766-07-4Relevant articles and documents
Decamethylosmocene-catalyzed efficient oxidation of saturated and aromatic hydrocarbons and alcohols with hydrogen peroxide in the presence of pyridine
Shul'Pin, Georgiy B.,Kirillova, Marina V.,Kozlov, Yuriy N.,Shul'Pina, Lidia S.,Kudinov, Alexander R.,Pombeiro, Armando J.L.
, p. 164 - 172 (2011)
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.
Vanadium(IV) complexes with picolinic acids in NaY zeolite cages: Synthesis, characterization and catalytic behaviour
Kozlov, Alexander,Asakura, Kiyotaka,Iwasawa, Yasuhiro
, p. 809 - 816 (1998)
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.
Facile Peroxidation of Cyclohexane Catalysed by In Situ Generated Triazole-Functionalised Schiff Base Copper Complexes
Bala, Muhammad D.,Ibrahim, Halliru,Lawal, Nasir S.
, (2021/07/21)
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.]
Tailoring the electron density of cobalt oxide clusters to provide highly selective superoxide and peroxide species for aerobic cyclohexane oxidation
Gaona-Miguélez, José,Gutiérrez-Tarri?o, Silvia,O?a-Burgos, Pascual
supporting information, p. 15370 - 15379 (2021/11/17)
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.
Method for catalytic oxidation of cycloalkane by confinement porphyrin Co (II)
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Page/Page column 8-10, (2020/05/01)
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.
