The preparation of fairly strained carbocyclic ring systems by intramolecular 5-exo-trig ring closure has been well documented, and the absence of proton transfers that would compromise such cyclizations is a hallmark of this chemistry. In an effort to explore the limitations of this approach to more highly strained systems, the preparation of a stellane (tricyclo[3.3.0.0(3,7)]octane) framework...

This transformation is intramolecular and would involve no exchange between the migratory hydrogen and hydrogen in the aqueous solvent. (2) The hydrogen may migrate as a proton (Fig. l), in which case exchange with the solvent would occur. In order to distinguish between these alternatives the conversion of fructose-6-phosphate (F-6-P) into glucose-6phosphate (G-6-P)) catalyzed by phosphoglucos...

In this paper, the silicon-containing sulfonated polystyrene/acrylate–ionic liquid (Si-SPS/A–IL)hybrid membranes was prepared to obtain the proton exchange membrane (PEM) materials withhigh methanol barrier and good selectivity. The Si-SPS/A–IL hybrid membranes characterized asthe function of IL to evaluate their potential as PEMs in direct methanol fuel cells (DMFCs).Fourdifferent Hybrid mater...

An H/Li exchange model is found to be applicable to describe the diffusion of protons when optical waveguides are formed in LiNbO3 by proton exchange methods where the proton doped crystal structure stays in the pure phase. The H and Li self-diffusion coefficients in the ion exchange model are determined as a function of the proton exchange temperature both for x-cut and z-cut LiNbO3. In this w...

A number of uncouplers and energy transfer inhibitors suppress photosystem II cyclic photophosphorylation catalyzed by either a proton/electron or electron donor. Valinomycin and 2,4-dinitrophenol also inhibit photosystem II cyclic photophosphorylation, but these compounds appear to act as electron transport inhibitors rather than as uncouplers. Only when valinomycin, KCl, and 2,4-dinitrophenol...

in this paper the role of super paramagnetic iron oxide nanoparticles (spi) on platinum nanoclusters on activated carbon (pt/c) for electrocatalytic oxygen reduction reaction was considered. four composites of pt/c and super paramagnetic iron oxide nanoparticles were prepared with the same total composites weight and different loading of pt/c (1.2, 0.6, 0.4 and 0.3 mg ). the composite attached ...

reduced graphene oxide film was synthesized on a glassy carbon electrode by electro reduction of graphene oxide powders in aqueous solution. then platinum nano particles were deposited on reduced graphene oxide film that was deposited on the glassy carbon electrode via electro reduction of platinum salt. the physical morphology of the platinum on reduced graphene oxide film was evaluated by sca...