Synthesis, crystal structure and biological activity of two binuclear Ag(I) complexes with bis-benzimidazole thioether ligands

Head-to-head bisbenzazole derivatives as antiproliferative agents: design, synthesis, in vitro activity, and SAR analysis

In the present work, a series of bisbenzazole derivatives were designed and synthesized as antiproliferative agents. The antiproliferative activity of these compounds was investigated using MTT assay. Bisbenzazole derivatives showed significant antiproliferative activity against all the four tested cancer cell lines. Among the various bisbenzazole derivatives, bisbenzoxazole derivatives exhibited the most promising anticancer activity followed by bisbenzimidazole and bisbenzothiazole derivatives. All the derivatives were found to be less toxic as compared to methotrexate (positive control) in normal human cells, indicating selective and efficient antiproliferative activity of these bisbenzazole derivatives. The structure-activity relationships of heteroaromatic systems and linkers present in bisbenzazole derivatives were analyzed in detail. In silico ADMET prediction revealed that bisbenzazole is a drug-like small molecule with a favorable safety profile. Compound 31 is a potential antiproliferative hit compound that exhibits unique cytotoxic activity distinct from methotrexate. Twenty-one bisbenzoxazole derivatives have been designed synthesized and evaluated to be an antiproliferative activity against four human tumor cell lines.

Electrochemical sensing of hydrogen peroxide on a carbon paste electrode modified by a silver complex based on the 1,3-bis(1H-benzimidazole-2-yl)propane ligand

A new carbon paste electrode (Ag-CPE) modified with a nitrogen heterocyclic silver(I) complex, [Ag2(BBP)2](pic)2·CH3OH (BBP = 1,3-bis(1H-benzimidazol-2-yl)propane, pic = picrate), was developed as a highly sensitive and simple electrochemical sensor for the determination of hydrogen peroxide. The Ag(I) complex was prepared by an interface reaction and characterized by elemental analysis, IR and UV/Vis spectra and single crystal X-ray diffraction. The Ag(I) complex shows a dinuclear cluster structure, which is formed by two BBP ligands bridging two Ag (I) centers and an Ag–Ag interaction (d Ag–Ag = 3.0875 Å). Cyclic voltammetry and chronoamperometry studies showed that the electrochemical sensing performance of Ag-CPE for H2O2 was improved in 0.2 m phosphate buffer solution (PBS, pH = 6). The electrochemical H2O2 sensor Ag-CPE exhibits a wide linear detection range from 0.5 to 4.0 mm and a lower detection limit of 0.39 μm with a relatively high sensitivity of 6.77 μA mm −1. Moreover, the sensor also shows good anti-interference properties and stability. The results prove that the Ag(I) complex based on the bis(benzimidazole) ligand may be an efficient component of electrode materials.

Synthesis, structure, fluorescence, electrochemical, and antioxidant studies of a new silver(I) complex with 2,6-bis(N-methylbenzimidazol-2-yl)pyridine

A new silver(I) complex of the type [Ag2(mbbp)2](pic)2·DMF·CH3OH [mbbp = 2,6-bis( N-methylbenzimidazol-2-yl)pyridine] is synthesized and analyzed using a range of spectroscopic and crystallographic techniques. This compound contains cationic Ag2(mbbp)2 dimers, in which the crossed eight-shaped structure is formed by two mbbp ligands bridging two silver(I) centers and Ag–Ag bonds. Two-dimensional supramolecular networks of the silver(I) complex are connected by π···π interactions and hydrogen bonds. Hirshfeld analyses are performed to support the aforementioned intermolecular interactions. The effect of π···π stacking interactions on the fluorescence properties of the complex is investigated. Cyclic voltammetry indicates two irreversible redox processes. In addition, an antioxidant assay in vitro demonstrates that the silver(I) complex displays excellent scavenging activity toward hydroxyl radicals.

Synthesis, structure, fluorescence, and electrochemical properties of a binuclear Ag(I) complex with 1,4-bis(benzo[d]oxazol-2-yl)butane as a ligand

Reaction of 1,4-bis(benzo[d]oxazol-2-yl)butane (BBO) with [Ag(CH3CN)4(ClO4)] afforded a new binuclear silver(I) complex, with composition [Ag2(BBO)2(ClO4)2], characterized by elemental analysis, UV/Vis and IR spectroscopy, and single-crystal X-ray diffraction. The results show that the Ag(I) complex consists of a centrosymmetric dimetallacyclic structure assembled from two Ag(I) atoms and two bridging BBO ligands. The coordination environment of silver(I) complex can be described as distorted trigonal planar, with one oxygen atom from a perchlorate anion and two nitrogen atoms from two BBO ligands. The luminescence properties of the ligand and the Ag(I) complex were studied in the solid state. The emission peaks of the Ag(I) complex are attributed to ligand-centered transitions. There is no effect of the complexation except for a partial quenching. The cyclic voltammograms of the Ag(I) complex indicated an irreversible Ag+/Ag couple.

Synthesis, crystal structure, fluorescence and antioxidant properties of a binuclear Ag(I) complex based on the SPPh3 ligand

The binuclear silver(I) complex [Ag2(η2-SPPh3)2(SPPh3)2](BF4)2 has been synthesized. Crystal analysis shows the coordination sphere around Ag(I) can be described as a three-coordinated slightly distorted planar triangular configuration with both monodentate and monoatomic bidentate bridging coordination modes for the SPPh3 ligand. The fluorescence properties of free SPPh3 and the Ag(I) complex have been studied in the solid state. The Ag(I) complex shows quasi-reversible Ag+/Ag pairs in its electrochemistry and has significant antioxidant activity against hydroxyl radicals.

Synthesis and Fluorescence Properties of a New Heterotrinuclear Co(II)-Ce(III)Complex Constructed from a bis(salamo)-Type Tetraoxime Ligand

[Co₂(L)Ce(OAc)₃(CH₃CH₂OH)]·1.5CH₃OH∙0.5CH₂Cl₂, a heterotrinuclear Co(II)-Ce(III) bis(salamo)-type complex with a symmetric bi(salamo)-type ligand H₄L and an acyclic naphthalenediol moiety, was designed, synthesized and characterized by elemental analyses, FT-IR, UV-Vis and fluorescence spectroscopy and X-ray crystallography. The X-ray crystallographic investigation revealed the heterotrinuclear complex consisted of two Co(II) atoms, one Ce(III) atom, one (L)^4‒ unit, three μ₂-acetate ions, one coordinated ethanol molecule, one and half crystallization methanol molecule and half crystallization dichloromethane molecule. Two Co(II) atoms located in the N₂O₂ coordination spheres, are both hexacoordinated, with slightly distorted octahedral geometries. The Ce(III) atom is nine-coordinated and located in the O₆ cavity possesses a single square antiprismatic geometry. In addition, supramolecular interactions exist in the Co(II)-Ce(III) complex. Two infinite 2D supramolecular structures are built via intermolecular O-H···O, C-H···O and C-H···π interactions, respectively.