Laser studies of pyridylindoles in supersonic jets

One- and two-photon spectroscopy has been used to study jet-cooled 2-(2'-py ridyl)indole (Pyln-0) and 3,3'-dimethylene2-(2'-pyridyl)indole (PyIn-2). Th e laser-induced fluorescence and resonance-enhanced photoionisation spectra of PyIn-2 are congested due to the flexibility of the ethylene chain. Sing le vibronic level fluorescence spectra allow identification of equivalent m odes in the ground and electronically excited states. Deuteration at nitrog en reveals a 4 cm(-1) red shift of the origin. Ab initio calculations were conducted at the TD B3LYP/6-31G(d,p) level of theory. We were able to repro duce the energies of pure electronic transitions both in PyIn-0 and PyIn-2. The properties of pyridylindoles in supersonic jets are compared with thos e for indole and 2-phenylindole. (C) 1999 Elsevier Science B.V. All rights reserved.