Photoinduced dynamics in protonated aromatic amino acid

TL;DR

This review discusses recent advances in understanding the photoinduced fragmentation and excited state dynamics of protonated aromatic amino acids, especially tryptophan, combining spectroscopy, ultrafast dynamics, and ab initio calculations.

Contribution

It provides a comprehensive synthesis of experimental and theoretical studies elucidating the electronic states and fragmentation mechanisms of protonated aromatic amino acids.

Findings

Spectroscopic studies reveal detailed excited state behaviors.

Ultrafast dynamics clarify femtosecond to nanosecond processes.

Calculations support the interpretation of fragmentation pathways.

Abstract

UV photoinduced fragmentation of protonated aromatics amino acids have emerged the last few years, coming from a situation where nothing was known to what we think a good understanding of the optical properties. We will mainly focus this review on the tryptophan case. Three groups have mostly done spectroscopic studies and one has mainly been involved in dynamics studies of the excited states in the femtosecond/picosecond range and also in the fragmentation kinetics from nanosecond to millisecond. All these data, along with high level ab initio calculations, have shed light on the role of the different electronic states of the protonated molecules upon the fragmentation mechanisms.