MURAL - Maynooth University Research Archive Library



    Vacuum Ultraviolet Spectroscopy and Photochemistry of Zinc Dihydride and Related Molecules in Low-Temperature Matrices


    Henchy, Chris and Gilmartin, Una and McCaffrey, John G. (2013) Vacuum Ultraviolet Spectroscopy and Photochemistry of Zinc Dihydride and Related Molecules in Low-Temperature Matrices. Journal of Physical Chemistry A, 117 (38). pp. 9168-9178. ISSN 1089-5639

    [img]
    Preview
    Download (479kB) | Preview


    Share your research

    Twitter Facebook LinkedIn GooglePlus Email more...



    Add this article to your Mendeley library


    Abstract

    Optical absorption spectra of thin film samples, formed by the codeposition of zinc vapor with D2 and CH4, have been recorded with synchrotron radiation. With sufficiently low metal vapor flux, samples deposited at 4 K were found to consist exclusively of isolated zinc atoms for both solids. The atomic absorption bands in the quantum solids D2 and CH4 were found to exhibit large bandwidths, behavior related to the high lattice frequencies of these low mass solids. The reactivity of atomic zinc was promoted with (1)P state photolysis leading to the first recording of electronic absorption spectra for the molecules ZnD2 and CH3ZnH in the vacuum ultraviolet (VUV) region. (3)P state luminescence of atomic zinc observed in the Zn/CH4 system points to the involvement of the spin triplet state in the relaxation of CH3ZnH system as it evolves into the C3v ground state. This state is not involved in the relaxation of the higher symmetry molecule ZnD2. Time dependent density functional theory (TD-DFT) calculations were conducted to predict the electronic transitions of the inserted molecular species. Comparisons with experimental data indicate the predicted transition energies are approximately 0.5 eV less than the recorded values. Possible reasons for the discrepancy are discussed. The molecular photochemistry of ZnD2 and CH3ZnH observed in the VUV was modeled successfully with a simple four-valence electron AH2 Walsh-type diagram.

    Item Type: Article
    Keywords: Vacuum Ultraviolet Spectroscopy; Photochemistry; Zinc Dihydride; Low-Temperature Matrices;
    Academic Unit: Faculty of Science and Engineering > Chemistry
    Item ID: 7764
    Identification Number: https://doi.org/10.1021/jp404695a
    Depositing User: Dr. John McCaffrey
    Date Deposited: 16 Jan 2017 17:01
    Journal or Publication Title: Journal of Physical Chemistry A
    Publisher: American Chemical Society
    Refereed: Yes
    URI:

    Repository Staff Only(login required)

    View Item Item control page

    Downloads

    Downloads per month over past year