Metal hydrazines studies

The hydrazine was chosen as appropriate reducing agent because it can be used at low temperature and it decomposes to NH3 and/or N2 after reduction takes place. The reduction with hydrazine depends on several parameters such as the nature of the metal, hydrazine concentration, pH, time of reduction and reduction temperature. In case of the noble metals such as palladium, this reaction occurred very easily at low temperature. In our case the hydrazine to palladium molar ratio was 100 (particle size is independent on hydrazine eoncentration). Under this condition the particle size should be mainly governed by the natme of solvent and surfactant. Moreover, in our study, the water to surfactant molar ratio was 6 which let us to suppose the presence of bounded and trapped water only. This is expected to result in very small size of palladium nanoparticles [4]. 

Gajapathy, D. (1983) Studies on metal-hydrazine system. Ph.D Thesis, Indian Institute of Science, Bangalore. 

The thermal analysis results of these complexes are at variance with those reported in earlier literature. Previous studies indicated the formation of corresponding metals as the end product, when DTA was carried out in an argon atmosphere. The formation of intermediates was not identified then. However, in this thermal analysis, metal oxides are obtained as the products of decomposition of metal hydrazine carboxylates, even when the decompositions are carried out in a nitrogen atmosphere. 

In earlier studies the in vitro transition metal-catalyzed oxidation of proteins and the interaction of proteins with free radicals have been studied. In 1983, Levine [1] showed that the oxidative inactivation of enzymes and the oxidative modification of proteins resulted in the formation of protein carbonyl derivatives. These derivatives easily react with dinitrophenyl-hydrazine (DNPH) to form protein hydrazones, which were used for the detection of protein carbonyl content. Using this method and spin-trapping with PBN, it has been demonstrated [2,3] that protein oxidation and inactivation of glutamine synthetase (a key enzyme in the regulation of amino acid metabolism and the brain L-glutamate and y-aminobutyric acid levels) were sharply enhanced during ischemia- and reperfusion-induced injury in gerbil brain. 

The IV-VI films are usually p-type, both as deposited and after annealing in air. One study, where PbS was deposited from a bath containing hydrazine, found the deposit on glass to be n-type temporarily but converted to p-type on air exposure. By depositing the PbS on a trivalent metal coating (such as Al), the n-type conductivity could be stabilized for a longer time. 

The earliest of these studies was on PbS. PbS can have either p- or n-type conductivity, although CD PbS is usually p-type. Based on the belief that the p-type conductivity may be due to alkali metal cations from the deposition solution, an alkali metal—free deposition, using lead acetate, thiourea, and hydrazine hydrate was used [33]. While initially n-type, the film converted to p-type in air. Attempts to stabilize the p-type material by adding trivalent cations to the deposition solution were unsuccessful. However, deposition of the PbS on a trivalent metal, such as Al, did stabilize the n-PbS, at least for a time. In this way, p-n junctions were made (the PbS close to the trivalent metal was n-type, while the rest of the film was p-type). Photovoltages up to 100 mV were obtained from these junctions at room temperature and almost 300 mV at low temperatures (90 K). 

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