- Solvent effects and energy transfer processes in luminescent composite
-
The combination of conjugated polymers and photochromic molecules can result in a composite, which can yield a new photoresponsive material. The efficiency of these materials is due to the process of energy transfer. In this work, the conjugated polymer poly (3-hexylthiophene-co-1,4-phenylene) (PTPh) was synthesized by Suzuki route and the photochromic molecule 4-aminoazobenzene (Azo), synthesized by diazonium salt coupling, were mixed forming a luminescent composite. This new material was obtained in four different solvents, in order to evaluate its influence. When the Azo is added in a solution of PTPh, it was observed a decrease of the emission spectra of the copolymer, indicating the suppression of PTPh due to F?ster's energy transfer from PTPh to Azo. The larger energy transfer has been found in ethanol. Density Functional Theory (DFT) calculations have been performed for Azo, an oligomeric model for the PTPh and a complex formed by the Azo and the oligomeric model for PTPh, with two different functionals. Computational results indicate the occurrence of C-H---π and N-H---S interactions in the optimized structure of PTPh/Azo complex. The LUMO orbital of the PTPh/Azo complex is mainly located in the Azo moiety, suggesting that Azo might receive energy from the polymer. Therefore, the joint computational-experimental study enables the understanding of the energy transfer that takes place in the PTPh/Azo systems.
- Menandro, Alessandra S.,Oliveira, Hueder P. M.,Péres, Laura O.,Siqueira, Leonardo J. A.
-
-
Read Online
- Polarity controlled reaction path and kinetics of thermal cis-to-trans isomerization of 4-aminoazobenzene
-
Spectral and kinetic behavior of thermal cis-to-trans isomerization of 4-aminoazobenzene (AAB) is examined in various solvents of different polarities. In contrast to azobenzene (AB), it is found the rate of thermal isomerization of AAB is highly dependent on solvent polarity. Accelerated rates are observed in polar solvents as compared to nonpolar solvents. Moreover, a decrease in the barrier height with an increase in medium polarity is observed. Our observations suggest that inversion is the preferred pathway in cis-to-trans thermal isomerization in a nonpolar medium; however, in a polar medium, the isomerization path deviates from the inversion route and rotational behavior is incorporated. Differences in the kinetics and in mechanisms of isomerization in different media are rationalized in terms of modulation in barrier height by polarity of the medium and solute-solvent interaction. It is found that kinetics as well as the mechanism of thermal isomerization in AAB is controlled by the polarity of the medium. ? 2014 American Chemical Society.
- Joshi, Neeraj Kumar,Fuyuki, Masanori,Wada, Akihide
-
-
Read Online
- Synthesis and experimental investigations on the photoconductivity of p-aminoazobenzene based non-conjugated polybenzoxazine system
-
In this paper, we report the study of a novel p-aminoazobenzene based non-conjugated, benzoxazine polymer, poly([4-(6-tert-butyl-4H-benzo[e][1,3]oxazin-3-yl)phenyl]-phenyldiazene) (AZO-PBZ) synthesized using solvent free, thermally activated cationic ring opening polymerization. The thermal, photophysical, electrochemical, and photoconducting properties of the polymer were investigated. The optical absorption band edges of AZO-PBZ thin film was observed at 555 nm. Photoinduced charge transfer nature of AZO-PBZ was studied by analyzing the fluorescence spectra and performing photoconductivity experiments. Incorporation of [6, 6]-phenyl-C61-butyric acid methyl ester denoted as PCBM into the polymer leads to quenching of the fluorescent intensity and exhibits significant photoconductivity. The photocurrent through the PCBM blend films was measured as a function of electric field to recognize the field dependence on carrier generation. Internal photocurrent efficiency of the polymer:PCBM blend samples was found to be in the order of 10?5 and photoconductive sensitivity was of the order of 10?11 S W?1cm, which is adequate for photorefractivity.
- Pillai, Jisha J.,Abbas, Anshad,Narayanan, Sona,Sreekumar,Kartha, C. Sudha,Joseph, Rani
-
-
Read Online
- Cannabinoid receptor light-operated ligand and preparation method and application thereof
-
The invention relates to the technical field of biology, in particular to a novel cannabinoid receptor light-operated ligand and a preparation method and application thereof. Disclosed is the cannabinoid receptor light-operated ligand or the isomer prodrug, the solvate and the pharmaceutically acceptable salt of the cannabinoid receptor light-operated ligand, wherein the structural formula of thecannabinoid receptor light-operated ligand is A-linker-B; A is a transmembrane domain ligand structure, and B is a light-operated element; Linker is a subunit which is linear and has no activity on acannabinoid receptor light-operated ligand. According to the invention, the cannabinoid receptor ligand is integrated with azobenzene through a proper connector, so that the ligand configuration is changed under an illumination condition, and the activation or inhibition state of the cannabinoid receptor is regulated and controlled.
- -
-
Paragraph 0066; 0073; 0106-0112
(2021/01/24)
-
- Calculated oxidation potentials predict reactivity in Baeyer-Mills reactions
-
Azobenzenes are widely used as dyes and photochromic compounds, with the Baeyer-Mills reaction serving as the most common method for their preparation. This transformation is often plagued by low yields due to the formation of undesired azoxybenzene. Here, we explore electronic effects dictating the formation of the azoxybenzene side-product. Using calculated oxidation potentials, we were able to predict reaction outcomes and improve reaction efficiency simply by modulating the oxidation potential of the arylamine component.
- Gingrich, Phillip W.,Olson, David E.,Tantillo, Dean J.,Tombari, Robert J.,Tuck, Jeremy R.,Yardeny, Noah
-
supporting information
p. 7575 - 7580
(2021/09/22)
-
- Photoreversible formation of nanotubes in water from an amphiphilic azobenzene derivative
-
An anionic azobenzene-appended derivative ofl-ValylGlycine self-assembles into nanotubes in water. Irradiation with 365 nm light provokestrans-cisisomerization of the azobenzene unit and subsequent tube disassembly. Thermal or photoinduced (457 nm light)
- Angulo-Pachón, César A.,Galindo, Francisco,Miravet, Juan F.,Navarro-Barreda, Diego
-
supporting information
p. 11545 - 11548
(2021/11/12)
-
- Synthesis method of p-phenylenediamine
-
The invention relates to a synthesis method of p-phenylenediamine, and belongs to the technical field of organic material preparation. Aniline adopted as a raw material undergoes a diazotization reaction and a heating rearrangement reaction to generate 4-aminoazobenzene, a proper amount of an acid is added, and the 4-aminoazobenzene is separated out; the 4-aminoazobenzene is dissolved in a propersolvent, a catalyst is added, the p-phenylenediamine product is obtained through a hydrogenation reduction reaction, filtration and reduced pressure distillation, and aniline is recovered as a byproduct and can be recycled as the raw material. Compared with an existing p-phenylenediamine production method, the method of the invention has the advantages of safe and environmentally-friendly preparation process, little emission of three wastes, easily available reaction raw materials, simple reaction steps, and high purity of the finally prepared product, so the method has good industrial implementation prospects.
- -
-
Paragraph 0032; 0034; 0036; 0038; 0040; 0042; 0044; 0046
(2020/03/12)
-
- Azo aryl urea derivative, and preparation method and application thereof
-
The invention relates to an azo aryl urea derivative, and a preparation and an application thereof, and concretely discloses a compound represented by formula (I), or an optical isomer, a cis-trans-isomer or a pharmaceutically acceptable salt thereof, and a preparation method thereof. Definitions of substituent groups in the general formula are described in the specification and claims. The invention further discloses a composition containing the above compound, and an application thereof. The compound has excellent anticancer activity on HepG2 liver cancer cells, MGC803 gastric cancer cells,HCT116 colon cancer and the like.
- -
-
-
- Dip-coated rapeseed meal composite as a green carrier for light-induced controlled release of pesticide
-
In this work, we report the novel fabrication of polymerized octadecylsiloxane (PODS)/4-aminoazobenzene (AAB) coated rapeseed meal (RSM) using a facile one-pot dip-coating method. The as-prepared RSM-PODS/AAB employs RSM as a carrier, the PODS coating endows the material with hydrophobicity, thus improving the loading rate of pinoxaden (Pxd) of RSM-PODS/AAB, and the AAB moieties act as light-driven “stirrers” to stir the release of Pxd. The structure and composition were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, ultraviolet-visible spectroscopy and contact angle measurements. The experimental results indicate that the loading rate of Pxd was increased by 21.38% compared with pristine RSM. More importantly, the Pxd-loaded RSM-PODS/AAB showed perfect UV-visible and sunlight controlled release performance, the excellent biodegradability of RSM effectively supplying the nutrient elements of plant growth in the soil. Overall, this system provides a promising way to improve controlled drug release with UV-visible- and sunlight-responsive behavior.
- Chenxi, Yang,Juan, Li,Jian, Wang,Zhen, Guo,Huanyuan, Wang,Chendi, Shi,Dongwen, Hua,Ling, Li
-
p. 15983 - 15993
(2020/10/08)
-
- TEMPO catalyzed oxidative dehydrogenation of hydrazobenzenes to azobenzenes
-
A metal-free direct oxidative dehydrogenation approach for the synthesis of azobenzenes from hydrazobenzenes has been developed by using TEMPO as an organocatalyst for the first time. The reaction proceeded in open air under mild reaction conditions. A wide range of hydrazobenzenes readily undergo dehydrogenation to give the corresponding azobenzenes in excellent yields.
- Fan, Baomin,Laishram, Ronibala Devi,Li, Jiayan,Luo, Yang,Lv, Haiping,More, Sagar,Su, Zhimin,Xu, Dandan,Yang, Yong,Zhan, Yong
-
supporting information
p. 3471 - 3474
(2020/05/25)
-
- Photoinduced viscosity control of lecithin-based reverse wormlike micellar systems using azobenzene derivatives
-
This report describes the controlled viscosity changes of photoresponsive reverse wormlike micellar systems formed by soybean lecithin (SoyPC), d-ribose, and azobenzene derivatives in decane. UV light irradiation produces a significant (150-fold) decrease in solution viscosity by triggering a structural transformation of the wormlike micelles. Subsequent visible light irradiation leads to recovery of the initial micellar structure and elevated solution viscoelasticity. This dramatic, reversible variation in solution viscosity by light irradiation can be applied to cosmetics, personal care products, and device components.
- Akamatsu, Masaaki,Shiina, Mayu,Shrestha, Rekha Goswami,Sakai, Kenichi,Abe, Masahiko,Sakai, Hideki
-
p. 23742 - 23747
(2018/07/13)
-
- Textile printing method, inkjet ink for textile printing, and electrophotographic toner for textile printing
-
A textile printing method that includes printing to a textile with a material including a dye expressed by the following general formula 1. In general formula 1, R1 to R16 is H, CH3, OH, NHC2H5, COOH, SO3H, SO3Na, NO2, or NH2.
- -
-
Page/Page column 6; 7
(2017/05/07)
-
- Manufacturing method of aromatic diamine from aromatic monoamine comprising a step utilizing an auxiliary substance dissolving nitrogen oxides
-
The present invention relates to a method for manufacturing aromatic diamine from aromatic monoamine by using an auxiliary matter in which nitrogen oxide is dissolved. Specifically, aniline which is the aromatic monoamine is formed as diazo by using an auxiliary substance performing a role of a stabilizer as a reaction medium. 1,3-diphenyltriazene which is a product is rearranged, and p-amino-azobenzene is manufactured. The p-amino-azobenzene is added with hydrogen and decomposed. So, p-phenylenediamine is manufactured. The method for manufacturing aromatic diamine from aromatic monoamine provides high economical feasibility and high stability.COPYRIGHT KIPO 2017
- -
-
Paragraph 0037; 0108-0127
(2017/10/28)
-
- Process for diazotization of aniline and rearrangement of 1,3-diphenyltriazene into p-aminoazobenzene using an auxiliary substance dissolving nitrogen oxides
-
The present invention relates to a process for diazotization of aniline and rearrangement of 1,3-diphenyltriazene into p-aminoazobenzene using an auxiliary substance in which nitrogen oxides are dissolved. Specifically, the aniline which is aromatic amine is formed as diazo by using an auxiliary substance performing a role of a stabilizer as a reaction medium. 1,3-diphenyltriazene which is a product thereof is rearranged, and p-amino-azobenzene which is a raw material of p-phenylenediamine is manufactured. The process for diazotization of aniline and rearrangement of 1,3-diphenyltriazene into p-aminoazobenzene provides high economical feasibility and high stability.COPYRIGHT KIPO 2017
- -
-
Paragraph 0034-0035; 0097-0116
(2017/10/31)
-
- Azobenzene-benzoylphenylureas as photoswitchable chitin synthesis inhibitors
-
Benzoylphenylureas (BPUs) are used as synthetic insect growth regulators for inhibiting chitin synthesis. Merging insecticidal BPUs with photoswitchable azobenzene generated photoresponsive chitin synthesis inhibitors. A prepared azobenzene-benzoylphenylurea can be activated upon irradiation with UV light, and shows 6-fold and 2-fold activity difference to armyworm (Mythimna separata) and German cockroach (Blattella germanica) sulfonylurea receptors, respectively. This is the first example of a photoswitchable BPU insecticide. The generation of such a photoresponsive BPU insecticide allows for modulation of the insecticidal activity by light, and may facilitate the spatiotemporal control over the sulfonylurea receptor and the mechanistic study of this kind of insecticide.
- Tian, Xue,Zhang, Chao,Xu, Qi,Li, Zhong,Shao, Xusheng
-
p. 3320 - 3323
(2017/04/21)
-
- Rapid and direct spectrophotometric method for kinetics studies and routine assay of peroxidase based on aniline diazo substrates
-
Peroxidases are ubiquitous enzymes that play an important role in living organisms. Current spectrophotometrically based peroxidase assay methods are based on the production of chromophoric substances at the end of the enzymatic reaction. The ambiguity regarding the formation and identity of the final chromophoric product and its possible reactions with other molecules have raised concerns about the accuracy of these methods. This can be of serious concern in inhibition studies. A novel spectrophotometric assay for peroxidase, based on direct measurement of a soluble aniline diazo substrate, is introduced. In addition to the routine assays, this method can be used in comprehensive kinetics studies. 4-[(4-Sulfophenyl)azo]aniline (λ max = 390 nm, ? = 32 880 M?1 cm?1 at pH 4.5 to 9) was introduced for routine assay of peroxidase. This compound is commercially available and is indexed as a food dye. Using this method, a detection limit of 0.05 nmol mL?1 was achieved for peroxidase.
- Mirazizi, Fatemeh,Bahrami, Azita,Haghbeen, Kamahldin,Shahbani Zahiri, Hossein,Bakavoli, Mehdi,Legge, Raymond L.
-
p. 1162 - 1169
(2016/10/09)
-
- Connectivity matters-ultrafast isomerization dynamics of bisazobenzene photoswitches
-
We have investigated the ultrafast dynamics of o-, m- and p-bisazobenzenes, which represent elementary building blocks for photoswitchable multiazobenzene nanostructures. The connectivity pattern within bisazobenzenes and the ensuing complex interactions between the individual azobenzene units determines the ultrafast dynamics of these compounds and their photochemical properties. While retaining a relatively high E → Z isomerization quantum yield, o-bisazobenzene exhibits a very high thermal relaxation rate (half-life of 1.6 ms). Our theoretical calculations reveal that the geometry allows intramolecular excitonic interaction between the azobenzene units, which is reflected in the femtosecond transient absorption data via the simultaneous bleaching of the two excitonic bands. In contrast, the properties of m-bisazobenzene are very similar to the monomeric azobenzene, with the two units acting nearly independently from each other. The highest degree of π conjugation extending over the two azobenzene units was observed for p-bisazobenzene, which results in strong planarity of the molecule, reduced excited state lifetime and relatively low isomerization quantum yield. Multiphotochromic systems bridge the gap between molecular photoswitches and macroscopic function and thus, understanding the properties of bisazobenzenes opens the way to the design and development of new structures with extensive and versatile applications.
- Slavov, Chavdar,Yang, Chong,Schweighauser, Luca,Boumrifak, Chokri,Dreuw, Andreas,Wegner, Hermann A.,Wachtveitl, Josef
-
p. 14795 - 14804
(2016/07/06)
-
- One pot synthesis and characterization of mono and di-substituted azo-containing amides
-
Azo-containing amides and their derivatives were synthesized by the reaction of 4-(phenyldiazenyl)aniline with different substituted benzoyl chlorides. The characterization of these synthesized compounds were based on their IR, 1H NMR spectra and elemental analysis with excellent yields.
- Khera, Rasheed Ahmad,Iqbal, Munawar,Tahir, M. Asif,Hanif, M. Asif,Langer, Peter
-
p. 2001 - 2004
(2015/11/27)
-
- A photochromic agonist for μ-opioid receptors
-
Opioid receptors (ORs) are widely distributed in the brain, the spinal cord, and the digestive tract and play an important role in nociception. All known ORs are G-protein-coupled receptors (GPCRs) of family A. Another well-known member of this family, rhodopsin, is activated by light through the cis/trans isomerization of a covalently bound chromophore, retinal. We now show how an OR can be combined with a synthetic azobenzene photoswitch to gain light sensitivity. Our work extends the reach of photopharmacology and outlines a general strategy for converting Family A GPCRs, which account for the majority of drug targets, into photoreceptors. Lighting up the opioid receptor: Photofentanyl-2 is a photochromic version of the well-known analgesic fentanyl. It is a potent agonist in the dark (or when illuminated with blue light) and loses activity when irradiated with UV light. It can be used to optically control the μ-opioid receptor, converting a G-protein-coupled receptor (GPCR) into a photoreceptor.
- Schoenberger, Matthias,Trauner, Dirk
-
supporting information
p. 3264 - 3267
(2014/04/03)
-
- A novel procedure to synthesize 3-chloro-1-(4a,10b-diazaphenanthrene-2-yl)- 4-phenyl azetidin-2-ones and exploration of their anti-inflammatory activity
-
Some new derivatives of 3-chloro-1-(4a,10b-diazaphenanthrene-2-yl)-4-phenyl azetidin-2-one were synthesized through the reaction of N-{4-[phenyldiazenyl] phenyl}-N-[phenyl methylene] amine with 4-[phenyldiazenyl] aniline. The resulting 3-chloro-4-phenyl-1-{4-[phenyldiazenyl] phenyl} azetidin-2-one intermediate in benzene was irradiated in a Pyrex vessel with 350 nm UV light in a photochemical reactor to give the desired derivatives (4a-j). Structures of the new compounds were verified on the basis of spectral and elemental methods of analyses. Nine of the prepared compounds were tested for their anti-inflammatory effects; most of these compounds showed potent and significant results compared with indomethacin.
- Sharma, Manisha,Maheshwari, Arti,Bindal, Nitin
-
p. E116-E120
(2013/06/04)
-
- Effect of photoisomerization on the electroactivity and electrochromic behavior of aniline pentamer-based polymers with azo chromophore as reversibly switchable pendant group
-
By an oxidative coupling polymerization approach, we have synthesized an electroactive polymer with good solubility containing alternating phenyl-capped aniline pentamer in the main chain and azo chromophores in the side chain. In this study, we present reversible example of photochemically induced switching of electroactivity by performing electrochemical CV in two ways: (i) in that the photochemical reaction switch can be photochemically reverted by reirradiation at a different wavelength (ii) in that a photoreaction is used that is thermally reversible. At the same time, electrochemical investigations of electrochromic properties of an aniline-pentamer-based electroactive poly(azine-azo) (EPAA) coating prepared by oxidative coupling polymerization are presented. The in-situ chemical oxidation of the reduced form of soluble, electroactive poly(azine-azo) (EPAA) in N-methyl-2-pyrrolidone (NMP) was monitored by UV-Visible absorption spectra. Moreover, the electrochromic performance of EPAA was investigated by measuring electrochromic photographs and UV absorption spectra.
- Huang, Hsiu-Ying,Jian, Jhong-Wei,Lee, Yu-Ting,Li, Yi-Ting,Huang, Tsao-Cheng,Chang, Jung-Hsiang,Yeh, Lu-Chen,Yeh, Jui-Ming
-
p. 4967 - 4976,10
(2012/12/12)
-
- Synthesis and properties of amphiphilic photoresponsive gelators for aromatic solvents
-
A sugar-based photoresponsive supergelator, N-glycosylazobenzene that shows selective gelation of aromatic solvents is described. The partial trans - cis isomerization of the azobenzene moiety allows photoinduced chopping of the entangled gel fibers to short fibers, resulting in controlled fiber length and gel - sol transition. The gelator is useful for the selective removal of toxic aromatic solvents from water.
- Rajaganesh, Ramanathan,Gopal, Anesh,Mohan Das, Thangamuthu,Ajayaghosh, Ayyappanpillai
-
p. 748 - 751
(2012/03/26)
-
- Photomechanical bending of 4-aminoazobenzene crystals
-
Upon photoirradiation at 365 nm, platelike microcrystals of trans-4-aminoazobenzene quickly bend away from the light source, returning to their initial linear shape when irradiation was terminated. However, relative to the observations upon cessation of 3
- Koshima, Hideko,Ojima, Naoko
-
scheme or table
p. 798 - 801
(2012/07/17)
-
- Electroactive polymer with oligoanilines in the main chain and azo chromophores in the side chain: Synthesis, characterization and dielectric properties
-
By an oxidative coupling polymerization approach, we have synthesized a novel electroactive polymer with good solubility containing alternating phenyl-capped aniline tetramer in the main chain and azo chromophores in the side chain. Dielectric properties of the as-synthesized polymer were investigated in detail and gratifying results have been observed. Firstly, a large enhancement in the dielectric constant was achieved utilizing the method of doping the conjugated oligoaniline segments with hydrochloric acid. Secondly, the adjustment of dielectric constant was implemented primarily by means of exposing the samples to UV and visible irradiation, mainly owing to the photoisomerization derived from azo chromophores in the side chain. The detailed characteristics of the as-synthesized polymer were systematically studied by Fourier-transform infrared (FTIR) spectra, nuclear magnetic resonance ( 1H NMR) and gel permeation chromatography (GPC). UV-vis spectra were used to monitor the photoisomerization and doping process of the polymer. The thermal characteristics of the polyamide were evaluated by thermogravimetric analysis (TGA). Moreover, the electrochemical activity of the polymer was explored by cyclic voltammogram (CV) measurement, showing that the intrinsic electroactivity of the oligoaniline was maintained in the polymer.
- He, Libing,Chao, Danming,Jia, Xiaoteng,Liu, Hongtao,Yao, Lei,Liu, Xincai,Wang, Ce
-
experimental part
p. 1852 - 1858
(2011/10/01)
-
- Azonium-ammonium tautomerism and inclusion complexation of 4-amino-2', 3-dimethylazobenzene
-
The spectral characteristics of 4-amino-2',3-dimethylazobenzene (GBC), 4-aminoazobenzene (AAB) and azobenzene (AB) have been studied in various solvents, varying hydrogen ion concentrations and in β-cyclodextrin (β-CD). The inclusion complexes of GBC, AAB and AB with β-CD have been analysed by UV-visible, fiuorometry, FT-IR,1H NMR, SEM and Cache-DFT methods. The solvent study shows that the azo form is present only in GBC and AAB molecules. No significant spectral difference is observed in GBC indicating that the presence of two methyl groups does not effectively change the spectral behaviour as compared to that of AAB. In acid solutions, unusual red shift is observed in the monocation suggesting that the azonium-ammonium tautomer is present in both molecules. The absorption maximum at ～500 nm, is due to the azonium cation while that at ～320 nm originates from the ammonium cation. In β-CD solutions, the increase in the fluorescence intensity and large bathochromic shift in S1 state indicates that both GBC and AAB form 2:2 inclusion complex, whereas AB forms 1:1 inclusion complex. Also, head-to-head dimer is formed in both the aminoazobenzene compounds.
- Prabhu, A. Antony Muthu,Venkatesh,Sankaranarayanan,Siva,Rajendiran
-
experimental part
p. 407 - 417
(2011/01/09)
-
- Modified clays as efficient acid-base catalyst systems for diazotization and diazocoupling reactions
-
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.
- Bahulayan, Damodaran,John, Litka,Lalithambika, Malathy
-
p. 863 - 869
(2007/10/03)
-
- Clay catalysed facile rearrangement of diazoaminobenzene to p-aminoazobenzene
-
Rearrangement of diazoaminobenzene in the presence of acidic cation-exchanged K10-montmorillonite gives exclusively p-aminoazobenzene at room temperature within three hours.
- Pitchumani, K.,Venkatachalapathy, C.,Sivasubramanian, S.
-
p. 187 - 189
(2007/10/03)
-
- Convenient reduction of azobenzenes and azoxybenzenes to hydrazobenzenes by sodium dithionite using dioctylviologen as an electron transfer catalyst
-
Various ezobenzenes and azoxybenzenes were reduced almost quantitatively to the corresponding hydrazobenzenes as sodium dithionite under mild conditions without the formation of aniline derivatives, using dioctyl viologen as an electron-transfer catalyst in acetonitrile-water.
- Park, Kwanghee Koh,Han, Sun Young
-
p. 6721 - 6724
(2007/10/03)
-
- Process for the manufacture of pigments, especially fluorescent pigments
-
A process for the manufacture of pigments comprising a coloured composition incorporated in a polycondensation resin said resin not containing aldehyde derivatives, especially formaldehyde derivatives, wherein the reactants for the formation of said polycondensation resin and the coloured composition are introduced continuously into a reactor and are mixed, the mixture travels forward in die reactor and at the end of reaction the product is withdrawn continuously from the said reactor. The process is particularly suitable for the preparation of fluorescent pigments. The reactor used is preferably an extruder. Also claimed are compositions comprising diketo-pyrrolo-pyrrole colourants and certain polyester or polyamide resins as well as a process for the preparation of said compositions.
- -
-
-
- A process for the manufacture of pigments
-
Fluorescent pigments comprising a coloured composition incorporated in a thermoset crosslinked resin obtained by continuous bulk polycondensation of a sulfonamide with an aldehyde and a substance containing at least two NH2 groups, each bonded to a carbon, itself bonded by a double bond to O, S or N.
- -
-
-
- Chromium complex compound
-
A chromium complex compound represented as the free acid form by the formula (I): STR1 wherein X1 represents a hydrogen atom, a methyl group, a methoxy group or a sulfonic acid group; X2, X3 and X4 represent independently a hydrogen atom, a chlorine atom, a methyl gorup, a methoxy group, a carboxyl group or a sulfonic acid group; Y represents a hydrogen atom or a sulfonic acid group; Z represents a chlorine atom, a fluorine atom or --N30 (R)3 (R represents a C1 to C4 -alkyl group), STR2 and M represents a hydrogen atom or an alkali metal, a process for producing the chromium complex compound (I) and a method for dyeing cellulosic fibers with the same. The chromium complex compound represented by formula (I) is excellent in affinity to cellulosic fibers and in color-yield, build-up properties and fastness properties. These compounds are dyes for cellulosic fibers.
- -
-
-
- Photochemical Decomposition of 4-Arylazo- and 4-Arylazoxy-N,N-dialkylaniline N-Oxides
-
The 4-aryl-N,N-dialkylaniline N-oxides (1a-c) decompose on u.v. irradiation in aprotic solvents, undergoing deoxygenation as well as intramolecular hydrogen abstraction, to give amides and dealkylated products.The latter process is more important for the diethyl derivative (1b) (photoCope elimination).Visible irradiation is ineffective.The 4-arylazoxy-N,N-dialkylaniline N-oxides (2a-d) undergo photochemical deoxygenation from the amino group (major process) as well as from the azo group.The mechanism of these photoprocesses is discussed in general and in relation to the possible involvement of these N-oxide derivatives in photofading of the related azo dyes.
- Albini, Angelo,Fasani, Elisa,Moroni, Micaela,Pietra, Silvio
-
p. 1439 - 1444
(2007/10/02)
-
- Studies on UV/VIS Absorption Spectra of Azo Dyes. XV. An Analysis of the Absorption Spectra of 4,4'-Diaminoazobenzenes
-
In the visible absorption spectrum 4,4'-bis-diethylaminoazobenzene shows two absorption maxima (λmax = 426 nm and λmax = 477 nm) with high intensity.Quantum chemical calculations and examinations by peak separation of six 4-substituted azobenzenes and six 4'-substituted 4-diethylaminoazobenzenes (1a-k) indicate that the longest wavelenght band is due to a n-?* transition and the other band is due to a ?-?*-transition.This is verified using an inrement system for ?-?* absorption maxima.A linear relation is found between intensity ratios of the two bands and the HAMMETT-?-constants of the substituents.With increasing electron releasing tendency of the substituents the absorption intensity of the n-?*-band increases.
- Haessner, C.,Mustroph, H.
-
p. 113 - 119
(2007/10/02)
-
- PHOTOCHEMISTRY OF 1,3-DIPHENYLTRIAZENE IN VARIOUS MEDIA. I: PHOTOLYSIS IN LIQUID SOLUTIONS.
-
1,3-Diphenyltriazene has been irradiated at 360 nm in various liquid solutions. Reversible trans-cis photoisomerization has been detected in solvents which do not form hydrogen bonds. Irreversible photolysis is observed with an appreciable amount of cage recombination products in all solvents. This reaction is well suited for a study in solid environments.
- Baro,Dudek,Luther,Troe
-
p. 1155 - 1161
(2007/10/02)
-
- PHOTOCHEMISTRY OF 1,3-DIPHENYLTRIAZENE IN VARIOUS MEDIA. II: SOLID STATE PHOTOLYSIS.
-
Solid 1,3-diphenyltriazene (DPT) has been photolyzed at 290 nm and 360 nm. The distribution of the photoproducts showed that recombination of the radicals produced after photochemical excitation was governed by a 'cage effect' favoring a minimum of motion of the recombining radicals. In many details the results differ from observations on the photochemistry of DPT in liquid solutions. The photolysis of DPT in polymethylmethacrylate films, however, resembles the photochemistry of DPT in liquid solutions.
- Baro,Dudek,Luther,Troe
-
p. 1161 - 1164
(2007/10/02)
-
- Possibility of the Intarmolecularity of Triazene Rearrangement
-
The mechanism for the ortho-rearrangement of diaryltriazenes still remains equivocal.An interesting result suggesting an intramolecular nature of the triazene rearrangement was obtained on the basis of the effect of concentration of added N,N-dimethylaniline in the ortho-rearrangement of 1,3-bis(4-methylphenyl)triazene (1).The ortho/para ratio for the rearrangement of 1,3-diphenyltriazene (4) tends to increase with an increase of the viscosity.The results are discussed on the basis of increasing nucleophilicity of free amine by H-bonding with dimethylaniline and favoring ortho-migratrion with viscosity, respectively.
- Ogata, Yoshiro,Nakagawa, Yoshiaki,Inaishi, Morio
-
p. 2853 - 2854
(2007/10/02)
-
- Bisazomethine dyes for metal-modified polyolefins
-
Bisazomethine dyes of the general formula: STR1 in which A and D are optionally substituted benzene or naphthalene nuclei, E is an optionally substituted salicylaldehyde or o-hydroxynaphthaldehyde nucleus and G is an optionally substituted 2-aminopyridine nucleus. Metal-modified polypropylene dyed with the bisazomethine dye has excellent fastness properties.
- -
-
-
- Insecticide evaporator comprising a stabilizer
-
Insecticide evaporator comprising at least one volatile phosphoric ester insecticide, an agent for stabilizing the said ester against decomposition by protonization and used in an amount of 0.2 to 20% based on the weight of phosphoric ester, characterized in that the stabilizing agent contains at least one compound selected from the compounds of the chemical class of 1,3-benzodioxoles and at least one diazene.
- -
-
-
- Evaporator system comprising a stabilized pesticidal phosphoric acid ester and method for stabilizing such ester enclosed in an evaporator
-
An evaporator system adapted for emitting insect killing vapors of an insecticide therefrom and comprising a liquid or solid composition enclosed therein, said insecticide consisting in at least one volatile phosphoric acid ester which is stabilized by at least one diazene compound.
- -
-
-
- Azo dye with a 3-cyano- or 3-carbamoyl-4-methyl-2,6-diamino-pyridine coupling component
-
Azo dyes of the formula STR1 wherein D is the diazo component, the R substituents represent hydrogen or various organic radicals and X is cyano or carbamoyl. The R members are hydrogen, an alkyl or other aliphatic group as well as other selected groups including heterocyclic rings formed by R + R1 and R2 + R3 with the nitrogen atom. The dyes are eminently suitable for dyeing polyamides, cellulose esters, acrylonitrile polymers and particularly polyesters brilliant yellow to blue shades of excellent fastness properties to dry-heat pleating and setting and also to light.
- -
-
-
