Controlled ultrafast ππ*-πσ* dynamics in tryptophan-based peptides with tailored micro-environment

Area of Science:

• Physical Chemistry
• Molecular Dynamics
• Spectroscopy

Background:

• Ultrafast molecular dynamics are governed by potential energy surfaces and environmental interactions.
• Understanding microscopic dynamics is challenging due to complex interactions.
• Controlling molecular processes requires precise manipulation of their environment.

Purpose of the Study:

• To investigate ultrafast photo-induced ππ*-πσ* dynamics in isolated tryptophan ions.
• To explore the influence of a controlled micro-environment on molecular dynamics.
• To determine how charged adducts affect charge and energy transfer timescales.

Main Methods:

• Utilized electrospray and mass spectrometry to generate isolated molecular ions.
• Introduced a single, charged adduct to tryptophan ions.
• Measured ultrafast photo-induced dynamics using advanced spectroscopic techniques.

Main Results:

• Observed a significant increase (over one order of magnitude) in dynamics timescale.
• Demonstrated that changing the adduct atom drastically alters the timescale.
• Proposed a model explaining adduct effects on electronic structure and dynamics.

Conclusions:

• The molecular micro-environment can be engineered to control ultrafast dynamics.
• Localized and delocalized electronic effects of adducts are key to controlling timescales.
• Angström-scale design of the micro-environment offers new avenues for controlling molecular processes.