نتایج جستجو برای: azo azomethine

تعداد نتایج: 5221  

Journal: :ChemistrySelect 2021

Polycaprolactone (PCL) nanofibers incorporating azo dye/γ-cyclodextrin inclusion complex (Azo/γ-CD-IC) were successfully produced. The characteristics of the Azo/γ-CD-IC and PCL/Azo/γ-CD-IC investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) thermogravimetric analysis (TGA). Based on SEM prepared nanofiber has a smooth surface with size diameter below 500 nm....

Four novel receptors were designed and synthesized for colorimetric detection of F− ions. The introduction of four electron withdrawing groups into the backbone of the receptors makes the two phenolic groups efficient hydrogen bonding sites. The binding properties of receptors with anions were examined for the first time by UV–Vis, 1H NMR and fluorescence spectroscopies. The addition of F− resu...

Journal: :Applied and environmental microbiology 1992
M B Pasti-Grigsby A Paszczynski S Goszczynski D L Crawford R L Crawford

Twenty-two azo dyes were used to study the influence of substituents on azo dye biodegradability and to explore the possibility of enhancing the biodegradabilities of azo dyes without affecting their properties as dyes by changing their chemical structures. Streptomyces spp. and Phanerochaete chrysosporium were used in the study. None of the actinomycetes (Streptomyces rochei A10, Streptomyces ...

Journal: :The Biochemical journal 1988
P D Kemp J E Scott

(1) Proteolytic digests of tissue elastin contain material which reacts with dimethylaminobenzaldehyde in acid solution (Ehrlich's reagent) to give a cherry-pink colour. This Ehrlich chromogen(s) [EC(s)] is similar to but not identical with EC(s) previously demonstrated in tissue collagens [Scott, Hughes & Shuttleworth (1979) Biosci. Rep. 1, 611-618]. Both ECs react with diazonium salts in acid...

Journal: :Molecules 2010
Uhood J Al-Hamdani Tarik E Gassim Howraa H Radhy

In this paper we present six select mesomorphic azo compounds distinguished by the presence of diverse substituents on a central benzene nucleus. All the synthesized compounds exhibit enantiotropic mesophases. The mesomorphic properties of the substituted compounds were compared with those of the unsubstituted parent compound to evaluate the effect of the nature and position of the substituents...

2013
Yiyu Feng Hongpo Liu Wen Luo Enzuo Liu Naiqin Zhao Katsumi Yoshino Wei Feng

Reduced graphene oxide-azobenzene (RGO-AZO) hybrids were prepared via covalent functionalization for long-term solar thermal storage. Thermal barrier (ΔEa) of cis to tran reversion and thermal storage (ΔH) were improved by molecular hydrogen bonds (H-bonds) through ortho- or para-substitution of AZO. Intramolecular H-bonds thermally stabilized cis-ortho-AZO on RGO with a long-term half-life of ...

2012
Ewelina WĘGLARZ-TOMCZAK

Introduction Azo dyes – a fatal threat or a new generation of drugs? In 1858 Griss developed the azo coupling reaction and obtained first azo dye – Aniline Yellow. Nowadays, around 10 thousands of these compounds are described and more than 2 thousands are applied to color various materials. Azo dyes are characterized by the presence of the azo moiety (–N=N–) in their structure, conjugated with...

Journal: :Molecules 2013
Jun He Guang Ouyang Zhixiang Yuan Rongsheng Tong Jianyou Shi Liang Ouyang

An efficient synthesis of novel dispirooxindoles has been achieved through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the decarboxylative condensation of isatin and an α-amino acid with the dipolarophile 5-benzylideneimidazolidine-2,4-dione. The improved procedure features mild reaction conditions, high yields, high diastereoselectivities, a one-pot proc...

Journal: :Journal of the American Chemical Society 2003
Chuo Chen Xiaodong Li Stuart L Schreiber

We report a new catalyst system that should enhance the use of enantioselective 1,3-dipolar cycloadditions of azomethine ylides with electronic-deficient olefins in the divergent pathways of diversity-oriented synthesis (DOS). The underlying reaction is of considerable interest in DOS because its stereospecificity enables stereochemical diversification of up to four tetrahedral centers on pyrro...

Journal: :Journal of Molecular Structure 2021

Two new carbazole-based soluble ?-conjugated polymers were synthetized and investigated: P1 is a poly(p-phenylenevinylene) analogue P2 poly-azomethine-type polymer. The macromolecular structures of confirmed by nuclear magnetic resonance infrared spectroscopies. effect vinylene (in P1) azomethine P2) ?-linkers on thermal, optical electrical properties the two macromolecules was mainly studied. ...

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