Discriminating Chiral Supramolecular Motions by Circularly Polarized Luminescence

Abstract

Molecular motions are closely associated with the behaviors and properties of organic materials. However, monitoring molecular motions is challenging. Herein, a chiral supramolecular system consisting of L-/D-phenylalanine (LPF/ DPF) as a chiral inducer and an achiral tetraphenylethene derivative (TPEF) as a molecular rotor has been proposed and explored for real-time discriminating the supramolecular motions by the visualization of circularly polarized luminescence (CPL) signal variations. Derived from the ordered molecular motions of TPEF induced by LPF/DPF, highly organized aggregates have been progressively assembled in a controlled manner with differentiated morphologies, including spherical particles, one-dimensional fibers, and floor-shaped supercrystals. Notably, increasing level of ordered aggregates, in turn, led to quenching emissions, while the CPL signals have been dramatically amplified accompanying by a sharp enhancement of luminescence dissymmetry factors (g lum ) from nearly 0 to À 0.1. The significant amplification of CPL is attributed to the ordered aggregates of supramolecules, leading to the decrease of electric transition dipole moments in supramolecular system. As a result of the chiral supramolecular motions powered by supramolecular crystallization, the supramolecular motions are conveniently discriminated by visual CPL signal variation with an enhancement of g lum value from 0 to À 0.1 in real time.

Probing the chirality and optical activity of organic molecules through the anisotropic photoluminescence of porous silicon

“…11,12 This technology can be used to study the migration rate of molecules as well as the interactions and energy transfers between molecular crystals [13][14][15] and chiral optical activity. [16][17][18][19][20][21] In the static FA measurement method, vertically polarized light is used to excite a sample and generate PL. The ratio of PL in the horizontal and vertical polarization states is measured to calculate the FA value, that is, the degree of polarization.…”

Highly Efficient Wavelength‐Tunable Circularly Polarized Luminescence Film Constructed by Responsive Chiral Aggregation‐induced Emission Luminophore

“…Circularly polarized luminescence (CPL) has gained enormous interest due to its charming properties for reflecting chiral information in excited states, [1][2][3] showing promising application prospects in chiral optoelectronics, 3D optical displays, information security encryption et al [4][5][6][7][8][9][10][11][12][13] Organic CPL materials with inherent benefits including structural regulation, easy availability, and high quantum efficiency show limitless possibilities in the optical application. [14][15][16][17][18] Aggregation-induced emission (AIE) compounds with high luminescence quantum yield (Φ F's ) in the solid state are superior to typical organic compounds for preparing CPL materials, which can produce effective photoluminescence without aggregation-caused quenching (ACQ) during the assembly process. [19][20][21] Especially, AIE-active molecule is employed for supramolecular self-assembly, which can dramatically increase the luminescence asymmetry factor (g lum ) of the CPL materials.…”