Reactivity of niobium cluster anions with nitrogen and carbon monoxide

Abstract Reactions of small niobium cluster anions, Nbn−(n = 2–7), with CO and N2 are investigated using a flow tube reactor (flowing afterglow) apparatus. Carbon monoxide chemisorption on niobium cluster anions occurs with faster reaction rates than nitrogen chemisorption on corresponding cluster sizes. N2 addition to niobium cluster anions is much more size-selective than is CO addition. These general trends follow those reported in the literature for reactions of neutral and cationic niobium clusters with CO and N2. Extensive fragmentation of the clusters is observed upon chemisorption. A small fraction of the larger clusters survive and sequentially add multiple CO or N2 units without fragmentation. However, chemisorption saturation is not reached at the experimentally accessible pressure and reagent concentration ranges. The thermochemistry of the adsorption processes and the nature of the adsorbed species, molecular or dissociated, are discussed.

[1]  M. R. Zakin,et al.  Dependence of metal cluster reaction kinetics on charge state. I. Reaction of neutral (Nbx) and ionic (Nb+x, Nb−x) niobium clusters with D2 , 1988 .

[2]  R. Smalley,et al.  Fourier transform ion cyclotron resonance studies of H2 chemisorption on niobium cluster cations , 1988 .

[3]  M. Knickelbein,et al.  Metal cluster—rare gas van der Waals complexes: NbnArm and FenKrm , 1991 .

[4]  M. R. Zakin,et al.  Effect of hydrogen chemisorption on the photoionization threshold of isolated transition metal clusters , 1987 .

[5]  L. Schmidt,et al.  Adsorption and solution of H2 and N2 by Ta and Nb , 1974 .

[6]  M. El-Sayed,et al.  Dependence of the reaction probability of benzene on the size of gaseous niobium clusters , 1987 .

[7]  Donald M. Cox,et al.  Electron binding and chemical inertness of specific Nbx clusters , 1986 .

[8]  Kent M. Ervin,et al.  Reactions of Copper Group Cluster Anions with Oxygen and Carbon Monoxide , 1994 .

[9]  M. R. Zakin,et al.  Infrared spectroscopy of unsupported metal cluster complexes using multiple photon dissociation , 1986 .

[10]  R. Smalley,et al.  Formation and photodetachment of cold metal cluster negative ions , 1985 .

[11]  R. L. Benbow,et al.  Synchrotron radiation study of chemisorptive bonding of CO on transition metals — Polarization effect on Ir(100)☆ , 1976 .

[12]  Kopin Liu,et al.  Metastable decay of photoionized niobium clusters: Clusters within a cluster? , 1988 .

[13]  H. Sellers.  Ab initio and relativistic effective core potential studies of niobium-nitrogen and niobium cluster systems , 1990 .

[14]  Menezes,et al.  Optical response of small niobium clusters. , 1992, Physical review letters.

[15]  Kent M. Ervin,et al.  Chemisorption of carbon monoxide on platinum cluster anions , 1993 .

[16]  T. Carrington,et al.  The structure of Nb3O and Nb3O+ determined by pulsed field ionization–zero electron kinetic energy photoelectron spectroscopy and density functional theory , 1995 .

[17]  K. M. Ervin,et al.  Chemisorption and oxidation reactions of nickel group cluster anions with N2, O2, CO2, and N2O , 1995 .

[18]  R. Smalley,et al.  Metal cluster ion photofragmentation , 1986 .

[19]  M. El-Sayed,et al.  Photochemical dehydrogenation of benzene chemisorbed on small niobium metal clusters , 1987 .

[20]  Gabor A. Somorjai,et al.  Chemistry in Two Dimensions: Surfaces , 1981 .

[21]  R. Smalley,et al.  Surface reactions of metal clusters. II. Reactivity surveys with D2, N2, and CO , 1985 .

[22]  A. Roggenkamp,et al.  ‘Black-body’ radiation of free niobium clusters heated by oxidation , 1995 .

[23]  S. Owen.  Electron counting in clusters: A view of the concepts , 1988 .

[24]  P. Armentrout,et al.  Collision-induced dissociation of niobium cluster ions: transition metal cluster binding energies , 1989 .

[25]  R. Smalley,et al.  Ultraviolet photoelectron spectroscopy of copper clusters , 1988 .

[26]  V. Bondybey,et al.  DEHYDROGENATION OF XYLENE ISOMERS ON NIOBIUM CLUSTER CATIONS NBN+ (N = 2-26) , 1995 .

[27]  Andreas Amrein,et al.  Multiphoton excitation, ionization, and dissociation decay dynamics of small clusters of niobium, tantalum, and tungsten: Time‐resolved thermionic emission , 1991 .

[28]  A. Kaldor,et al.  Hydrogen chemisorption on gas-phase transition-metal clusters , 1990 .

[29]  Kent M. Ervin,et al.  Nickel group cluster anion reactions with carbon monoxide: Rate coefficients and chemisorption efficiency , 1994 .

[30]  M. Bowers.  Gas phase ion chemistry , 1979 .

[31]  M. Knickelbein,et al.  Isomers of niobium clusters: direct spectroscopic evidence , 1990 .

[32]  M. El-Sayed,et al.  Bromine abstraction versus dehydrogenation in the reaction of gaseous niobium clusters with saturated and unsaturated organic bromides , 1988 .

[33]  D. Salahub,et al.  Metal-ligand interactions : from atoms, to clusters, to surfaces , 1992 .

[34]  K. Jennings.  Fundamentals of gas phase ion chemistry , 1991 .

[35]  M. R. Zakin,et al.  Reaction of niobium clusters with benzene-h6 and -d6: evidence for cluster-induced dehydrogenation , 1987 .

[36]  S. Anderson,et al.  CHEMISTRY OF METAL AND SEMIMETAL CLUSTER IONS , 1992 .

[37]  K. C. Reichmann,et al.  CO chemisorption on free gas phase metal clusters , 1988 .

[38]  G. W. Lemire,et al.  Evidence of structural isomerism in small niobium clusters , 1988 .

[39]  P. Armentrout,et al.  Oxidation reactions at variably sized transition metal centers: Fe+n and Nb+n +O2 (n=1–3) , 1989 .

[40]  M. El-Sayed,et al.  Cluster size dependence of the chemical stereoselectivity in the niobium clusters + bromine cyanide reaction , 1988 .

[41]  M. Knickelbein,et al.  Photodissociation spectroscopy of NbnArm complexes , 1993 .

[42]  M. Knickelbein,et al.  Photoionization studies of niobium clusters: Ionization potentials for Nb2–Nb76 , 1990 .

[43]  V. Bondybey,et al.  Reactions of simple hydrocarbons with Nb n : Chemisorption and physisorption on ionized niobium clusters , 1995 .

[44]  Richard E. Smalley,et al.  Charge dependence of chemisorption patterns for transition metal clusters , 1986 .

[45]  M. R. Zakin,et al.  Size‐selective dehydrogenation of benzene by gas‐phase niobium cluster ions (Nb+x) , 1988 .

[46]  M. El-Sayed,et al.  Reactivity of gas-phase niobium clusters toward several cyclic hydrocarbons , 1987 .