Photofragmentations, state interactions, and energetics of Rydberg and ion-pair states: Two-dimensional resonance enhanced multiphoton ionization of HBr via singlet-, triplet-, Ω 0 and 2 states

Jingming Long, Helgi Rafn Hróðmarsson, Huasheng Wang, Ágúst Kvaran*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

Mass spectra were recorded for one-colour resonance enhanced multiphoton ionization (REMPI) of H iBr (i 79, 81) for the two-photon resonance excitation region 79 040-80 300 cm -1 to obtain two-dimensional REMPI data. The data were analysed in terms of rotational line positions, intensities, and line-widths. Quantitative analysis of the data relevant to near-resonance interactions between the F 1Δ 2(v′ 1) and V 1Σ -(v′ m 7) states gives interaction strengths, fractional state mixing, and parameters relevant to dissociation of the F state. Qualitative analysis further reveals the nature of state interactions between ion-pair states and the E 1Σ - (v′ 1) and H 1Σ -(v′ 0) Rydberg states in terms of relative strengths and J′ dependences. Large variety in line-widths, depending on electronic states and J′ quantum numbers, is indicative of number of different predissociation channels. The relationship between line-widths, line-shifts, and signal intensities reveals dissociation mechanisms involving ion-pair to Rydberg state interactions prior to direct or indirect predissociations of Rydberg states. Quantum interference effects are found to be important. Moreover, observed bromine atom (2 1) REMPI signals support the importance of Rydberg state predissociation channels. A band system, not previously observed in REMPI, was observed and assigned to the k 3Π 0(v′ 0) ←← X transition with band origin 80 038 cm -1 and rotational parameter Bv′=7.238 cm -1.

Original languageEnglish
Article number214315
JournalJournal of Chemical Physics
Volume136
Issue number21
DOIs
Publication statusPublished - 7 Jun 2012

Bibliographical note

Funding Information:
The financial support of the University Research Fund, University of Iceland, the Icelandic Science Foundation as well as the Norwegian Research Council is gratefully acknowledged.

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