CHIREXCO - Induced Chirality by Excitonic Coupling on Chiral Surfaces: A Multiscale Computational Approach
The main scientific objective of CHIREXCO (PEPR LUMA) led by local PI : D. Jacquemin, PI : T. Le Bahers Lyon, is the understanding, with theoretical tools, of the mechanism of the chiral induction from a large chiral inorganic structure towards a much smaller molecular self-assembled layer.
Project summary
The ChirExCo project aims to develop a multiscale modelling procedure to understand the origin of the chirality induction from chiral surface (such as a helical silica) to achiral adsorbed molecules.
The induction of chirality in achiral chromophores via adsorption on helical silica has been demonstrated experimentally by several groups and applied, for instance, in circularly polarized light emission. It has also been observed that the efficiency of this induction is related to the packing density of the adsorbed molecules. While the phenomenon is well documented, the underlying mechanism of this chirality induction is still unknown. Unravelling this mechanism at the atomistic level will open the way to a rational design of hybrid interfaces with many applications such as in circularly polarized light emission and enantioselective photochemistry.
The ChirExCo consortium identified three scientific questions to understand the chirality induction mechanism:
1- By which mechanism can a surface featuring a chiral structure and not photo-active on the scale of dozens of nanometers induce chirality in sub-nanometer molecules?
2- How do surface geometry and molecular packing density influence chiroptic responses?
3- To what extent does excitonic coupling contribute to the induced chiral properties?
The consortium decided to tackle these questions using a multiscale modelling approach based on molecular mechanics and quantum chemistry.
Project members
T. Le Bahers
ENS Lyon
Project leader
D. Jacquemin
CEISAM
WP leader
A. LAURENT
CEISAM
M. VACHER
CEISAM
External partners
T. Le Bahers
ENS Lyon
Project leader
A. Fihey
U. Rennes
M. Barbatti
Aix Marseille University