These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Mechanisms of the reactions of W and W+ with NOx (x=1, 2): a computational study.
    Author: Chen HT, Musaev DG, Irle S, Lin MC.
    Journal: J Phys Chem A; 2007 Feb 08; 111(5):982-91. PubMed ID: 17266241.
    Abstract:
    The mechanisms of the reactions of W and W+ with NOx (x=1, 2) were studied at the CCSD(T)/[SDD+6-311G(d)]//B3LYP/[SDD+6-31G(d)] level of theory. It was shown that the insertion pathway of the reaction W(7S)+NO2(2A1) is a multistate process, which involves several lower lying electronic states of numerous intermediates and transition states, and leads to oxidation, WO(3Sigma)+NO(2Pi), and/or nitration, WN(4Sigma)+O2(3Sigmag-), of the W-center. Oxidation products WO(3Sigma)+NO(2Pi) lie 87.6 kcal/mol below the reactants, while the nitration channel is only 31.0 kcal/mol exothermic. Furthermore, it was shown that nitration of W with NO2 is kinetically less favorable than its oxidation. The addition-dissociation pathway of the reaction W(7S)+NO2(2A1) proceeds via the octet (ground) state potential energy surface of the reaction, requires 3.3 kcal/mol barrier, and leads exclusively to oxidation products. Calculations show that oxidation of the W+ cation by NO2 is a barrierless process in the gas phase, proceeds exclusively via the insertion pathway, and is exothermic by 82.9 kcal/mol. The nitration of W+ by NO2 is only 14.1 kcal/mol exothermic and could be accessible only under high-temperature conditions. Reactions of M=W/W+ with NO are also barrierless processes in the gas phase and lead to the N-O insertion product NMO, which are 105.4 and 77.4 kcal/mol lower than the reactants for W and W+, respectively.
    [Abstract] [Full Text] [Related] [New Search]