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    Structures of Cu n + (n = 3-10) Clusters Obtained by Infrared Action Spectroscopy

    , Article Journal of Physical Chemistry Letters ; Volume 10, Issue 9 , 2019 , Pages 2151-2155 ; 19487185 (ISSN) Lushchikova, O. V ; Huitema, D. M. M ; López Tarifa, P ; Visscher, L ; Jamshidi, Z ; Bakker, J. M ; Sharif University of Technology
    American Chemical Society  2019
    Abstract
    Coinage metal clusters are of great importance for a wide range of scientific fields, ranging from microscopy to catalysis. Despite their clear fundamental and technological importance, the experimental structural determination of copper clusters has attracted little attention. We fill this gap by elucidating the structure of cationic copper clusters through infrared (IR) photodissociation spectroscopy of Cu n + -Ar m complexes. Structures of Cu n + (n = 3-10) are unambiguously assigned based on the comparison of experimental IR spectra in the 70-280 cm -1 spectral range with spectra calculated using density functional theory. Whereas Cu 3 + and Cu 4 + are planar, starting from n = 5, Cu n +... 

    First principles study of oxygen adsorption on nickel-doped graphite

    , Article Molecular Physics ; Volume 110, Issue 13 , Feb , 2012 , Pages 1437-1445 ; 00268976 (ISSN) Nahali, M ; Gobal, F ; Sharif University of Technology
    2012
    Abstract
    Density functional theory is used in a spin-polarized plane wave pseudopotential implementation to investigate molecular oxygen adsorption and dissociation on graphite and nickel-doped graphite surfaces. Molecular oxygen physisorbs on graphite surface retaining its magnetic property. The calculated adsorption energy is consistent with the experimental value of 0.1eV. It is found that substituting a carbon atom of the graphite surface by a single doping nickel atom (2.8% content) makes the surface active for oxygen chemisorption. It is found that the molecular oxygen never adsorbs on doping nickel atom while it adsorbs and dissociates spontaneously into atomic oxygens on the carbon atoms... 

    Adsorption and dissociation of hydrogen peroxide on small Pd xM3-x (M = Pt, Cu; X = 1-3) clusters: A hybrid density functional study

    , Article Molecular Physics ; Volume 109, Issue 14 , May , 2011 , Pages 1797-1804 ; 00268976 (ISSN) Nahali, M ; Gobal, F ; Arab, R ; Sharif University of Technology
    2011
    Abstract
    The adsorption and dissociation of H2O2 on small PdxM3-x (M=Pt, Cu; x = 1-3) clusters is investigated using the B3PW91 hybrid density functional method. Natural bond orbitals are analysed to obtain partial charges on atoms, dipole moments, bond orders, and hybrid orbitals of the PdxM3-x-H2O2 systems. The calculated adsorption energies are in the range of -0.32 to -2.12 eV. Generally, H2O2 adsorbs on top positions through one of its oxygen atoms and only in a few cases reacts with the cluster through both oxygen and hydrogen sides. In the latter case the cluster sites which are negatively charged interact with the hydrogen atoms. Interestingly, on the triplet Pd2Pt cluster, H2O2 dissociates... 

    Multielectron dissociative ionization of methane and formaldehyde molecules with optimally tailored intense femtosecond laser pulses

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 185 , 2017 , Pages 298-303 ; 13861425 (ISSN) Irani, E ; Anvari, A ; Sadighi Bonabi, R ; Monfared, M ; Sharif University of Technology
    Abstract
    The multielectron dissociative ionization of CH4 and CH2O molecules has been investigated using optimum convolution of different dual tailored short laser pulses. Based on three dimensional molecular dynamics simulations and TDDFT approach, the dissociation probability is enhanced by designing the dual chirped-chirped laser pulses and chirped-ordinary laser pulses for formaldehyde molecule. However, it is interesting to notice that the sensitivity of enhanced dissociation probability into different tailored laser pulses is not significant for methane molecule. In this presented modifications, time variation of bond length, velocity, time dependent electron localization function and evolution...