Bond Dissociation Energies of TiSi, ZrSi, HfSi, VSi, NbSi, and TaSi
Document Type
Article
Publication Date
8-22-2017
Publication Title
Journal of Chemical Physics
DOI
10.1063/1.4986213
ISSN
1089-7690
Abstract
Predissociation thresholds have been observed in the resonant two-photon ionization spectra of TiSi, ZrSi, HfSi, VSi, NbSi, and TaSi. It is argued that because of the high density of electronic states at the ground separated atom limit in these molecules, the predissociation threshold in each case corresponds to the thermochemical bond dissociation energy. The resulting bond dissociation energies are D0(TiSi) = 2.201(3) eV, D0(ZrSi) = 2.950(3) eV, D0(HfSi) = 2.871(3) eV, D0(VSi) = 2.234(3) eV, D0(NbSi) = 3.080(3) eV, and D0(TaSi) = 2.999(3) eV. The enthalpies of formation were also calculated as Δf,0KH°(TiSi(g)) = 705(19) kJ mol−1, Δf,0KH°(ZrSi(g)) = 770(12) kJ mol−1, Δf,0KH°(HfSi(g)) = 787(10) kJ mol−1, Δf,0KH°(VSi(g)) = 743(11) kJ mol−1, Δf,0KH°(NbSi(g)) = 879(11) kJ mol−1, and Δf,0KH°(TaSi(g)) = 938(8) kJ mol−1. Using thermochemical cycles, ionization energies of IE(TiSi) = 6.49(17) eV and IE(VSi) = 6.61(15) eV and bond dissociation energies of the ZrSi− and NbSi− anions, D0(Zr–Si−) ≤ 3.149(15) eV, D0(Zr−–Si) ≤ 4.108(20) eV, D0(Nb–Si−) ≤ 3.525(31) eV, and D0(Nb−–Si) ≤ 4.017(39) eV, have also been obtained. Calculations on the possible low-lying electronic states of each species are also reported.
Recommended Citation
Sevy, Andrew, Jason J. Sorensen, Thomas D. Persinger, Jordan A. Franchina, Eric L. Johnson, Michael D. Morse.
2017.
"Bond Dissociation Energies of TiSi, ZrSi, HfSi, VSi, NbSi, and TaSi."
Journal of Chemical Physics, 147 (8): AIP Publishig.
doi: 10.1063/1.4986213 source: https://aip.scitation.org/doi/10.1063/1.4986213
https://digitalcommons.georgiasouthern.edu/chem-facpubs/94
