Synthesis and structure characterization of Pt(IV) and Cd(II) 1,10-phenanthroline complexes; fluorescence, antitumor and photocatalytic property

Abstract

The room temperature addition of an aqueous solution of chloroplatinic acid hydrate or cadmium nitrate tetrahydrate to a mixture of an aqueous acetonitrile solution of 1,10-phenanthroline ligand (phen) and sodium azide affords new complexes of [Pt(N3)6Na2(phen)6], (1) and [Cd(phen)2(NO3)2], (2). The complexes 1, 2 were structurally characterized by elemental analysis, Fourier-transform infrared (FT-IR), Ultraviolet–visible (UV–vis), and nuclear magnetic resonance (NMR) spectroscopic techniques. The crystal structure of complexes 1, 2 was examined by single crystal X-ray diffraction. The complex 1 consists of two ionic complexes of [Pt(N3)6]2–and [Na(phen)3]+. The coordination geometry of Pt(IV) ion in complex 1 is distorted octahedral through six N atoms of the six terminal azide groups, while the sodium ion bonded to three phen ligand through six nitrogen atoms. In complex 2, phen and nitrate group act as bidentate ligands coordinating to Cd(II) through their nitrogen and oxygen atoms to form eight coordination. The two phen and nitrate ligands are coordinated to the cadmium in a cis geometry to each other. Three-dimensional supramolecular frameworks of complexes 1, 2 are produced by hydrogen bonding and π-π stacking interactions. The complex 1 was tested for cytotoxicity impact on two tumor cell lines: hepatocellular carcinoma HePG-2 and mammary gland breast cancer MCF-7 using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results indicate that complex 1 has strong activity on the two cancer cell lines HePG-2 and MCF-7. Also, complex 1 was screened for its antioxidant and anti-haemolytic activities. In addition, complex 2 was used as a heterogeneous catalyst for the degradation of Indigo carmine dye (IC) in the presence of H2O2 as oxidant. Additionally, the luminescence spectra of 1,10-phenanthroline ligand and complexes 1,2 were discussed.