title: State-resolved distribution of OH X 2Pi products arising from electronic quenching of OH A 2Sigma+ by N2.
abstract: The nascent OH X (2)Pi product state distribution arising from collisional quenching of electronically excited OH A (2)Sigma(+) by N(2) has been determined using a pump-probe technique. The majority of OH X (2)Pi products are observed in their lowest vibrational level, v(")=0, with significantly less population in v(")=1. The OH (v(")=0) products are generated with a substantial degree of rotational excitation, peaking around N(")=18, with an average rotational energy of approximately 6500 cm(-1). A preference is found for the OH Pi(A(')) Lambda-doublet, indicating some degree of ppi orbital alignment. The branching fraction into OH X (2)Pi product states demonstrates that nonreactive quenching is the dominant decay pathway for quenching of OH A (2)Sigma(+) by N(2). The topography of the conical intersection region that couples the electronically excited and ground state potential energy surfaces is also examined theoretically. The rotational excitation of the OH X (2)Pi products and branching fraction are found to be dynamical signatures of nonadiabatic passage through the conical intersection region.
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.
authors.forename: Logan P
authors.initials: LP
authors.lastname: Dempsey
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Sechler
authors.forename: Craig
authors.initials: C
authors.lastname: Murray
authors.forename: Marsha I
authors.initials: MI
authors.lastname: Lester
authors.forename: Spiridoula
authors.initials: S
authors.lastname: Matsika