Abstract
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The synthesis, characterization and crystal structures of copper complexes with chelate ligation derived from the compound 2.2′-diphenylglycine (DpgH) are reported. Compounds [CuCl(Dpg)(EtOH)]2 (1) and [(CuBr2)2(Dpg)2Cu(EtOH)4] (2) were found to be of low toxicity using against cancerous cell lines (HCT116 and HT29) with the IC50 values for complex 1 lower than that of cisplatin, while the opposite was observed for 2. These complexes were found to be inactive in the homo- and co-ring opening polymerization (ROP) of cyclic esters (ε-caprolactone rac-lactide) and epoxides (propylene oxide and cyclohexene oxide).
•Diphenylglycine-derived complexes were synthesized.•The molecular structures of four copper(II) complexes were determined by single crystal XRD.•The cytotoxicity of two of the complexes (1 and 2) was investigated.•The complexes were screened for their ability of ring open polymerize cyclic esters and epoxides.
The treatment of CuX2 (X = Cl, Br) with an equimolar amount of 2-2ʹ-diphenylglycine (DpgH) in EtOH at reflux afforded, after work up, the complexes [CuCl(Dpg)(EtOH)]2 (1) and [(CuBr2)2(Dpg)2Cu(EtOH)4] (2), respectively. The compounds were obtained microanalytically pure in low to moderate yield (13 and 27%, respectively) and were fully characterised. Synthetic attempts towards Cu-alkoxide species led to the isolation of the heterobimetallic species [(CuCl2)(Dpg)Li(THF)]·THF (3·THF). Finally, complex 4, bearing an imine ligand derived from the decarboxylation of DpgH, was serendipitously obtained from the synthesis of 3. These complexes were found to be inactive in the homo- and co-ring opening polymerization (ROP) of cyclic esters (ε-caprolactone and rac-lactide) and epoxides (propylene oxide and cyclohexene oxide). Compounds 1 and 2 were shown to be non-toxic against cancerous cell lines HCT116 and HT-29.