Freon electrochemistry in room-temperature ionic liquids

Harnessing Marine Biocatalytic Reservoirs for Green Chemistry Applications through Metagenomic Technologies

In a demanding commercial world, large-scale chemical processes have been widely utilised to satisfy consumer related needs. Chemical industries are key to promoting economic growth and meeting the requirements of a sustainable industrialised society. The market need for diverse commodities produced by the chemical industry is rapidly expanding globally. Accompanying this demand is an increased threat to the environment and to human health, due to waste produced by increased industrial production. This increased demand has underscored the necessity to increase reaction efficiencies, in order to reduce costs and increase profits. The discovery of novel biocatalysts is a key method aimed at combating these difficulties. Metagenomic technology, as a tool for uncovering novel biocatalysts, has great potential and applicability and has already delivered many successful achievements. In this review we discuss, recent developments and achievements in the field of biocatalysis. We highlight how green chemistry principles through the application of biocatalysis, can be successfully promoted and implemented in various industrial sectors. In addition, we demonstrate how two novel lipases/esterases were mined from the marine environment by metagenomic analysis. Collectively these improvements can result in increased efficiency, decreased energy consumption, reduced waste and cost savings for the chemical industry.

Reductive cleavage of carbon-chlorine bonds at catalytic and non-catalytic electrodes in 1-butyl-3-methylimidazolium tetrafluoroborate

Dissociative electron transfer (DET) to a series of organic chlorides at glassy carbon (GC), silver and copper electrodes has been studied in 1-butyl-3-methylimidazolium tetrafluoroborate. The overall results of this study show that the ionic liquid behaves like molecular solvents such as acetonitrile and dimethylfomamide. It is found that aromatic chlorides follow a stepwise mechanism, whereas concerted electron transfer/bond cleavage is the preferred reaction mechanism for alkyl and benzyl chlorides. Ag and Cu show catalytic effects only when the DET follows a concerted mechanism, but Ag proves to be a much better electrocatalyst than Cu. A series of substituted benzyl chlorides (Z-C6H4CH2Cl, Z = H, 3-OCH3, 3-F, 4-Cl, and 3-CF3) show interesting results providing some insight into the reaction dynamics. The process occurs by a concerted mechanism and, albeit a constant standard potential for the whole series, Ep on GC and Cu, which does not show catalytic activity, is significantly affected by the substituents. In contrast, Ag shows good catalytic activity and, as expected, Ep does not change with the substituent. This difference in behavior may be rationalized by considering ion-dipole interactions between R˙ and Cl(-) as opposed to adsorption of the fragments on the electrode surface.