Rotationally resolved electronic S1 spectra of tryptoline and oxindole: Reversal of the 1La and 1Lb state character

Rotationally resolved S-1 <- S-0 fluorescence excitation spectra of the lowest electronic transitions (origin bands) of tryptoline (TRY) and oxindole (OXI) have been recorded and analyzed. A higher vibronic band of OXI has also been observed and assigned. The derived inertial parameters from the fits provide detailed information about their conformational or tautomeric structures in both the ground and excited electronic states. These molecules exhibit significantly different transition dipole moment orientations relative to the parent reference frame of indole that signify S-1 state characters having principal parentage in a L-1(a) state for OXI and a L-1(b) state for TRY. (C) 2021ElsevierB.V. Allrightsreserved.

Automated summary

The rotationally resolved S-1 <- S-0 fluorescence excitation spectra of tryptoline (TRY) and oxindole (OXI) were analyzed to provide detailed information about their conformational structures in both ground and excited electronic states. These molecules exhibit significantly different transition dipole moment orientations relative to the parent reference frame of indole.