scholarly journals Solvent- and Light-Sensitive AIEE-Active Azo Dye: From Spherical to 1D and 2D Assemblies

2022 ◽  
Vol 23 (2) ◽  
pp. 965
Author(s):  
Mina Han ◽  
Ikue Abe ◽  
Jihun Oh ◽  
Jaehoon Jung ◽  
Young Ji Son ◽  
...  

Fluorescent molecular assembly systems provide an exciting platform for creating stimuli-responsive nano- and microstructured materials with optical, electronic, and sensing functions. To understand the relationship between (i) the plausible molecular structures preferentially adopted depending on the solvent polarity (such as N,N-dimethylformamide [DMF], tetrahydrofuran [THF], and toluene), (ii) the resulting spectroscopic features, and (iii) self-assembled nano-, micro-, and macrostructures, we chose a sterically crowded triangular azo dye (3Bu) composed of a polar molecular core and three peripheral biphenyl wings. The chromophore changed the solution color from yellow to pink-red depending on the solvent polarity. In a yellow DMF solution, a considerable amount of the twisted azo form could be kept stable with the help of favorable intermolecular interactions with the solvent molecules. By varying the concentration of the DMF solution, the morphology of self-assembled structures was transformed from nanoparticles to micrometer-sized one-dimensional (1D) structures such as sticks and fibers. In a pink-red toluene solution, the periphery of the central ring became more planar. The resulting significant amount of the keto-hydrazone tautomer grew into micro- and millimeter-sized 1D structures. Interestingly, when THF-H2O (1:1) mixtures were stored at a low temperature, elongated fibers were stacked sideways and eventually developed into anisotropic two-dimensional (2D) sheets. Notably, subsequent exposure of visible-light-irradiated sphere samples to solvent vapor resulted in reversible fluorescence off↔on switching accompanied by morphological restoration. These findings suggest that rational selection of organic dyes, solvents, and light is important for developing reusable fluorescent materials.

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940038
Author(s):  
Gyounglyul Jo ◽  
Solip Choi ◽  
Jae Won Jeong ◽  
Gyun Taek Lim ◽  
Jaehan Jung ◽  
...  

A facile solution treatment strategy for controlling the microstructure of conjugated polymers using a non-solvent vapor is introduced. The content of well-ordered poly(3-hexylthiophene) (P3HT) aggregates in solution was precisely controlled by varying the non-solvent vapor exposure time. P3HT chains were self-assembled upon exposure to the non-solvent vapor to minimize the unfavorable interactions with the non-solvent molecules. The effect of solvent vapor on the molecular ordering and morphologies of P3HT films was investigated by UV-Vis spectroscopy, atomic force microscopy, and polarized optical microscopy. These studies reveal that the self-assembled P3HT aggregates have well-ordered nanofibrillar structures formed via [Formula: see text]–[Formula: see text] stacking. This strategy paves the way toward fabricating well-ordered polymeric structures, especially in the field of opto-electronic applications including FETs, LEDs, and lasers, where proper alignment or molecular assembly is in great demand.


1995 ◽  
Vol 60 (9) ◽  
pp. 1448-1456 ◽  
Author(s):  
Ivo Šafařík ◽  
Miroslava Šafaříková ◽  
Vlasta Buřičová

Magnetic composite based on poly(oxy-2,6-dimethyl-1,4-phenylene) (PODMP) was prepared by melting the polymer with ε-caprolactam in a presence of fine magnetite particles. Magnetic PODMP was used for sorption of water soluble organic compounds (dyes belonging to triphenylmethane, heteropolycyclic and azo dye groups) from water solutions. There were considerable differences in the binding of the dyes tested. In general, heteropolycyclic dyes exhibited the lowest sorption.


2021 ◽  
Author(s):  
Santanu Panja ◽  
Dave J. Adams

Stimuli responsive dynamic changes in the networks of self-assembled gels result in an alteration of physical and chemical properties of the gel with time.


2021 ◽  
Vol 22 (11) ◽  
pp. 5740
Author(s):  
Ramón Cervera-Procas ◽  
José-Luis Serrano ◽  
Ana Omenat

Highly functional macromolecules with a well-defined architecture are the key to designing efficient and smart materials, and these polymeric systems can be tailored for specific applications in a diverse range of fields. Herein, the formation of a new liquid crystalline polymeric network based on the crosslinking of dendrimeric entities by the CuI-catalyzed variant of the Huisgen 1,3-dipolar cycloaddition of azides and alkynes to afford 1,2,3-triazoles is reported. The polymeric material obtained in this way is easy to process and exhibits a variety of properties, which include mesomorphism, viscoelastic behavior, and thermal contraction. The porous microstructure of the polymer network determines its capability to absorb solvent molecules and to encapsulate small molecules, like organic dyes, which can be released easily afterwards. Moreover, all these properties may be easily tuned by modifying the chemical structure of the constituent dendrimers, which makes this system a very interesting one for a number of applications.


Nano Today ◽  
2021 ◽  
Vol 38 ◽  
pp. 101119
Author(s):  
Masoud Delfi ◽  
Rossella Sartorius ◽  
Milad Ashrafizadeh ◽  
Esmaeel Sharifi ◽  
Yapei Zhang ◽  
...  

ACS Nano ◽  
2015 ◽  
Vol 9 (6) ◽  
pp. 5741-5749 ◽  
Author(s):  
Stanislav Fillipov ◽  
Yuttapoom Puttisong ◽  
Yuqing Huang ◽  
Irina A. Buyanova ◽  
Suwaree Suraprapapich ◽  
...  

2009 ◽  
Vol 65 (3) ◽  
pp. m139-m142 ◽  
Author(s):  
Rajesh Koner ◽  
Israel Goldberg

The title compound, (5,10,15,20-tetra-4-pyridylporphyrinato)zinc(II) 1,2-dichlorobenzene disolvate, [Zn(C40H24N8)]·2C6H4Cl2, contains a clathrate-type structure. It is composed of two-dimensional square-grid coordination networks of the self-assembled porphyrin moiety, which are stacked one on top of the other in a parallel manner. The interporphyrin cavities of the overlapping networks combine into channel voids accommodated by the dichlorobenzene solvent. Molecules of the porphyrin complex are located on crystallographic inversion centres. The observed two-dimensional assembly mode of the porphyrin units represents a supramolecular isomer of the unique three-dimensional coordination frameworks of the same porphyrin building block observed earlier. The significance of this study lies in the discovery of an additional supramolecular isomer of the rarely observed structures of metalloporphyrins self-assembled directly into extended coordination polymers without the use of external ligand or metal ion auxiliaries.


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