Pyrolysis of organometallic compounds

Pyrolysis of organometallic compounds containing cyclopentadiene and carbonyl groups to produce W2C [10.11]. 

Pyrolysis of organometallic compounds with hydrocarbons Reaction of metal chloride or metal carbonyl with hydrocarbons, hydrogen, or CO by chemical vapor deposition... 

Chiu, W.S., Radiman, S., Abdullah, M.H., Khiew, P.S., Huang, N.M. and Abd-Shukor, R. (2007) One pot synthesis of monodisperse Fe304 nanocrystals by pyrolysis reaction of organometallic compounds. Materials Chemistry and Physics, 106 (2-3), 231-235. 

Finally, the fact that these organoarsonic acids are released upon oil shale pyrolysis has important implications in the various synthetic fuel processes, where the role of organometallic compounds in poisoning process catalysts and contributing to environmental problems, is paramount. (32,33)... 

Some other contributions of organometallic compounds to fundamental research are (a) the detection of free alkyl radicals by the pyrolysis of lead alkyls (b) the classification of hydrocarbon acidity via organoalkali compounds (c) the study of Lewis acid-base interactions with Group III alkyls (d) the development of the concept of electron-deficient compounds by the study of metal alkyls (e) the discovery of stereospecific olefin polymerization and (f) the investigation of nucleophilic additions to unsaturated organic compounds via reactive metal alkyls. 

The recent technique of nebulized spray pyrolysis (NSP) has been used to prepare aligned MWNTs bundles [62]. This technique consists in a spray generated by an ultrasonic atomizer. MWNTs with fairly uniform diameters, as well as ahgned MWNT bundles, have been obtained by using solutions of organometallic compounds, such as ferrocine, in benzene, toluene, and other hydrocarbon solvents. The advantage of NSP is the ease of scahng up to an industrial process where the reactants are fed into the furnace continuously. 

In connection with the participation of metals in the preparation of organometallic compounds, attention might be called to a reaction involving metallic thallium as a product. We have presented evidence for the formation of the phenylthallium radical by pyrolysis of triphenylthallium in xylene. 

PBE dendrons coordinate to the surface of II-VI semiconductor nanocrystals (e.g., CdSe [33] and CdSe/ZnS core/shell structure [34, 35]) to modulate the photoluminescence of the nanocrystals [32]. Trioctylphosphine oxide (TOPO)-capped II-VI semiconductor nanocrystals of several-nanometers diameter have been synthesized by a pyrolysis reaction of organometallics in TOPO [33-35]. The capping ligand (TOPO) can be replaced by stronger ligands such as thiol compounds [36], suggesting that dendrons bearing sulfur atom(s) at the focal point replace TOPO as well. 

Membranes with extremely small pores ( < 2.5 nm diameter) can be made by pyrolysis of polymeric precursors or by modification methods listed above. Molecular sieve carbon or silica membranes with pore diameters of 1 nm have been made by controlled pyrolysis of certain thermoset polymers (e.g. Koresh, Jacob and Soffer 1983) or silicone rubbers (Lee and Khang 1986), respectively. There is, however, very little information in the published literature. Molecular sieve dimensions can also be obtained by modifying the pore system of an already formed membrane structure. It has been claimed that zeolitic membranes can be prepared by reaction of alumina membranes with silica and alkali followed by hydrothermal treatment (Suzuki 1987). Very small pores are also obtained by hydrolysis of organometallic silicium compounds in alumina membranes followed by heat treatment (Uhlhom, Keizer and Burggraaf 1989). Finally, oxides or metals can be precipitated or adsorbed from solutions or by gas phase deposition within the pores of an already formed membrane to modify the chemical nature of the membrane or to decrease the effective pore size. In the last case a high concentration of the precipitated material in the pore system is necessary. The above-mentioned methods have been reported very recently (1987-1989) and the results are not yet substantiated very well. 

Pyrolysis of Alkali-Metal Organometallic Compounds Hydro-metallo-elimination... 

Pyrolysis of alkyl or aryl azides 8-18 Reaction between oxime sulfonates and organometallic compounds... 

Microwave treatment is widely used to prepare various refractory inorganic compounds and materials (double oxides, nitrides, carbides, semiconductors, glasses, ceramics, etc.) [705], as well as in organic processes [706,707] pyrolysis, esterification, and condensation reactions. Microwave syntheses of coordination and organometallic compounds, discussed in this chapter, are presented in a relatively small number of papers in the available literature. As is seen, the use of microwaves in coordination chemistry began not long ago and, due to the highly limited number of results, these works can be considered as a careful pioneer experimentation, in order to establish the suitability of this technique for synthetic coordination chemistry. 

The investigations carried out on the organometallic synthesis of carbosilanes and presented in this paper indicate the progress achieved in this field in the years between 1967 and 1971 in cooperation with Dr. P. Schober, Dr. M. Hahnke and Dr. G. Maas. The yields of these syntheses are not all satisfactory yet, in most cases with the cyclization reaction. There is no doubt that the procedures described can be extended and simplified. However, it is also apparent that only some of the compounds (and their derivatives) which arise from the pyrolysis of the methylchlorosilanes and of tetramethylsilane can be obtained by organometallic synthesis38. The development of this field of chemistry requires extensive advances in methods for synthesis. 

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