| Abstrakt: |
The B(1/2 2P3/2)→X(1/2 2Σ+) transition in XeBr is recorded at high resolution, using a CCD array detector to record spectra from Tesla discharge sources containing isotopically pure 136Xe with 81Br2 or 79Br2. The high signal/noise capabilities of the detector permit the measurement of discrete vibrational structure in this system, which has normally been treated as a purely bound–free transition. The assignments comprise 119 υ′–υ″ bands for 136Xe81Br and 86 for 136Xe79Br, spanning υ′=0–33 and υ″=0–16. The van der Waals ground state is analyzed through fits to the customary polynomials in (υ+1/2) and to near-dissociation expansions. Franck–Condon calculations are used to locate the X-state potential on the internuclear axis relative to the B state, which is modeled as a Rittner potential. The following fundamental spectroscopic constants (units cm-1, for 136Xe81Br) are obtained from the analysis: Te′=35 863.2, ωe′=135.72, ωexe′=0.32, ωe″=25.7, ωexe″=0.62. The ground state has a dissociation energy De″=254±2 cm-1 and supports 24 bound vibrational levels. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
