Rotationally resolved S1 ← S0 fluorescence excitation experiments have been performed on a solute-solvent complex of indole and water in a molecular beam. The results show that the complex whose S1 ← S0 origin is shifted by 132 cm-1 below the bare molecule origin is a 1:1 complex, with the water molecule linked to the indole frame via a quasi-linear N-H⋯OH2 σ hydrogen bond. The results also show that both the position and the orientation of the attached water molecule change when the photon is absorbed. The properties of the intermolecular potential-energy surfaces that govern these motions in both electronic states are derived from an analysis of the high-resolution spectrum.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry