Color‐Tunable Circularly Polarized Luminescence with Helical Polyacetylenes as Fluorescence Converters

Abstract

parameter for judging the material performance, [30] in which the maximum |g lum | value is 2 when absolutely left-handed or right-handed CPL emission is generated. Nevertheless, the |g lum | values of most reported CPL-active materials are mainly located between 10 −5 and 10 −2 , which are far from our expectation and cannot satisfy the demands for future applications. On the other hand, it is well-acknowledged that multicolor emissions especially RGB colors are important in display technology. Therefore, in consideration of the demands in practical applications, constructing CPL-active materials with both color-tunable emissions and high g lum values is of great significance. In the previous study, we have reported that chiral polyacetylenes with helical structures are good candidates for constructing CPL-active materials with high g lum values up to 10 −1. [31] Subsequently, we found that chiral helical polyacetylenes could serve as handedness-selective fluorescence filters to powerfully transform unpolarized fluorescent light into CPL emission. [32] Following this strategy, full-color and white-color CPL-active materials were easily constructed by combining chiral helical polyacetylenes with achiral fluorescence dyes. [32,33] Based on the above investigations, the relationship between helical structures and light shows unique charm and deserves more attention. The importance of such direction is more clearly demonstrated when considering the widespread helical structures and circularly polarized light in nature and living organisms. [34-38] In this contribution, we report our success in fabricating color-tunable CPL emissions by taking helical polyacetylenes as fluorescence converters. When blue-color circularly polarized light passes through the helical polyacetylenes with different conjugated lengths, multicolor CPL emissions of cyan, green, and orange are obtained, with high g lum values in the range of 10 −2-10 −1. It should be pointed out that, in spite of some publications concerning multicolor CPL materials reported by our group and others, [32,33,39-42] the multicolor CPLs therein are mainly realized from various fluorescent substances with different emission wavelength. In the present study, however, color-tunable CPL emissions are conveniently achieved from a single fluorescence substance, merely by tuning the conjugated length of helical polyacetylenes with commercial organic solvents. In particular notably, neither any covalent nor noncovalent interaction is required during the CPL color-tuning process, demonstrating the universality and superiority of the strategy established in the present work. Circularly polarized luminescence (CPL) materials are currently drawing rapidly increasing interest. However, constructing color-tunable CPL materials is still a big challenge, primarily due to the lack of simple, powerful, and universal preparation strategies. In this contribution, color-tunable CPL emissions are easily realized by taking helical polyacetylenes as fluorescence converters. The investigat...

Frontiers in circularly polarized luminescence: molecular design, self-assembly, nanomaterials, and applications

“…[ [164][165][166] and Ma et al [167] have further demonstrated the "Matching Rule" is potentially applicable to numerous chiral matters and achiral fluorophores, clearly confirming the wide universality and superiority of the strategy. Although striking advancements have been and are being achieved continuously, the development of polymer-based CPL materials is still at the infant state.…”

Modulation of Chirality and Intensity of Circularly Polarized Luminescence Emitting from Cholesteric Liquid Crystals Triggered by Photoresponsive Molecular Motor

“…To avoid the limitation, emerging advanced materials presenting high performance CPL have been put forward including chiral lanthanide complexes, [10] small organic molecules and chiral polymers. [11][12][13][14] The g lum value in most research is in the range of 10 -3 -10 -1 , which is so far from the practical application. [2] Cholesteric liquid crystals (CLC), as one kind of spontaneous supramolecular self-assembly system, can be obtained upon doping chiral dopants into nematic liquid crystal (LC) host and is often regarded as 1D photonic crystal.…”

“…The novel chiral motor MM was judiciously designed with the functional modification of an ethylene glycol spacer on the rotor and synthesis details were shown in Scheme S3 (Supporting Information). The chemical structure of the molecule was comprehensively confirmed by 1 H and 13 C NMR spectroscopies (SI). Our previous studies have proved that the rigid substituent on rotor of the MM resulted in the decrease of the chirality and long half-life time.…”

Circularly Polarized Luminescence from Chiral p‐Terphenylene‐Based Supramolecular Aggregates

“…Generally, luminescence dissymmetry factor (g lum = 2(I L -I R )/(I L + I R ), I L and I R are the intensity of the left-and right-handed CPL emissions, respectively) and luminescence quantum yield (QY) are two important parameters to evaluate the level of CPL property. [1,5] So far, sustained efforts have been devoted to new structures and strategies towards CPL-active materials, e.g., chiral luminescent lanthanide and transition-metal complexes, [6] conjugated polymers, [7] small organic molecules, etc., [8] have been exploited. However, one of the greatest challenges on the path toward the practical applications of these CPL-active materials is the dilemma in possessing large g lum and high QY simultaneously.…”