Work

Interplay of Orbital Overlap and Exciton Coupling in the Optical Properties of Adamantylethynyl‐Substituted Pyrene Molecular Crystals

Year: 2026

Type: article

Abstract: Molecular crystals of apolar π-conjugated hydrocarbons exhibit pronounced solution-to-crystal spectral shifts, yet the interplay between band formation and exciton coupling remains unclear. Adamantylethynyl-pyrene derivatives were designed to adopt unidirectional crystal packing, providing a model system to disentangle these effects. Large redshifts of up to -203 meV are observed, which cannot be explained by exciton coupling alone but require a substantial contribution from band dispersion, identified here as a narrowing of frontier crystal orbital energy levels. The remaining discrepancies between experiment and the full-coherence limit correspond to coherence lengths of four to seven molecules, consistent with literature values. These results provide a basis for interpreting more complex organic crystalline materials and highlight the need for a more comprehensive understanding of the photophysical properties of molecular crystals.

Source: Chemistry - A European Journal

DOI: 10.1002/chem.70949

Authors: Benedikt Herbert, Kazutaka Shoyama

Institution: University of Würzburg

Language: English

Topic: Photochemistry and Electron Transfer Studies

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,640

Funder: Deutsche Forschungsgemeinschaft