Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MO: Molekülphysik
MO 5: Photodissoziation I
MO 5.2: Vortrag
Dienstag, 17. März 1998, 14:15–14:30, M629
Double Resonance Overtone Photofragment Spectroscopy of trans-HONO — •Rainer Beck1, Thomas R. Rizzo1, Florian Reiche2, and Bernd Abel2 — 1Laboratoire Chimie Physique Moleculaire, EPFL-Lausanne, Switzerland — 2Institut f"ur Physikalische Chemie, Universit"at G"ottingen, Germany
Double resonance overtone photofragment spectroscopy (DROPS) has been used to study the previously unobserved vOH = 5,6, and 7 overtones of gas phase trans-nitrous acid in its electronic ground state. Double resonance excitation via individual rovibrational states of vOH =1 or 2 is used to selectively populate single ro- vibrational states belonging to the vOH = 5, 6, or 7 overtones of the O-H local mode vibration. Absorption into quasibound states above the dissociation limit is detected through laser induced fluoresence of the OH fragment. Observing dissociation from different rovibrational states of the vOH = 5 band near thre- shold determines precisely the HO-NO bond energy to be D0 16784.6 +- 1.9 cm−1. We also report band orgins and spectroscopic constants as well as homogeneous linewidths for vOH = 5,6, and 7 of trans-HONO. The results of the study on HONO demonstrate that DROPS is a powerful technique to study vibrational overtone transitions and to measure precise bond energies of molecules even if these are only minority species in a mixture.