Excited state reaction dynamics of Ti(a5FJ)+O2→TiO(A,B)+O studied by a crossed-beam technique.

Oxidation reactions of the gas-phase titanium atom in its excited state with oxygen molecule, Ti(a⁵F_J)+O₂→TiO(A³[uppercase_phi_synonym],B³Π)+O, were studied by a crossed-beam technique. Metastable excited Ti, Ti(a⁵F_J), was generated by an optical pumping method and the reaction products were detected by the chemiluminescence spectroscopy. The chemiluminescence from TiO(A³[uppercase_phi_synonym],B³Π) was analyzed to determine vib-rotational state distributions of both excited states and their branching ratio. The vib-rotational state distribution of TiO(B) was represented by the statistical energy disposal and the branching ratio of TiO(A)/TiO(B) was also consistent with the statistical expectation. These results suggested the presence of long-lived intermediates in the course of the reactions of the excited Ti(a⁵F_J) atom with O₂. Also observed was the significant deviation of the vibrational state distribution of TiO(A) from the statistical one and another reaction pathway which may not proceed via the long-lived intermediates was implied. [ABSTRACT FROM AUTHOR]