Stoichiometric and Chiral Stacking Tailoring of Dibenzocarbazole Analog–TCNB Charge‐Transfer Cocrystals via Supramolecular Assembly for Variable Optical Behaviors

Abstract

In this paper, three new donor–acceptor complex forms (zBC) containing a helical‐shape dibenzocarbazole analog (DBCz) as the electron donor and 1,2,4,5‐tetracyanobenzene (TCNB) as the electron acceptor via a simple solution‐processing strategy are reported. The beginning components self‐assembled into supramolecular frameworks with glamorous alignment modes and different molar ratios: ≈1:1 P or M‐enantiomer for α‐cocrystal, alternated P/M‐column stacking in mesmeric 2:3 β‐cocrystal, and segregated stacking of γ‐cocrystal. As a result, α‐cocrystal exhibits bright solid‐state red fluorescent, β‐cocrystal shows significant optical waveguide behavior with a low optical loss coefficient of ≈0.018 dB µm−1, and no visual light emission is observed for γ‐cocrystal under ultraviolet radiation. Interestingly, the α‐zBC crystal is not only emissive but also chiroptically active with dissymmetry factor (glum) of 0.004. This study on chiral stacking tailoring paves a way for functional design of organic charge‐transfer complex toward application in high‐performance organic optoelectronics.

Customizable Organic Charge-Transfer Cocrystals for the Dual-Mode Optoelectronics in the NIR (II) Window

“…For the photodetectors, the detectivity at 1064 nm can reach 1.76 × 10 14 Jone, which is comparable to some NIR photodetector properties (Figure a). ,,,− In addition, rod-shaped cocrystals can be fabricated as optical waveguide devices to realize a low optical-loss coefficient of 0.0097 dB/μm at 950 nm. This excellent optical performance is comparable to the previous studies in both the visible and NIR regions, showing superior photon transmission characteristics, which contributes to the highly promising applications in the field of photonics information technology (Figure b). ,,− …”

Synthesis and photophysical properties of charge transfer cocrystals based on TCNB and fluorene and its derivatives

“…Furthermore, TCNB exhibits high structural stability and low reactivity towards most donors, rendering it widely utilized in the preparation and investigation of organic luminescent cocrystals. 33–35 From a structural perspective, TCNB is a planar molecule, while FR and its derivatives are polycyclic aromatic hydrocarbons containing two benzene rings. The structural compatibility between TCNB and donor molecules promotes the formation of charge transfer cocrystals.…”