FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1991001415> ?p ?o ?g. }

• W1991001415 endingPage "1735" @default.
• W1991001415 startingPage "1721" @default.
• W1991001415 abstract "The use of carbon dioxide as a carbon source for the synthesis of organic chemicals can contribute to a more sustainable chemical industry. Because CO2 is such a thermodynamically stable molecule, few effective catalysts are available to facilitate this transformation. Currently, the major industrial processes that convert CO2 into viable products generate urea and hydroxybenzoic acid. One of the most promising new technologies for the use of this abundant, inexpensive, and nontoxic renewable resource is the alternating copolymerization of CO2 and epoxides to provide biodegradable polycarbonates, which are highly valuable polymeric materials. Because this process often generates byproducts, such as polyether or ether linkages randomly dispersed within the polycarbonate chains and/or the more thermodynamically stable cyclic carbonates, the choice of catalyst is critical for selectively obtaining the expected product.In this Account, we outline our efforts to develop highly active Co(III)-based catalysts for the selective production of polycarbonates from the alternating copolymerization of CO2 with epoxides. Binary systems consisting of simple (salen)Co(III)X and a nucleophilic cocatalyst exhibited high activity under mild conditions even at 0.1 MPa CO2 pressure and afforded copolymers with >99% carbonate linkages and a high regiochemical control (∼95% head-to-tail content). Discrete, one-component (salen)Co(III)X complexes bearing an appended quaternary ammonium salt or sterically hindered Lewis base showed excellent activity in the selectively alternating copolymerization of CO2 with both aliphatic epoxides and cyclohexene oxide at high temperatures with low catalyst loading and/or low pressures of CO2. Binary or one-component catalysts based on unsymmetric multichiral Co(III) complexes facilitated the efficient enantioselective copolymerization of CO2 with epoxides, providing aliphatic polycarbonates with >99% head-to-tail content. These systems were also very efficient in catalyzing the terpolymerization of cyclohexene oxide, propylene oxide and CO2. The resulting terpolymer had a single glass-transition temperature and a single thermolysis peak.This Account also provides a thorough mechanistic understanding of the high activities, excellent selectivities, and unprecedented stereochemical control of these Co(III)-based catalysts in the production of CO2 copolymers . The catalysis occurs through a cooperative monometallic mechanism, in which the Lewis acidic Co(III) ion serves as electrophile to activate then epoxide and the nucleophilic counterion or cocatalyst serves as a nucleophile to initiate polymer-chain growth. The high activity and excellent regioselectivity observed in the epoxide ring-opening reactions results from epoxide activation through the moderate electrophilicity of the Co(III) ion, the fast insertion of CO2 into the Co–O bond, and the facile dissociation of the propagating carboxylate species from the central metal ion. The reversible intra- or intermolecular Co–O bond formation and dissociation helps to stabilize the active Co(III) species against reversion to the inactive Co(II) ion. We also describe our laboratory’s recent preparation of the first crystalline CO2-based polymer via highly stereospecific copolymerization of CO2 and meso-cyclohexene oxide and the selective synthesis of perfectly alternating polycarbonates from the coupling of CO2 with epoxides bearing an electron-withdrawing group." @default.
• W1991001415 created "2016-06-24" @default.
• W1991001415 creator A5037176858 @default.
• W1991001415 creator A5041602237 @default.
• W1991001415 creator A5048926918 @default.
• W1991001415 date "2012-08-02" @default.
• W1991001415 modified "2023-10-04" @default.
• W1991001415 title "CO₂ Copolymers from Epoxides: Catalyst Activity, Product Selectivity, and Stereochemistry Control" @default.
• W1991001415 cites W1927730430 @default.
• W1991001415 cites W1969266128 @default.
• W1991001415 cites W1972027918 @default.
• W1991001415 cites W1972060868 @default.
• W1991001415 cites W1980864184 @default.
• W1991001415 cites W1986448254 @default.
• W1991001415 cites W1988593925 @default.
• W1991001415 cites W2000635172 @default.
• W1991001415 cites W2008643556 @default.
• W1991001415 cites W2011887848 @default.
• W1991001415 cites W2016670499 @default.
• W1991001415 cites W2017589181 @default.
• W1991001415 cites W2018505828 @default.
• W1991001415 cites W2022778939 @default.
• W1991001415 cites W2025230985 @default.
• W1991001415 cites W2031791596 @default.
• W1991001415 cites W2033823517 @default.
• W1991001415 cites W2049203091 @default.
• W1991001415 cites W2056945293 @default.
• W1991001415 cites W2059212126 @default.
• W1991001415 cites W2063869050 @default.
• W1991001415 cites W2071105954 @default.
• W1991001415 cites W2072049621 @default.
• W1991001415 cites W2080898720 @default.
• W1991001415 cites W2082882995 @default.
• W1991001415 cites W2089110129 @default.
• W1991001415 cites W2090123693 @default.
• W1991001415 cites W2103857876 @default.
• W1991001415 cites W2122232989 @default.
• W1991001415 cites W2133736815 @default.
• W1991001415 cites W2151669278 @default.
• W1991001415 cites W2155632989 @default.
• W1991001415 cites W2161652710 @default.
• W1991001415 cites W2322844794 @default.
• W1991001415 cites W2332399007 @default.
• W1991001415 cites W3005133281 @default.
• W1991001415 cites W94258974 @default.
• W1991001415 doi "https://doi.org/10.1021/ar300035z" @default.
• W1991001415 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/22857013" @default.
• W1991001415 hasPublicationYear "2012" @default.
• W1991001415 type Work @default.
• W1991001415 sameAs 1991001415 @default.
• W1991001415 citedByCount "560" @default.
• W1991001415 countsByYear W19910014152012 @default.
• W1991001415 countsByYear W19910014152013 @default.
• W1991001415 countsByYear W19910014152014 @default.
• W1991001415 countsByYear W19910014152015 @default.
• W1991001415 countsByYear W19910014152016 @default.
• W1991001415 countsByYear W19910014152017 @default.
• W1991001415 countsByYear W19910014152018 @default.
• W1991001415 countsByYear W19910014152019 @default.
• W1991001415 countsByYear W19910014152020 @default.
• W1991001415 countsByYear W19910014152021 @default.
• W1991001415 countsByYear W19910014152022 @default.
• W1991001415 countsByYear W19910014152023 @default.
• W1991001415 crossrefType "journal-article" @default.
• W1991001415 hasAuthorship W1991001415A5037176858 @default.
• W1991001415 hasAuthorship W1991001415A5041602237 @default.
• W1991001415 hasAuthorship W1991001415A5048926918 @default.
• W1991001415 hasConcept C118792377 @default.
• W1991001415 hasConcept C15920480 @default.
• W1991001415 hasConcept C161790260 @default.
• W1991001415 hasConcept C178790620 @default.
• W1991001415 hasConcept C178907741 @default.
• W1991001415 hasConcept C185592680 @default.
• W1991001415 hasConcept C188027245 @default.
• W1991001415 hasConcept C201194858 @default.
• W1991001415 hasConcept C2776920199 @default.
• W1991001415 hasConcept C2777505466 @default.
• W1991001415 hasConcept C2777801237 @default.
• W1991001415 hasConcept C2779879930 @default.
• W1991001415 hasConcept C521977710 @default.
• W1991001415 hasConceptScore W1991001415C118792377 @default.
• W1991001415 hasConceptScore W1991001415C15920480 @default.
• W1991001415 hasConceptScore W1991001415C161790260 @default.
• W1991001415 hasConceptScore W1991001415C178790620 @default.
• W1991001415 hasConceptScore W1991001415C178907741 @default.
• W1991001415 hasConceptScore W1991001415C185592680 @default.
• W1991001415 hasConceptScore W1991001415C188027245 @default.
• W1991001415 hasConceptScore W1991001415C201194858 @default.
• W1991001415 hasConceptScore W1991001415C2776920199 @default.
• W1991001415 hasConceptScore W1991001415C2777505466 @default.
• W1991001415 hasConceptScore W1991001415C2777801237 @default.
• W1991001415 hasConceptScore W1991001415C2779879930 @default.
• W1991001415 hasConceptScore W1991001415C521977710 @default.
• W1991001415 hasIssue "10" @default.
• W1991001415 hasLocation W19910014151 @default.
• W1991001415 hasLocation W19910014152 @default.
• W1991001415 hasOpenAccess W1991001415 @default.
• W1991001415 hasPrimaryLocation W19910014151 @default.

• next