Work

Bridge rigidity affects the source and magnitude of line broadening in covalently linked squaraine dimers

Year: 2025

Type: article

Abstract: Covalently linked squaraine dimers exhibit characteristic collective excitonic effects based on their packing geometries, which can be controlled by a bridge linking two monomers. A previous study showed that the bridge moiety strongly impacted the excitonic line broadening. Here, we use ultrabroadband two-dimensional electronic spectroscopy to quantify the homogeneous and inhomogeneous line-broadening components. Both rigid and flexible bridges reduce homogeneous broadening relative to the monomer, but the flexible bridge increased inhomogeneous broadening and thereby masked the exchange-narrowing effect. These results reveal that one can design a bridge structure of covalently linked dimers to control both line broadening and packing geometry. • Proposed uses of molecular aggregates are light harvesting & quantum information. • Squaraine dimers exhibit desirable collective excitonic effects. • Rigid (flexible) bridge leads to homogeneous (disordered) sample. • 2D spectroscopy can reveal exchange narrowing even in disordered samples. • All dimers exhibit exchange narrowing, even in presence of disorder.

Source: Chemical Physics Letters

DOI: 10.1016/j.cplett.2025.142516

Authors: Joohyun Lee, Jeunghoon Lee, William B. Knowlton, Ryan D. Pensack, Daniel B. Turner

Institution: Boise State University

Language: English

Topic: Spectroscopy and Quantum Chemical Studies

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,270