Complete Raman and IR spectra were recorded for the tetrachloro phosphonium salts of tetrachloro-aluminate, gallate, indate and ferrate. The spectra are interpreted on the basis of these complexes being of ionic structure of the general formula: PCL;MCI;. All the accordingly expected fundamentals have been observed and assigned.

Colloidal ca. 40 Á diameter CdS semiconductors have been in situ generated and in situ coated by rhodium in 800-1000 Á diameter dioctadecyldimethylammonium chloride (DODAC) and dioctadecyldimethylammonium bromide (DODAB) surfactant vesicles. Vesicles controlled the sizes and stabilities of CdS, generated by H2S from adsorbed Cd/EDTA. Fluorescence emission of DODAC or DODAB vesicle incorporated CdS was visible only when the dispersion was sonicated at a pH higher than 6. This fluorescence was unaffected by additional EDTA but efficiently quenched by PhSH. Direct evidence of conduction band electron transfer from excited CdS to methylviologen was observed by laser flash photolysis. Photolysis by visible light of DODAC and DODAB vesicle entrapped Rh-coated CdS particles in the presence of PhSH (the sacrificial electron donor) has led to hydrogen formation which could be sustained until nearly complete consumption of PhSH. Hydrogen evolution was equally or more efficient from externally formed CdS particles, even though they did not show a detectable fluorescence. Hydrogen generation has been optimized by examining the effects of catalyst concentration, its mode of formation, the concentration of added PhSH, and the methods of CdS and vesicle preparation.

No abstract

No abstract

No abstract