PHYS 559 |
| We present high-resolution vibrational spectra of Br-HBr and Br-DBr entrance channel complexes isolated in solid parahydrogen at liquid helium temperatures. Weakly bound Br-HBr radical complexes are formed via co-deposition of Br2 and HBr in solid parahydrogen followed by 355 nm in situ photodissociation of Br2. Nearly complete photodissociation of the Br2 precursor is achieved and confirmed spectroscopically by observation of the Br atom spin-orbit transition. The sample is thermally annealed at 4.3 K to permit formation of the Br-HBr complexes. Infrared spectra reveal relatively large entrance channel complex induced shifts of the HBr and DBr vibrational frequencies (36.44 and 30.23 cm-1, respectively), quantitative 79Br/81Br isotopic splittings, and sharp transition linewidths (0.02-0.04 cm-1). These spectroscopic observations suggest the Br-HBr and Br-DBr complexes adopt hydrogen bonding geometries within the parahydrogen host consistent with the van der Waals minima predicted by recent fully relativistic calculations of the open-shell intermolecular potentials. |
|
PHYS Poster Session - Computational Spectroscopy and Reaction Dynamics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Division of Physical Chemistry |