Enhanced Circularly Polarized Luminescence in Emissive Charge‐Transfer Complexes

Abstract

Achieving a large dissymmetry factor (glum) is a challenge in the field of circularly polarized luminescence (CPL). A chiral charge‐transfer (CT) system consisting of chiral electron donor and achiral electron acceptor shows bright circularly polarized emission with large glum value. The chiral emissive CT complexes could be fabricated through various approaches, such as grinding, crystallization, spin coating, and gelatinization, by simply blending chiral donor and achiral acceptor. The structural synergy originating from π–π stacking and strong CT interactions resulted in the long‐range ordered self‐assembly, enabling the formation of supramolecular gels. Benefiting from the large magnetic dipole transition moment in the CT state, the CPL activity of CT complexes exhibited large circular polarization. Our design strategy of the chiral emissive CT complexes is expected to help the development of new molecular engineering strategies for designing highly efficient CPL‐active materials.

Boosting Circularly Polarized Luminescence of Organic Conjugated Systems via Twisted Intramolecular Charge Transfer

“…The dynamic rotational movements of o-carborane moieties may lead to a small jμj value and enhance the corresponding jmj value, arising an enhancement of the g lum value [41]. This is why o-1 manifests a larger g lum than that of o-2 in crystalline states [42]. Moreover, the choice of 3,3′-and 6,6′-substituted o-carborane in o-1 and o-2 can regulate their arrangement of dipoles in the crystalline and even resolve their electronic spin directions upon photoexcited states, which have a direct correction with their chirality organizations, as shown in Figure 1(d).…”

Chirality induction to achiral molecules by silica‐coated chiral molecular assemblies

“…Chiral ions or ionic molecules are attractive owing to their asymmetric catalytic activity, 1–4 enantioselectivity, 5 or their chiroptical properties 6,7 . Chiral co‐crystallization, 8 chiral molecular assemblies, 9–15 or confinement of achiral ions in chiral cyclodextrins 16 can be used to induce chiroptical properties to achiral ions or molecules and/or enhancing chiral signals with promising advantages such as (1) tunability of the chiral properties, (2) versatility of choices of chromophores (molecules, ions particles, etc. ), and (3) transparency of solutions in the UV–vis region due to the nanometric size of the assemblies.…”

Fast Crystallization-Deposition of Orderly Molecule Level Heterojunction Thin Films Showing Tunable Up-Conversion and Ultrahigh Photoelectric Response

“… 17 To achieve large circular polarization, Duan and co-workers demonstrated a chiral charge-transfer (CT) cocrystal system with chiral electron donor and acceptor by various approaches. 5 By crafting a periodic molecular barrier into cocrystal matrices, Zhang and co-workers provided a new approach to preventing the formation of dark triplet states in organic semiconductors. 2 Additionally, we also illustrated that the construction of D–A cocrystal materials can provide an energy transfer route to accelerate the generation of triplet states for long-lived room-temperature phosphorescence.…”