Triplet state solvation dynamics: extending the accessible timescale by using indole as local probe

Area of Science:

• Physical Chemistry
• Chemical Physics
• Materials Science

Background:

• Triplet state solvation dynamics (TSD) is a localized measurement technique using dye probes in solvents.
• TSD has been applied to study glassy dynamics and confinement effects.
• Existing TSD probes have limitations in timescale coverage.

Purpose of the Study:

• To identify and characterize new TSD probes: indole and cbz-tryptophan.
• To extend the accessible timescale for mechanical and dielectric solvation measurements.
• To enable in-depth investigations of solvation dynamics in biological systems.

Main Methods:

• Characterization of indole and cbz-tryptophan as TSD probes.
• Measurement of phosphorescence lifetimes to determine timescale extension.
• Analysis of solvation response functions.

Main Results:

• Indole and cbz-tryptophan were successfully identified and characterized as TSD probes.
• Their longer phosphorescence lifetimes significantly extend the measurement timescale.
• A combined measurement window of up to five orders of magnitude in time is achievable.
• The indole unit in cbz-tryptophan acts as the primary phosphorescence center.

Conclusions:

• Indole and cbz-tryptophan are valuable new probes for TSD measurements.
• These probes enhance the ability to study solvation dynamics over extended timescales.
• Future research can leverage these probes for biological applications.