1689-82-3Relevant academic research and scientific papers
Stereoregular hybrid azobenzene-cyclosiloxanes with photoinduced reversible solid to liquid transition properties
Bakirov, Artem,Buzin, Mikhail,Cherkaev, Georgij,Migulin, Dmitry,Shchegolikhina, Olga,Vysochinskaya, Yulia
, (2021)
A new type of stereoregular hybrid azobenzene-organocyclosiloxane discrete molecular structures with photoactive azobenzene groups unidirectionally connected to rigid cyclosiloxane frames through alkyl spacers of different lengths were developed for the first time. The kinetics and thermodynamics of nondegradative reversible trans-cis photoisomerization processes of the synthesized azobenzene-cyclosiloxane conjugates investigated using UV/Vis spectroscopy, DSC and XRD methods showed dependency on their molecular structures. It has been observed that room temperature UV (365 nm) irradiation of the synthesized hybrids leads to photoliquefaction effect consisting of a photoinduced phase transition of crystal solids into liquids. The photoliquefaction process was observed and confirmed with DSC, XRD and POM methods. Backward solidification process was generated with visible light and by heating. The tetra-azobenzene substituted cyclosiloxane single molecule compounds described in this work can be regarded as promising candidates for the development of new hybrid smart materials with many potential high-tech applications.
Dual-Stimuli Responsive 2D Supramolecular Organic Framework for the Detection of Azoreductase Activity
Zhang, Hao,Liang, Feng,Yang, Ying-Wei
, p. 198 - 205 (2020)
A 2D supramolecular organic framework (SOF) based on synthetic macrocycles has been constructed in water by a self-assembly strategy. Two new organic monomers of this SOF, possessing viologen and azobenzene functional groups, form a stimuli-responsive host–guest system upon cooperatively binding with cucurbit[8]uril rings. The reversible formation and dissociation of 2D SOF can be realized by the isomerization of azobenzene under ultraviolet and visible light. The light-responsive property of the SOF is highly reversible and stable for up to four cycles. Moreover, azoreductase produced by Escherichia coli can reduce the N=N double bond of azobenzene entities, resulting in fluorescence recovery of the system. As an excellent and effective fluorescent probe, the SOF can detect azoreductase activity for real-time monitoring of the growth process of Escherichia coli. The dual-stimuli responsive 2D SOF is envisioned to drive the development of responsive devices with complex functions.
Rearrangement of azoxybenzocrowns into chromophoric hydroxyazobenzocrowns and the use of hydroxyazobenzocrowns for the synthesis of ionophoric biscrown compounds
Szarmach, Miros?aw,Wagner-Wysiecka, Ewa,Luboch, Elzbieta
, p. 10893 - 10905 (2013)
The Wallach rearrangement was used as a method for preparing p-hydroxyazobenzocrown ethers starting from different azoxybenzocrowns as substrates. Synthesis of a series of p-hydroxyazobenzocrowns under modified conditions and characterization of the obtained products are presented. o-Hydroxyazobenzocrowns were identified among the products of the photochemical rearrangement of azoxybenzocrowns. Novel biscrowns were synthesized from p-hydroxyazobenzocrown ethers. The synthesized host molecules, differing in the size of the macrocycles and in the substituents in the aromatic rings, have the same dioxymethylene linkers. They were used as potential sodium or potassium ionophores in classic and miniature (screen-printed) ion-selective electrodes. The properties (tautomerism, acid-base equilibrium) of newly prepared o-hydroxyazobenzocrown ethers and their p-substituted analogs were studied using spectroscopic methods and compared.
Preparation of photoirradiation molecular imprinting polymer for selective separation of branched cyclodextrins
Fan, Haoran,Wang, Jinpeng,Meng, Qingran,Xu, Xueming,Fan, Tianming,Jin, Zhengyu
, (2017)
In the present study, photoirradiation molecularly imprinted polymer (MIP) with azobenzene was used as a functional monomer for the selective separation of the branched cyclodextrins. The functional monomer 4-methacryloyloxy azobenzene (MAA) and the molecular template 6-O-α-D-maltosyl-β-cyclodextrin (G2-β-CD) were implemented for the molecular imprinting. The core-shell structure of photoirradiation MIP was visualized by the transmission electron microscopy (TEM). With Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), we identified that G2-β-CD was imprinted into the polymer and removed from the MIP. The binding association constant (Ka) and the maximum number of the binding site (Nmax ) were 1.72 × 104 M-1 and 7.93 μmol·g-1 MIP, respectively. With alternate irradiation at 365 and 440 nm light, the prepared MIP reversibly released and rebound to the G2-β-CD, which resulted in the nearly zero amount of G2-β-CD in the solution. The HPLC results indicated that the purity of G2-β-CD could reach 90.8% after going through MIP. The main finding of our study was that the photoirradiation of MIP was an easy and effective method for the selective separation of the branched cyclodextrins.
DNA/BSA binding studies of peripherally tetra substituted neutral azophenoxy zinc phthalocyanine
Amitha,Vasudevan, Suni
, (2020)
A tetra substituted neutral zinc phthalocyanine (ZnPc-4) bearing 4-phenylazophenoxy group at the periphery had been prepared from zinc acetate dihydrate Zn(CH3COO)2·2H2O and 4-(phenylazophenoxy)phthalonitrile. The interaction of neutral metallophthalocyanine, ZnPc-4 with Calf Thymus (CT) DNA was investigated using absorption titrations, competitive Fluorescent Intercalator Displacement (FID) assay, minor groove binding assay and viscosity measurement. The binding studies revealed a probable intercalative mode of interaction of ZnPc-4 with DNA with an appreciable binding constant. The bovine serum albumin (BSA) binding activity of ZnPc-4 was evaluated by fluorescence titration.
Fabrication of highly durable hydrophobic PBZ/SiO2 surfaces
Parveen, A. Shakila,Thirukumaran,Sarojadevi
, p. 43601 - 43610 (2015)
The structure of the synthesized precursors [4-phenyl(diazenyl)phenol (PAP)] & [N,N′-bis(4-aminophenyl)terephthalamide (APTA)] and benzoxazine monomer [bis(6-phenyl diazenyl-3,4-dihydro-2H-1,3-benzoxazinyl)terephthalamide (BZO-TA)] were confirmed by Fourier Transform Infrared (FT-IR) and Nuclear Magnetic Resonance (1H & 13C-NMR) spectroscopy. The miscibility and curing behaviour of the SiO2 nanoparticles with benzoxazine was examined by Differential Scanning Calorimetric (DSC) analysis. Polybenzoxazine-silica nano hybrids [PBZ:SiO2] with different weight ratios of SiO2 nanoparticles (1, 3 and 5 wt%) were prepared by a thermal curing method. Surface morphological studies from SEM (Scanning Electron Microscopy) and AFM (Atomic Force Microscopy) revealed that the PBZ:SiO2 hybrids with same compositions show hierarchically structured roughness. FT-IR was used to investigate the thermal-curing reactions and hydrogen bonding interactions in both polybenzoxazine and its hybrids. Contact angle analysis indicated that the hybrids have a hydrophobic nature and low wettability. The thermal and mechanical stabilities of the hybrids were studied using Thermogravimetric (TGA) and Dynamic Mechanical Analysis (DMA).
Nano-MnOx on activated carbon prepared by hydrothermal process for fast and highly efficient degradation of azo dyes
Xu, Lili,Li, Xingfa,Ma, Jianqing,Wen, Yuezhong,Liu, Weiping
, p. 91 - 98 (2014)
Azo dyes are recalcitrant and refractory pollutants that pose a threat to environmental safety. Therefore, it is of significance to develop fast, cheap and highly effective materials for removal of azo dyes in water. Herein, fast oxidative removal of azo dyes by highly active nano-MnOx on activated carbon prepared via hydrothermal process was explored. Active manganese oxide was supported on coconut shell activated carbon (CSAC) via hydrothermal method and was characterized. The hydrothermal treatment changed the morphology of the MnOx@CSAC and led to the in situ synthesis of nano-MnOx onto CSAC surfaces with the incorporation of the multi-valence oxidation states (Mn4+ and Mn3+) of manganese. The decolorization reactions by MnOx@CSAC were fast and the dye removal was most pronounced at pH 3 (99.1%). Through GC-MS analyses, the most detectable degradation products were identified and possible degradation pathway was proposed. Additionally, the MnOx@CSAC also could effectively degrade other anionic dyes. The oxidative degradation of C. I. Acid Red 73 was still strong after 20 usage cycles, with a maximum removal rate of 99.1% and a minimum removal rate of 89.7% from the same sample. Overall, these results indicate that highly active nano-MnOx@CSAC prepared via a hydrothermal method is very attractive, implying that this material has potential practical applications for treating azo dyeing effluent.
Synthesis, liquid crystal characterization and photo-switching studies on fluorine substituted azobenzene based esters
Gan,Yuvaraj,Lutfor,Mashitah,Gurumurthy, Hegde
, p. 6279 - 6285 (2015)
A series of fluorinated azobenzene esters have been synthesized and studied by polarized optical microscopy (POM) and UV-Vis spectrophotometry. The -CO2C2H5 group with monofluoro-substituted azobenzene exhibited nematic and smectic phases whereas difluoro-substituted azobenzene showed only the nematic phase. The addition of the electronegative fluorine atom plays an important role in photoisomerization of the azobenzene molecules. The monofluoro-substituted azobenzene gave strong photoisomerization in solution as compared with its diflouro counterparts. In these systems, trans-cis isomerization occurred after 4 minutes and cis-trans isomerization occurred after 22 hours which is much longer than expected for fluorine-substituted azobenzene systems. The presented results might have an influence on creating optical data storage devices.
Synthesis and photochemical properties of cationic cyclopentadienyliron containing arylazo chromophores
Li, Guang-Lei,Ye, Hui,Chen, Yu,Zhao, Bao-Dong,Wang, Tao
, p. 1516 - 1519 (2011)
Two kinds of cationic cyclopentadienyliron complexes containing arylazo chromophores (Azo-Fc) were synthesized through the nucleophilic aromatic substitution reactions of cyclopentadienyliron chlorobenzene complexes. The synthesized Azo-Fc was characterized by LC-MS, IR, and 1H NMR. The influence of substituents and the aryl ring on spectral data of the synthesized compounds is described. Unlike other cationic cyclopentadienyliron complexes, Azo-Fc hardly underwent photolysis and showed no photo-initiating abilities in the cationic polymerization under photo-irradiation; in addition, trans/cis isomerization by irradiation is possible at different wavelengths.
Synthesis of peripherally tetra substituted neutral azophenoxy zinc phthalocyanine and its application in bulk hetero junction solar cells
Amitha,Ameen, M. Yoosuf,Reddy, V. Sivaji,Vasudevan, Suni
, p. 425 - 431 (2019)
Neutral zinc phthalocyanine bearing 4-phenylazopohenoxy group at the periphery (ZnPc-4) has been synthesized from zinc acetate dihydrate Zn(CH3COO)2·2H2O and 4-(phenylazophenoxy)phthalonitrile. The synthesized zinc phthalocyanine ZnPc-4 was characterized using UV–visible, FTIR, 1H NMR and MALDI-TOF mass spectral measurements. Solution processed bulk hetero junction solar cells were fabricated using ZnPc-4 as the donor material and [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) as the acceptor material. A power conversion efficiency of 0.69% was achieved by optimizing the donor:acceptor weight ratio. Variation in device performance with the donor:acceptor weight ratio was investigated using atomic force microscopy.
