A novel bimetallic MOFs combined with gold nanoflakes in electrochemical sensor for measuring bisphenol A.

In this paper, a novel bimetallic Fe-Cu metal-organic framework combined with 1,3,5-benzenetricarboxylic acid (Fe-Cu-BTC) are synthesized using hydrothermal reaction. The bimetallic Fe-Cu-BTC with high BET (1504 cm3 g-1) and high Langmuir surface area (1831 cm3 g-1) is composited by gold nanoparticles to improve the conductivity and to develop their synergistic effect. A novel bisphenol A (BPA) sensor was prepared by dropcasting Fe-Cu-BTC on glassy carbon electrodes (GCE) followed by AuNPs electrodeposition. The Fe-Cu-BTC framework were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy studies (TEM), FT-IR, BET measurements and EDX spectra. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were carried out for surveying the electrochemical properties of the sensors and for the quantification of BPA. Two linear ranges of BPA concentrations 0.1-1.0 µM and 1.0-18 µM with 18 nM limit of detection were obtained. The developed sensor was used to measure the concentration of BPA in samples extracted from rain coat with the recovery ranging from 85.70 to 103.23%.

Electrocatalytic H2 evolution using binuclear cobalt complexes as catalysts.

We report herein on the use of two binuclear cobalt complexes with the N,N'-bis(salicylidene)-phenylmethanediamine ligand as catalysts for the H2 evolution in DMF solution with acetic acid as proton source. Both experimental analyses (electrochemical analysis, spectroscopy analysis) and theoretical analysis (foot-of-the wave analysis) were employed. These catalysts required an overpotential of ca. 470 mV to catalyze the H2 evolution and generated H2 gas with a faradaic efficiency of 85-95% as calculated on the basis of after 5 hour bulk electrolysis. The kinetic investigation showed the maximal TOF value of 50 s-1 on the basis of an ECEC mechanism. Two cobalt centers, standing at a long distance of 4.175 Å, operated independently during catalysis without a synergetic effect or cooperation capability.

Synthesis of new simplified hemiasterlin derivatives with α,ß-unsaturated carbonyl moiety.

In this Letter, we report a convenient and efficient method for the synthesis of new simplified derivatives of hemiasterlin in which the α,α-dimethylbenzylic moiety A is replaced by α,ß-unsaturated aryl groups as Michael acceptor. Most of these derivatives have a strong cytotoxic activity on three human tumor cell lines (KB, Hep-G2 and MCF7). Analogs 17b and 17f showed a high cytotoxicity against KB and Hep-G2 cancer cell lines comparable to paclitaxel and ellipticine.