Shufang Chen

Cytotoxicity towards human alimentary system carcinoma cells resulting from diverse copper(II) complexes

To investigate the potential cytotoxicity of copper(II)-based complexes, three coordination compounds with heterocyclic ligands, Cu(pbmbt)Cl2(CH3OH) (1), Cu2(ddbib)2(NO3)4·3CH3OH (2), and Cu3(ttmtmb)2Cl6·2.5H2O (3), which include mononuclear, dinuclear, and trinuclear structures, have been synthesized from reactions of corresponding copper(II) salts with 1-((2-pyrazinyl)-1H-benzoimidazol-1-yl)methyl)-1H-benzotriazole (pbmbt), 2-(2,3-dihydropyrazin-2-yl)-1-((4-((2-(2,3-dihydropyrazin-2-yl)-1H-benzo[d]imidazol-1-yl)methyl)phenyl)methyl)-1H-benzo[d]imidazole (ddbib), and 1,1′,1′′-((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene)tris(2-methyl-1H-benzoimidazole) (ttmtmb), respectively. IC50 values revealed that 2 and 3 show strong cytotoxicity, whereas 1 is weakly cytotoxic after being tested against a panel of several human alimentary system carcinoma cell lines (SGC7901, EC109, SMMC7721, and HT29). The number of copper centers and different structures could make a tremendous difference on their cytotoxicity. Graphical Abstract Three coordination compounds with heterocyclic ligands were constructed to investigate the potential cytotoxicity of copper(II)-based complexes. IC50 values revealed that complexes 2 and 3 show strong cytotoxicity, whereas complex 1 is weakly cytotoxic after being tested by MTT assay against a panel of several human alimentary system carcinoma cell lines.

Photoluminescent and cytotoxic properties of multinuclear complexes and multinuclear-based polymers with group 12 metals and a tripodal ligand

Four novel multinuclear complexes and multinuclear-based polymers with group 12 metal centers, namely, Zn3(tpbb)Cl6 (1), {[Cd6(tpbb)2Cl12]·2CHCl3·0.5H2O}n (2), Hg4(tpbb)Br8 (3), and Hg4(tpbb)I8 (4), have been synthesized with respect to a new flexible tripodal ligand, 1,3,5-tris((2-(pyridine-2-yl)-1H-benzo[d]imidazol-1-yl)methyl)benzene (tpbb). Complex 1 is a trinuclear cluster, as determined by X-ray crystallography, while 2 features an unprecedented hexanuclear metallacycle-based 2D network with chloride ion bridges. The similar umbrella-like tetranuclear architectures of 3 and 4 with different Hg(II)-halide salts demonstrate that halides with the same tetrahedral coordination geometries of metal centers do not greatly affect the structure of the complexes. Photoluminescent studies indicate that complexes 1 and 2 reveal enhanced and red-shifted solid-state fluorescence at room temperature compared with the ligand, tpbb, while 3 and 4 show prominent phosphorescence behaviors at cryogenic temperatures with lifetimes in the microsecond range. In addition, when tested against a panel of several human carcinoma cell lines (SH-SY5Y, QBC939 and EC109) by standard MTT assay, complex 1 displayed potential cytotoxicity against SH-SY5Y and QBC939 cells and selectivity to different tumor cell lines.

Two cyclohexane-type octadecanuclear metalla-macrocycle-based metal organic frameworks and adsorption properties

Two novel porous metal–organic frameworks (MOFs) with {M18(Hbtib)36} (M = Ni(II), Zn(II)) as the basic building unit, namely, [Ni(Hbtib)2]n (1) and [Zn(Hbtib)2·H2O]n (2) [H2btib = 4-((2-butyl-5-(2-carboxy-3-(thiophen-2-yl)prop-1-enyl)-1H-imidazol-1-yl)methyl)] were synthesized using solvothermal reactions. Gas adsorption (N2, H2, CO2 and CH4) studies show that the desolvated solid 1 is a highly effective absorbent for CO2 over CH4 at 273 and 298 K. The results suggest that 1 has potential application in gas separation or purification. In addition, the photoluminescence properties of 2 were also investigated.

Group IIB metal directed complexes with flexible benzimidazole-based connector

Four group IIB metal complexes, namely [ZnCl2(Mbibix)]n (I), [Cd2(Ac)4(Mbibix)2] · (H2O) (II), [HgCl2(DMF)(Mbibix)]2 (III) and [HgI2(Mbibix)]2 (IV), have been achieved via the reaction of corresponding metal salts and organic spacer Mbibix (Mbibix = 1-(3-((2-methyl-1H-benzimidazol-1-yl)methyl)benzyl)-2-methyl-1Hbenzimidazole). Crystal structure analyses reveal that complex I is one-dimensional (1D) zigzag chain, whereas II, III and IV are binuclear motifs (CIF files CCDC nos. 1006224 (I), 1006225 (II), 1006226 (III), 1006227 (IV)). These structures are further stacked into 3D supramolecular architectures via hydrogen bonding and π ⋯ π interactions. The result indicates that the metal centers imparted their influences on the structures and fluorescence behaviors.

Anion-driven Ag(I) coordination architectures: structural diversity and photoluminescence behaviors

Abstract To observe anion impact on structural diversity of coordination architectures, three 1-D Ag(I) complexes with distinct features have been prepared, {[Ag(bpbib)2(NO3)]·C3NH9O)}n (1), [Ag2(bpbib)2·(BF4)2]n (2), and [Ag2(bpbib)2·(ClO4)2]n (3), by the reactions of 4,4′-bis((2-(pyridin-2-yl)-1H-benzo[d]imidazol-1-yl)methyl)biphenyl (bpbib) with Ag(I) salts. Complex 1 is a 1-D helical chain, whereas 2 and 3 bear ligand-unsupported Ag(I)···Ag(I) interaction-directed 1-D structural motif, with synergetic working of flexible organic linker and anions. All complexes exhibit strong triplet state emission at cryogenic temperatures, which profits from the reduction of nonradiative transitions.

Cytotoxicity, dual-targeting apoptosis induction evaluation of multinuclear cu complexes based on pyrazine-benzimidazole derivative

To investigate the cytotoxicity and mechanism of action of multinuclear Cu complexes against tumor cell lines, two complexes, Cu6(bpbib)4Br8 (1) and Cu2(bpbib)2(BF4)2Cl2 (2) (bpbib = 1,4-bis((2-(pyrazin-2-yl)-1H-benzo[d]imidazol-1-yl)methyl)benzene) were synthesized and characterized. Both Cu complexes showed high selectivity toward cancer and not normal cells, and the SMMC7721 cell line showed most sensitivity toward both complexes. Complex 1 exhibited more potent cytotoxicity and enhanced cellular uptake, and therefore, was comprehensively investigated. Complex 1 exhibited dual effects in the inhibition of tumor cell proliferation of SMMC7721 cells, causing nuclear DNA damage and mitochondrial dysfunction involving simultaneous reactive oxygen species (ROS) generation and Ca2+ increase. DNA binding studies suggest that intercalation might be the most probable binding mode. Fluorescence spectrometry also detected a medium affinity of complex 1 to bovine serum albumin (BSA) at distinct temperatures and resulted in BSA fluorescence static quenching.

Structurally diverse complexes from a bifunctional benzimidazole-carboxylate ligand

Three new complexes, namely {Ag2(Hmbbc)2(SO3CF3)2}n (1), Ag2(Hmbbc)2(NO3)2(DMF)2(CH3OH) (2), and Hg2(Hmbbc)2(I)4(DMF)2 (3) were constructed by the reaction of 4′-[4-methyl-6-(1-methyl-1H-benzimidazolyl-l-2-group)-2-n-propyl-1H-benzimidazolyl methyl]-biphenyl-2-carboxylic acid (Hmbbc) with Ag(I) or Hg(II) salts under solvothermal or solution reactions. In the complexes, the Hmbbc ligand exhibits different coordination modes, giving various crystal architectures. X-ray analysis demonstrates that 1 has a 2D layer structure, while 2 and 3 are binuclear. All three complexes are further extended into 3D supramolecular architectures through hydrogen bonds and π···π interactions. They exhibit luminescence emission in the solid state at room temperature.