The transfer hydrogenation of diphenylacetylene to yield cis- and trans-stilbenes was achieved using a variety of amines as hydrogen donors and the complex 1 ([(dippe)Ni(μ-H)]2) in catalytic amounts (0.5% mol). The use of nucleophilic amines such as pyrrolidine in neat conditions afforded the hydroamination of diphenylacetylene, in moderate to high yields. Cyclization of 2-ethynylaniline also was carried out under similar conditions, with 1 in catalytic amounts, but in low yield, mainly due to the formation of homocoupling products of the starting material. The hydrogenation of diphenylacetylene by using other nitrogenated compounds such as aromatic N-heterocycles was addressed to give a metal-mediated process, using 1 in stoichiometric amounts.

ReO3 were prepared by thermal treatment of the macromolecular Chitosan•(ReCl3)X and PSP-4-PVP•(ReCl3)X precursors. The plasmon band in the visible region for the as obtained ReO3 from their visible spectra was observed at max of 640 nm. The nature of the polymeric precursor is acting as a solid state template and influences the size and morphology of the metal oxides. For the first time, the photocatalytic degradation of methylene blue using ReO3 was measured founding a moderated and high activity for ReO3 arise from Chitosan and PSP-4-PVP precursors respectively. The inclusion of ReO3 into SiO2 was performed using a combined solution of the Chitosan and PVP precursors by the sol-gel method. Subsequent pyrolysis of the solid precursors Chitosan•(ReCl3)X(SiO2)y and PSP-4-PVP•(ReCl3)X.(SiO2)y give rise to the nanocomposites ReO3//SiO2. The as obtained ReO3 nanoparticles inside SiO2 are small as 1nm. The ReO3 nanoparticles are distributed uniformly inside the matrix of SiO2, leading to stable semi porous materials suitable for high temperature catalytic application. The composites ReO3/SiO2 exhibit a moderate photocatalytic activity toward the degradation of methylene blue and similar to that of ReO3.

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The medium effect of the optical and catalytic degradation of methylene blue was studied in the NiO/SiO2, NiO/TiO2, NiO/Al2O3, and NiO/Na4.2Ca2.8(Si6O18) composites, which were prepared by a solid-state method. The new composites were characterized by XRD (X-ray diffraction of powder), SEM/EDS, TEM, and HR-TEM. The size of the NiO nanoparticles obtained from the PSP-4-PVP (polyvinylpyrrolidone) precursors inside the different matrices follow the order of SiO2 > TiO2 > Al2O3. However, NiO nanoparticles obtained from the chitosan precursor does not present an effect on the particle size. It was found that the medium effect of the matrices (SiO2, TiO2, Al2O3, and Na4.2Ca2.8(Si6O18)) on the photocatalytic methylene blue degradation, can be described as a specific interaction of the NiO material acting as a semiconductor with the MxOy materials through a possible p-n junction. The highest catalytic activity was found for the TiO2 and glass composites where a favorable p-n junction was formed. The isolating character of Al2O3 and SiO2 and their non-semiconductor behavior preclude this interaction to form a p-n junction, and thus a lower catalytic activity. NiO/SiO2 and NiO/Na4.2Ca2.8(Si6O18) showed a similar photocatalytic behavior. On the other hand, the effect of the matrix on the optical properties for the NiO/SiO2, NiO/TiO2, NiO/Al2O3, and NiO/Na4.2Ca2.8(Si6O18) composites can be described by the different dielectric constants of the SiO2, TiO2, Al2O3, Na4.2Ca2.8(Si6O18) matrices. The maxima absorption of the composites (λmax) exhibit a direct relationship with the dielectric constants, while their semiconductor bandgap (Eg) present an inverse relationship with the dielectric constants. A direct relationship between λmax and Eg was found from these correlations. The effect of the polymer precursor on the particle size can explain some deviations from this relationship, as the correlation between the particle size and absorption is well known. Finally, the NiO/Na4.2Ca2.8(Si6O18) composite was reported in this work for the first time.