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Various organic functions can undergo oxidation reactions, and the chemical industry increasingly seeks to develop processes based on the Green Chemistry approach in the search for more sustainable practices. Electrochemical electron transfer processes using metal complexes thus appear as an important alternative in these oxidative processes since they exploit numerous reactions in aqueous media and use catalytic amounts of the complex. The purpose of this work was to test the electrocatalytic ability of a new ruthenium (II) diarsenic aqua complex, [Ru(L)(totpy)(OH2)](ClO4)2 (L=Ph2AsCH2CH2AsPh2); (totpy=4'-(4-tolyl)-2,2':6',2"-terpyridine), in electrooxidation experiments of organic substances with different functions. The experiments were conducted at a constant potential of +1.00 V (vs ECS) in a solution of 7:3 phosphate buffer: t-butanol, pH 8.1, with a ratio of 1.00 mmol.L-1 of the aqua complex [Ru(L)(totpy)(OH2)](ClO4)2 to 50.00 mmol.L-1 of each organic substrate. The oxidized organic starting materials and the respective products obtained therefrom were benzyl alcohol (benzaldehyde), benzaldehyde (benzoic acid), benzyl butyl ether (benzaldehyde and benzoic acid) and 1-phenylethanol (acetophenone). Selective reactions with good yields for the products were observed. The electrochemical process used here revealed some benefits over other classic oxidative methods, such as biological advantages and inorganic oxidants, emphasizing the speed, the possibility of using aqueous media in the reactions, selectivity in the formation of products, and the possibility of using small amounts of catalyst. [ABSTRACT FROM AUTHOR]

Sorbitol is an important platform molecule with applications in the food, cosmetics and pharmaceutical sectors and with potential in biopolymers. It is obtained in batch reactors through the hydrogenation of glucose, on Ni-Raney catalysts. The leaching of nickel in the reaction media involves additional purification steps and makes the product more expensive. This work evaluates the current and future market of sorbitol, considering its applications. In addition, it collects information on the use of different metals and supports that offer higher selectivity in obtaining sorbitol from glucose or directly from cellulose, from biomass residues. It was verified that the sorbitol market presents an expectation of growth of more than 5 % until 2022. Even though the Ni-Raney catalyst is the most economically competitive, it can be replaced efficiently by the ruthenium supported in different materials. [ABSTRACT FROM AUTHOR]

The quenching of the excited state of [Ru(deeb)(bpy)2] (PF6)2 where bpy is 2,2'-bipyridine and deeb is 4,4'-(COOEt)2-2,2'-bipyridine was studied in fluid acetonitrile solution and anchored to nanocrystalline titanium dioxide thin films. To quench the excited state, the cobaloximes [Co(py)(Cl)(dmgH)2] and [Co(py)(Bu)(dmgH)2] where py is pyridine, Bu is n-butyl and dmgH is dimethylglyoximate were used. These cobaloximes are efficient quenchers of the excited state both in fluid solution and when the ruthenium complex is bound to titanium dioxide. The quenching process can be adequately described using the Stern-Volmer model, which indicates that quenching is dominated by diffusion processes and is coherent with a photo induced electron transfer process. [ABSTRACT FROM AUTHOR]

La α-alquilación de cetonas es uno de los métodos fundamentales para la mformación de enlaces C-C. Los compuestos de rutenio tienen una amplia versatilidad en este tipo de reacciones. El objetivo de este trabajo de investigación es realizar la síntesis y caracterización de catalizadores de rutenio, evaluar su actividad en reacciones de alquilación de metilcetonas. Se realizó la síntesis de los derivados pirazólicos de azo iminas (4-((E)-(4-R-phenyl) diazenyl)-2-((E)-(5-tert-butyl-1Hpyrazol- 3-ylimino)methyl)phenol y su caracterización por las diferentes técnicas espectroscópicas IR, RMN, DSC, UV-VIS y espectrometría de masas. Los compuestos derivados pirazólicos de azo iminas se coordinaron a rutenio. Se realizaron las reacciones de alquilación de metilcetonas evaluando la actividad y selectividad de los sistemas catalíticos en donde se observó el efecto de la temperatura de reacción (80, 100, 120 °C), efecto de la base (NaOH, KOH, y K2CO3), efecto de las relaciones molares. Esto se hizo tomando muestras que se analizaron por cromatografía de masas a las 2, 4, 6 y 12 horas de reacción. Se realizaron los cálculos del porcentaje de conversión, porcentaje de selectividad, TON y TOF. Los complejos en la reacción de alquilación de metilcetonas fueron activos y selectivos y generando como subproducto agua. [ABSTRACT FROM AUTHOR]