590-18-1Relevant articles and documents
CATALYTIC ACTIVITIES OF La2O3, Y2O3, AND CeO2 FOR DECOMPOSITION OF 4-HYDROXY-4-METHYL-2-PENTANONE AND ISOMERIZATION OF BUTENES.
Fukuda,Hattori,Tanabe
, p. 3150 - 3153 (1978)
The decomposition of 4-hydroxy-4-methyl-2-pentanone and the isomerization of 1-butene were carried out over La//2O//3, Y//2O//3, and CeO//2. The activities for both types of reactions were in the following order: La//2O//3 greater than Y//2O//3 greater than CeO//2. With La//2O//3, the change in the activity for the decomposition with the pretreatment temperature of the catalyst correlated well with the change in basicity, the activity and basicity maxima being observed when the catalyst was pretreated at 500 degree C. Yttrium sesquioxide showed a maximum activity for the decomposition when pretreated at 700 degree C. For the isomerizations of 1-butene and cis-2-butene, La//2O//3 exhibited activity maxima when pretreated at 700 degree C. This work is relevant to catalysts.
Alkali metals on nanoporous carbon: New solid-base catalysts
Stevens, Mark G.,Foley, Henry C.
, p. 519 - 520 (1997)
Caesium entrapped in nanoporous carbon is not pyrophoric, is thermally stable towards desorption up to 773 K, but retains its ability to produce hydrogen from water, and is a strong basic catalyst, providing a greater than 9:1 ratio of the less stable cis-but-2-ene over the trans isomer in the isomerization of but-1-ene at 273 K.
The Isomerization of 1-Butene to cis-2-Butene over CaO by Means of the Pulse-Reaction Method
Arata, Kazushi,Hino, Makoto,Kobayashi, Sakari
, p. 565 - 566 (1988)
The title reaction was studied over CaO catalysts which had been prepared by the calcination of Ca(OH)2 in air, followed by heating in a He stream or by thermal decomposition in a He flow.The former catalysts gave high cis/trans ratios (up to 21.6), while the latter ones were higher in activity but showed much lower ratios (ca. 1).
Solid-State Molecular Organometallic Catalysis in Gas/Solid Flow (Flow-SMOM) as Demonstrated by Efficient Room Temperature and Pressure 1-Butene Isomerization
Furfari, Samantha K.,Martínez-Martínez, Antonio J.,Royle, Cameron G.,Suriye, Kongkiat,Weller, Andrew S.
, p. 1984 - 1992 (2020)
The use of solid-state molecular organometallic chemistry (SMOM-chem) to promote the efficient double bond isomerization of 1-butene to 2-butenes under flow-reactor conditions is reported. Single crystalline catalysts based upon the σ-alkane complexes [Rh(R2PCH2CH2PR2)(η2η2-NBA)][BArF 4] (R = Cy, tBu; NBA = norbornane; ArF = 3,5-(CF3)2C6H3) are prepared by hydrogenation of a norbornadiene precursor. For the tBu-substituted system this results in the loss of long-range order, which can be re-established by addition of 1-butene to the material to form a mixture of [Rh(tBu2PCH2CH2PtBu2)(cis-2-butene)][BArF 4] and [Rh(tBu2PCH2CH2PtBu2)(1-butene)][BArF 4], in an order/disorder/order phase change. Deployment under flow-reactor conditions results in very different on-stream stabilities. With R = Cy rapid deactivation (3 h) to the butadiene complex occurs, [Rh(Cy2PCH2CH2PCy2)(butadiene)][BArF 4], which can be reactivated by simple addition of H2. While the equivalent butadiene complex does not form with R = tBu at 298 K and on-stream conversion is retained up to 90 h, deactivation is suggested to occur via loss of crystallinity of the SMOM catalyst. Both systems operate under the industrially relevant conditions of an isobutene co-feed. cis:trans selectivites for 2-butene are biased in favor of cis for the tBu system and are more leveled for Cy.
Well-Defined Molybdenum Oxo Alkyl Complex Supported on Silica by Surface Organometallic Chemistry: A Highly Active Olefin Metathesis Precatalyst
Merle, Nicolas,Le Quéméner, Frédéric,Bouhoute, Yassine,Szeto, Kai C.,De Mallmann, Aimery,Barman, Samir,Samantaray, Manoja K.,Delevoye, Laurent,Gauvin, Régis M.,Taoufik, Mostafa,Basset, Jean-Marie
, p. 2144 - 2147 (2017)
The well-defined silica-supported molybdenum oxo alkyl species ( SiO?)MoO(CH2tBu)3 was selectively prepared by grafting of MoO(CH2tBu)3Cl onto partially dehydroxylated silica (silica700) using the surface organometallic chemistry approach. This surface species was fully characterized by elemental analysis and DRIFT, solid-state NMR, and EXAFS spectroscopy. This new material is related to the active species of industrial supported MoO3/SiO2 olefin metathesis catalysts. It displays very high activity in propene self-metathesis at mild (turnover number = 90 000 after 25 h). Remarkably, its catalytic performance outpaces those of the parent imido derivative and its tungsten oxo analogue.
Features of Butene-1 Adsorption on H-Beta Zeolite
Volnina,Kipnis,Khadziev
, p. 177 - 180 (2019)
Abstract: The adsorption of butene-1 on Beta zeolite (H form) is studied via flow-adsorption calorimetry. Upon feeding a mixture of 2 vol % of butene-1 in nitrogen over the pre-calcined zeolite (500°C) at room temperature, an exothermic effect is observed that is associated with the adsorption and transformations of butene, particularly its isomerization to cis- and trans-butenes-2. The thermal desorption of adsorbed butene?1 results in formation of hydrocarbon products showing that oligomerization proceeds during adsorption. It is found that zeolite pretreated with moist nitrogen adsorbs water up to 9.2 wt %. A?weak exothermic effect is observed when butene-1 is adsorbed on this rehydrated zeolite, due apparently to the physical adsorption of butene-1. When the rehydrated zeolite is held for long periods of time in a stream of a butene/nitrogen mixture, cis-butene-2 is detected at the reactor outlet, indicating the gradual replacement of water with butene-1 on the active sites of zeolite.
AN OLEFIN INVERSION VIA cis-CHLOROTELLURATION-trans-DECHLOROTELLURATION
Baeckvall, Jane-E.,Engman, Lars
, p. 1919 - 1922 (1981)
Tellurium tetrachloride addition to olefins, followed by treatment of the 2-chloroalkyltellurium trichloride adduct with aqueous Na2S, results in separation of elemental tellurium and formation of the inverted olefin.
SUPERBASICITY OF RUBIDIUM OXIDE AND CAESIUM OXIDE, AND THEIR REACTION PROFILES OF ISOMERIZATION OF BUTENES
Tsuchiya, Susumu,Takase, Shigeyuki,Imamura, Hayao
, p. 661 - 664 (1984)
The superbasic sites on a rubidium oxide and a caesium oxide have been revealed by means of the benzoic acid titration method.The double-bond-migration and the cis-trans isomerization of butenes took place over the rubidium oxide and the caesium oxide; but the skeletal isomerization was not observed.
Desulfurization of organic sulfur compounds mediated by a molybdenum/cobalt/sulfur cluster
Riaz, Umar,Curnow, Owen J.,Curtis, M. David
, p. 4357 - 4363 (1994)
The bimetallic cluster Cp′2Mo2Co2S3(CO)4 (1) reacts with organic sulfur compounds, e.g. tBuSH, Me2CHCH2CH2SH, PhSH, tBuNCS, cis-2,3-dimethylthiirane, and thiophene, to give the cubane cluster Cp′2Mo2Co2S4(CO) 2(2) in high yield. With the thiols, the organic products are the parent hydrocarbons. The thiophene desulfurization products are saturated and unsaturated C1-C4 hydrocarbons, and the thiocyanates produce RNC that reacts with 1 and 2 to form the carbonyl substitution products Cp′2Mo2Co2S3(CO) 3(RNC) and Cp′2Mo2Co2S4(CO)(RNC), respectively. The cis-2,3-dimethylthiirane produces cis-2-butene stereospecifically. The mechanistic implications are discussed, and the desulfurization reactions are compared to the hydrodesulfurization (HDS) reactions catalyzed by an alumina-supported Mo/Co/S composition.
CH3-ReO3 on γ-Al2O3: Activity, selectivity, active site and deactivation in olefin metathesis
Salameh, Alain,Baudouin, Anne,Soulivong, Daravong,Boehm, Volker,Roeper, Michael,Basset, Jean-Marie,Coperet, Christophe
, p. 180 - 190 (2008)
The active sites (15% of total Re) of CH3ReO3 supported on alumina arise solely from the reaction of the C{single bond}H bond of CH3ReO3 with reactive AlS{single bond}OS sites of a γ-Al2O3 surface to yield [AlSCH2ReO3], whereas the major species, inactive, corresponds to MeReO3 chemisorbed through its oxo ligand(s) on Lewis acid sites of alumina. Monitoring the active sites of CH3ReO3 supported on alumina by solid-state NMR spectroscopy shows that no carbenic signals are observed and that the resting states of the catalyst in the metathesis of propene correspond to μ-methylene and μ-ethylidene species, so that the propagating carbenic species are likely formed only in the presence of olefins. Although this system is highly active in the metathesis of propene, with initial rates similar to some of the best catalysts, it undergoes fast deactivation, which is due to the propene metathesis products, most likely ethene.
