REACTIONS OF SIMPLE HYDROCARBONS WITH NB-N(+) - CHEMISORPTION AND PHYSISORPTION ON IONIZED NIOBIUM CLUSTERS

被引:198
作者
BERG, C
SCHINDLER, T
NIEDNERSCHATTEBURG, G
BONDYBEY, VE
机构
[1] Institut für Physikalische und Theoretische Chemie, Technische Universität München, 85747 Garching
关键词
D O I
10.1063/1.469535
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
In a Fourier transform-ion cyclotron resonance mass spectrometer the gas phase reactivities of niobium clusters Nbn+ (n =1-28) with molecular hydrogen, water, methane, ethane, n-propane, n-heptane, cyclohexane, acetylene, ethylene, allene, benzene, propene, toluene, xylene, and acetonitrile were investigated under single collision conditions as well as the reactivities of oxidized niobium cluster cations with ethylene and benzene. The reactions of larger clusters with a variety of unsaturated hydrocarbons are believed to proceed via long lived "physisorbed" addition intermediate complexes, which subsequently rearrange to form "chemisorbed," extensively dehydrogenated final products. The overall reaction seems to proceed with near collision rates, almost independent of cluster size. In some cases also the physisorbed primary products are stabilized and detected. Their yields depend sensitively on the specific nature of the reactant, and on the niobium cluster size n. Fully saturated hydrocarbons unable to form the long lived complexes are unreactive with respect to the larger (n>7) Nbn+ clusters. Smaller clusters with n≤7 seem to react by a different, prompt reaction mechanism. The rate of this reaction steeply decreases, and the degree of product dehydrogenation increases with n. © 1995 American Institute of Physics.
引用
收藏
页码:4870 / 4884
页数:15
相关论文
共 42 条
[1]   ETHYLENE COMPLEXES - BONDING, ROTATIONAL BARRIERS, AND CONFORMATIONAL PREFERENCES [J].
ALBRIGHT, TA ;
HOFFMANN, R ;
THIBEAULT, JC ;
THORN, DL .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1979, 101 (14) :3801-3812
[2]   POLYENE-ML2 AND POLYENE-ML4 COMPLEXES - CONFORMATIONAL PREFERENCES AND BARRIERS OF ROTATION [J].
ALBRIGHT, TA ;
HOFFMANN, R ;
TSE, YC ;
DOTTAVIO, T .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1979, 101 (14) :3812-3821
[3]  
ALBRIGHT TA, 1979, J AM CHEM SOC, V101, P3821
[4]   DISSOCIATIVE CHEMISORPTION OF H-2 ON NIOBIUM CLUSTER IONS - A SUPERSONIC CLUSTER BEAM FT-ICR EXPERIMENT [J].
ALFORD, JM ;
WEISS, FD ;
LAAKSONEN, RT ;
SMALLEY, RE .
JOURNAL OF PHYSICAL CHEMISTRY, 1986, 90 (19) :4480-4482
[5]  
Bond GC, 1987, HETEROGENEOUS CATALY
[6]   LASER-INDUCED FLUORESCENCE OF METAL-CLUSTERS PRODUCED BY LASER VAPORIZATION - GAS-PHASE SPECTRUM OF PB-2 [J].
BONDYBEY, VE ;
ENGLISH, JH .
JOURNAL OF CHEMICAL PHYSICS, 1981, 74 (12) :6978-6979
[7]  
BOWERS MT, 1991, NATO ASI SERIES
[8]   GAS-PHASE REACTIONS OF NB+ AND TA+ WITH ALKANES AND ALKENES - C-H-BOND ACTIVATION AND LIGAND-COUPLING MECHANISMS [J].
BUCKNER, SW ;
MACMAHON, TJ ;
BYRD, GD ;
FREISER, BS .
INORGANIC CHEMISTRY, 1989, 28 (18) :3511-3518
[9]   HETERODINUCLEAR TRANSITION-METAL CLUSTER IONS IN THE GAS-PHASE - THERMOCHEMISTRY AND REACTIVITY OF NBFE plus AND NBFEL+ (L=O,CO,H2O, AND ALKENES) [J].
BUCKNER, SW ;
FREISER, BS .
JOURNAL OF PHYSICAL CHEMISTRY, 1989, 93 (09) :3667-3673
[10]  
CHATT J, 1953, J CHEM SOC, P2339