METHANOL CLUSTERS OF TRYPTOPHAN ANALOGUES BY PHOTOIONIZATION SPECTROSCOPY

The Department of Chemistry and The James Franck Institute University of Chicago, Chicago Illinois 60637Author Institution:Methanol clusters of two tryptophan analogues, tryptamine and 3-indole propionic acid have been studied in a supersonic molecular beam using resonantly enhaned one and two color photoionization spectroscopy. The two species exhibit spectral shifts upon complexation which differ both in magnitude and direction. The effect of the solvent molecule on the qualitative features of the two spectra is markedly diferent as well. The spectra of indole propionic acid and tryptamine exhibit more than one line in the origin region. These lines have been of the complexed indole propionic acid is similar to that of the parent species, in the tryptamine spectrum in single feature predominates. Some implications of these results for understanding intermolecular interactions within these two clusters will be discussed

HYDROGEN BONDED CLUSTERS OF TRYPTOPHAN AND RELATED COMPOUNDS

Author Institution: James Franck Institute, Univ, of ChicagoThe spectra of various hydrogen bonded clusters of the amino acid tryptophan and related molecules have been obtained using both fluorescence excitation and resonantly enhanced two photon ionization spectroscopies. In the jet cooled spectra of tryptophan, tryptamine, and indole propionic acid multiple distinct conformations of each of these molecules can be identified. In several cases, the preferred conformation of the molecule appears to be different in the cluster than in the isolated species. As a result, these clusters exhibit solvent, induced shifts which are anomalous when compared to those observed for the common chromophore indole. The effect of complexation on other properties of the electronic states of these molecules will be discussed as well