Differential pulse voltammetric determination of albendazole and mebendazole in pharmaceutical formulations based on modified sonogel carbon paste electrodes with perovskite-type LaFeO3 nanoparticles.

Benzimidazoles, such as albendazole (AB) and mebendazole (MB), are common anthelmintic agents, widely used throughout the world to combat parasitic diseases. The electroanalytical sensing of AB and MB based on Perovskite-Type LaFeO3 nanoparticles modified sonogel carbon paste electrodes has been reported for the first time. Perovskite-type LaFeO3 nanoparticles were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD indicates the formation of monophase perovskite LaFeO3 and FT-IR spectrum shows a band at 570 cm-1 which is associated to the formation of lanthanum ferrite. Microscopy images show that the distribution in pore size and shape is not well defined. The particles sizes are found to be above 200 nm. It was found that sonogel carbon paste modified electrodes with Perovskite-type LaFeO3 nanoparticles exhibit higher catalytic activity and sensitivity toward the detection of AB and MB compared to the unmodified electrode. The limits of detection for albendazole and mebendazole were reported to be 0.3 μM and 0.6 μM respectively and the limits of quantification 0.8 μMand 1.7 μMrespectively. The electroanalytical protocol was successfully applied for the sensing of AB and MB in pharmaceutical formulations

Mesoionic triazolylidene nickel complexes: synthesis, ligand lability, and catalytic C–C bond formation activity

A set of triazolylidene (trz) nickel(II) complexes [NiCpX(trz)] was synthesized by a direct metalation of the corresponding triazolium salt with nickelocene, NiCp2. While at short reaction times and in the presence of a coordinating anion X the mono-carbene complex is preferably formed, long reaction times induce the gradual transformation of [NiCpX(trz)] to the bis-carbene complexes [Ni(Cp)(trz)2]+. Kinetic analyses lend strong support to a consecutive pathway involving triazolylidene dissociation from [NiCpX(trz)] en route to the bis-carbene complex. Similar carbene transfer is observed in a solid-state reaction upon heating the complex [NiCpI(trz)] in vacuo, which induces disproportionation to [NiI2(trz)2] and NiCp2, confirming that the Ni–C(trz) bond is kinetically labile. The complexes [Ni(Cp)(trz)2]+ and [NiCpX(trz)] were both efficient catalyst precursors for Suzuki–Miyaura cross-coupling of aryl bromides and phenylboronic acid, with turnover frequencies exceeding 228 h–1. Complex degradation after short reaction times, identified in separate experiments, prohibits high turnover numbers, and for high conversions, repetitive additions of triazolylidene nickel complex and phenylboronic acid are necessary.European Research Counci