15min:

KANA TAKEMATSU, NATHAN EDDINGSAAS AND MITCHIO OKUMURA, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125; JOHN STANTON, Department of Chemistry, University of Texas at Austin, Austin, TX 78712.

Despite its simplicity and atmospheric significance, the lowest electronic states of NO₃ remain poorly understood. The A²E'' state is Jahn-Teller (JT) active and is pseudo-JT coupled to the ground X²A₂' and excited B²E'' states. While the band origin 0⁰₀ of the A X transition is purely electric forbidden, the cavity ringdown spectrum of the vibronically-allowed A X bands has shown rotationally-resolvable structures. We have detected the magnetic dipole-allowed origin ( 7060 cm^-1) via CRD spectroscopy. Analysis of the band contour along with its implications of the JT/Pseudo-JT couplings in the dark A state of NO₃ will be discussed.