Clusters pyrolysis

Synthesis depends on gas-phase pyrolysis techniques , and interconversion is by electrochemical oxidation . Understanding of the mechanisms by which the boranes interconvert and build up into larger clusters is growing . 

Intact bacteria were first introduced into a mass spectrometer for analysis of molecular biomarkers without processing and fractionation around 1975.6 The ionization techniques available at the time limited analysis to secondary metabolites that could be volatilized, such as quinines and diglycerides, and vigorous pyrolysis of bacteria was explored as an alternative.7 Although biomarkers were destroyed in pyrolysis strategies, computer-supported cluster analysis was developed to characterize pure samples. 

The latter were assumed to have the 1,3-disubstitution pattern. Both sets of compounds proved to be considerably more air and thermally sensitive than the parent system. Whereas irradiation in sealed tubes did not result in any observable change, simple heating produced insoluble clusters ( 3). In an effort to suppress bimolecular reactions two of the complexes [R = C6H5(CH2)35 C6H5CHCH3(CH2)2] were subjected to flash vacuum pyrolysis at low contact times (300-950°C, 2xl0-l+torr) (57 ). The resulting... 

The formation of carbido-carbonyl cluster compounds with ruthenium and osmium appears to be common in pyrolysis reactions the basic reaction may be viewed as the transformation of the coordinated carbon monoxide to carbide and carbon dioxide. Small variations in... 

Pyroglycolytic pathway, production, 38 383 Pyrolysis reactions, in synthesis of carbonyl clusters, 30 141-143 a-Pyrone complexes with cobalt, 12 283 with iron, 12 275... 

The various methods of preparation employed to prepare nanoscale clusters include evaporation in inert-gas atmosphere, laser pyrolysis, sputtering techniques, mechanical grinding, plasma techniques and chemical methods (Hadjipanyas Siegel, 1994). In Table 3.5, we list typical materials prepared by inert-gas evaporation, sputtering and chemical methods. Nanoparticles of oxide materials can be prepared by the oxidation of fine metal particles, by spray techniques, by precipitation methods (involving the adjustment of reaction conditions, pH etc) or by the sol-gel method. Nanomaterials based on carbon nanotubes (see Chapter 1) have been prepared. For example, nanorods of metal carbides can be made by the reaction of volatile oxides or halides with the nanotubes (Dai et al., 1995). 

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