### Abstract

Photodissociation of (C_{6}H_{6})_{2}
^{+} is studied with photon energies between 1.29 and 2.81 eV. Massselected ion beam of (C_{6}H_{6})_{2}
^{+} is photodissociated by a pulsed laser beam in the field-free region of a reflectron-type time-of-flight mass spectrometer. The average relative translational energy, 〈ε_{t}〉, and the angular distributions of the photofragments (C_{6}H_{6}
^{+} and C_{6}H _{6}) are measured as a function of photon energy. With a photon energy of 2.81 eV, the (C_{6}H_{6})_{2}
^{+} ions are promoted to a bound upper state correlated to C_{6}H_{6}
^{+}(ππ) + C_{6}H_{6}(X). Only a small fraction (≈3%) of the available energy is partitioned into the translational energy of the fragments and the product angular distribution is isotropic. Absorption of a photon in the range of 1.29-2.14 eV induces a charge resonance transition to a repulsive upper state which correlates to C_{6}H_{6}
^{+}(X) + C_{6}H_{6}(X). The observed values for 〈ε_{t}〉 are at most 10% of the available energy, although the statistical phase space calculation shows that the complete randomization of the available energy is not achieved. As the photoexcited (C _{6}H_{6})_{2}
^{+} moves apart on the dissociative potential surface, ≈90% of the available energy flows into the intramolecular modes of the fragments. The energy partitioning becomes almost statistical regardless of the photoexcitation to a dissociative state.

Original language | English |
---|---|

Pages (from-to) | 390-398 |

Number of pages | 9 |

Journal | The Journal of Chemical Physics |

Volume | 98 |

Issue number | 1 |

DOIs | |

Publication status | Published - Jan 1 1993 |

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### All Science Journal Classification (ASJC) codes

- Physics and Astronomy(all)
- Physical and Theoretical Chemistry

### Cite this

_{6}H

_{6})

_{2}

^{+}

*The Journal of Chemical Physics*,

*98*(1), 390-398. https://doi.org/10.1063/1.464632

**Photodissociation dynamics of (C _{6}H_{6})_{2}
^{+}
.** / Ohashi, Kazuhiko; Nishi, Nobuyuki.

Research output: Contribution to journal › Article

_{6}H

_{6})

_{2}

^{+}',

*The Journal of Chemical Physics*, vol. 98, no. 1, pp. 390-398. https://doi.org/10.1063/1.464632

_{6}H

_{6})

_{2}

^{+}The Journal of Chemical Physics. 1993 Jan 1;98(1):390-398. https://doi.org/10.1063/1.464632

}

TY - JOUR

T1 - Photodissociation dynamics of (C6H6)2 +

AU - Ohashi, Kazuhiko

AU - Nishi, Nobuyuki

PY - 1993/1/1

Y1 - 1993/1/1

N2 - Photodissociation of (C6H6)2 + is studied with photon energies between 1.29 and 2.81 eV. Massselected ion beam of (C6H6)2 + is photodissociated by a pulsed laser beam in the field-free region of a reflectron-type time-of-flight mass spectrometer. The average relative translational energy, 〈εt〉, and the angular distributions of the photofragments (C6H6 + and C6H 6) are measured as a function of photon energy. With a photon energy of 2.81 eV, the (C6H6)2 + ions are promoted to a bound upper state correlated to C6H6 +(ππ) + C6H6(X). Only a small fraction (≈3%) of the available energy is partitioned into the translational energy of the fragments and the product angular distribution is isotropic. Absorption of a photon in the range of 1.29-2.14 eV induces a charge resonance transition to a repulsive upper state which correlates to C6H6 +(X) + C6H6(X). The observed values for 〈εt〉 are at most 10% of the available energy, although the statistical phase space calculation shows that the complete randomization of the available energy is not achieved. As the photoexcited (C 6H6)2 + moves apart on the dissociative potential surface, ≈90% of the available energy flows into the intramolecular modes of the fragments. The energy partitioning becomes almost statistical regardless of the photoexcitation to a dissociative state.

AB - Photodissociation of (C6H6)2 + is studied with photon energies between 1.29 and 2.81 eV. Massselected ion beam of (C6H6)2 + is photodissociated by a pulsed laser beam in the field-free region of a reflectron-type time-of-flight mass spectrometer. The average relative translational energy, 〈εt〉, and the angular distributions of the photofragments (C6H6 + and C6H 6) are measured as a function of photon energy. With a photon energy of 2.81 eV, the (C6H6)2 + ions are promoted to a bound upper state correlated to C6H6 +(ππ) + C6H6(X). Only a small fraction (≈3%) of the available energy is partitioned into the translational energy of the fragments and the product angular distribution is isotropic. Absorption of a photon in the range of 1.29-2.14 eV induces a charge resonance transition to a repulsive upper state which correlates to C6H6 +(X) + C6H6(X). The observed values for 〈εt〉 are at most 10% of the available energy, although the statistical phase space calculation shows that the complete randomization of the available energy is not achieved. As the photoexcited (C 6H6)2 + moves apart on the dissociative potential surface, ≈90% of the available energy flows into the intramolecular modes of the fragments. The energy partitioning becomes almost statistical regardless of the photoexcitation to a dissociative state.

UR - http://www.scopus.com/inward/record.url?scp=0000428402&partnerID=8YFLogxK

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U2 - 10.1063/1.464632

DO - 10.1063/1.464632

M3 - Article

AN - SCOPUS:0000428402

VL - 98

SP - 390

EP - 398

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 1

ER -