Self-Assembly Tuning of α-Cyanostilbene Fluorogens: Aggregates to Nanostructures

Abstract

Two AIE active α-cyanostilbene fluorophores substituted with octyl and hexadecyl chains were synthesized and examined for their absorption and fluorescence properties. The alkoxy substitution tunes the self-assembly in water and exhibits an intensity enhanced bathochromic shift, resulting in well-defined nanospheres with the formation of nice dendrimeric structures. Monte Carlo simulations validate our experimental observations and show the greater propensity of self-assembly formation for cyanostilbene containing a hexadecyl chain compared to a derivative containing an octyl chain. The results are substantiated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and dynamic light scattering (DLS) studies. Such tunable self-assembled nanostructures seem promising for material and biological applications.

New white light-emitting halochromic stilbenes with remarkable quantum yields and aggregation-induced emission

“…Finally, the fluorescence was quenched by further increasing water fraction to 90%, indicative of aggregation-caused quenching (ACQ) for AADSB . The increase in the fluorescence of chromophore ASDSB (after addition of more than 70% water) and AADSB (up to 60% water portion in the solvents mixture) can be explained by the aggregate formation of the chromophores in poor solvents restricting the intermolecular rotations 61 , 62 . These results were representative of the AIE character in chromophore ASDSB and AADSB .…”

Emissive Platinum(II) Macrocycles as Tunable Cascade Energy Transfer Scaffolds

“…The higher enhancement in emission intensity and quantum yield upon aggregation in case of 3 b indicates the impact of alkyl chain length on the self-assembly process, where longer chain length promotes better aggregation. [17] To understand the morphologies of 3 a and 3 b in the aggregate state, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses were performed, which suggested the formation of spherical particles. On the other hand, dynamic light scattering (DLS) analysis revealed a narrow size distribution with the average hydrodynamic diameter of � 228 nm for the aggregates of 3 a in 90 % water-acetone (Figure 3).…”

Synthesis, photophysical and electropolymerization properties of thiophene-substituted 2,3-diphenylbuta-1,3-dienes

“…1,5 As such, the AIE effect has enabled to take advantage of the aggregation process and has triggered to new developments in an array of fields including bioimaging, [6][7][8][9] therapy, [10][11][12] chemosensing, [13][14][15][16] optoelectronics [17][18] and stimuli-responsive systems. [19][20][21][22][23] Due to this dynamic research, a wide variety of AIEgens has been developed such as tetraphenylethylene (TPE) [24][25][26] , silole 27,28 , quinoline malononitrile (QM) 29,30 , triarylamine [31][32][33][34] , cyanostilbene 35,36 or 9,10distyrylanthracene (DSA) 37,38 derivatives.…”