Mutually exclusive hole and electron transfer coupling in cross stacked acenes

Area of Science:

• Materials Science
• Theoretical Chemistry
• Organic Electronics

Background:

• Frontier molecular orbital (FMO) topology strongly influences charge transfer coupling.
• Achieving consistent optoelectronic properties across different monomers based on aggregate architecture is rare.

Purpose of the Study:

• To investigate the charge transfer properties of stacked acene systems in a Greek cross (+) orientation.
• To understand how molecular arrangement affects hole and electron transfer couplings.
• To explore the potential for designing advanced optoelectronic materials.

Main Methods:

• Theoretical investigation of stacked dimeric systems of linear and non-linear acenes.
• Analysis of frontier molecular orbital (HOMO/LUMO) overlaps in specific orientations.
• Application of semiclassical Marcus theory to evaluate charge transport.

Main Results:

• The Greek cross (+) stacked orientation exhibits mutually exclusive hole and electron transfer couplings.
• This selectivity arises from zero inter-orbital overlap between gerade symmetry HOMOs or LUMOs.
• (4n+2) and 4n π-electronic systems show distinct selective charge transfer behaviors.
• Orthogonal acene stacks lead to negligible exciton coupling and null exciton splitting.

Conclusions:

• The Greek cross (+) orientation offers a design principle for selective charge carrier mobility in acene-based materials.
• Precise angular control of chromophores can lead to emergent optoelectronic properties.
• This study provides insights for the rational design of novel optoelectronic materials.