Synthesis, characterization, crystal structure, redox-reactivity and antiproliferative activity studies of Cu(II) and Pd(II) complexes with F, CF3 bearing 3,5-di-tert-butylsalicylaldimines

Abstract

In this work, based on 3,5-di-tert-butyl-2-hydroxybenzaldehyde and F, CF3-substituted anilines [2-fluoro-3-(trifluromethyl)aniline, 2-fluoro-5-(trifluromethyl)aniline, 3,5-bis(trifluoromethylaniline and 2-fluoro-3-(trifluromethyl)benzylaniline], the corresponding salicylaldimine ligands (HLx, X = 1, 2, 3, 4) and their CuLx2 and PdLx2 complexes were synthesized. The structures of these compounds were characterized by spectroscopic (IR, UV/Vis, 1H and 19F NMR, ESR) and X-ray diffraction techniques. Chemical oxidation of the tert-buylated HLx ligands and their CuLx2 complexes using Ce(IV) under anaerobic and aerobic conditions at room temperature (r.t.) in DMF solution revealed the generation of phenoxyl radicals. An X-ray structural study revealed that thanks to CH⋯F and CH⋯π bonds both the CuL21 and PdL21 molecules crystallize as hydrated dimers that pack differently. The antiproliferative potentials of all the compounds against Mat-LyLu cell lines were determined.