TY - JOUR
T1 - Ionization photophysics and Rydberg spectroscopy of diacetylene
AU - Schwell, Martin
AU - Bénilan, Yves
AU - Fray, Nicolas
AU - Gazeau, Marie Claire
AU - Es-sebbar, Et-touhami
AU - Gaie-Levrel, François
AU - Champion, Norbert
AU - Leach, Sydney Sydney
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2012/7/11
Y1 - 2012/7/11
N2 - Photoionization of diacetylene was studied using synchrotron radiation over the range 8-24 eV, with photoelectron-photoion coincidence (PEPICO) and threshold photoelectron-photoion coincidence (TPEPICO) techniques. Mass spectra, ion yields, total and partial ionization cross-sections were measured. The adiabatic ionization energy of diacetylene was determined as IE ad=(10.17±0.01) eV, and the appearance energy of the principal fragment ion C4H+ as AE=(16.15±0.03) eV. Calculated appearance energies of other fragment ions were used to infer aspects of dissociation pathways forming the weaker fragment ions C+ 4, C3H+, C+3 and C 4H+. Structured autoionization features observed in the PEPICO spectrum of diacetylene in the 11-13 eV region were assigned to vibrational components of three new Rydberg series, R1(nsσg, n=4-11), R2(ndσg, n=4-7) and R3(ndδg, n=4-6) converging to the A2Πu state of the cation, and to a new series R01(nsσg, n=3) converging to the B' 2Σ+u state of the cation. The autoionization mechanisms and their consistence with specific selection rules are discussed. © 2012 Taylor and Francis.
AB - Photoionization of diacetylene was studied using synchrotron radiation over the range 8-24 eV, with photoelectron-photoion coincidence (PEPICO) and threshold photoelectron-photoion coincidence (TPEPICO) techniques. Mass spectra, ion yields, total and partial ionization cross-sections were measured. The adiabatic ionization energy of diacetylene was determined as IE ad=(10.17±0.01) eV, and the appearance energy of the principal fragment ion C4H+ as AE=(16.15±0.03) eV. Calculated appearance energies of other fragment ions were used to infer aspects of dissociation pathways forming the weaker fragment ions C+ 4, C3H+, C+3 and C 4H+. Structured autoionization features observed in the PEPICO spectrum of diacetylene in the 11-13 eV region were assigned to vibrational components of three new Rydberg series, R1(nsσg, n=4-11), R2(ndσg, n=4-7) and R3(ndδg, n=4-6) converging to the A2Πu state of the cation, and to a new series R01(nsσg, n=3) converging to the B' 2Σ+u state of the cation. The autoionization mechanisms and their consistence with specific selection rules are discussed. © 2012 Taylor and Francis.
UR - http://hdl.handle.net/10754/565863
UR - https://www.tandfonline.com/doi/full/10.1080/00268976.2012.704084
UR - http://www.scopus.com/inward/record.url?scp=84872356278&partnerID=8YFLogxK
U2 - 10.1080/00268976.2012.704084
DO - 10.1080/00268976.2012.704084
M3 - Article
SN - 0026-8976
VL - 110
SP - 2843
EP - 2856
JO - Molecular Physics
JF - Molecular Physics
IS - 21-22
ER -