary to HL, 1 has distinctly impeded the proliferation of lung adenocarcinoma A549 cell lines in a dose-dependent way. Compound 1 has been employed as a potential therapeutic agent for promising cellular transformation of malevolent A549 cell lines. The programmed cell death mechanism of 1 reveals characteristic apoptotic changes in cellular morphology like chromatin condensation, fragmented nuclei, nuclear shrinkage along with blebbing, elevated number of nuclear body fragments and distorted nucleus, while round, clear edged, intact nucleus and uniformly stained round nuclei have been observed in the negative control. Variable-temperature magnetic studies show an antiferromagnetic Cu⋯Cu coupling of −44.6(2) cm⁻¹. The g value as determined by EPR measurement of 1 in frozen N,N-dimethylformamide solution corroborates the experimental magnetic susceptibility values.