Intermolecular electronic excitation transfer in a confined space: a first-principles study

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Computational Chemistry

Background:

• Intermolecular electronic excitation transfer (EET) is crucial for energy transport in molecular systems.
• Confined molecular arrangements, like wires within zeolites, offer unique platforms for studying EET.
• Understanding EET mechanisms in such systems requires detailed theoretical investigation.

Purpose of the Study:

• To model and investigate intermolecular electronic excitation transfer (EET) in a monodimensional supramolecular arrangement.
• To explore EET dynamics in a chlorine molecule wire confined within the channels of zeolite bikitaite.
• To elucidate the microscopic details of excitation energy transfer at the molecular level.

Main Methods:

• First-principles molecular dynamics simulations were employed to model the system.
• The time evolution of the system in its first excited singlet state was described using the restricted open-shell Kohn-Sham formalism.
• Analysis focused on the electronic structure modifications induced by EET.

Main Results:

• Excitation energy, initially localized on a guest chlorine molecule, was observed to transfer to an adjacent molecule.
• This transfer occurred on the picosecond timescale, characteristic of a Dexter-type short-range EET mechanism.
• The process was identified as collision-induced, highlighting dynamic interactions within the confined space.

Conclusions:

• The study successfully modeled and investigated intermolecular EET in a confined supramolecular system.
• Dexter-type EET is the dominant mechanism for excitation transfer in this chlorine-zeolite model.
• The findings provide valuable insight into the microscopic dynamics of energy transfer in tailored molecular architectures.