摘要:
A synthetic process for the selective preparation of reactive polyhedral oligomeric silsesquioxanes (POSS) as well as polyhedral oligomeric silicate (POS) (spherosilicate) is provided. The method claimed herein employs metal catalyzed metathesis reactions for the selective reaction of .alpha.-olefin containing polyhedral oligomeric silsesquioxanes or silicates with olefinic reagents bearing functionalities useful for grafting reactions, polymerization chemistry and sol-gel processes. The use of metal catalyzed metathesis chemistry to form both linear or network polyhedral silsesquioxane polymers directly from .alpha.-olefin-containing polyhedral oligomeric silsesquioxanes is also described.
摘要:
Method is provided for reacting silsesquioxane resins or polyhedral oligomeric silsesquioxanes (POSS) bearing one or more olefinic groups with strong acids to cleave one or more olefin bonds of the olefinic groups to form POSS species of monomers or polymers having one or more functionalities suitable for reaction with a wide range of polymeric systems, to thus form new POSS derived compounds. Also provided are the new compounds so formed.
摘要:
Method is provided for selectively opening rings of polyhedral oligomeric silsesquioxane (POSS) compounds to from functionalized derivatives thereof or new POSS species. Per the inventive method, the POSS compound is reacted with an acid to selectively cleave bonds in the POSS rings to add functionalities thereto for grafting, polymerization or catalysis, to thus form new familes of POSS derived compounds. Also provided are the new compounds so formed. Method is also provided for expanding rings of POSS compounds. Per the inventive method, a POSS compound is reacted with silane reagents to obtain an expanded POSS framework with added Si ring substituends to form new families of POSS compounds. Also provided are the new compounds so formed.
摘要:
A synthetic process for the selective preparation of reactive polyhedral oligomeric silsesquioxanes (POSS) as well as polyhedral oligomeric silicate (POS) (spherosilicate) is provided. The inventive process employs the use of metal catalyzed hydrosilylation reactions for the selective reaction of silane containing polyhedral oligomeric silsesquioxanes or silicates with olefinic reagents bearing functionalities useful for grafting reactions, polymerization chemistry and sol-gel processes. The invention also discloses metal-catalyzed hydrosulfidation reactions and metal-catalyzed hydrophosphidation reacttions for functionalization of polycyclic silicones.
摘要:
Method is provided for controlling the stereo chemistry of functionalities or X groups to exo or endo positions on a polyhedral oligomeric silsesquioxane (POSS) compound by adding certain reagents to said X groups to change one or more positions thereof to endo or exo. Also provided are the POSS species formed by the above inventive method. Method is also provided for inserting a ring substituent into a POSS compound. Also provided are the POSS species formed by such inventive method.
摘要:
The present invention relates to a process for converting methane into a higher alkane mixture, preferably a liquid alkane mixture, comprising (C3+) alkanes having 3 carbon atoms and more, preferably (C4+) alkanes having 4 carbon atoms, especially (C5+) alkanes having 5 carbon atoms and more. The process comprises:—a stage (1) comprising contacting methane with a metal catalyst (C1) capable of producing, in contact with alkane, reactions involving the splitting and recombining of C—C and/or C—H and/or C-metal bonds, so as to form by a non-oxidative methane coupling reaction a mixture (M1) comprising ethane and hydrogen,—preferably a stage (2) comprising fractionating the mixture (M1) so as to separate and to isolate the ethane, and—a stage (3) comprising, preferably simultaneously, (i) contacting the mixture (M1) or preferably the ethane isolated in stage (2) with a metal catalyst (C2) capable of producing, in contact with alkane, reactions involving the splitting and recombining of C—C and/or C—H and/or C-metal bonds, said catalyst being identical to or different from catalyst (C1), so as to form by simultaneous ethane self- and cross-metathesis reactions a mixture (M2) comprising methane and the higher alkane mixture, and (ii) fractionating the mixture (M2) so as to separate and to isolate said higher alkane mixture, preferably in liquid form, and particularly the methane which is preferably recycled into stage (1). The hydrogen produced in stage (1) is preferably separated and isolated in stage (2) and then used for various applications and stages, e.g. for producing thermal and/or electrical energies preferably employed to run the process.
摘要:
The present invention relates to a process for the manufacture of alkanes comprising a catalytic reaction resulting from contacting methane with at least one other starting alkane (I) in the presence of a metal compound (C) capable of catalysing a reaction for the splitting and/or recombination of a carbon-carbon bond and/or of a carbon-hydrogen bond and/or of a carbon-metal bond, which catalytic reaction results in the formation of at least one final alkane (II) having a number of carbon atoms equal to or greater than (2). In the process, the contacting operation is carried out under a methane partial pressure equal to or greater than 0.1 MPa, preferably in the range from 0.1 to 100 MPa. The metal compound (C) can be chosen from metal compounds supported on and dispersed over a solid support, metal compounds supported on and grafted to a solid support and non-supported metal compounds. Under these conditions, it was found that the yield of the catalytic reaction was improved, and that the catalytic stability and activity of the metal compound (C) over timer were greatly enhanced.
摘要:
The invention relates to a process for producing ethane comprising contacting methane with a metal catalyst selected from metal hydrides, metal organic compounds and mixtures thereof. It also relates to a process for the conversion of methane to carbon-containing products comprising contacting methane with a metal catalyst comprising at least one metal, Me, chosen from the lanthanides, the actinides and the metals from Groups 2 to 12 of the Periodic Table of the Elements, so as to produce ethane in a proportion of at least 65%, especially at least 98% or 99% by weight with respect to carbon-containing products formed in the process. The process can be a single-step process, preferably carried out under conditions involving a non-oxidative catalytic coupling of methane, in particular under operating conditions maintained substantially constant, preferably continuously, during the ethane production, e.g. at a temperature ranging from −30° C. to +80° C., preferably from 20° C. to 500° C., under a total absolute pressure ranging from 10−3 to 100 MPa, preferably from 0.1 to 50 MPa. The metal catalyst may be chosen from metal catalysts supported on and preferably grafted to a solid support. One of the main advantages of the present invention is to produce ethane with a very high selectivity.
摘要:
The invention relates to a process for producing ethane comprising contacting methane with a metal catalyst selected from metal hydrides, metal organic compounds and mixtures thereof. It also relates to a process for the conversion of methane to carbon-containing products comprising contacting methane with a metal catalyst comprising at least one metal, Me, chosen from the lanthanides, the actinides and the metals from Groups 2 to 12 of the Periodic Table of the Elements, so as to produce ethane in a proportion of at least 65%, especially at least 98% or 99% by weight with respect to carbon-containing products formed in the process. The process can be a single-step process, preferably carried out under conditions involving a non-oxidative catalytic coupling of methane, in particular under operating conditions maintained substantially constant, preferably continuously, during the ethane production, e.g. at a temperature ranging from −30° C. to +80° C., preferably from 20° C. to 500° C., under a total absolute pressure ranging from 10−3 to 100 MPa, preferably from 0.1 to 50 MPa. The metal catalyst may be chosen from metal catalysts supported on and preferably grafted to a solid support. One of the main advantages of the present invention is to produce ethane with a very high selectivity.
摘要:
The invention relates to a supported metal compound, comprising a support made from aluminium oxide to which a tungsten hydride is grafted. The support may be selected from the homogeneous supports with a composition based on aluminum oxide and from heterogeneous supports made from aluminium oxide with aluminum oxide essentially on the surface of said support. The support may in particular comprise aluminium oxide, mixed aluminium oxides and modified aluminium oxides particularly comprising one or more elements of groups 15 to 17 of the periodic table of the elements, such as phosphorus, sulphur, fluorine or chlorine. A support made from porous, non-porous or mesoporous aluminas is preferred. The degree of oxidation of the tungsten may have a value of from 2 to 6. The tungsten atom is generally bonded to one or several hydrogen atoms and optionally to one or several hydrocarbon groups. According to the invention, the compound may be prepared by a dispersion step and grafting of a tungsten organometallic precursor to the support made from aluminium oxide then hydrogenation of the resulting product. The product may be used as catalyst in reactions of cleavage and recombination of hydrocarbons, particularly in hydrocarbon metathesis reactions most particularly of alkanes. The product has a surprising, extremely high catalytic activity in this type of reaction and in particular, a high selectivity for the formation of n-alkanes with relation to iso-alkanes.