- Decamethylosmocene-catalyzed efficient oxidation of saturated and aromatic hydrocarbons and alcohols with hydrogen peroxide in the presence of pyridine
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Decamethylosmocene, (Me5C5)2Os (1), is a pre-catalyst in a very efficient oxidation of alkanes with hydrogen peroxide in acetonitrile at 20-60 °C. The reaction proceeds with a substantial lag period that can be reduced by the addition of pyridine in a small concentration. The lag period can be removed if 1 is incubated with pyridine and/or H 2O2 in MeCN prior to the alkane oxidation. Alkanes, RH, are oxidized primarily to the corresponding alkyl hydroperoxides, ROOH. Turnover numbers attain 51,000 in the case of cyclohexane (maximum turnover frequency was 6000 h-1) and 3600 in the case of ethane. The oxidation of benzene and styrene also occurs with a lag period to afford phenol and benzaldehyde, respectively. A kinetic study of cyclohexane oxidation and selectivity parameters (measured in the oxidation of n-heptane, methylcyclohexane, isooctane, cis- and trans-dimethylcyclohexanes) indicates that the oxidation of saturated, olefinic, and aromatic hydrocarbons proceeds with the participation of hydroxyl radicals. The 1/H2O 2/py/MeCN system also oxidizes 1-phenylethanol to acetophenone.
- Shul'Pin, Georgiy B.,Kirillova, Marina V.,Kozlov, Yuriy N.,Shul'Pina, Lidia S.,Kudinov, Alexander R.,Pombeiro, Armando J.L.
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- Copper(II) complex of the 2-pyridinecarbaldehyde aminoguanidine Schiff base: Crystal structure and catalytic behaviour in mild oxidation of alkanes
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The new neutral dichloro-copper(II) Schiff base complex [CuCl2L]·dmf 2, where L results from condensation of 2-pyridinecarbaldehyde and aminoguanidine, was prepared, while the ligand itself was isolated in its protonated form as the dinitrate salt (H2L)(NO3)2 1. Extended conjugation is responsible for the planarity of the H2L2?+ cation in 1. On coordination, L forms two fused 5-membered chelate rings occupying three equatorial positions of the distorted square pyramidal copper polyhedron in 2. The catalytic investigations disclosed a prominent activity of the copper compound 2 towards oxidation of cyclohexane with hydrogen peroxide in the presence of various promoters (nitric and acetic acids, pyridine and pyrrole), showing overall yields of products (cyclohexanol and cyclohexanone) up to 21% based on the substrate.
- Buvaylo, Elena A.,Kokozay, Vladimir N.,Vassilyeva, Olga Yu.,Skelton, Brian W.,Nesterova, Oksana V.,Pombeiro, Armando J.L.
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- Vanadium(IV) complexes with picolinic acids in NaY zeolite cages: Synthesis, characterization and catalytic behaviour
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Encapsulated vanadium picolinic complexes have been synthesized by treatment of a dehydrated form of VO2+-NaY zeolite with molten picolinic acids and characterized by X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS), X-ray absorption near-edge structure (XANES), EPR, FTIR and UV-VIS spectroscopies, and XRD. It was suggested by XRD and XPS that the complexes were located in the zeolite cavities. Differences in the spectroscopic properties of encapsulated and impregnated samples were explained in terms of coordination of vanadium complexes with zeolite -OH groups. The stability of VO(pic)2 and its adduct with pyridine depended strongly on the complex location. The encapsulated vanadium picolinate complex retained solution-like activity in the liquid-phase oxidation of hydrocarbons and alcohols with hydrogen peroxide.
- Kozlov, Alexander,Asakura, Kiyotaka,Iwasawa, Yasuhiro
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- Synthesis, characterization and catalase-like activity of the tetranuclear iron(III) complex involving a (μ-oxo)(μ-hydroxo)bis(μ-alkoxo) tetra(μ-carboxylato)tetrairon core
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The synthesis, characterization and catalase-like activity of the tetranuclear complex [Fe4(μ-O)(μ-OH)(μ-OAc) 4(L)2](ClO4)3 (HL is the ligand 1,3-bis[(2-aminoethyl)amino]-2-propanol) is described herein. The complex was obtained from the self-assembly of Fe(ClO4)3· xH2O, NaOAc·3H2O and HL. The X-ray structural elucidation, together with spectroscopic and ESI-MS data, disclosed a (μ-oxo)(μ-hydroxo)bis(μ-alkoxo)tetra(μ-carboxylato)tetrairon core structure that can be described as a dimer of dimer, where the four metallic centers are embedded in the same chemical environment. The kinetics of the catalase-like activity was investigated in water, TRIS buffer and acetonitrile, and it revealed a Michaelis-Menten behavior. The progress of H2O 2 disproportionation reactions was followed by UV-Vis, ESI-MS/Q-TOF and EPR, indicating the disruption of the tetranuclear core, which was accelerated at higher proton concentration. The rate constant was higher in CH3CN than in aqueous solution (kobs(CH3CN) > kobs(buffer) > kobs(H2O)).
- Pires, Bianca M.,Silva, Daniel M.,Visentin, Lorenzo C.,Drago, Valderes,Carvalho, Nakédia M.F.,Faria, Roberto B.,Antunes
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- Efficient oxidation of cycloalkanes with simultaneously increased conversion and selectivity using O2 catalyzed by metalloporphyrins and boosted by Zn(AcO)2: A practical strategy to inhibit the formation of aliphatic diacids
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The direct sources of aliphatic acids in cycloalkanes oxidation were investigated, and a strategy to suppress the formation of aliphatic acids was adopted through enhancing the catalytic transformation of oxidation intermediates cycloalkyl hydroperoxides to cycloalkanols by Zn(II) and delaying the emergence of cycloalkanones. Benefitted from the delayed formation of cycloalkanones and suppressed non-selective thermal decomposition of cycloalkyl hydroperoxides, the conversion of cycloalkanes and selectivity towards cycloalkanols and cycloalkanones were increased simultaneously with satisfying tolerance to both of metalloporphyrins and substrates. For cyclohexane, the selectivity towards KA-oil was increased from 80.1% to 96.9% meanwhile the conversion was increased from 3.83 % to 6.53 %, a very competitive conversion level with higher selectivity compared with current industrial process. This protocol is not only a valuable strategy to overcome the problems of low conversion and low selectivity lying in front of current cyclohexane oxidation in industry, but also an important reference to other alkanes oxidation.
- Shen, Hai-Min,Wang, Xiong,Ning, Lei,Guo, A-Bing,Deng, Jin-Hui,She, Yuan-Bin
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- Tailoring the electron density of cobalt oxide clusters to provide highly selective superoxide and peroxide species for aerobic cyclohexane oxidation
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The catalytic aerobic cyclohexane oxidation to cyclohexanol and cyclohexanone (KA oil) is an industrially relevant reaction. This work is focused on the synthesis of tailor-made catalysts based on the well-known Co4O4 core in order to successfully deal with cyclohexane oxidation reaction. The catalytic activity and selectivity of the synthesized catalysts can be correlated with the electronic density of the cluster, modulated by changing the organic ligands. This is not trivial in cyclohexane oxidation. Furthermore, the reaction mechanism is discussed on the basis of kinetics and spin trapping experiments, confirming that the electronic density of the catalyst has a clear influence on the distribution of the reaction products. In addition, in situ Raman spectroscopy was used to characterize the oxygen species formed on the cobalt cluster during the oxidation reaction. Altogether, it can be concluded that the catalyst with the highest oxidation potential promotes the formation of peroxide and superoxide species, which is the best way to oxidize inactivated CH bonds in alkanes. Finally, based on the results of the mechanistic studies, the contribution of these cobalt oxide clusters in each single reaction step of the whole process has been proposed.
- Gaona-Miguélez, José,Gutiérrez-Tarri?o, Silvia,O?a-Burgos, Pascual
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supporting information
p. 15370 - 15379
(2021/11/17)
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- Facile Peroxidation of Cyclohexane Catalysed by In Situ Generated Triazole-Functionalised Schiff Base Copper Complexes
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A set of facile room temperature catalytic systems for the oxidation of cyclohexane C–H bonds was developed from in situ generated triazole-functionalised Schiff base copper complexes. The combination of a new triazolium-functionalised Schiff base, [(E)-3-methyl-1-propyl-4-(2-(((2-(pyridin-2-yl)ethyl)imino)methyl)phenyl)-1H-1,2,3-triazol-3-ium hexafluorophosphate(V), 2] with a range of bench-top Cu(I) and Cu(II) salts (Cu2O, CuO, Cu(CH3CN)4PF6, CuSO4·5H2O, Cu2(OAc)4·2H2O, CuCl2, Cu(NO3)2·3H2O) as catalysts were screened under varying reaction conditions for the peroxidation of cyclohexane using hydrogen peroxide as a green source of oxygen. High conversions to oxidised products were obtained with up to 80% in 6?h for the 2/CuSO4·5H2O system at 1?mol% catalyst concentration under optimised reaction conditions. All the copper salts yielded the ketone–alcohol (K–A) oil containing varying ratios of cyclohexanol and cyclohexanone. The results also showed that at room temperature, the various in situ generated copper catalysts exclusively yielded only the K–A oil. Furthermore, by changing the reaction temperature to reflux in acetonitrile and depending on the starting substrate (cyclohexane, cyclohexanol or cyclohexanone), 23–100% of adipic acid was also obtained. The kinetics study for the peroxidation reaction reveals activation energy of 12.29 ± 2?kJ/mol following a copper initiated radical mechanism. Graphic Abstract: [Figure not available: see fulltext.]
- Bala, Muhammad D.,Ibrahim, Halliru,Lawal, Nasir S.
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- Method for synergistically catalyzing and oxidizing cycloparaffin through confined metalloporphyrin cobalt (II)/Cu (II) salt
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The invention discloses a method for synergistically catalyzing and oxidizing cycloparaffin through confined metalloporphyrin cobalt (II)/Cu (II) salt. The preparation method comprises the following steps: dispersing confined metalloporphyrin cobalt (II) (0.001%-5%, g/mol) and Cu (II) salt (0.01%-10%, mol/mol) into cycloparaffin; and sealing the reaction system, heating the temperature to 90-150 DEG C while stirring, introducing an oxidant, keeping the set temperature and pressure, carrying out stirring and reacting for 2.0-24.0 hours, and carrying out after-treatment on the reaction solutionto obtain the products cycloalkyl alcohol and cycloalkyl ketone. The method disclosed by the invention has the advantages of high cycloalkyl alcohol and cycloalkyl ketone selectivity, low reaction temperature, few byproducts, small environmental influence and the like. In addition, the content of cycloalkyl hydroperoxide is low, and the safety coefficient is high. The invention provides an efficient, feasible and safe method for synthesizing cycloalkyl alcohol and cycloalkyl ketone through selective catalytic oxidation of cycloparaffin.
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Paragraph 0065-0068
(2020/12/10)
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- Method for catalytic oxidation of cycloalkane by confinement porphyrin Co (II)
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The invention relates to a method for catalytic oxidation of cycloalkane by confinement porphyrin Co (II). The method comprises the following steps: dispersing confinement cobalt porphyrin (II) in cycloalkane, sealing the reaction system, heating to 100-130 DEG C while stirring, introducing oxygen to 0.2-3.0 MPa, keeping the set temperature and oxygen pressure, stirring to react for 3.0-24.0 h, and carrying out post-treatment on a reaction solution to obtain products naphthenic alcohol and naphthenic ketone. The method achieves high selectivity of naphthenic alcohol and naphthenic ketone, andeffectively inhibits the generation of aliphatic diacid. The aliphatic diacid is low in selectivity, so that the continuity of the cycloalkane oxidation process and the separation of the products arefacilitated; the method has the potential of solving the problem that naphthenic alcohol and naphthenic ketone are easily and deeply oxidized to generate aliphatic diacid in the industrial cycloalkanecatalytic oxidation process; and the method is a novel efficient and feasible method for selective catalytic oxidation of cycloalkane.
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Page/Page column 8-10
(2020/05/01)
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- Confinement porphyrin Co (II), and preparation method and application thereof
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Confinement porphyrin Co (II). A preparation method includes: under acidic condition, performing condensation on aromatic aldehyde and pyrrole in equal molar ratio to obtain a phenylporphyrin compound, and carrying out metallization in a chloroform-methanol solution to obtain porphyrin Cu (II), performing bromination and demetalization by perchloric acid to obtain confinement porphyrin, performingstirring reflux on the confinement porphyrin in a methanol solution for 12.0-24.0 h to obtain confinement porphyrin Co (II). An application includes: dissolving the confinement porphyrin Co (II) in naphthenic hydrocarbon and sealing the reaction system, stirring and heating the reaction system to 100-130 DEG C and feeding oxygen to 0.2-3.0 MPa; maintaining the set temperature and oxygen pressureand performing a stirring reaction for 3.0-24.0 h; performing after treatment on the reaction liquid to prepare the product. In the invention, generation of fatty diacid is effectively inhibited, andcontinuity of a naphthenic hydrocarbon oxidization process and product separation is facilitated. The invention has the potential of solving the problem that naphthene alcohols and naphthene ketones are liable to undergo deep oxidization and form the fatty diacid in an industrial naphthenic hydrocarbon catalytic oxidation process.
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Paragraph 0061-0098; 0107-0108
(2020/04/17)
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- Generation of gold nanoclusters encapsulated in an MCM-22 zeolite for the aerobic oxidation of cyclohexane
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In this work, we will report the generation of Au clusters in a purely siliceous MCM-22 zeolite. The catalytic properties of these Au clusters have been tested for the selective oxidation of cyclohexane to cyclohexanol and cyclohexanone (KA-oil). The Au clusters encapsulated in the MCM-22 zeolite are highly active and selective for the oxidation of cyclohexane to KA-oil, which is superior to Au nanoparticles on the same support. These results suggest that Au clusters are highly active for the activation of oxygen to produce radical species.
- Liu, Lichen,Arenal, Raul,Meira, Debora M.,Corma, Avelino
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supporting information
p. 1607 - 1610
(2019/02/07)
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- Ru(III) complexes of phenoxy-imine ligands: Synthesis, characterisation and testing as oxidation catalysts
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Summary: A series of new mononuclear Ru(III) complexes bearing phenoxy-imine Schiff base tetradentate ligands (phenylimino, 4-chlore phenylimino, 3,4-dichlore phenylimino) have been prepared and characterized by elemental analysis, TGA, UV-VIS, FT-IR, 1H-NMR and 13C NMR spectra. The proposed structure of the ligands have a O2N2 core to form mononuclear Ru (III) complexes. Preliminary studies on the catalytic performances of the compounds in the cycloalkane oxydation are described. The catalytic effect of all Ru complexes results in the epoxidation reaction of cyclohexane, as shown in the substrate conversion reaction appears to be very high.
- ?apan, Ali,Ceyhan, G?khan,S?nmez, Mehmet
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p. 758 - 769
(2019/10/28)
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- Method for preparing naphthenic alcohol and naphthenone by using molecular oxygen to selectively oxidize naphthenic hydrocarbon under synergistic catalysis of cobalt (II) salt/copper (II) salt
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The invention provides a method for preparing naphthenic alcohol and naphthenone by using molecular oxygen to selectively oxidize naphthenic hydrocarbon under synergistic catalysis of a cobalt (II) salt/copper (II) salt. The method comprises the following steps: in an agate ball-milling tank, ball-milling a main catalyst cobalt (II) salt and a cocatalyst copper (II) salt at room temperature according to a molar ratio to obtain a cobalt (II) salt/copper (II) salt composite catalyst; in a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene liner, dispersing the cobalt (II) salt/copper (II) salt composite catalyst into the naphthenic hydrocarbon, sealing the reaction kettle, conducting stirring and heating, and introducing an oxidizing agent oxygen; maintaining a settemperature and oxygen pressure to perform stirring reaction; and after the reaction, adding triphenylphosphine into a reaction mixture, and conducting stirring to reduce a generated peroxide at roomtemperature, so as to obtain the naphthenic alcohol and the naphthenone. The catalyst is cheap and easily available and the synthesis cost is low; the selectivity is high and generation of aliphatic diacid is effectively inhibited; and the aliphatic diacid selectivity is low, and continuity of the naphthenic hydrocarbon oxidization process and separation of products are facilitated.
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Paragraph 0058-0065; 0078-0079; 0096-0101; 0114-0115
(2020/01/03)
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- Method for (II) preparing/cycloalkanol and cycloalkanone by synergetic (II) catalysis of molecular oxygen-selective oxidation of cycloalkane by using cobalt salt, namely, zinc salt of zinc salt (by machine translation)
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In a stainless steel (II) high /(II) pressure reaction kettle with a polytetrafluoroethylene inner container, the cobalt salt is stirred and heated at room temperature to give an oxidant oxygen (II); a set temperature (II) and an oxygen pressure stirring reaction are kept; and the reaction (II) mixture/is (II) stirred and reduced to generate a peroxide, namely cycloalkanol and cycloalkanone (II)/(II). The catalyst has the advantages of cheap and easily available catalyst, low synthesis cost, high selectivity, effective inhibition of generation of aliphatic diacid, low selectivity of aliphatic diacid, and facilitation of serialization of the naphthenic acid process and separation of products. (by machine translation)
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Paragraph 0055-0100; 0107-0112
(2019/12/08)
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- New mononuclear dioxidomolybdenum(VI) complexes with hydrazone ligands: Synthesis, crystal structures and catalytic performance
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Three new dioxomolybdenum (VI) complexes, [MoO2L1(MeOH)] (1), [MoO2L2(MeOH)] (2) and [MoO2L3(H2O)]·EtOH (3), where L1, L2 and L3 are the dianionic form of N′-(2-hydroxybenzylidene)-3-methylbenzohydrazide, 4-bromo-N′-(2-hydroxybenzylidene)benzohydrazide and 2-bromo-N′-(2-hydroxy benzylidene)benzohydrazide, respectively, have been prepared and characterized by IR, UV–Vis and NMR spectra, as well as single crystal X-ray diffraction. The Mo atoms in the complexes are in octahedral coordination, with the ONO donor set of the hydrazone ligands, O atoms of the solvents, and two oxo groups. Crystals of the complexes are stabilized by hydrogen bonds of types O–H?N and O–H?O. Moreover, the catalytic properties of complexes 1–3 are compared in cyclohexane oxidation. It was found that sebacic acid and FeCl3 could promote the catalytic activities of the complexes.
- Wang, Cong,Xing, Na,Feng, Wenjing,Guo, Sihan,Liu, Mingyang,Xu, Yue,You, Zhonglu
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p. 625 - 635
(2018/12/05)
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- Vanadium complexes of different nuclearities in the catalytic oxidation of cyclohexane and cyclohexanol-an experimental and theoretical investigation
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The mono-, bi-and tri-nuclear oxidovanadium(v) complexes [VO(OEt)(L1)] (1), [{VO(OEt)(EtOH)}2(L2)] (2) and [{VO(OMe)(H2O)}3(L3)]·2H2O (3) (L1 = 2-hydroxy-(2-hydroxybenzylidene)benzohydrazide, L2 = bis(2-hydroxybenzylidene)terephthalohydrazide and L3 = tris(2-hydroxybenzylidene)benzene-1,3,5-tricarbohydrazide) (3 was synthesized for the first time) were used to investigate the role of vanadium nuclearity in the catalytic oxidation of cyclohexane and cyclohexanol. They are active homogeneous catalysts for the microwave-assisted neat peroxidative oxidation of cyclohexane (with aq. H2O2 to cyclohexanol and cyclohexanone) and cyclohexanol (with aq. tBuOOH to cyclohexanone). A mechanism of the HO radical generation-the rate limiting step of the cyclohexane oxidation by H2O2-was investigated in detail by theoretical DFT methods. The mechanism is different from those usually accepted for the Fenton or Fenton-like systems and it includes (i) coordination of H2O2 to the catalyst molecule, (ii) proton transfer from ligated H2O2 to the methoxy ligand and elimination of the formed methanol molecule and (iii) coordination of the second H2O2 molecule followed by HO-OH bond cleavage to give HO. The activation of the ligated H2O2 towards this cleavage is associated with the redox active nature of the ligand L in the catalyst molecule, which acts (instead of the metal) as the reducing agent of the H2O2 ligand.
- Sutradhar, Manas,Martins, Luísa M. D. R. S.,Roy Barman, Tannistha,Kuznetsov, Maxim L.,Guedes Da Silva, M. Fátima C.,Pombeiro, Armando J. L.
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p. 17557 - 17570
(2019/11/25)
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- New oxidovanadium(iv) complex with a BIAN ligand: synthesis, structure, redox properties and catalytic activity
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Reaction of VCl3 with bis[N-(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) in air afforded [VOCl2(dpp-bian)] (1). The complex was characterized by IR and UV-vis spectroscopies and elemental analysis. The crystal structure of 1 was determined by X-ray diffraction (XRD) analysis. The vanadium atom is in a square-pyramidal OCl2N4 coordination environment. The cyclic voltammogram (CV) in dichloromethane reveals an irreversible oxidation process at +1.40 V (vs. Ag/AgCl) assigned to the V(iv)/V(v) couple, and two consecutive quasi-reversible one-electron reduction processes at ?0.32 V and ?1.05 V (vs. Ag/AgCl), respectively, assigned to the bian/bian?/ and bian?//bian2? couples, followed by irreversible reduction at ?1.6 V (vs. Ag/AgCl). The EPR spectrum of 1 in toluene shows a single 8-line signal typical for oxidovanadium(iv) complexes with d1 configuration. The magnetic behavior of 1 confirms the presence of one unpaired electron (μeff (330 K) = 1.67 μB), and the isolation of the paramagnetic centers. Application of 1 to oxidation of alkanes documented high catalytic activity under mild conditions. The kinetics and selectivity of alkane oxygenation by the 1/H2O2 and 1/PCA/H2O2 systems (PCA is pyrazine-2-carboxylic acid) were studied. The reaction is more efficient in the presence of PCA.
- Fomenko, Iakov S.,Gushchin, Artem L.,Shul'pina, Lidia S.,Ikonnikov, Nikolay S.,Abramov, Pavel A.,Romashev, Nikolay F.,Poryvaev, Artem S.,Sheveleva, Alena M.,Bogomyakov, Artem S.,Shmelev, Nikita Y.,Fedin, Matvey V.,Shul'pin, Georgiy B.,Sokolov, Maxim N.
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supporting information
p. 16200 - 16210
(2018/10/04)
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- High Catalytic Activity of Vanadium Complexes in Alkane Oxidations with Hydrogen Peroxide: An Effect of 8-Hydroxyquinoline Derivatives as Noninnocent Ligands
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Five monomeric oxovanadium(V) complexes [VO(OMe)(NO)2] with the nitro or halogen substituted quinolin-8-olate ligands were synthesized and characterized using Fourier transform infrared, 1H and 13C NMR, high-resolution mass spectrometry-electrospray ionization as well as X-ray diffraction and UV-vis spectroscopy. These complexes exhibit high catalytic activity toward oxidation of inert alkanes to alkyl hydroperoxides by H2O2 in aqueous acetonitrile with the yield of oxygenate products up to 39% and turnover number 1780 for 1 h. The experimental kinetic study, the C6D12 and 18O2 labeled experiments, and density functional theory (DFT) calculations allowed to propose the reaction mechanism, which includes the formation of HO· radicals as active oxidizing species. The mechanism of the HO· formation appears to be different from those usually accepted for the Fenton or Fenton-like systems. The activation of H2O2 toward homolysis occurs upon simple coordination of hydrogen peroxide to the metal center of the catalyst molecule and does not require the change of the metal oxidation state and formation of the HOO· radical. Such an activation is associated with the redox-active nature of the quinolin-8-olate ligands. The experimentally determined activation energy for the oxidation of cyclohexane with complex [VO(OCH3)(5-Cl-quin)2] (quin = quinolin-8-olate) is 23 ± 3 kcal/mol correlating well with the estimate obtained from the DFT calculations.
- Gryca, Izabela,Czerwińska, Katarzyna,MacHura, Barbara,Chrobok, Anna,Shul'Pina, Lidia S.,Kuznetsov, Maxim L.,Nesterov, Dmytro S.,Kozlov, Yuriy N.,Pombeiro, Armando J. L.,Varyan, Ivetta A.,Shul'Pin, Georgiy B.
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supporting information
p. 1824 - 1839
(2018/02/27)
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- High-Cluster (Cu9) Cage Silsesquioxanes: Synthesis, Structure, and Catalytic Activity
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Unusual high-cluster (Cu9) cage phenylsilsesquioxanes were obtained via complexation of in situ CuII,Na-silsesquioxane species formed with phenanthroline and neocuproine. In the first case, phenanthroline, acting as "a silent ligand" (not participating in the composition of the final product), favors the formation of an unprecedented cagelike phenylsilsesquioxane of Cu9Na6 nuclearity, 1. In the second case, neocuproine ligands withdraws two Cu ions from the metallasilsesquioxane matrix, producing two cationic fragments Cu+(neocuproine)2. The remaining metallasilsesquioxane is rearranged into an anionic cage of Cu9Na4 nuclearity, finalizing the formation of a specific ionic complex, 2. The impressive molecular architecture of both types of complexes, e.g., the presence of different (cyclic/acyclic) types of silsesquioxane ligands, was established by single-crystal X-ray diffraction studies. Compound 1 was revealed to be highly active in the oxidative amidation of benzylic alcohol and the catalyst loading could be reduced down to 100 ppm of Cu. Catalytic studies of compound 1 demonstrated its high activity in hydroperoxidation of alkanes with H2O2 and oxidation of alcohols to ketones with tert-BuOOH.
- Astakhov, Grigorii S.,Bilyachenko, Alexey N.,Korlyukov, Alexander A.,Levitsky, Mikhail M.,Shul'Pina, Lidia S.,Bantreil, Xavier,Lamaty, Frédéric,Vologzhanina, Anna V.,Shubina, Elena S.,Dorovatovskii, Pavel V.,Nesterov, Dmytro S.,Pombeiro, Armando J. L.,Shul'Pin, Georgiy B.
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supporting information
p. 11524 - 11529
(2018/09/13)
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- Peroxidative oxidation of alkanes and alcohols under mild conditions by Di- and TetranuclearCopper (II) Complexes of Bis (2-Hydroxybenzylidene) Isophthalohydrazide
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Bis(2-hydroxybenzylidene)isophthalohydrazide (H4L) has been used to synthesize the dinuclear [Cu2(1κNO2:2κN′O′2-H2L)(NO3)2(H2O)2] (1) and the tetranuclear [Cu4(μ-1κNO2:2κN′O2- H2L)2(μ-NO3)2(H2O)4]·2C2H5OH (2) complexes. The solvent plays an important role in determining the ligand behaviour in the syntheses of the complexes. An ethanol-acetonitrile mixture of solvents favours partials enolization in the case of 2. Both complexes have been characterized by elemental analysis, infrared radiation (IR), single crystal X-ray crystallography and electrochemical methods. The variable temperature magnetic susceptibility measurements of 2 show strong antiferromagnetic coupling between the central nitrato-bridged Cu (II) ions. The catalytic activity of both 1 and 2 has been screened toward the solvent-free microwave-assisted oxidation of alcohols and the peroxidative oxidation of alkanes under mild conditions. Complex 1 exhibits the highest activity for both oxidation reactions, leading selectively to a maximum product yield of 99% (for the 1-phenylethanol oxidation after 1 h without any additive) and 13% (for the cyclohexane oxidation to cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone after 3 h).
- Sutradhar, Manas,Alegria, Elisabete C.B.A.,Da Silva, M. Fátima C. Guedes,Liu, Cai-Ming,Pombeiro, Armando J.L.
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- A new “bicycle helmet”-like copper(ii),sodiumphenylsilsesquioxane. Synthesis, structure and catalytic activity
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A new “bicycle helmet”-like copper(ii),sodiumphenylsilsesquioxane Ph12Si12O12(OH)(O?)11Cu5Na(bipy)3(H2O) exhibited high catalytic efficiency in two homogeneous reactions: (i) functionalization of C-H compounds; (ii) formation of benzamides from alcohols.
- Kulakova, Alena N.,Bilyachenko, Alexey N.,Korlyukov, Alexander A.,Shul'pina, Lidia S.,Bantreil, Xavier,Lamaty, Frédéric,Shubina, Elena S.,Levitsky, Mikhail M.,Ikonnikov, Nikolay S.,Shul'pin, Georgiy B.
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p. 15666 - 15669
(2018/11/23)
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- Method For Producing Ketone And/Or Alcohol, And System Thereof
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This invention provides producing having an objective ketone and/or alcohol by decomposing of a hydrocarbon compound rapidly and selectively having a same number of carbon atoms as a hydrocarbon compound by decomposing a hydroperoxide in a reaction solution obtained from oxidizing the hydrocarbon compound using molecular oxygen of this invention involves, a hydroperoxide decomposition step for decomposing the hydroperoxide into the ketone and/or alcohol by contacting the reaction solution with an aqueous solution containing a carbonate of an alkaline earth metal or a carbonate of an alkali metal and a transition metal compound, a separation step for separating into an oil phase comprising the ketone and/or alcohol, and a water phase comprising the carbonate of an alkaline earth metal or carbonate of an alkali metal and the transition metal compound, a recovery step for recovering the carbonate of an alkali metal or carbonate of an alkaline earth metal and the transition metal compound by combusting the water phase, and a recycling step for recycling to the hydroperoxide decomposition step by dissolving at least the carbonate of the alkali metal or the carbonate of the alkaline earth metal among the recovered substances obtained from the recovery step in water.
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Paragraph 0110-0119
(2017/11/16)
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- Synthesis of Mono- and Dinuclear Vanadium Complexes and Their Reactivity toward Dehydroperoxidation of Alkyl Hydroperoxides
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Several vanadium(V) complexes with either dipic-based or Schiff base ligands were synthesized. The complexes were fully characterized by elemental analysis, IR, 1H, 13C, and 51V NMR spectroscopy, as well as mass spectrometry and X-ray diffraction. Furthermore, they were tested toward their catalytic deperoxidation behavior and a significant difference between 4-heptyl hydroperoxide and cyclohexyl hydroperoxide was observed. In the case of 4-heptyl hydroperoxide, the selectivity toward the corresponding ketone was higher than with cyclohexyl hydroperoxide. DFT calculations performed on the vanadium complex showed that selective decomposition of secondary hydroperoxides with vanadium(V) to yield the corresponding ketone and water is indeed energetically feasible. The computed catalytic path, involving cleavage of the O-O bond, hydrogen transfer, release of ketone/water, and finally addition of hydroperoxide, can proceed without the generation of radical species.
- Schmidt, Anna-Corina,Hermsen, Marko,Rominger, Frank,Dehn, Richard,Teles, Joaquim Henrique,Sch?fer, Ansgar,Trapp, Oliver,Schaub, Thomas
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supporting information
p. 1319 - 1332
(2017/02/15)
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- A heterometallic (Fe6Na8) cage-like silsesquioxane: Synthesis, structure, spin glass behavior and high catalytic activity
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The exotic "Asian Lantern" heterometallic cage silsesquioxane [(PhSiO1.5)20(FeO1.5)6(NaO0.5)8(n-BuOH)9.6(C7H8)] (I) was obtained and characterized by X-ray diffraction, EXAFS, topological analyses and DFT calculation. The magnetic property investigations revealed that it shows an unusual spin glass-like behavior induced by a particular triangular arrangement of Fe(iii) ions. Cyclohexane and other alkanes as well as benzene can be oxidized to the corresponding alkyl hydroperoxides and phenol, respectively, by hydrogen peroxide in air in the presence of catalytic amounts of complex I and nitric acid. The I-catalyzed reaction of cyclohexane, c-C6H12, with H216O2 in an atmosphere of 18O2 gave a mixture of labeled and non-labeled cyclohexyl hydroperoxides, c-C6H11-16O-16OH and c-C6H11-18O-18OH, respectively, with an 18O incorporation level of ca. 12%. Compound I also revealed high efficiency in the oxidative amidation of alcohols into amides: in the presence of complex I, only 500 ppm of iron was allowed to reach TON and TOF values of 1660 and 92 h-1.
- Bilyachenko, Alexey N.,Levitsky, Mikhail M.,Yalymov, Alexey I.,Korlyukov, Alexander A.,Vologzhanina, Anna V.,Kozlov, Yuriy N.,Shul'Pina, Lidia S.,Nesterov, Dmytro S.,Pombeiro, Armando J. L.,Lamaty, Frédéric,Bantreil, Xavier,Fetre, Amandine,Liu, Diyang,Martinez, Jean,Long, Jér?me,Larionova, Joulia,Guari, Yannick,Trigub, Alexander L.,Zubavichus, Yan V.,Golub, Igor E.,Filippov, Oleg A.,Shubina, Elena S.,Shul'Pin, Georgiy B.
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p. 48165 - 48180
(2016/06/09)
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- Stereoselective alkane oxidation with meta-chloroperoxybenzoic acid (MCPBA) catalyzed by organometallic cobalt complexes
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Cobalt pi-complexes, previously described in the literature and specially synthesized and characterized in this work, were used as catalysts in homogeneous oxidation of organic compounds with peroxides. These complexes contain pi-butadienyl and pi-cyclopentadienyl ligands: [(tetramethylcyclobutadiene)(benzene)cobalt] hexafluorophosphate, [(C4Me4)Co(C6H6)]PF6 (1); diiodo(carbonyl)(pentamethylcyclopentadienyl)cobalt, Cp?Co(CO)I2 (2); diiodo(carbonyl) (cyclopentadienyl)cobalt, CpCo(CO)I2 (3); (tetramethylcyclobutadiene)(dicarbonyl)(iodo) cobalt, (C4Me4)Co(CO)2I (4); [(tetramethylcyclobutadiene)(acetonitrile)(2,2′-bipyridyl)cobalt] hexafluorophosphate, [(C4Me4)Co(bipy)(MeCN)]PF6 (5); bis[dicarbonyl(B-cyclohexylborole)]cobalt, [(C4H4BCy)Co(CO)2]2 (6); [(pentamethylcyclopentadienyl)(iodo)(1,10-phenanthroline)cobalt] hexafluorophosphate, [Cp?Co(phen)I]PF6 (7); diiodo(cyclopentadienyl)cobalt, [CpCoI2]2 (8); [(cyclopentadienyl)(iodo)(2,2′-bipyridyl)cobalt] hexafluorophosphate, [CpCo(bipy)I]PF6 (9); and [(pentamethylcyclopentadienyl)(iodo)(2,2′-bipyridyl)cobalt] hexafluorophosphate, [Cp?Co(bipy)I]PF6 (10). Complexes 1 and 2 catalyze very efficient and stereoselective oxygenation of tertiary C-H bonds in isomeric dimethylcyclohexanes with MCBA: cyclohexanols are produced in 39 and 53% yields and with the trans/cis ratio (of isomers with mutual trans- or cis-configuration of two methyl groups) 0.05 and 0.06, respectively. Addition of nitric acid as co-catalyst dramatically enhances both the yield of oxygenates and stereoselectivity parameter. In contrast to compounds 1 and 2, complexes 9 and 10 turned out to be very poor catalysts (the yields of oxygenates in the reaction with cis-1,2-dimethylcyclohexane were only 5%-7% and trans/cis ratio 0.8 indicated that the oxidation is not stereoselective). The chromatograms of the reaction mixture obtained before and after reduction with PPh3 are very similar, which testifies that alkyl hydroperoxides are not formed in this oxidation. It can be thus concluded that the interaction of the alkanes with MCPBA occurs without the formation of free radicals. The complexes catalyze oxidation of alcohols with tert-butylhydroperoxide (TBHP). For example, tert-BuOOH efficiently oxidizes 1-phenylethanol to acetophenone in 98% yield if compound 1 is used as a catalyst.
- Shul'pin, Georgiy B.,Loginov, Dmitriy A.,Shul'pina, Lidia S.,Ikonnikov, Nikolay S.,Idrisov, Vladislav O.,Vinogradov, Mikhail M.,Osipov, Sergey N.,Nelyubina, Yulia V.,Tyubaeva, Polina M.
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- Heteropolytungstate nanoparticles: Microemulsion-mediated preparation and investigation of their catalytic activity in the epoxidation of olefins
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Keggin type Q3PW12O40 nanoparticles (Q = cetyltrimethylammonium cation) were synthesized in water-in-oil (w/o) microemulsion consisted of water/cetyltrimethylammonium bromide/n-butanol/isooctane. Reaction of Na2WO4, Na2HPO4 and hydrochloric acid within water containing nanoreactors of reverse micelles resulted in the preparation of Q3PW12O40 nanoparticles. The resultant nanoparticles were analyzed by physicochemical methods such as FT-IR spectroscopy, X-ray diffraction, energy-dispersive X-ray analysis, thermogravimetric analyses (TGA-DTA), scanning and transmission electron microscopy and atomic force microscopy which show nearly uniform spherical nanoparticles with size of about 15 nm. Finally, catalytic activity of the Q3PW12O40 nanoparticles was examined in the epoxidation of olefins with H2O2. The prepared nanoparticles acted as recoverable and reusable catalyst in the epoxidation of olefins with H2O2.
- Masteri-Farahani,Ghorbani
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p. 332 - 337
(2016/01/15)
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- Copper-Catalyzed Oxidation of Alkanes with H2O2under a Fenton-like Regime
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Copper complexes bearing readily available ligand systems catalyzed the oxidation of alkanes with H2O2as the oxidant with high efficiency in remarkable yields (50–60 %). The reactions proceeded with unprecedented selectivity to give alkyl hydroperoxides as the major products. Detailed scrutiny of the reaction mechanism suggests the involvement of C-centered and O-centered radicals generated in a Fenton-like fashion.
- Garcia-Bosch, Isaac,Siegler, Maxime A.
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supporting information
p. 12873 - 12876
(2016/10/04)
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- Synthesis, characterization and activity of homogeneous and heterogeneous (SiO2, NaY, MCM-41) iron(III) catalysts on cyclohexane and cyclohexene oxidation
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This work deals with the synthesis and characterization of two homogeneous and three heterogeneous iron(III) catalysts, which were evaluated in the oxidation of cyclohexane and cyclohexene, using H2O2 as oxidant. The homogeneous catalyst [Fe2(BPA)2(μ-OCH3)2(Cl)2], (1), where BPA is the deprotonated form of N-(2-hydroxybenzyl)-N-(pyridin-2-ylmethyl) amine, is a dinuclear iron(III) compound, as determined by X-ray diffraction studies. Compound [FeIII(HBPCNOL)(Cl)2], (2), where HBPCNOL is N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)(3-chloro)(2-hydroxy) propylamine, is a mononuclear iron(III) compound. The reaction of the ligand HBPA with the 3-glycidoxypropyltrimethoxysilane molecule followed by the reaction with different inorganic matrices (silica-gel, NaY zeolite, MCM-41) resulted in the organo functionalized solids SiL, NaYL and MCM-41L, respectively. These materials were reacted with iron(III) salt, affording the heterogeneous catalysts SiLFe, NaYLFe and MCM-41LFe, respectively. They were characterized by elemental analyses, HR-CS AAS, solid state MAS NMR (29Si, 13C), IR, UV-vis, TGA, Mossbauer, and textural analyses. The major product formed in all the oxidation reactions was the hydroperoxide derivative. When cyclohexane was the substrate, the homogeneous catalysts were more efficient than the heterogeneous ones. In contrast, the heterogeneous systems showed better results with cyclohexene than with cyclohexane, reaching about 30% in the presence of NaYLFe.
- Machado, Paula M.A.,Lube, Leonardo M.,Tiradentes, Marcione D.E.,Fernandes, Christiane,Gomes, Clícia A.,Stumbo, Alexandre M.,San Gil, Rosane A.S.,Visentin, Lorenzo C.,Sanchez, Dalber R.,Frescura, Vera L.A.,Silva, Jessee S.A.,Horn, Adolfo
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p. 119 - 129
(2015/10/20)
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- OXIDATION OF CYCLOALKANES IN THE PRESENCE OF A SUPPORTED BIMETALLIC GOLD-PALLADIUM CATALYST
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The present invention relates to a process for the oxidation of cycloalkanes utilising a supported gold and palladium catalyst and the use of the supported gold and palladium catalyst for the oxidation of cycloalkanes. Also described is a process for the preparation of the supported catalyst.
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-
Paragraph 0060-0061; 0064
(2015/02/18)
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- Oxidation of alkanes and benzene with hydrogen peroxide catalyzed by ferrocene in the presence of acids This article is dedicated to the memory of Aleksandr Evgenievich Shilov (1930-2014).
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The efficient (turnover numbers attained 1200) oxidation of alkanes to the corresponding alkyl hydroperoxides by H2O2 in the presence of catalytic amounts of ferrocene proceeds in MeCN at 40-50 °C. Benzene is oxidized in the same system to phenol. An obligatory component of the catalytic system for both reactions is pyrazine-2-carboxylic acid (PCA) or trifluoroacetic acid (TFA). Kinetic study as well as selectivity parameters testified that the oxidation proceeds with the participation of hydroxyl radicals. In the case of PCA as a co-catalyst the initial rate W0 of the reaction with both cyclohexane and benzene depends quadratically on [Cp2Fe]0 whereas the two reactions in the presence of TFA are of half order in ferrocene. The ferrocene-catalyzed reaction of cyclohexane with H2O216 in an atmosphere of labeled 18O2 gave after 2 h a mixture of labeled and unlabeled cyclohexyl hydroperoxide (total yield 20% based on starting cyclohexane) containing up to 69% of 18O (the analysis was after reduction of cyclohexyl hydroperoxide into cyclohexanol with PPh3).
- Shul'pina, Lidia S.,Kudinov, Aleksandr R.,Mandelli, Dalmo,Carvalho, Wagner A.,Kozlov, Yuriy N.,Vinogradov, Mikhail M.,Ikonnikov, Nikolay S.,Shul'pin, Georgiy B.
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p. 217 - 231
(2015/09/01)
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- Fabrication of CuCr2O4 spinel nanoparticles: A potential catalyst for the selective oxidation of cycloalkanes via activation of Csp3-H bond
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We report here preparation of CuCr2O4 spinel nanoparticle catalyst, mediated by cationic surfactant CTAB in hydrothermal route. XRD revealed the formation of CuCr2O4 spinel phase and TEM showed the particle size of 30-60 nm. The catalyst was speculated to be highly active for selective oxidation of cyclohexane to cyclohexanone with H2O2. A cyclohexane conversion of 70% with 85% cyclohexanone selectivity was achieved over this catalyst at 50 °C temperature. Moreover, the catalyst did not show any significant activity loss even after 8 reuses and proved its efficacy in the oxidation of other cycloalkanes also.
- Acharyya, Shankha S.,Ghosh, Shilpi,Adak, Shubhadeep,Tripathi, Deependra,Bal, Rajaram
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supporting information
p. 145 - 150
(2015/01/09)
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- Novel coordination polymers with (Pyrazolato)-based tectons: Catalytic activity in the peroxidative oxidation of alcohols and cyclohexane
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Coupling five rigid or flexible bis(pyrazolato)-based tectons with late transition metal ions allowed us to isolate 18 coordination polymers (CPs). As assessed by thermal analysis, all of them possess a remarkable thermal stability, their decomposition temperatures lying in the range of 340-500 °C. As demonstrated by N2 adsorption measurements at 77 K, their Langmuir specific surface areas span the rather vast range of 135-1758 m2/g, in agreement with the porous or dense polymeric architectures retrieved by powder X-ray diffraction structure solution methods. Two representative families of CPs, built up with either rigid or flexible spacers, were tested as catalysts in (i) the microwave-assisted solvent-free peroxidative oxidation of alcohols by t-BuOOH, and (ii) the peroxidative oxidation of cyclohexane to cyclohexanol and cyclohexanone by H2O2 in acetonitrile. Those CPs bearing the rigid spacer, concurrently possessing higher specific surface areas, are more active than the corresponding ones with the flexible spacer. Moreover, the two copper(I)-containing CPs investigated exhibit the highest efficiency in both reactions, leading selectively to a maximum product yield of 92% (and TON up to 1.5 × 103) in the oxidation of 1-phenylethanol and of 11% in the oxidation of cyclohexane, the latter value being higher than that granted by the current industrial process.
- Timokhin, Ivan,Pettinari, Claudio,Marchetti, Fabio,Pettinari, Riccardo,Condello, Francesca,Galli, Simona,Alegria, Elisabete C. B. A.,Martins, Luísa M.D.R.S.,Pombeiro, Armando J. L.
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p. 2303 - 2317
(2015/05/13)
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- Greener selective cycloalkane oxidations with hydrogen peroxide catalyzed by copper-5-(4-pyridyl)tetrazolate metal-organic frameworks
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Microwave assisted synthesis of the Cu(I) compound [Cu(μ4-4-ptz)]n [1, 4-ptz = 5-(4-pyridyl)tetrazolate] has been performed by employing a relatively easy method and within a shorter period of time compared to its sister compounds. The syntheses of the Cu(II) compounds [Cu3(μ3-4-ptz)4(μ2-N3)2(DMF)2]n·(DMF)2n (2) and [Cu(μ2-4-ptz)2(H2O)2]n (3) using a similar method were reported previously by us. MOFs 1-3 revealed high catalytic activity toward oxidation of cyclic alkanes (cyclopentane, -hexane and -octane) with aqueous hydrogen peroxide, under very mild conditions (at room temperature), without any added solvent or additive. The most efficient system (2/H2O2) showed, for the oxidation of cyclohexane, a turnover number (TON) of 396 (TOF of 40 h?1), with an overall product yield (cyclohexanol and cyclohexanone) of 40% relative to the substrate. Moreover, the heterogeneous catalytic systems 1-3 allowed an easy catalyst recovery and reuse, at least for four consecutive cycles, maintaining ca. 90% of the initial high activity and concomitant high selectivity.
- Martins, Luísa,Nasani, Rajendar,Saha, Manideepa,Mobin, Shaikh,Mukhopadhyay, Suman,Pombeiro, Armando
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p. 19203 - 19220
(2015/11/27)
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- Oxidation of cyclohexane to adipic acid catalyzed by Mn-doped titanosilicate with hollow structure
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One-step oxidation of cyclohexane to adipic acid (AA) was carried out at 413 K over manganese-doped titanium silicalite with hollow structure (HTS) using oxygen as oxidant without any initiator or solvent. The catalyst exhibited high conversion (13.4%) and reasonable product (AA) selectivity (57.5%). Hot-separation and catalyst-recycle tests proved that the catalyst acted as a heterogeneous one and it could be reused four times without losing its activity. The synthesized materials were characterized by N2 adsorption-desorption isotherm, FT-IR, UV-vis and XPS techniques.
- Zou, Guoqiang,Zhong, Wenzhou,Xu, Qiong,Xiao, Jiafu,Liu, Chang,Li, Yongqiang,Mao, Liqiu,Kirk, Steven,Yin, Dulin
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- Oxidation of hydrocarbons with H2O2/O2 catalyzed by osmium complexes containing p-cymene ligands in acetonitrile
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The soluble osmium complexes containing p-cymene (π-p-cym) ligands, [(η6-p-cym)OsCl2]2 (1), [(η6-p-cym)Os(bipy)Cl]PF6 (2), and [(η6-p-cym)2Os2(μ-H)3]PF 6 (3), are efficient catalysts for the oxidation of alkanes (cyclohexane, n-heptane, methylcyclohexane, isooctane, and cis- and trans-1,2-dimethylcyclohexane) with hydrogen peroxide in air to the corresponding alkyl hydroperoxides in acetonitrile solution if a small amount of pyridine is present in the solution. The binuclear complex 1 is the most active precatalyst in the oxidation whereas compound 2 containing the bipyridine ligand is much less efficient. The oxidation of cyclohexane at 60 °C and low concentration [1]0 = 10-7 M gave a turnover number (TON) of 200200 after 24 h. A study of the selectivity parameters in the oxidation of linear and branched alkanes and the kinetic peculiarities of the cyclohexane oxidation led to the conclusion that the main reaction mechanism includes the formation of hydroxyl radicals. The effective activation energy Ea for the cyclohexane oxidation catalyzed by complex 1 was 10 ± 2 kcal mol-1. A kinetic analysis verified also that monomerization of complex 1 occurs before the oxidizing species is involved in the catalytic cycle. The 1-catalyzed reaction of cyclohexane, c-C6H12, with H216O2 in an atmosphere of 18O2 gave labeled cyclohexyl hydroperoxide, c-C 6H11-18O-18OH. In addition, a small amount of "light" cyclohexanone, c-C6H10 16O, is produced apparently via a mechanism which includes neither hydroxyl radicals nor incorporation of molecular oxygen from the atmosphere. The oxidation of benzene with H216O2 under 18O2 gave phenol which did not contain the 18O isotope. The reactions with cyclohexane and benzene were shown to proceed also via an alternative minor mechanism with oxo derivatives of high-valent osmium "Os=O" as key oxidizing species. the Partner Organisations 2014.
- Vinogradov, Mikhail M.,Kozlov, Yuriy N.,Nesterov, Dmytro S.,Shul'pina, Lidia S.,Pombeiro, Armando J.L.,Shul'pin, Georgiy B.
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p. 3214 - 3226
(2014/08/18)
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- PROCESS FOR PREPARING CYCLOHEXANOL AND CYCLOHEXANONE WITH CYCLOHEXANE SERVING AS RAW MATERIAL
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A process for preparing cyclohexanol and cyclohexanone from cyclohexane includes steps of: (1) non-catalyticly oxidizing cyclohexane with molecular oxygen to obtain an oxidized mixture liquid containing cyclohexyl hydroperoxide (CHHP) as a main product; (2) performing a homogenous catalytic decomposition with an oil-soluble transitional metal compound serving as a catalyst, and serving as a scale inhibitor by 1-hydroxy ethidene-1,1 -diphosphonic acid (di)octyl ester, or a combination of 1-hydroxy ethidene-1,1-diphosphonic acid (di)octyl ester and phosphoric acid octyl ester, to decompose the CHHP in the oxidized mixture liquid into cyclohexanol and cyclohexanone; and (3) rectifying to obtain products of the cyclohexanol and the cyclohexanone.
- -
-
Paragraph 0023
(2015/01/18)
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- Preparation, characterization and catalytic activity of MgO/SiO2 supported vanadium oxide based catalysts
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Vanadium oxide-based catalyst obtained by grafting VOCl3 on Florisil (MgO:SiO2) with the molar ratio of 15:85 have been studied for the selective oxidation of cyclohexane in order to obtain cyclohexyl hydroperoxide, cyclohexanol and
- Aboelfetoh, Eman Fahmy,Pietschnig, Rudolf
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- A new binuclear oxovanadium(v) complex as a catalyst in combination with pyrazinecarboxylic acid (PCA) for efficient alkane oxygenation by H 2O2
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A new binuclear oxovanadium(v) complex [{VO(OEt)(EtOH)}2L] (1) where H4L is bis(2-hydroxybenzylidene)terephthalohydrazide has been synthesized and fully characterized. The combination of 1 with pyrazine-2-carboxylic acid (PCA; a cocatalyst) affords a catalytic system for the efficient oxidation of saturated hydrocarbons, RH, with hydrogen peroxide and air in acetonitrile solution at 50°C to produce alkyl hydroperoxides, ROOH, as the main primary products. Very high turnover numbers (TONs) have been attained in this reaction: for example, after 2220 min, TON = 44 000 and initial TOF (turnover frequency) = 3300 h-1 per molecule of complex 1. The estimated activation energy of the cyclohexane oxygenation in the presence of 1/PCA is Ea = 16 ± 2 kcal mol-1. This value is identical to that obtained for the cyclohexane oxidation with H 2O2 catalyzed by the (n-Bu4N)[VO 3]/PCA combination (17 ± 2 kcal mol-1). The dependences of initial oxidation rates W0 on the initial concentrations of all components of the reaction mixture have been determined. Based on these kinetic data and on the regio- and bond-selectivity parameters measured in the oxidation of linear and branched alkanes a mechanism of the oxidation has been proposed which includes the generation of hydroxyl radicals in the crucial stage. The Royal Society of Chemistry.
- Sutradhar, Manas,Shvydkiy, Nikita V.,Guedes Da Silva, M. Fátima C.,Kirillova, Marina V.,Kozlov, Yuriy N.,Pombeiro, Armando J. L.,Shul'Pin, Georgiy B.
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supporting information
p. 11791 - 11803
(2013/09/02)
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- Hexanuclear and undecanuclear iron(iii) carboxylates as catalyst precursors for cyclohexane oxidation
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Two multinuclear complexes [Fe6(μ3-O) 2(μ4-O2)L10(OAc) 2(H2O)2]·2.625Et2O·2. 375H2O (1) and [FeIII11Cl(μ4-O) 3(μ3-O)5L16(dmf) 2.5(H2O)0.5]·Et2O·1. 25dmf·3.8H2O (2), where HL = 3,4,5-trimethoxybenzoic acid and dmf = dimethylformamide, have been prepared from trinuclear iron(iii) carboxylates via their structural rearrangement in dimethylformamide or diethyl ether-dimethylformamide 9:1, respectively, and slow vapor diffusion of diethyl ether into the reaction mixture. Both compounds have been characterized by X-ray diffraction, optical, Moessbauer spectroscopy, and magnetic measurements. Complex 1 possesses a hexanuclear ferric peroxido-dioxido {Fe6(O 2)(O)2}12+ core unit, which adopts a recliner conformation, while complex 2 contains an unprecedented {Fe11O 8Cl}16+ core, in which 9 ferric ions are six-coordinate and the remaining two are five-coordinate. Another structural feature of note of the undecanuclear core is the presence of a deformed cubane entity {Fe 4(μ3-O)(μ4-O)3}4+. Both complexes act as catalyst precursors for the oxidation of cyclohexane to cyclohexanol and cyclohexanone with aqueous H2O2, in the presence of pyrazinecarboxylic acid. Remarkable TONs and TOFs (the latter mainly for 1) with concomitant quite good yields have been achieved under mild conditions. Moreover, 1 exhibits remarkably high activity in an exceptionally short reaction time (45 min), being unprecedented for any metal catalyzed alkane oxidation by H2O2. The catalytic reactions proceed via Fenton type chemistry.
- Milunovic, Miljan N. M.,Martins, Luisa M.D.R.S.,Alegria, Elisabete C. B. A.,Pombeiro, Armando J. L.,Krachler, Regina,Trettenhahn, Guenter,Turta, Constantin,Shova, Sergiu,Arion, Vladimir B.
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p. 14388 - 14401
(2013/10/08)
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- Oligomerization reaction of the Criegee intermediate leads to secondary organic aerosol formation in ethylene ozonolysis
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Ethylene ozonolysis was investigated in laboratory experiments using a Teflon bag reactor. A negative ion chemical ionization mass spectrometer (NI-CIMS) using SO2Cl- and Cl- as reagent ions was used for product analysis. In addition to the expected gas-phase products, such as formic acid and hydroperoxymethyl formate, oligomeric hydroperoxides composed of the Criegee intermediate (CH2OO) as a chain unit were observed. Furthermore, we observed secondary organic aerosol (SOA) formation from the ethylene ozonolysis, and the particle-phase products were also analyzed by NI-CIMS. The CH2OO oligomers were also observed as particle-phase components, suggesting that the oligomeric hydroperoxides formed in the gas phase partition into the particle phase. By adding methanol as a stabilized Criegee intermediate scavenger, both the gas-phase oligomer formation and SOA formation were strongly suppressed. This indicates that CH2OO plays a critical role in the formation of oligomeric hydroperoxides followed by SOA formation in ethylene ozonolysis. A new formation mechanism for the oligomeric hydroperoxides, which includes sequential addition of CH2OO to hydroperoxides, is proposed.
- Sakamoto, Yosuke,Inomata, Satoshi,Hirokawa, Jun
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p. 12912 - 12921
(2014/01/06)
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- Activation of molecular oxygen by a metal-organic framework with open 2,2′-bipyridine for selective oxidation of saturated hydrocarbons
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A metal-organic framework with open 2,2′-bipyridine sites can efficiently activate molecular oxygen for selective oxidation of a variety of saturated hydrocarbons with unprecedented activities and selectivities.
- Long, Jilan,Wang, Liming,Gao, Xingfa,Bai, Cuihua,Jiang, Huanfeng,Li, Yingwei
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supporting information
p. 12109 - 12111
(2013/01/16)
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- Cyclohexane selective oxidation over metal-organic frameworks of MIL-101 family: Superior catalytic activity and selectivity
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Mesoporous metal-organic frameworks Cr- and Fe-MIL-101 are highly efficient, true heterogeneous and recyclable catalysts for solvent-free selective oxidation of cyclohexane with molecular oxygen and/or tert-butyl hydroperoxide under mild conditions. The Royal Society of Chemistry 2012.
- Maksimchuk, Nataliya V.,Kovalenko, Konstantin A.,Fedin, Vladimir P.,Kholdeeva, Oxana A.
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supporting information; experimental part
p. 6812 - 6814
(2012/07/31)
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- Tetradentate Schiff base ligands and their complexes: Synthesis, structural characterization, thermal, electrochemical and alkane oxidation
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Three Schiff base ligands (H2L1-H2L 3) with N2O2 donor sites were synthesized by condensation of 1,5-diaminonapthalene with benzaldehyde derivatives. A series of Cu(II), Co(II), Ni(II), Mn(II) and Cr(III) complexes were prepared and characterized by spectroscopic and analytical methods. Thermal, electrochemical and alkane oxidation reactions of the ligands and their metal complexes were investigated. Extensive application of 1D (1H, 13C NMR) and 2D (COSY, HETCOR, HMBC and TOSCY) NMR techniques were used to characterize the structures of the ligands and establish the 1H and 13C resonance assignments of the three ligands. Ligands H2L1 and H2L3 were obtained as single crystals from THF solution and characterized by X-ray diffraction. Both molecules are centrosymmetric and asymmetric unit contains one half of the molecule. Catalytic alkane oxidation reactions with the transition metal complexes investigated using cyclohexane and cyclooctane as substrates. The Cu(II) and Cr(III) complexes showed good catalytic activity in the oxidation of cyclohexane and cyclooctane to desired oxidized products. Electrochemical and thermal properties of the compounds were also investigated.
- Ceyhan, G?khan,K?se, Muhammet,McKee, Vickie,Uru?, Serhan,G?lcü, Ay?egül,Tümer, Mehmet
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experimental part
p. 382 - 398
(2012/08/07)
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- PROCESS FOR PREPARING ALKYL HYDROPEROXIDE COMPOUNDS
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A method for making alkyl hydroperoxide compounds, specifically the preparation of cyclohexyl hydroperoxide is described. The preparation of cyclohexyl hydroperoxide by means of the oxidation of cyclohexane by oxygen in a multi-stage reactor or in reactors connected in series is also described. In these methods, the reactor surfaces in contact with the oxidation medium can be protected by a layer of heat-resistant PFA polymer.
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Page/Page column 2-3
(2012/11/13)
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- METHOD FOR OXIDIZING HYDROCARBONS WITH OXYGEN
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A method for oxidizing saturated hydrocarbons with oxygen, preferably saturated cyclic hydrocarbons such as cyclohexane, to produce alkyl hydroperoxide is described. A method for oxidizing saturated hydrocarbons with oxygen in a plurality of consecutive steps to control the rate of the reaction and obtain a high degree of alkyl hydroperoxide selectivity is also described. The described methods can relate to methods for condensing oxidation gases recovered in an oxidation reactor and recycling thereof.
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Page/Page column 3
(2012/12/14)
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- Heterometallic CoIII4FeIII2 schiff base complex: Structure, electron paramagnetic resonance, and alkane oxidation catalytic activity
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The heterometallic complex [Co4Fe2OSae 8]·4DMF·H2O (1) was synthesized by one-pot reaction of cobalt powder with iron chloride in a dimethylformamide solution of salicylidene-2-ethanolamine (H2Sae) and characterized by single crystal X-ray diffraction analysis, magnetic measurements, high frequency electron paramagnetic resonance (HF-EPR), and Moessbauer spectroscopies. The exchange coupling in the Fe(III)-Fe(III) pair is of antiferromagnetic behavior with J/hc = -190 cm-1. The HF-EPR spectra reveal an unusual pattern with a hardly detectable triplet signal of the Fe(III) dimer. The magnitude of D (ca. 13.9 cm-1) was found to be much larger than in related dimers. The catalytic investigations disclosed an outstanding activity of 1 toward oxidation of cycloalkanes with hydrogen peroxide, under mild conditions. The most efficient system showed a turnover number (TON) of 3.57×10 3 with the concomitant overall yield of 26% for cyclohexane, and 2.28×103/46%, respectively, for cyclooctane. A remarkable turnover frequency (TOF) of 1.12×104 h-1 (the highest initial rate W0 = 3.5×10-4 M s-1) was achieved in oxidation of cyclohexane. Kinetic experiments and selectivity parameters led to the conclusion that hydroxyl radicals are active (attacking C-H bonds) species. Kinetic and electrospray ionization mass spectrometry (ESI-MS) data allowed us to assume that the trinuclear heterometallic particle [Co2Fe(Sae)4]+, originated from 1 in solution, could be responsible for efficient generation of hydroxyl radicals from hydrogen peroxide.
- Nesterov, Dmytro S.,Pombeiro, Armando J. L.,Chygorin, Eduard N.,Kokozay, Volodymyr N.,Bon, Volodymyr V.,Boca, Roman,Kozlov, Yuriy N.,Shul'Pin, Georgiy B.,Shul'Pina, Lidia S.,Jezierska, Julia,Ozarowski, Andrew
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p. 9110 - 9122,13
(2020/08/31)
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- New FeII and CuII complexes bearing azathia macrocycles-catalyst precursors for mild peroxidative oxidation of cyclohexane and 1-phenylethanol
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The new mononuclear FeII and CuII complexes [FeCl2(L1,3)] [L1 (1), L3 (4)], [Cu(OTf)2(L1,2)] [L1 (2), L2 (3)] and [Cu(OTf)(L3)(H2O)](OTf) (5) were generated by the treatment of iron(II) chloride or copper(II) triflate in THF solution at ambient temperature with the 14-membered N2S2 macrocycles 6,7,13,14,15,16,17,18-octahydrodibenzo(e,m)-1,4,8,11- dithiadiazacyclotetradecine (L1), 8,11-dimethyl-5,6,7,8,9,10,16,17- octahydrodibenzo(e,m)-1,4-dithia-8,11-diazacyclotetradecane (L2), and a new nine-membered NS2 macrocycle bearing a pendant 2-methylpyridyl arm 7-(2-methylpyridyl)aza-1,4-dithiacyclononane (L3). Complexes 1-5 were characterized by IR spectroscopy, ESI-MS(+), elemental analysis and single-crystal X-ray diffraction (for 2, 4 and 5). The oxidation catalytic properties of 1-5 were evaluated in two model reactions: (i) the mild oxidation of cyclohexane to cyclohexanol and cyclohexanone by H2O2 in MeCN and (ii) the solvent-free oxidation of 1-phenylethanol to acetophenone by tBuOOH under low microwave (MW) irradiation power (10 W). The FeII complexes 1 and 4 exhibited the highest efficiency in both homogeneous oxidation systems, leading to maximum product yields (based on substrate) of up to 21 and 92% in the oxidation of cyclohexane and 1-phenylethanol, respectively. In the latter transformation, markedly high values of TONs (up to 1200) and TOFs (up to 4200 h-1) were also attained.
- Fernandes, Ricardo R.,Lasri, Jamal,Kirillov, Alexander M.,Guedes Da Silva, M. Fatima C.,Da Silva, Jose A. L.,Frausto Da Silva, Joao J. R.,Pombeiro, Armando J. L.
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experimental part
p. 3781 - 3790
(2011/11/12)
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- Antioxidant, electrochemical, thermal, antimicrobial and alkane oxidation properties of tridentate Schiff base ligands and their metal complexes
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In this study, two Schiff base ligands (HL1 and HL2) and their Cu(II), Co(II), Ni(II), Pd(II) and Ru(III) metal complexes were synthesized and characterized by the analytical and spectroscopic methods. Alkane oxidation activities of the metal complexes were studied on cyclohexane as substrate. The ligands and their metal complexes were evaluated for their antimicrobial activity against Corynebacterium xerosis, Bacillus brevis, Bacillus megaterium, Bacillus cereus, Mycobacterium smegmatis, Staphylococcus aureus, Micrococcus luteus and Enterococcus faecalis (as Gram-positive bacteria) and Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Yersinia enterocolitica, Klebsiella fragilis, Saccharomyces cerevisiae, and Candida albicans (as Gram-negative bacteria). The antioxidant properties of the Schiff base ligands were evaluated in a series of in vitro tests: 1,1-diphenyl-2- picrylhydrazyl (DPPH) free radical scavenging and reducing power activity of superoxide anion radical generated non-enzymatic systems. Electrochemical and thermal properties of the compounds were investigated.
- Ceyhan, Goekhan,Celik, Cumali,Urus, Serhan,Demirtas, Ibrahim,Elmastas, Mahfuz,Tuemer, Mehmet
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experimental part
p. 184 - 198
(2011/12/02)
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- Superhydrophobic materials as efficient catalysts for hydrocarbon selective oxidation
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A new type of superhydrophobic material, FP-Co-SiO2 was prepared with organic groups immobilized on the surface of the SiO2-based nanocomposite. This material showed much higher catalytic activity for selective oxidation of hydrocarbons than an equivalent hydrophilic catalyst.
- Chen, Chen,Xu, Jie,Zhang, Qiaohong,Ma, Yinf,Zhou, Lipeng,Wang, Min
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supporting information; body text
p. 1336 - 1338
(2011/03/22)
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- Relationships between the efficiency of cyclohexane oxidation and the electrochemical parameters of the reaction solution
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Vanadyl(IV)-acetylacetonate-catalyzed oxidation of cyclohexane with H 2O2, at 40 °C under air atmosphere, has been studied in the presence of small quantities of oxalic acid. The process efficiency is increased by this additive and depends on the nature of the solvent (MeCN ≥ MeOH > Me2CO ≥ 2-PrOH > EtOH). The relationships between the results (conversion, yield) and the electrochemical characteristics of the reaction solution (relative permittivity, redox-potential) are highlighted and discussed.
- Pokutsa, Alexander,Fliunt, Orest,Kubaj, Yulia,Pacze?niak, Tomasz,Blonarz, Pawel,Prystanskiy, Ruslan,Muzart, Jacques,Makitra, Roman,Zaborovskyi, Andriy,Sobkowiak, Andrzej
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scheme or table
p. 15 - 21
(2011/10/19)
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- Synthesis, characterization and catalytic activity of two novel cis-dioxovanadium(V) complexes: [VO2(L)] and [VO2(HLox)]
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Two novel complexes, [VO2(L)] (1) and [VO2(HLox)] (2), were synthesized and characterized by IV, UV-Vis and NMR spectroscopy, cyclic voltammetry, elemental analysis and X-ray diffraction. The synthesis of a new ligand, H2Lox, is also
- Silva, Nata?lia M. L.,Pinheiro, Carlos B.,Chacon, Eluzir P.,Resende, Jackson A. L. C.,De M. Carneiro, Jose? Walkimar,Ferna?ndez, Tatiana L.,Scarpellini, Marciela,Lanznaster, Mauricio
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experimental part
p. 660 - 668
(2012/02/01)
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