62-53-3Relevant articles and documents
Magnetic Field Effects on and Mechanism of Photoredox Reaction of Aromatic Nitro Group
Mutai, Kiyoshi,Nakagaki, Ryoichi,Tukada, Hideyuki
, p. 920 - 926 (1993)
Photoredox reaction mechanism of a homologous series p-O2NC6H4O(CH2)nNHPh (1) in acetonitrile and benzene is studied.The major products are p-ONC6H4O(CH2)n-1CHO (3) and aniline derived from intramolecular reaction, but the presence of minor amounts of intermolecular reaction products, p-O2NC6H4O(CH2)n-1CHO (4) and p-ONC6H4O(CH2)nNHPh (5) is confirmed in the reaction mixture.In the presence of an external magnetic field, the yield of 3 is suppressed and those of 4 and 5 are correspondingly increased, while the rates of the disappearance of 1 and of the formation of aniline remain unchanged, suggesting the presence of biradical recombination process accompanied by intersystem crossing in a rate-determining step.On the basis of these observations, two reaction schemes are proposed.The magnetic field effects provide strong evidence for the presence of a transient species with (nitro)N(OH)-O-CHN group generally supposed for nitro oxygen transfer process in this type photoreaction.
Structure and Catalytic Activity of Cr-Doped BaTiO3 Nanocatalysts Synthesized by Conventional Oxalate and Microwave Assisted Hydrothermal Methods
Srilakshmi, Chilukoti,Saraf, Rohit,Prashanth,Rao, G. Mohan,Shivakumara
, p. 4795 - 4805 (2016)
In the present study synthesis of BaTi1-xCrxO3 nanocatalysts (x = 0.0 ≤ x ≤ 0.05) by conventional oxalate and microwave assisted hydrothermal synthesis methods was carried out to investigate the effect of synthesis methods on the physicochemical and catalytic properties of nanocatalysts. These catalysts were thoroughly characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 physisortion, and total acidity by pyridine adsorption method. Their catalytic performance was evaluated for the reduction of nitrobenzene using hydrazine hydrate as the hydrogen source. Structural parameters refined by Rietveld analysis using XRD powder data indicate that BaTi1-xCrxO3 conventional catalysts were crystallized in the tetragonal BaTiO3 structure with space group P4mm, and microwave catalysts crystallized in pure cubic BaTiO3 structure with space group Pm3μm. TEM analysis of the catalysts reveal spherical morphology of the particles, and these are uniformly dispersed in microwave catalysts whereas agglomeration of the particles was observed in conventional catalysts. Particle size of the microwave catalysts is found to be 20-35 nm compared to conventional catalysts (30-48 nm). XPS studies reveal that Cr is present in the 3+ and 6+ mixed valence state in all the catalysts. Microwave synthesized catalysts showed a 4-10-fold increase in surface area and pore volume compared to conventional catalysts. Acidity of the BaTiO3 catalysts improved with Cr dopant in the catalysts, and this could be due to an increase in the number of Lewis acid sites with an increase in Cr content of all the catalysts. Catalytic reduction of nitrobenzene to aniline studies reveals that BaTiO3 synthesized by microwave is very active and showed 99.3% nitrobenzene conversion with 98.2% aniline yield. The presence of Cr in the catalysts facilitates a faster reduction reaction in all the catalysts, and its effect is particularly notable in conventional synthesized catalysts.
Pd nanoparticles immobilized on halloysite decorated with a cyclodextrin modified melamine-based polymer: a promising heterogeneous catalyst for hydrogenation of nitroarenes
Sadjadi, Samahe,Akbari, Maryam,Monflier, Eric,Heravi, Majid M.,Leger, Bastien
, p. 15733 - 15742 (2018)
For the first time, a hybrid system composed of halloysite (Hal) and a cyclodextrin modified melamine-based polymer is developed and employed for immobilization of Pd(0) nanoparticles. The resulting catalytic hybrid system, Pd@HTMC, was then applied as a
Mesoporous silica supported cobalt catalysts for gas phase hydrogenation of nitrobenzene: role of pore structure on stable catalytic performance
Kondeboina, Murali,Enumula, Siva Sankar,Gurram, Venkata Ramesh Babu,Yadagiri, Jyothi,Burri, David Raju,Kamaraju, Seetha Rama Rao
, p. 15714 - 15725 (2018)
Highly dispersed cobalt nanoparticles were prepared over mesoporous silica with different pore structures (2D-hexagonal COK-12 and 3D-cubic SBA-16). These catalysts were evaluated for gas phase hydrogenation of nitrobenzene to aniline at atmospheric H2 pressure. A combination of catalytic activity and characterization results were assessed to establish the role of the support pore structure on hydrogenation activity. XRD, N2-physisorption, SEM and TEM analysis confirmed the presence of mesoporous structures in the supported cobalt catalysts. H2-TPR, H2-pulse chemisorption and TEM studies demonstrated higher dispersion of cobalt nanoparticles in Co/SBA-16 than in the Co/COK-12 catalyst. During the time-on-stream study the Co/SBA-16 catalyst experienced a gradual deactivation whereas the Co/COK-12 catalyst exhibited constant catalytic performance with respect to the hydrogenation of nitrobenzene. The interconnected cage type pores in Co/SBA-16 catalyst allowed the product molecules to participate in further reactions. This resulted in the formation of condensed products and coke deposition. The Co/SBA-16 catalyst was rapidly deactivated due to pore blocking through coke deposition. N2-Physisorption, TGA, H2-TPR and CHNS elemental analysis of spent catalysts confirmed the severe coke deposition in the Co/SBA-16 catalyst compared to the Co/COK-12 catalyst.
Well-dispersed bimetallic nanoparticles confined in mesoporous metal oxides and their optimized catalytic activity for nitrobenzene hydrogenation
Liu, Juanjuan,Zou, Shihui,Xiao, Liping,Fan, Jie
, p. 441 - 446 (2014)
Well-dispersed bimetallic nanoparticles (BMNPs = PtPd/AuPd/AuPt) confined in mesoporous metal oxides (MMOs = TiO2/Al2O 3/SiO2/ZrO2) are synthesized by a general and mild one-step sol-gel strategy. Thi
Palladium nanoparticles supported on silicate-based nanohybrid material: highly active and eco-friendly catalyst for reduction of nitrobenzene at ambient conditions
Ebadati, Esmat,Aghabarari, Behzad,Bagheri, Mozhgan,Khanlarkhani, Ali,Martinez Huerta, Maria Victoria
, p. 569 - 578 (2021)
In this study, spent bleaching earth (SBE), a hazardous industrial waste was used as raw material to synthesis carbon/silicate nanohybrid material (CSNH) as support for mono and bimetallic palladium and nickel nanoparticles. The synthesized catalysts were
Efficient reduction catalysis of viologen-bound iron porphyrin and its application to six-electron reduction of nitrobenzene to aniline
Sakaki, Shigcyoshi,Koga, Hiroaki,Tao, Kou-Ichiro,Yamashita, Takafumi,Iwashita, Tetsuro,Hamada, Taisuke
, p. 1015 - 1017 (2000)
A newly synthesized methylviologen-bound iron porphyrin chloro(5-{4-[3-(1′-methyl-4,4′-bipyridinium)ethylcarboxyamidyl] phenyl}-10,15,20-triphenylporphyrin)iron dichloride, efficiently catalyzes six-electron reduction of nitrobenzene to aniline, a model reaction of NO2- conversion to NH4+ by nitrite reductase. The Royal Society of Chemistry 2000.
A Modification of the Sheverdina-Kocheshkov Amination: The Use of Methoxyamine-Methyllithium as a Convenient Synthetic Equivalent for NH2+
Beak, Peter,Kokko, Bruce J.
, p. 2822 - 2823 (1982)
Direct stoichiometric amination of organolithiums can be achieved in high yields by methoxyamine and methyllithium in hexane-ether.The synthetic advantages of this approach are noted.
Transition Metal Catalyzed Reduction of Azidoarenes to Aminoarenes with Carbon Monoxide-Water System
Shim, Sang Chul,Choi, Kui Nam,Yeo, Young Kuk
, p. 1149 - 1150 (1986)
Azidoarenes were readily transformed to aminoarenes in good yields under mild conditions with carbon monoxide and water in the presence of a catalytic amount of rhodium(III) complex, which is more catalytically active than rhodium(I) or palladium(II) complexes.
Pd immobilized on polymeric network containing imidazolium salt, cyclodextrin and carbon nanotubes: Efficient and recyclable catalyst for the hydrogenation of nitroarenes in aqueous media
Sadjadi, Samahe,Koohestani, Fatemeh
, (2020)
A novel polymeric network benefiting from the chemistry of imidazolium salt (IL), cyclodextrin (CD) and carbon nanotube (CNT) is fabricated through a multi-step process, in which silica coated CNTs were vinyl functionalized and polymerized with poly (ethy
