Metal hydrazines synthesis

Unsupported Catalysts. - Most of the research work is focused on the preparation of noble metal catalysts using microemulsions in the metal particle synthesis. It is now well known that the early work of Boutonnet et al opened a new and simple way to preparing stable reduced noble metal particles from their salt precursors. In their work, metallic particles of platinum, rhodium, palladium and iridium were obtained from their salt precursors, HaPtCl, RhCh, PdCh and IrCh, respectively, in water in oil (w/o) microemulsions. For Pt and Pd, the most suitable reducing agent was hydrazine. In the case of Rh " and Ir the... 

Several nanocrystalhne metal oxides have been prepared by the combustion method and the topic has been reviewed by Patil et al. [5]. Combustion of metal hydrazine carboxylates, [e.g. MCjO (N H )J is generally anployed to obtain the nanoparticles of oxides such as y-Fefiy ZnO and NiO. Mixed-metal oxides like cobaltites (MCo O ), ferrites (MFe,0 ), manganites (MMn O ) and titanates (MTiOj) are prepared by the combustion of mixed-metal carboxylate hydrazinates in the temperature range of 165-345 °C [6,7]. Solution combustion synthesis has been used to prepare nanocrystalline oxides such as Al Oj, CeO, ZrO, TiO, ... 

Patil, K.C. and Seker, M.M.A. (1994) Synthesis, structure and reactivity of metal hydrazine carboxylates combustible precursors to fine particle oxide materials. International Journal of Self-Propagating High-Temperature Synthesis, 3, 181-196. 

Common synthetic methods practiced for the preparation of metal hydrazines, and some single-crystal structures, are discussed briefly in Chapter 1. A direct method of synthesis of metal hydrazines has been developed that involves adding metal powders to hydrazine salts (preparation of salts discussed in Chapter 2). Details of the synthesis of several simple and mixed metal hydrazines by this and other methods, along with their spectral characterization and thermal reactivity, are now described. 

The synthesis of metal hydrazine complexes with thiocyanate or isothiocyanate as anions can be carried out by the following methods [8]. In the first case, stoichiometric quantities of metal(II) salts like chlorides or sulfates of Mn, Fe, Co, Ni, Zn, and Cd in an alcohol-water mixture (1 1 by volume) are added to hydrazinium thiocyanate. The latter is metathet-ically formed by the reaction of NH4SCN -I- N2H4 H2O (1 1 mole ratio) (Chapter 2) ... 

Transition metal hydrazine perchlorate, nitrate, and azide complexes are explosive in nature, as indicated by DTA experiments and impact sensitivity measurements. Special precautions have to be taken during the synthesis and characterization of these materials. Small quantities of up to 1 g can be prepared without any explosion. Special mention should be made of the nickel hydrazine azide complex, which is prepared from NiCli + NaNa-I-2N2H4 H2O. The product is highly friction sensitive, especially in dry state, and so samples are to be handled with a Teflon spatula. A few milligrams are used for DTA and impact sensitivity tests. 

Patil, K.C., Nesamani, C., and Pai Verneker, V.R. (1982) Synthesis and characterization of metal hydrazine nitrate, azide and perchlorate complexes. Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry, 12, 383-395. 

Saravanan, K., Govindarajan, S., and Chellappa, D. (2004) Preparation, characterization, and thermal reactivity of divalent transition metal hydrazine pyridine-2, n-dicarboxylates (n 5 3, 4, 5, and 6). Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry, 34, 353-369. 

The complexes crystallize in a few hours to a few days. Interestingly, as the products are formed from the process of crystallization, they are single crystals of high purity. This chapter describes the synthesis, infrared spectra, electronic spectra, and thermal reactivity of several simple and mixed metal hydrazine carboxylate complexes prepared by this method. 

Metal hydrazine complexes of azide and nitrate have been investigated as initiators. For example, the synthesis of nickel nitrate hydrazine [Ni (N03)2(N2H4)2] described in Chapter 3 has been commercially developed for use as detonators (blasting caps) in China. 

Hydrazine, bis(allylthiocarbamido)-in gravimetry, 1, 534 liquid-liquid extraction, 1,546 Hydrazines, 2, 101 macrocyclic synthesis, 2,904 metal complexes, 2, 30 in plutonium extraction, 6, 948 Hydrazoic acid... 

The formation of semiconductor nanoparticles and related stmctures exhibiting quantum confinement within LB films has been pmsued vigorously. In 1986, the use of the metal ions in LB films as reactants for the synthesis of nanoscale phases of materials was described [167]. Silver particles, 1-2 mn in size, were produced by the treatment of silver be-henate LB films with hydrazine vapor. The reaction of LB films of metal salts (Cd, Ag, Cu, Zn, Ni, and Pb ) of behenic acid with H2S was mentioned. The use of HCl, HBr, or HI was noted as a route to metal halide particles. In 1988, nanoparticles of CdS in the Q-state size range (below 5 mn) were prepared inside LB films of cadmium arachi-... 

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