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Abstract: Three new tridentate copper(II) complexes [Cu(dthp)Cl2] (1) (dthp=2,6-di(thiazol-2-yl)pyridine), [Cu(dmtp)Cl2] (2) (dmtp=2,6-di(5-methyl-4H-1,2,4-triazol-3-yl)pyridine) and [Cu(dtp)Cl2] (3) (dtp=2,6-di(4H-1,2,4-triazol-3-yl)pyridine) have been synthesized and characterized. Crystal structure of complex 1 shows that the complex existed as distorted square pyramid with five co-ordination sites occupied by the tridentate ligand and the two chlorine anions. Ethidium bromide displacement assay, viscosity measurements, circular dichroism studies and cyclic voltammetric experiments suggested that these complexes bound to DNA via an intercalative mode. Three Cu(II) complexes were found to efficiently cleave DNA in the presence of sodium ascorbate, and singlet oxygen (1O2) and hydrogen peroxide were proved to contribute to the DNA cleavage process. They exhibited anticancer activity against HeLa, Hep-G2 and BEL-7402 cell lines. Nuclear chromatin cleavage has also been observed with AO/EB staining assay and the alkaline single-cell gel electrophoresis (comet assay). The results demonstrated that three Cu(II) complexes cause DNA damage that can induce the apoptosis of BEL-7402 cells. [Copyright &y& Elsevier]

[Display omitted] • Two lanthanide − titanium oxo clusters EuTi 9 and TbTi 9 protected by four kinds of ligands were prepared. • The EuTi 9 and TbTi 9 cluster core containing ten metal ions shows pyramid-like structure. • EuTi 9 and TbTi 9 display the temperature-dependent luminescence properties. Two pyramid-like lanthanide − titanium − oxo clusters formulated as LnTi 9 (µ 2 -O) 5 (µ 3 -O) 7 (µ 3 -OH) 2 (O i Pr)(acac) 2 (TCA) 10 (THF) (LnTi 9 , Ln = Eu / Tb, HTCA = 2-thiophenecarboxylic acid) were prepared through the reaction of Ln(acac) 3 , 2-thiophenecarboxylic acid (HTCA), Ti(O i Pr) 4 and THF. The 10-nuclearity-metal-core [LnTi 9 (µ 2 -O) 5 (µ 3 -O) 7 (µ 3 -OH) 2 ]13+ is protected by four kinds of ligands. EuTi 9 and TbTi 9 exhibit characteristic emissions of Eu3+ / Tb3+ under ultraviolet excitation. The temperature-dependent luminescence results show EuTi 9 shows a good linear relationship between the luminescence intensity and temperature range of 80–320 K, while TbTi 9 has high temperature-sensitivity in different temperature ranges. [ABSTRACT FROM AUTHOR]