Photo-controlled chirality transfer and FRET effects based on pseudo[3]rotaxane

Abstract

A photochromic pseudo[3]rotaxane exhibited chirality transfer and FRET abilities was constructed. The transferred chiral signals could be controlled by UV light and heating, which will provide deep insight into developing chiral advanced materials.

Controllable Circularly Polarized Electroluminescence Performance Improved by the Dihedral Angle of Chiral-Bridged Binaphthyl-Type Dopant Inducers

“…Interestingly, regular arrangement fibers were observed only in the blended films (F8BT + 15% S -1 or 5% S -6 ) after thermal annealing (Figure S12). We think that these two inducers S -1 and S -6 with small dihedral angles (θ = 50.01 and 52.38°) show a highly rigid conformation, which can promote intermolecular π–π stacking interactions and benefit chirality induction on F8BT . Taking the blended films (F8BT + 5% S -6 ) as an example, we further observed the alignment texture for these blend films under a cross-polarized optical microscope (POM).…”

“…We think that these two inducers S-1 and S-6 with small dihedral angles (θ = 50.01 and 52.38°) show a highly rigid conformation, which can promote intermolecular π−π stacking interactions and benefit chirality induction on F8BT. 36 Taking the blended films (F8BT + 5% S-6) as an example, we further observed the alignment texture for these blend films under a cross-polarized optical microscope (POM). These blended films show remarkable difference from their textures and colors by thermal annealing (Figure S13), demonstrating that thermal annealing treatment can not only lead to the arrangement transfer of helical fibers from isotropic into anisotropic but also the enhanced chirality induction mechanism.…”

The endeavor of vibration-induced emission (VIE) for dynamic emissions

“…1a, the dual bands of an individual uorophore can generally be divided into small (normal) and large (abnormal) Stokes-shied emissions. [11][12][13] The overlap of the normal short-wavelength emission with the lowest-lying absorption band originates from the initial emissive state near the Franck-Condon excited state, while the red-shied emission far from the absorption band arises from the structurally transformed emissive state formed by additional excited-state transformations, such as enhanced charge transfer, [14][15][16][17][18][19] energy transfer, [20][21][22][23][24][25] complex formation, [26][27][28][29][30][31] and structural and/or conformational changes. Due to the signicant congurational and/or structural changes in the excited state, the ratio of short-and long-wavelength bands can be manipulated in a controllable and dynamic manner, activating unprecedented multi-colour luminescence.…”

“…Due to the signicant congurational and/or structural changes in the excited state, the ratio of short-and long-wavelength bands can be manipulated in a controllable and dynamic manner, activating unprecedented multi-colour luminescence. 9,[56][57][58][59][60][61] Regarding the specic p-conjugated structures and luminescent mechanisms, scientists have made notable achievements with intriguing systems and concepts, such as the excimer/exciplex, [26][27][28]30,31 uorescence resonance energy transfer (FRET), [20][21][22][23][24][25] twisted intramolecular charge transfer (TICT), [48][49][50][51][52][53][54][55] and excited-state intramolecular proton transfer (ESIPT). [36][37][38][39][40][41][42] Most of the mechanisms originate from the accidental discovery of a specic uorescence phenomenon, [62][63][64][65][66][67][68][69][70][71][72][73]...…”

Optimization of FRET Behavior in Photoswitchable [2]Rotaxanes Containing Bifluorophoric Naphthalimide Donor and Merocyanine Acceptor with Sensor Approaches toward Sulfite Detection

“…Mechanically interlocked molecules (MIMs) as a sort of interesting supramolecular architectures have been exquisitely designed, prepared, investigated, and reported, which not only possess highly ordered and complicated structures with an abundance of multicomponent supermolecules but also perform appealing physical and chemical responsive properties in a large range of various application fields. − As one of the most crucial kinds of MIMs, rotaxanes have become one of the popular issues in supramolecular chemistry due to their enticing and unique structures with the feasibility for further extensive functionality, in which a macrocyclic wheel molecule is interlocked onto an axle molecule through mechanical linkages by two bulky end groups as two stoppers at both sides of the axle chain to restrain the dissociation of the macrocyclic ring. − In particular, rotaxanes are often composed of two or more distinct binding sites on the axle component, and the macrocyclic molecule can shuttle freely and reversibly along the axle chain between these binding stations under the consequence of diverse external stimuli (such as light, acid–base, solvent, temperature, redox process, and chemical signal), leading to rigorous changes in the molecular structures. Interestingly, the reversible shuttling movements of the constituent parts in rotaxanes can obviously change the electrical or photophysical properties based on their drastic structural change of the molecules. − To additionally investigate the potential applications of rotaxanes as functional materials, the integration of varied functional groups into the inherent structures of rotaxanes can induce the achievements of specific and functional rotaxanes by the increasing structural complexities of molecular structures, in many cases, so the correlating properties can be altered controllably and reversibly. − Moreover, it is desirable to establish more sophisticated and functional molecules that reveal a variety of intercomponent interactions, e.g., energy-transfer, electron-transfer, charge-transfer interactions, etc., arising in the rotaxane structures, and the distinguished states of rotaxane shuttles can be observed by recognizable output signals, such as UV–vis absorption, fluorescence emission, cyclic voltammetry, circular dichroism, and so on. − …”