Kinetics and mechanism of the germane decomposition

✍ Scribed by C. G. Newman; J. Dzarnoski; M. A. Ring; H. E. O'Neal

• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: English
• Weight: 545 KB
• Volume: 12
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550120907

✦ Synopsis

The homogeneous gas-phase thermal decomposition kinetics of germane have been measured in a single-pulse shock tube between 950 and 1060 K at pressures around 4000 torr. The initial decomposition is GeH4 -GeH2 + H2 in its pressure-dependent regime, with log k ~~~~( 4 m ) = 13.83 f 0.78 -50,750 f 3570 ca1/2.303RT. RRKM calculations suggest that the high-pressure Arrhenius parameters are log k GeH4(Ma) = 15.5 -54,300 cd2.303RT. Extrapolations to static system pyrolysis conditions (T -600 K, P -200 torr) give homogeneous reaction rates which are much slower than those observed, hence the static system pyrolysis of germane must be predominantly heterogeneous. Shock-initiated pyrolysis reaction stoichiometry is 2 mol H2 per mole GeH4, suggesting that the subsequent decomposition of germylene is essentially quantitative. Investigations of the hydrogen product yields for pyrolysis of GeD4 in @CH3 further indicate that the germylene decomposition reaction is mainly GeHz -H2 + Ge, hut that a small amount of reaction to H atoms may also occur.