Steering Triplet–Triplet Annihilation Upconversion through Enantioselective Self-Assembly in a Supramolecular Gel

Abstract

Research on chiral selection and recognition not only is of fundamental importance in resolving the origin of biological homochirality, but also is instructive in the fabrication of controlled molecular organization in supramolecular systems to modulate their chirality-related functional properties. Here we report an enantioselective assembly process between a chiral energy donor and two enantiomeric energy acceptors, which further results in chirality-controlled energy transfer and enantioselective triplet− triplet annihilation upconversion (TTA-UC). It is found that the chiral energy donor Pd(II) octaethylporphyrin derivative PdOEP-LG12 (R D ) can selectively coassemble with the chiral energy acceptor LGAn (R A ) with the same chiral scaffold but tends to form segregation with the energy acceptor DGAn (S A ) with the opposite chiral scaffold in a thermodynamic equilibrium state. Thus, the coassembly of R A /R D shows more effective triplet−triplet energy transfer (TTET) and stronger upconverted luminescence and upconverted circularly polarized luminescence in comparison to the segregation of S A /R D . The establishment of such an enantioselective TTA-UC system highlights the applications of chirality-regulated triplet fusion in optoelectronic materials.

Light-Reconfiguring Inhomogeneous Soft Helical Pitch with Fatigue Resistance and Reversibility

“…However, it is still an insurmountable challenge to achieve the broadband and high-degree circularly polarized light through the conventional physical method due to the limitation of the wavelength dependence of the common quarter-wave plate. Hence, many chiral luminescent materials were developed for the broadband circularly polarized light, with the aim of overcoming the limitations of physical methods, − including chiral supramolecular assembly − and photon up-conversion, , enhancing the CPL intensity and g lum value. Nevertheless, the limitations of molecular structure and distortion of long-range order always result in a relatively low g lum value, currently in the range of 10 –2 –10 –1 , which is still far from the theoretical g lum value of 2 .…”

Triplet–triplet annihilation upconversion combined with afterglow phosphors for multi-dimensional anti-counterfeiting and encoding

“…In consequence, to develop solid-state TTA-UC with high efficiency and good processability has always been a research hotspot. 62 To pursue this aim, many types of soft matters, including organogel, hydrogel, microcapsule, nanoparticle and polymer film, were reported as solid-state TTA-UC carriers, [63][64][65] which exhibited solid form at macroscopic scale and kept liquid state at microscopic scale. Whereas, few research works have focused on the processability of solid-state TTA-UC.…”

Regulating the Helical Chirality of Racemic Polyacetylene by Chiral Polylactide for Realizing Full-Color and White Circularly Polarized Luminescence

“…Recently, circularly polarized luminescence (CPL) has attracted extensive attention, not only because it can reflect the excited chiral structure information of chiral compounds but also due to the significant potential applications in organic light-emitting diodes, information storage and encryption, chemical sensors, optical communication for spintronics, circularly polarized lasers, biological detection and probes, and so forth. − To date, numerous CPL-active materials have been elegantly developed from lanthanide complexes, organic small molecules, , polymers, − liquid crystals, ,− and self-assembly systems. − Among the CPL materials, synthetic helical polymer-based CPL materials are attracting more and more interest because of the merits of relatively high stability, good processability, and unique helical chirality of polymer backbones, which are more favorable to realize a high luminescence dissymmetry factor ( g lum ). − Also worthy to be highlighted is that dynamic helical polymers additionally offer opportunities and pathways to tune CPL properties. , In our earlier studies, we utilized chiral helical polyacetylenes to construct thin solid films and nanomaterials that show CPL emission with relatively high g lum values. ,,− We further conjecture that coupling chirality transfer among synthetic helical macromolecules and CPL generation in one entirety may provide a new methodology for preparing CPL-active materials, which may also afford significant insights into understanding hierarchical chirality transfer in complex and multifunctional structures.…”