Arsines thermolysis

The technical/commercial importance of the arsine thermolysis mechanisms is the role of decomposition intermediates in the deleterious incorporation of carbon into the growth of MOCVD-produced GaAs. Wendt and Speckman in their investigations into the thermal decomposition of arsines show the crucial importance of the production of AsHj radicals in the formation of low-carbon GaAs. 

Thermolysis of (LH)2[RuCl5(NO)] (L = benzimidazole, imidazole, 5-nitrobenzimidazole, benzo-triazole, py) leads to the initial formation of [RuC NOJL]- with subsequent reaction to afford [RuCl3(NO)L2].M6 When solutions of RuCl with NaNCS in pyridine are refluxed for three days, a product formulated as [Ru(NCS)2py4] can be isolated.667 Nitrosyl and thionitrosyl complexes containing heterocycles with arsine or phosphine ligands have been reported.668... 

The thermolysis of arsine and the arsines has become of great commercial as well as scientific interest due to their role in the formation of gallium arsenide films by MOCVD processes. The now classical MOCVD preparation of gallium arsenide developed by Manasevit (equation 11) is undergoing continuing refinement as new gallium and arsenic precursor compounds are investigated. 

The arsonium ylides are the most synthetically useful of the organoarsenic(V) compounds. Trimethylarsonium methylide and triphenylarsonium benzylide undergo thermolysis under the mild conditions of refluxing benzene, affording the arsine and an olefin. 

Some interest has been shown in using aminoarsines, As(NR2)3, as MOCVD arsenic precursors, since they are volatile and relatively less toxic than AsHj . Bi(NR2)3 (sublimes at 10 torr at 30°C) is also being investigated. The thermolysis of azido arsines is a process to approach with extreme caution since explosions with azides are not unknown Sowerby and Revitt prepared diarsines by thermolytic nitrogen elimination ... 

The thermolysis of cyclopolyarsines has been briefly reviewed. In general (AsR) compounds decompose into the arsine ASR3 and elemental arsenic AS4 or the diarsine... 

The method is applicable for triorganoarsenic compounds bearing aryl or vinyl substituents (equations 76 , 77 and 78 ), while for the preparation of alkylarsenic halides this method has not been useful since only adduct formation and redox reactions have been reported between R3AS and AsXj (equations 79a and b) . Reaction of tris(trifluoromethyl) arsine with arsenic iodide, however, has been reported to afford a mixture of halides (equation 80) . In the reaction of unsymmetrically substituted compounds such as 4, cleavage of the aryl-arsenic bond is preferred to that of the alkyl-arsenic bond (equation 78 ). The cleavage of 4 by this method is in contrast to that of 3 in thermolysis (equation 75). 

The thermolysis of (Bu As), affords polycyclic arsines such as BugAsg (5). 

The procedure by which the first representatives were obtained <78TL44l, 78JOM(i54)l> proved very effective. It starts with the four-membered chain of a 2-aminoalkylphosphine/arsine or 2-aminophenylphosphine/arsine and completes the ring by condensation with a carboxyUc acid derivative. In the former case full unsaturation is reached by thermolysis of the condensation product... 

Several triosmium complexes derived from phosphines or arsines, by loss or orthometallation of phenyl groups, have been isolated (this is a long-known process, see, e.g., ref. 186). Thermolysis of Os3(CO)n(AsPh3) leads to... 

---