Facile and environmentally friendly one-step synthesis of hexanuclear Cu(II)–Ni(II) and Cu(II)–Co(II) clusters and their binding interactions with bovine serum albumin

Abstract

The novel hexanuclear {K6[Cu4Co2(μ3-OH)4(μ4-O)(OAc)8][Cu(OAc)4](OH)2}·3H2O (1) and {K6[Cu4Ni2(μ3-OH)4(μ4-O)(OAc)8][Cu(OAc)4](OH)2}·3H2O (2) clusters have been prepared. The clusters were synthesized by the self-assembly of Cu(OAc)2 and M(OAc)2 (M ​= ​Co, Ni) in aqueous solution without any additional other organic ligands. The two clusters were well-characterized with single-crystal X-ray diffraction, FT-IR spectra and elemental analyses. Crystallographic studies revealed that the molecular core type was M6(μ3-OH)4(μ4-O) in both 1 and 2. Solid-state DC magnetization indicated that 2 exhibited strong Ni–O–Ni associated antiferromagnetic interaction, while 1 displayed merely weak antiferromagnetic interaction. The protein binding affinity of two clusters was tested with bovine serum albumin (BSA). Both two clusters showed good affinity with BSA, with a binding constant (Kb) of 4.97 ​× ​104 ​M−1and 2.14 ​× ​104 ​M−1, respectively. Cytotoxic activity was performed by MTT assay. It was observed that the complex exhibited low toxicity against the SH-SY5Y and A549 cancer cells.