201858-51-7Relevant articles and documents
Dual-responsive ALS-type organogelators based on azobenzene-cholesteryl conjugates and their self-assemblies
Kuo, Sheng-Yang,Liu, Chun-Yen,Balamurugan, Rathinam,Zhang, Yan-Song,Fitriyani, Sri,Liu, Jui Hsiang
, p. 15555 - 15563 (2017)
Two structurally isomeric azobenzene- and cholesteryl-based derivatives with varying alkyl chain lengths were developed as ALS-type gelators (N2 and N4) and synthesized and characterized spectroscopically. Of the two, N4 acted as a more efficient gelator than N2 since N4 could gel a larger number of solvents. The critical gelation concentration (CGC) of N4 was found to be less than that of N2 in the same solvent system. The morphological analyses of both gelators using SEM and TEM revealed that N4 exhibited self-assembled fibrous structures, whereas N2 exhibited spherical nanoparticles. The van der Waals interactions between the cholesteryl units, hydrogen bonding between the amide linkages and π-π stacking between the azobenzene units provided the driving force for the aggregation and gel formation. These driving forces were evidenced by temperature dependent 1H-NMR, FTIR and XRD analyses. Increasing the temperature of the gels shifted (upfield and downfield) the protons in the 1H-NMR spectra as well as the absorption bands in the FTIR spectra indicating that the intermolecular forces between the molecules became disrupted and caused gel → sol transitions. These transitions were reversible after cooling to room temperature. Similarly, the gel → sol transitions could be triggered by UV light (due to trans/cis isomerization); however, the transition was irreversible in the presence of visible light due to the formation of the more stable cis isomer. Hence, the gel state could be retained by heating and cooling the cis-conformation. In addition, the length of the molecule as determined by simulation software was found to match the values observed from the XRD analysis, and the interlayer distances were found to be 1.78 and 1.85 nm for N2 and N4, respectively. Based on this evidence, an aggregation mechanism was proposed. The differential scanning calorimetry (DSC) and polarized optical microscopy (POM) results revealed that both gelators exhibited grainy nematic mesophase textures during the heating and cooling cycles. These gelators underwent phase-selective gelation in the solvent mixtures containing gelling and nongelling solvents, which demonstrated the applicability of these gelators for the separation and purification of solvents.
On the azo dyes derived from benzoic and cinnamic acids used as photosensitizers in dye-sensitized solar cells
Matovi?, Luka,Tasi?, Nikola,Tri?ovi?, Nemanja,La?arevi?, Jelena,Vitnik, Vesna,Vitnik, ?eljko,Grgur, Branimir,Mijin, Du?an
, p. 1183 - 1203 (2019/09/10)
In order to get a better insight into the relationship between molecular structure and photovoltaic performance, six monoazo dye molecules containing benzoic and cinnamic acid moieties were synthesized and their photovoltaic properties were studied. Three of them have not been previously used in solar cells. Spectroscopic measurements of the investigated compounds coupled with theoretical calculations were performed. Short-circuit current density, open-circuit voltage, and fill-factor were determined. It was found that a larger amount of short-circuit current density will be generated if the HOMO–LUMO energy gap is lower, determined by the stability of the molecule and the electronic effect of the donor moiety. Among both series of synthesized dye molecules, the highest obtained values of short-circuit current density were achieved with (2-hydroxynaphthalene-1-ylazo)benzoic acid and (2-hydroxynaphthalene-1-ylazo)cinnamic acid, and thus they were regarded as promising candidates for application in dye-sensitized solar cells.
The photochemical behavior of polyhydroxy styrene with azofragments containing free methacrylic double bounds
Nadtoka, Oksana,Vretik, Lyudmyla,Gavrylko, Tetiana,Syromyatnikov, Volodymyr
, p. 115 - 123 (2017/02/15)
Polymer material which combines advantages of photoaligning azo-compounds with thermal stability of the induced anisotropy provided by free methacryloyl groups was synthesised. FTIR spectroscopy was employed for clarification its photochemical behavior. T
Alternatives for Conventional Alkane Solvents
Harrell, Mary L.,Malinski, Thomas,Torres-López, Coralys,Gonzalez, Kimberly,Suriboot, Jakkrit,Bergbreiter, David E.
supporting information, p. 14650 - 14657 (2016/11/18)
The studies described in this paper show that hydrocarbon oligomers are alternatives for low molecular weight alkane solvents. These oligomeric solvents are nontoxic, nonvolatile, and recyclable alternatives to heptane in thermomorphic solvent mixtures th
Modified clays as efficient acid-base catalyst systems for diazotization and diazocoupling reactions
Bahulayan, Damodaran,John, Litka,Lalithambika, Malathy
, p. 863 - 869 (2007/10/03)
Diazotization and diazocoupling reactions of aniline and its substituted derivatives with phenol and other aromatic amines over ecofriendly clay catalysts is described. This inexpensive, non-corrosive and reusable catalysts were found to exhibit bifunctional catalytic properties for these reactions. No considerable decrease in the efficiency of the catalysts were observed after five cycles of operation. The new method totally avoids the use of acids and alkalies.
