Direct observation of intersystem crossing in benzene by laser photoelectron spectroscopy

Photoelectron spectroscopy of S1 toluene: II. Intramolecular dynamics of selected vibrational levels in S1 toluene studied by nanosecond and picosecond time-resolved photoelectron spectroscopies

“…In the course of studies of the excited states of small aromatic molecules attention is often paid to issues such as intramolecular vibrational energy redistribution ͑IVR͒, [1][2][3][4][5][6][7][8] intersystem crossing and internal conversion, [9][10][11][12][13][14] torsional motion of side groups, 6,[15][16][17] and conformation. 18 Toluene in its first excited electronic state, S 1 , has been the subject of a number of extensive studies, 1,6 and is known to undergo intersystem crossing out of v =0, 10,13 and both internal conversion and IVR at higher levels of vibrational excitation.…”

Time-delayed two-color photoelectron spectra of aniline, 2-aminopyridine, and 3-aminopyridine: Snapshots of the nonadiabatic curve crossings

“…[41][42][43][44][45][46] In particular, the recognition that molecules may be ionized out of states that are dark in absorption or emission has led to the development of time-resolved two-photon ionization schemes that are well suited to study radiationless transitions. [19][20][21][22][23][24][25][26][45][46][47][48][49][50] In its simplest form, the experiment observes the ion yield as a function of the delay time between two successive laser pulses that ionize the molecule. 21,45,46,49,50 Much more information is obtained if one records the photoelectron spectrum.…”

“…21,45,46,49,50 Much more information is obtained if one records the photoelectron spectrum. The time-delayed photoelectron technique has been successfully applied to study electronic curve crossings in pyrazine and benzene, 21,26 intramolecular vibrational relaxation ͑IVR͒ in the excited electronic state of aniline's alkyl derivatives, 25 and the internal conversion from S 2 to S 1 in naphthalene. 19 The time resolution of the technique is limited by the laser pulse durations, which in many cases was in the nanosecond range.…”

Resonant two photon ionization of phenanthrene via its transientS 2 state

“…A Franck-Condon analysis of photoelectron spectra obtained by ionizing a molecule from its ground state via a vibronic intermediate state selected by the laser frequency yields a relation between the potential energy surface of the intermediate electronic state and the final state of the ion: if one of them is known from separate studies, such as fluorescence emission, then the photoelectron spectrum characterizes the other electronic surface [1][2][3][4][5][6]. A particularly interesting twist of resonant two-photon ionization photoelectron spectroscopy is the possibility to introduce a time delay between the two photons [7][8][9]. In this mode the analysis of the time dependent Franck-Condon factors reveals the time evolution of the wavepacket in the intermediate resonance state.…”