Photodissociation dynamics of pyrimidine

Journal Article · Tue Feb 28 04:00:00 EST 2006 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.2174011· OSTI ID:20783236

Mingfu, Lin; Dyakov, Yuri A; Tseng, C -M; Mebel, Alexander M; Lin, S H; Lee, Yuan T; Ni, C -K ^[1]

---

1. Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan (China)

Photodissociation of pyrimidine at 193 and 248 nm was investigated separately using vacuum ultraviolet photoionization at 118.4 and 88.6 nm and multimass ion imaging techniques. Six dissociation channels were observed at 193 nm, including C{sub 4}N{sub 2}H{sub 4}{yields}C{sub 4}N{sub 2}H{sub 3}+H and five ring opening dissociation channels, C{sub 4}N{sub 2}H{sub 4}{yields}C{sub 3}NH{sub 3}+HCN, C{sub 4}N{sub 2}H{sub 4}{yields}2C{sub 2}NH{sub 2}, C{sub 4}N{sub 2}H{sub 4}{yields}CH{sub 3}N+C{sub 3}NH, C{sub 4}N{sub 2}H{sub 4}{yields}C{sub 4}NH{sub 2}+NH{sub 2}, and C{sub 4}N{sub 2}H{sub 4}{yields}CH{sub 2}N+C{sub 3}NH{sub 2}. Only the first four channels were observed at 248 nm. Photofragment translational energy distributions and dissociation rates indicate that dissociation occurs in the ground electronic state after internal conversion at both wavelengths. The dissociation rates were found to be >5x10{sup 7} and 1x10{sup 6} s{sup -1} at 193 and 248 nm, respectively. Comparison with the potential energies from ab initio calculations have been made.

• OSTI ID: 20783236
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 8 Vol. 124; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
DISSOCIATION
ENERGY SPECTRA
GROUND STATES
INTERNAL CONVERSION
PHOTOIONIZATION
PHOTOLYSIS
PHOTON-MOLECULE COLLISIONS
PYRIMIDINES
REACTION KINETICS
ULTRAVIOLET RADIATION