Remotely Modulating\nthe Optical Properties of Organic\nCharge-Transfer Crystallites via Molecular Packing

Organic charge-transfer complex (CTC) formation has emerged\nas\nan effective molecular engineering strategy for achieving the desired\noptical properties via intermolecular interactions. By synthesizing\norganic CTCs with carbazole-based electron donors and a 7,7,8,8-tetracyanoquinodimethane\nacceptor and adopting a molecular linker located remotely from the\ncharge-transfer interface within the donors, we were able to modulate\nnear-infrared absorptive and short-wavelength infrared emissive properties.\nStructural characterizations performed by using single-crystal X-ray\ndiffraction confirmed that the unique molecular arrangements induced\nby the steric hindrance from the remotely located linker significantly\ninfluence the electronic interactions between the donor and acceptor\nmolecules, resulting in different photophysical properties. Our findings\noffer an improved understanding of the interplay between molecular\npacking and optoelectronic properties, providing a foundation for\ndesigning advanced materials for optoelectronic applications.