Photodissociation of aryl halides in the gas phase studied with femtosecond pump-probe spectroscopy

Multireference calculations of the phosphorescence and photodissociation of chlorobenzene

“…1,2 The properties of their excited states have also received attention in both experimental [3][4][5][6] and theoretical [7][8][9][10] studies.…”

“…Experimentally, the photodissociation dynamics of ClBz has been studied at 266 nm by femtosecond pump-probe spectroscopy 5 and crossed laser-molecular-beam technique. 15 Experiments have also been published for excitations by an excimer laser at 248 ͑Ref.…”

“…The photodissociation at 266 nm has been given alternative explanations. On one hand, it was proposed to be due to a hot molecule mechanism by Wang et al 15 On the other hand, Kadi et al 5 assigned it to the decay of an initially excited ͑ , *͒ state to a repulsive triplet (n, *) state due to spin-orbit coupling, and they observed its time constant to be 1 ns. 5 The experimental explanation of the photodissociation channels of ClBz must thus, in many ways, still be regarded as tentative.…”

“…On one hand, it was proposed to be due to a hot molecule mechanism by Wang et al 15 On the other hand, Kadi et al 5 assigned it to the decay of an initially excited ͑ , *͒ state to a repulsive triplet (n, *) state due to spin-orbit coupling, and they observed its time constant to be 1 ns. 5 The experimental explanation of the photodissociation channels of ClBz must thus, in many ways, still be regarded as tentative. For example, we still do not know if the first channel at 193 nm is due to direct dissociation or fast predissociation, or which specific states contribute to the photodissociation at the longer wavelengths.…”

Dynamics of Br(2Pj) Formation in the Photodissociation of Bromobenzene

“…6,[11][12][13][14][15][16][17][18][19] By far-UV excitation, aryl halides are excited to the lowest singlet state (π,π*), which is delocalized on the benzene ring, and X atoms are produced via predissociation to the triplet (n,σ*) localized on the C-X bond. 16,20 The dynamics of the predissociation depend on the coupling strength between these electronic states, which is influenced by the type of halogen, 13 the substituents on the benzene ring, [21][22][23][24] and the excitation wavelength. In particular, the photodissociation dynamics of bromobenzene has been investigated using photofragment translational spectroscopy, photofragment ion-imaging, and femtosecond spectroscopy.…”