Xi:Irritant;
92-52-4Relevant articles and documents
Effect of Chain Length on the Energy Gap in Radical Ions of Oligomeric p-Phenylene
Khanna, Rajive K.,Jiang, Yong M.,Creed, David
, p. 5451 - 5453 (1991)
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Selective Solid State Photooxidant
Morkin, Tracy L.,Turro, Nicholas J.,Kleinman, Mark H.,Brindle, Cheyenne S.,Kramer, Wolfgang H.,Gould, Ian R.
, p. 14917 - 14924 (2003)
Irradiation of biphenyl encapsulated in the cavities of a NaZSM-5 zeolite framework has been reported to result in the formation of an extremely long-lived radical cation. Here, we show that such zeolite encapsulated radical cations can act as irreversible one-electron oxidants for simple alkenes and dienes, in a solid-state analogue to solution-phase cosensitization. Compared to the well-known semiconductor photooxidizers, such as titanium dioxide, the NaZSM-5 zeolite-based solid photooxidants exhibit enhanced selectivity based on oxidation potential, molecular size and shape, and Lewis base character.
Pd nanoparticle supported reduced graphene oxide and its excellent catalytic activity for the Ullmann C-C coupling reaction in a green solvent
Rana, Surjyakanta,Bidita Varadwaj, G. Bishwa,Jonnalagadda, Sreekantha B.
, p. 13332 - 13335 (2019)
An efficient and easy route to synthesize reduced graphene oxide with well dispersed palladium (Pd) nanoparticles (Pd(0)-RGO) is described. The synthesized materials were fully characterized by different techniques such as: XRD, FTIR, Raman, SEM, and TEM. An average particle size of 7.5 nm for the metal particles was confirmed by TEM analysis. Pd(0)-RGO demonstrated outstanding catalytic activity for Ullmann coupling with 97% yield and good reusability (4 cycles).
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Forbes,M.H. et al.
, p. 2762 - 2769 (1961)
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Davis
, p. 3330,3345 (1931)
Development of reactive Pd/Fe bimetallic nanotubes for dechlorination reactions
Zahran, Elsayed M.,Bhattacharyya, Dibakar,Bachas, Leonidas G.
, p. 10454 - 10462 (2011)
We described the synthesis and characterization of a new class of bimetallic nanotubes based on Pd/Fe and demonstrated their efficacy in the dechlorination of PCB 77, a polychlorinated biphenyl. One-dimensional iron metal nanotubes of different diameters were prepared by electroless deposition within the pores of PVP-coated polycarbonate membranes using a simple technique under ambient conditions. The longitudinal nucleation of the nanotubes along the pore walls was achieved by mounting the PC membrane between two halves of a U-shape reaction tube. The composition, morphology, and structure of the Pd/Fe nanotubes were characterized by transmission electron microscopy, scanning electron microscopy, inductively coupled plasma-atomic emission spectroscopy, and X-ray powder diffraction spectroscopy. The as-prepared Pd/Fe bimetallic nanotubes were used in dechlorination of 3,3′,4,4′-tetrachlorobiphenyl (PCB 77). In comparison with Pd/Fe nanoparticles, the Pd/Fe nanotubes demonstrated higher efficiency and faster dechlorination of the PCB.
Bardsley,Hercules
, p. 4545 (1968)
The isomers of [12]annulyne and their reactive relationships to heptalene and biphenyl
Rose, Brad D.,Reiter, Richard C.,Stevenson, Cheryl D.
, p. 8714 - 8718 (2008)
(Chemical Equation Presented) [12]Annulyne not like benzyne: The base-initiated condensation of hexadiyne in nonpolar solvents leads directly to the symmetrical isomers of [12]annulyne, i.e. the all cis isomer, which exists as its cumulene, and the 6,9-tr
Hirokami et al.
, p. 1511,1512 (1971)
Harkins,Gans
, p. 2578,5165, 5169 (1930)
Complete and truly catalytic degradation method of PCBs using Pd/C-Et3N system under ambient pressure and temperature
Sajiki, Hironao,Kume, Akira,Hattori, Kazuyuki,Nagase, Hisamistu,Hirota, Kosaku
, p. 7251 - 7254 (2002)
Since PCBs are persistent toxic pollutants and do not degrade easily, the development of a safe and perfect methodology for destruction of such remains is of great importance. We have found that the catalyst activity of Pd/C toward the hydrodechlorination of PCBs was outstandingly activated by the addition of triethylamine. PCBs could be thoroughly dechlorinated under ambient temperature and pressure, and no product other than biphenyl has been detected by GC/MS.
Catalytic hydrogenolysis of an aryl-aryl carbon-carbon bond with a rhodium complex
Perthuisot,Jones
, p. 3647 - 3648 (1994)
In catalytic hydrogenolysis of an aryl-aryl carbon-carbon bond with a rhodium complex, we used a rhodium system that should provide a thermodynamically favored C-C cleavage complex by making strong metal-aryl bonds. The cleavage of the well-hidden carbon-carbon bond of biphenylene is described which relies both on a strained four membered ring and on the formation of a stable pentametallacycle. The results show that C-H activation and coordination are probably involved in the process leading to C-C bond cleavage.
Desulfurization of dibenzothiophene and oxidized dibenzothiophene ring systems
Morales, Diego P.,Taylor, Alexander S.,Farmer, Steven C.
, p. 1265 - 1269 (2010)
Lithium, used in conjunction with sodium metal, produces a high yield of biphenyl when reacted with dibenzothiophene, dibenzothiophene sulfoxide or dibenzothiophene sulfone.
A new method for preparing the hydrocarbons, "diphenyl" and "iso-dinaphthyl," and on the action, at a high temperature, of metallic chlorides upon certain hydrocarbons
Smith, Watson
, p. 30 - 33 (1876)
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Synthesis, characterization and catalytic performance of meso-microporous material Beta-SBA-15-supported NiMo catalysts for hydrodesulfurization of dibenzothiophene
Zhang, Dengqian,Duan, Aijun,Zhao, Zhen,Wang, Xianqin,Jiang, Guiyuan,Liu, Jian,Wang, Chengyin,Jin, Mingcheng
, p. 477 - 484 (2011)
Micro-mesoporous composite material Beta-SBA-15 (BS) with the Beta structure and SBA-15 mesoporous structure was synthesized and used as catalyst support for hydrodesulfurization (HDS) of dibenzothiophene (DBT). The supports and catalysts were characterized by various techniques including XRD, nitrogen adsorption, SEM, TEM, 27Al MAS NMR, and Pyridine-FTIR. The characterization results demonstrated that NiMo/BS had similar acidity to NiMo/Beta, and possessed more acid sites and stronger acidity than NiMo/SBA-15 and NiMo/Al2O3. Activity evaluation results showed that NiMo/BS exhibited the highest DBT HDS activity among all the catalysts that were studied, and the DBT conversion on NiMo/BS was about 1.6 times as much as that on NiMo/Al2O3 at weight time of 0.75 g min mol -1. The better catalytic performance of NiMo/BS was attributed to the superiorities of the pore structure and large amounts of acid sites of micro-mesoporous BS.
Efficient catalysis of the Suzuki-Miyaura reaction under mild conditions with cyclopalladated N,N-dimethylaminomethylferrocene
Gorunova,Zykov,Livantsov,Kochetkov,Grishin,Dunina
, p. 1840 - 1842 (2010)
High catalytic activity of N,N-dimethylaminomethylferrocene cyclopalladated derivative was demonstrated in the the Suzuki-Miyaura cross-coupling of aryl bromides with phenylboronic acid, which allowed us to carry out the reaction under extremely mild conditions.
The dechlorination of polychlorinated biphenyls by UV-irradiation. IX. Reactions of monochlorobiphenyls in a 2-propanol solution
Nishiwaki,Shinoda,Anda,Hida
, p. 3569 - 3572 (1982)
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Highly active palladium-based catalyst system for the aerobic oxidative direct coupling of benzene to biphenyl
Liu, Yangqing,Wang, Xiaochen,Cai, Xiaochun,Chen, Guojian,Li, Jing,Zhou, Yu,Wang, Jun
, p. 448 - 454 (2016)
A highly efficient Pd-containing catalytic system for the intermolecular direct C-H homocoupling of benzene to biphenyl has been developed. The catalytic system was composed of Pd(OAc)2 with trifluoromethanesulfonic acid (TfOH) as an additive and O2 as the sole oxygen source in the absence of any metal-containing cocatalyst. An excellent efficiency of PdII with the acidic additive was attained in the aerobic oxidation of benzene to biphenyl. A high yield (25.3 %) and selectivity (98 %) were achieved by using a small amount of Pd(OAc)2 (0.07 mol %) and TfOH, which gave a high turnover number (180) for Pd species. Theoretical calculation by DFT and UV/Vis absorption spectra illustrated that the formation of electropositive PdII species in the presence of TfOH contributed to the high efficiency of the catalytic system. The acids have it: A highly efficient Pd-based catalytic system is constructed for the direct oxidative coupling of benzene with dioxygen to biphenyl with the C-H activation strategy. The system exhibits an extremely high turnover number of 180, which is accomplished with the aid of CF3SO3H without a metal-bearing cocatalyst.
Sc3+-triggered oxoiron(IV) formation from O2 and its non-heme iron(II) precursor via a Sc3+-peroxo-Fe3+ intermediate
Li, Feifei,Van Heuvelen, Katherine M.,Meier, Katlyn K.,Muenck, Eckard,Que, Lawrence
, p. 10198 - 10201 (2013)
We report that redox-inactive Sc3+ can trigger O2 activation by the FeII(TMC) center (TMC = tetramethylcyclam) to generate the corresponding oxoiron(IV) complex in the presence of BPh 4- as an electron donor. To model a possible intermediate in the above reaction, we generated an unprecedented Sc3+ adduct of [FeIII(η2-O2)(TMC)]+ by an alternative route, which was found to have an Fe3+-(μ- η2:η2-peroxo)-Sc3+ core and to convert to the oxoiron(IV) complex. These results have important implications for the role a Lewis acid can play in facilitating O-O bond cleavage during the course of O2 activation at non-heme iron centers.
Photochemistry of dibenzothiophene-S,S-dioxide: Reactions of a highly constrained biradical
Jenks, William S.
, p. 7155 - 7158 (1994)
Photolysis of dibenzothiophene sulfoxide in isopropranol provides biphenyl in quantitative yield via two sequential photochemical reactions. Mechanistic aspects of the reaction are discussed, including the unusual observation that isoprene increases the quantum of loss of starting material.
Kinetic Control in Two-Electron Homogeneous Redox Electrocatalysis. Reduction of Monohalobiphenyls
Arena, James V.,Rusling, James F.
, p. 3368 - 3373 (1987)
Kinetic control of the two-electron electrocatalytic dehalogenation of monohalobiphenyls to biphenyl was elucidated by analyzing voltammetric data with expanded-grid digital simulation/nonlinear regression.The method involves comparing goodness of fit of limited and mixed kinetic simulation models to the data and is applicable to second-order conditions.The rate-determining step in the dehalogenations was confirmed as electron transfer between the electrochemically generated phenanthridine anion radical and 4-chloro- (4-CB) and 4-bromobiphenyl (4-BB), rather than decomposition of the halobiphenyl anion radical.Rate constants for this step of (1.42 +/- 0.12) * 103 M-1 s-1 for 4-CB and (5.1 +/- 1.8) * 104 M-1 s-1 for 4-BB showed considerably improved precision (and accuracy in the latter case) over rate constants obtained under pseudo-first-order conditions, where the catalytic current had to be extracted from large currents for direct reduction of excess substrate.The simulation/regression method is general for two-electron homogeneous electrocatalytic reactions following similar mechanisms.Synthetic data were used to show that, for systems under mixed kinetic control, rate constants for both homogeneous electron transfer and decomposition of the haloaromatic anion radical can be estimated simultaneously.
Magnetically retrievable silica-based nickel nanocatalyst for Suzuki-Miyaura cross-coupling reaction
Sharma, Rakesh Kumar,Yadav, Manavi,Gaur, Rashmi,Monga, Yukti,Adholeya, Alok
, p. 2728 - 2740 (2015)
A new magnetically recoverable silica-based nickel nanocatalyst was synthesized, characterized and applied for the first time as a catalyst in Suzuki-Miyaura cross-coupling reaction. Excellent catalytic activity, ease of recovery and reusability up to six cycles without appreciable loss of performance make the present protocol beneficial from industrial and environmental viewpoints.
Hydrodesulfurization of dibenzothiophene using Pd-promoted Co-Mo/Al2O3 and Ni-Mo/Al2O3 catalysts coupled with ionic liquids at ambient operating conditions
Muhammad, Yaseen,Rahman, Ata Ur,Rashid, Haroon Ur,Sahibzada, Maria,Subhan, Sidra,Tong, Zhangfa
, p. 10371 - 10385 (2019)
Sulfur compounds in fuel oils are a major source of atmospheric pollution. This study is focused on the hydrodesulfurization (HDS) of dibenzothiophene (DBT) via the coupled application of 0.5 wt% Pd-loaded Co-Mo/Al2O3 and Ni-Mo/Al2O3 catalysts with ionic liquids (ILs) at ambient temperature (120 °C) and pressure (1 MPa H2). The enhanced HDS activity of the solid catalysts coupled with [BMIM]BF4, [(CH3)4N]Cl, [EMIM]AlCl4, and [(n-C8H17)(C4H9)3P]Br was credited to the synergism between hydrogenation by the former and extractive desulfurization and better H2 transport by the latter, which was confirmed by DFT simulation. The Pd-loaded catalysts ranked highest by activity i.e. Pd-Ni-Mo/Al2O3 > Pd-Co-Mo/Al2O3 > Ni-Mo/Al2O3 > Co-Mo/Al2O3. With mild experimental conditions of 1 MPa H2 pressure and 120 °C temperature and an oil:IL ratio of 10:3.3, DBT conversion was enhanced from 21% (by blank Ni-Mo/Al2O3) to 70% by Pd-Ni-Mo/Al2O3 coupled with [(n-C8H17)(C4H9)3P]Br. The interaction of polarizable delocalized bonds (in DBT) and van der Waals forces influenced the higher solubility in ILs and hence led to higher DBT conversion. The IL was recycled four times with minimal loss of activity. Fresh and spent catalysts were characterized by FESEM, ICP-MS, EDX, XRD, XPS and BET surface area techniques. GC-MS analysis revealed biphenyl as the major HDS product. This study presents a considerable advance to the classical HDS processes in terms of mild operating conditions, cost-effectiveness, and simplified mechanization, and hence can be envisaged as an alternative approach for fuel oil processing.
A mild and efficient process for detoxifying polychlorinated biphenyls
Boyer,McKenna,Karliner,Nirsberger
, p. 3677 - 3680 (1985)
Polychlorinated biphenyls (PCBs) were effectively dechlorinated to biphenyl under mild conditions using an aqueous solution of sodium hypophosphite in the presence of a palladium catalyst.
Beck,Thomas
, p. 3856,3858,3859 (1972)
Research on the decomposition kinetics and thermal hazards of aniline diazonium salt
Du, Lei,Wang, Ben,Xie, Chuanxin,Yuan, Yucan
, (2022/01/22)
Diazotization reaction, strong exothermic characteristics and thermal instability of diazonium salts make the production process high risk. To research thermal hazards of aniline diazonium salt, dynamic experiments are carried out by the differential scanning calorimeter (DSC) to obtain thermodynamic parameters. Moreover, the kinetic parameters are analyzed by Advanced Kinetics and Technology Solutions (AKTS) software. Finally, the GC-MS and UV spectrum are used to further study the decomposition mechanism of the aniline diazonium salt. The results indicate that aniline diazonium salt is very easy to decompose. When the heating rate is 2 K/min, the onset decomposition temperature is only 27.21 ℃ (Tonset). The apparent activation energy of the decomposition process calculated by Friedman and Ozawa methods are respectively 98-85 kJ/mol and 110-100 kJ/mol. Under the ideal adiabatic conditions (φ = 1), the initial temperatures of TMRad for 24 h is only 6.2 ℃ (TD24), which is predicted by the AKTS software. The decomposition process of aniline diazonium salt is inconsistent with a single reaction mechanism.
AgF-Mediated Electrophilic Amination of Alkoxyarylsilanes with Azodicarboxylates
Deng, Shijun,Li, Dong,Shimokawa, Jun,Yorimitsu, Hideki,Zhang, Qian
supporting information, (2022/01/31)
A facile and efficient AgF-mediated electrophilic amination of alkoxyarylsilanes with azodicarboxylates was developed. The reaction proceeds in green solvent under simple and mild conditions to generate the corresponding aryl hydrazines. AgF acts both as a stoichiometric fluoride source and a reagent for transmetalation to the arylsilver intermediate that eventually reacts with azodicarboxylates to provide aryl hydrazines.
Palladium-catalyzed aryl group transfer from triarylphosphines to arylboronic acids
Enright, Dale R.,Gogate, Akash R.,Smoliakova, Irina P.,Vasireddy, Purna C. R.
, (2021/11/11)
A study of Pd-catalyzed arylation of arylboronic acids with triarylphosphines is presented. Various parameters of this transformation, such as the oxygen presence, choice of solvent, temperature, palladium source, bases and oxidants, were tested and the optimal conditions of the aryl transfer were determined. The effect of electron-withdrawing and electron-donating substituents on the aryl groups of both reactants was also investigated. The unusual transfer of the acetate group from Pd(OAc)2 to p-nitrophenylboronic acid in the presence of PAr3 is reported. A plausible mechanism of the Pd-catalyzed aryl group transfer from PAr3 to the arylboronic acid is proposed.
