engleski

The interplay between photocatalysis and mechanochemical synthesis - New opportunities for Green Chemistry

As one of the goals of Green Chemistry, incorporated into the Twelve Principles, is the development of safer and more efficient modes of chemical syntheses. In this respect, mechanochemistry by solid state ball milling, which allows the solvent-free approach in synthesis, has been recognized as an environmentally-friendly alternative to existing solution-based methods. At the same time, novel concepts of enhancing reactivity through organo- or metal-catalysis and photocatalysis are gaining significant impact on the design of chemical processes on both laboratory and industrial scale. In this contribution, the first example of transition metal-free photocatalysis in the solid state aided by mechanochemical ball milling will be presented. Our recent efforts to completely exclude solvents from photocatalytic reactions by combining the benefits of mechanochemical synthesis and photocatalysis were demonstrated on the aerobic oxidation of diphenylacetylene to yield 1, 2-diketone benzil. This transformation was affected in a solvent-free manner by simultaneous visible-light irradiation and milling of the reaction mixture in what we termed "mechanochemically-assisted solid state photocatalysis" or MASSPC. Furthermore, preliminary results on the application of MASSPC methodology for an environmentally-friendly photocatalytic desulfurization of aromatic thioureas will be also disclosed.

mechanochemistry ; solid state ; photocatalysis

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