Accession Number : ADA206038

Title :   Bromine Abstraction Versus Dehydrogenation in the Reaction of Gaseous Niobium Clusters with Saturated and Unsaturated Organic Bromides.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY AND BIOCHEMISTRY

Personal Author(s) : Song, Li ; El-Sayed, M. A.

Report Date : 20 FEB 1989

Pagination or Media Count : 11

Abstract : Small gaseous niobium clusters (Nb(x), x=1-12) synthesized by the laser evaporation technique are reacted with 1-bromopropene, 3-bromopropene, bromoethane, and 2-bromopropane in a fast flow reactor. While Bromine abstraction on all Niobium clusters takes place with both saturated and unsaturated bromides, addition-dehydrogenation occurs only with the unsaturated compounds at similar concentrations. The abstraction reaction probability is independent of x, but the dehydrogenation reaction has a threshold (at x=6) beyond which the reaction probability is greatly enhanced, and increases with cluster size from x=6 to 10. Thus the two reactions (bromide abstraction and addition-dehydrogenation) are not competitive, and may result from different types of collisions, impulsive and sticky collisions, respectively. Reprints. (aw)

Descriptors :   *BROMIDES, *BROMINE, *DEHYDROGENATION, *NIOBIUM, *EXTRACTION, *ORGANIC COMPOUNDS, CLUSTERING, EVAPORATION, FAST REACTORS, FLOW, GASES, LASERS, PROBABILITY, REPRINTS, RESPONSE, SATURATION, SIZES(DIMENSIONS), PROPENES, PROPANE, ETHANES.

Subject Categories : Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE