2050-16-0Relevant articles and documents
Shape memory polyurethanes containing azo exhibiting photoisomerization function
Zhang, Yaoming,Wang, Chao,Pei, Xianqiang,Wang, Qihua,Wang, Tingmei
, p. 9976 - 9981 (2010)
A series of azobenzene-containing polyurethanes (azoPU) was synthesized. The structure of the azoPU and the synthesis process were detected by FTIR and nuclear magnetic resonance (NMR), and the transition temperature was determined by differential scanning calorimetry (DSC). Tensile and cyclic thermomechanical experiment results revealed that excellent mechanical properties, shape fixity (Rf), and shape recovery (Rr) were obtained by the addition of azo to the chain of PU. Rr and Rf of azoPU increased with the increase of hard segment (HS) content. The higher HS content enhanced interaction among polymer chains as the chances of induced dipole-dipole interaction between aromatic rings increased in the presence of azo in the main chain. The materials presented trans-cis isomerization under UV irradiation in addition to the shape memory effect. The UV-vis spectrum indicated that photoisomerization occurred both in solution and solid state. It is expected that the work may be helpful in expanding the application of shape memory PU in areas of drug release and optical data storage.
Cyclodextrin-based ordered rotaxane-monolayers at gold surfaces
Sun, Ruyi,Zhu, Liangliang
, p. 73527 - 73533 (2016)
Decorating metal surfaces with well-defined architectures can be categorized as one of the currently interesting fields of nanomaterials and supramolecular chemistry, since the leading hybrid materials assembled in specific patterns exhibit unprecedented excellent properties which is different from their individual components and subunits. In this work a class of cyclodextrin based redox-active hemi-rotaxane structures were synthesized. After an investigation of their complexation properties in solution, the successful preparation of corresponding rotaxane monolayers with different orderliness on gold surfaces was demonstrated. Due to the complexation-to-deaggregation effect of the macrocyclic ring, construction of the monolayers with each unit encircled by one or two α-cyclodextrin rings has been accompanied with an increased orderliness at the surface. Such a system was suggested to be potentially useful as components for redox driven molecular electronics and optical controlling devices.
Functionalized azobenzene platinum(II) complexes as putative anticancer compounds
Samper, Katia G.,Lorenzo, Julia,Capdevila, Mercè,Palacios, òscar,Bayón, Pau
, p. 435 - 453 (2021)
The synthesis and characterization of four platinum(II) complexes using azobenzenes conveniently functionalized as ligands has been carried out. The characteristic photochemical behavior of the complexes due to the presence of azobenzene-type ligands and the role of the ligands in the activation of the complexes has been studied. Their promising cytotoxicity observed in HeLa cells prompted us to study the mechanism of action of these complexes as cytostatic agents. The interaction of the compounds with DNA, studied by circular dichroism, revealed a differential activity of the Pt(II) complexes upon irradiation. The intercalation abilities of the complexes as well as their reactivity with common proteins present in the blood stream allows to confirm some of the compounds obtained as good anticancer candidates.
Sequential self-assembly for construction of Pt(ii)-bridged [3]rotaxanes on gold nanoparticles
Zhu, Liangliang,Yan, Hong,Nguyen, Kim Truc,Tian, He,Zhao, Yanli
, p. 4290 - 4292 (2012)
An effective self-assembly route for construction of Pt(ii)-bridged [3]rotaxane functionalized gold nanoparticles was developed through a stepwise introduction of Pt(ii) coordination and gold-thiol binding in turn. The sequential self-assembly process can be quantitatively controlled and directly monitored by the naked eye. The Royal Society of Chemistry 2012.
Designing ternary Co-crystals with stacking interactions and weak hydrogen bonds. 4,4′-bis-hydroxyazobenzene
Chakraborty, Shaunak,Rajput, Lalit,Desiraju, Gautam R.
, p. 2571 - 2577 (2014)
Three ternary co-crystals of the title compound are reported. The design strategy hinges on the identification of a robust synthon with O-H...N hydrogen bonds in a binary co-crystal. Construction of this module allows the tuning of π...π stacking interactions and weak hydrogen bonds to incorporate the third component into the crystal structure. Screening of various co-formers showed that a delicate balance of electrostatics is required for stacking to favor the formation of ternaries. A C-H...N hydrogen-bonded motif was also found to occur repetitively in the ternary co-crystals. The directional nature of weak hydrogen bonds allows them to be used effectively in this study.
Reversible photo-responsive gel-sol transitions of robust organogels based on an azobenzene-containing main-chain liquid crystalline polymer
Wang, Jing,Jiang, Qian,Hao, Xingtian,Yan, Hongchao,Peng, Haiyan,Xiong, Bijin,Liao, Yonggui,Xie, Xiaolin
, p. 3726 - 3733 (2020)
Stimuli-responsive supramolecular gels have been widely investigated, but the construction of a liquid crystalline gel with a high mechanical property and reversible photo-response still remains a challenge. This is due to the difficulty of designing gelators with liquid crystal properties and gelation abilities in organic solvents simultaneously. In this study, an azobenzene-containing main-chain polyester (Azo-mLCP) with a pendant amide group was synthesized. The organogel of Azo-mLCP via a hydrogen bond in dioxane possessed reversible thermal- A nd photo-responsive behaviours. The organogel exhibited a good self-supporting ability when the concentration of the gelator was more than 7.5 wt%. The rapid trans-to-cis isomerization of Azo-mLCP in solution was studied via UV-Vis absorption spectra. In addition, the gel-to-sol transition of the organogel could be triggered efficiently by an incomplete trans-to-cis conversion strategy. This study opens a way for the main-chain liquid crystalline polymers to serve in potential applications in photo-responsive robust actuators, electro-optical devices, and so on.
Synthesis and characterization of azobenzene-functionalized hyperbranched polymers
Alam, Md. Zahangir,Ogata, Tomonari,Kuwahara, Yutaka,Kurihara, Seiji
, p. 25 - 31 (2010)
Azobenzene functionalized hyperbranched polymers (HBAzPs) have been synthesized by polycondensation of 4,4'-di((2-hydroxyethoxy)azobenzene and 1,3,5-benzenetricarboxylic acid chloride in presence of triethylamine at room temperature through A2+B3 polymerization approach. The structure and properties of HBAzPs were characterized by 1H NMR, IR, GPC, DSC and UV-Visible spectrometry. Molecular weights as well as properties of HBAzPs were found to be greatly influenced by molar ratio of monomers, amount of triethylamine and monomer concentration. HBAzP solutions in THF showed absorbances at 356nm and 450nm corresponding to -* and n-* electronic transitions of azobenzene chromophores, respectively. A reversible trans-cis photoisomerization of HBAzPs was observed upon irradiation of UV and visible light. Taylor & Francis Group, LLC.
Photocontrolled Reversible Conversion of Nanotube and Nanoparticle Mediated by β-Cyclodextrin Dimers
Sun, He-Lue,Chen, Yong,Zhao, Jin,Liu, Yu
, p. 9376 - 9380 (2015)
A photochemically interconvertible supramolecular nanotube-nanoparticle system was constructed through secondary assembling of self-aggregates of amphiphilic porphyrin derivatives mediated by trans- and cis-azobenzene-bridged bis(permethyl-β-cyclodextrin). Significantly, these nanotubes and nanoparticles were able to interconvert upon irradiation at different wavelengths, and this photocontrolled morphological conversion is reversible and recyclable for tens of times, which will provide a feasible and convenient way to construct the ordered nanostructure with various morphologies that can be smartly controlled by the environmentally benign external stimulus. Photodriven interconversion: A photoswitchable supramolecular nanotube-nanoparticle system was constructed through secondary assembly of self-aggregates of amphiphilic porphyrin derivatives (see picture). These nanoassemblies repeatedly interconvert upon irradiation at 365 and 450 nm.
Rational design of a photoswitchable DNA glue enabling high regulatory function and supramolecular chirality transfer
Crespi, Stefano,Dohno, Chikara,Feringa, Ben L.,Kobauri, Piermichele,Kobayashi, Shotaro,Nakatani, Kazuhiko,Simeth, Nadja A.,Szymanski, Wiktor
, p. 9207 - 9220 (2021)
Short, complementary DNA single strands with mismatched base pairs cannot undergo spontaneous formation of duplex DNA (dsDNA). Mismatch binding ligands (MBLs) can compensate this effect, inducing the formation of the double helix and thereby acting as a molecular glue. Here, we present the rational design of photoswitchable MBLs that allow for reversible dsDNA assembly by light. Careful choice of the azobenzene core structure results in excellent band separation of theEandZisomers of the involved chromophores. This effect allows for efficient use of light as an external control element for duplex DNA formation and for an in-depth study of the DNA-ligand interaction by UV-Vis, SPR, and CD spectroscopy, revealing a tight mutual interaction and complementarity between the photoswitchable ligand and the mismatched DNA. We also show that the configuration of the switch reversibly dictates the conformation of the DNA strands, while the dsDNA serves as a chiral clamp and translates its chiral information onto the ligand inducing a preference in helical chirality of theZisomer of the MBLs.
A novel poly(aryl ether) containing azobenzene chromophore and pendant oligoaniline: Synthesis and electrochromic properties
Chao, Danming,Zheng, Tian,Liu, Hongtao,Yang, Rui,Jia, Xiaoteng,Wang, Shutao,Berda, Erik B.,Wang, Ce
, p. 253 - 258 (2012)
A novel poly(aryl ether), containing pendant oligoaniline and azobenzene moieties (Azo-PAE-p-OA), was synthesized by nucleophilic polycondensation. The structures were confirmed spectroscopically via nuclear magnetic resonance (NMR) and Fourier-transform infrared spectra (FTIR), morphological data was ascertained via X-ray diffraction (XRD), and the thermal stability was probed via thermogravimetric analysis (TGA). Due to the coexistence of oligoaniline and azobenzene groups, Azo-PAE-p-OA shows reversible electroactivity and expectable photoresponse to light irradiation, chemical redox and electrochemical modulation. The electrochromic performance of a Azo-PAE-p-OA film on indium tin oxide (ITO) was investigated by spectrochronoamperometry, and exhibited electrochromic properties with high contrast value, good coloration efficiency, moderate switching times, and acceptable stability.
