Proton transfer with a twist? Femtosecond Dynamics of 7‐(2‐pyridyl)indole in Condensed Phase and in Supersonic Jets

Abstract

Twist-assisted proton transfer: Excited-state intramolecular proton transfer (ESIPT) in 7-(2-pyridyl)indole proceeds in a barrierless fashion and is coupled with mutual twisting of the pyridine and indole moieties. As a result, the reaction is slower in a condensed phase than in the supersonic jet-isolated molecule (1 ps vs. about 300 fs). Ultrafast radiationless deactivation of the phototautomer occurs via a conical intersection (CI).