# Structure‐Response Relationships in Rigid C 2‐Symmetric Excitonic Systems: Principles, Modulation, and Functional Design Strategies

## TL;DR

This review explains how the structure of rigid, symmetric molecules affects their chiroptical properties, offering design strategies for advanced materials.

## Contribution

The paper provides a structural blueprint for designing chiroptical materials using rigid C2-symmetric systems.

## Key findings

- Rigid C2-symmetric chromophores enable direct correlations between molecular geometry and chiroptical responses.
- Conformational locking and dipole orientation modulate exciton coupling and g-factor amplification.
- Design principles are transferable to supramolecular and polymeric systems for enhanced chiroptical effects.

## Abstract

Exciton coupling model provides one of the most intuitive and powerful frameworks to directly connect molecular structure with chiroptical responses. This review focuses on rigid architectures with C
2 symmetry, in which conformational rigidity, symmetry constraints, and independent chromophores allow for direct correlations among molecular geometry, Davydov splitting, and electronic circular dichroism intensity. After introducing the theoretical basis of exciton coupling and its crucial role in absolute configuration assignment, we analyze how molecular design strategies control the conformational space, as well as how the electron transition dipole moments of interacting chromophores enable the modulation of dissymmetry factors (g‐factors). Next, we expand these principles from isolated molecules to supramolecular assemblies, thin films, and polymers, where cooperative effects and new structural constraints can come into play to amplify or distort excitonic signatures. Overall, this review compiles transferable design principles to guide the development of next‐generation chiroptical materials with broad relevance for sensing, optoelectronic, and spintronic applications.

Rigid C
2‐symmetric chromophores reveal how transition dipole orientation, magnitude, and conformational locking govern exciton coupling and g‐factor amplification, providing a structural blueprint for the rational design of advanced chiroptical molecular and material architectures.© 2026 WILEY‐VCH GmbH