A dimerization reaction induced by hydrogen atoms: from B(CH 3) 3 adsorbed on C/Pt(100) to B 2H 2(CH 3) 4
Abstract
Monolayers of trimethylborane, B(CH 3) 3, were prepared on graphite-monolayer-covered Pt(100) surfaces. The interaction of gaseous hydrogen atoms with these monolayers was investigated by thermal desorption and high-resolution electron energy-loss spectroscopies. At 80 K substrate temperature, tetramethyldiborane, B 2H 2(CH 3) 4, was observed as an adsorbed reaction product. The reaction cross-section of 0.4 Å 2 is compatible with a direct, Eley-Rideal type reaction mechanism. From similar experiments with deuterium atoms it is apparent that H/D exchange at the methyl groups through a sequence of abstraction and addition also occurs, although with a smaller cross-section. The reaction pathway to tetramethyldiborane involves dimerization of a BH(CH 3) 2 intermediate. Three possibilities for the reaction pathway to this intermediate are discussed.
- Publication:
-
Surface Science
- Pub Date:
- September 1998
- DOI:
- 10.1016/S0039-6028(98)00534-2
- Bibcode:
- 1998SurSc.414..290H