The indole chromophore: Separation of the 1La and 1Lb components by a methyl substitution perturbation technique

The quantum chemical solvation of indole: accounting for strong solute–solvent interactions using implicit/explicit models

“…While characterisation of these states remains unchanged, we still observe the longitudinal state as the emitting state, with an oscillator strength of 0.065, much closer to the expected value of 0.05 reported by Britten and Lockwood. 65 Here again, energies are overestimated, with recorded absorption and emission energies of 4.91 eV and 4.29 eV respectively for the L a state. However, the L b state remains largely unchanged with respect to the results obtained using the PCM.…”

“…31 However, the oscillator strengths do not compare well with the literature. Britten and Lockwood 65 showed that the transverse state should have a smaller oscillator strength of 0.12, while the longitudinal state should have a larger oscillator strength of 0.05. Similar numbers of 0.13 and 0.02 for the L a and L b state were reported by Strickland and Billups.…”

Position matters: competing O–H and N–H photodissociation pathways in hydroxy- and methoxy-substituted indoles

“…9 Structurally, the bi-cyclic system indole is comprised L b state. 13 These findings were subsequently complemented by complete active space self consistent field (CASSCF) and complete active space with second order perturbation theory (CASPT2) ab initio calculations. [14][15][16] Recent combined rotationally resolved electronic spectroscopy and ab initio studies 17,18 assigned vibrational structure evident in the previously reported 1+1 resonance enhanced multiphoton ionisation (REMPI) excitation spectrum of indole 19,20 and deduced strong vibronic interaction between the 1 L b and 1 L a states.…”

External electric field effect on the lowest excited states of indole: ab initio and molecular dynamics study

“…The variation of the Trp fluorescence lifetime or of its indole chromophore has also been the subject of many investigations in both the condensed and gas phases. 1,[4][5][6][7][8][9][10][11][12][13][14][15][16] However, no clear picture emerges from these works that allows to understand why the fluorescence lifetime (or the fluorescence quantum yield) is varying by more than two orders of magnitude, depending on the environment. To account for this effect, the existence of very fast non-radiative decay channels that efficiently quench the fluorescence is anticipated.…”