Density functional studies on chromium catalyzed ethylene trimerization

Bhaduri, Sumit; Mukhopadhyay, Sudipta; Kulkarni, Sudhir A.

doi:10.1016/j.jorganchem.2008.12.012

Cited by 42 publications

(17 citation statements)

References 60 publications

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“…Importantly, this DFT transition-state model is accurate and relatively fast to use. New ligands can be virtually screened by calculating the energies of transition-state conformation ensembles for TS1 and TS2 (Scheme 1b), [52][53][54][55][56][57][58][59][60][61][62][63] which can then be used in our linear correlation model to provide a predicted 1-hexene : 1-octene ratio for given set of reaction conditions. Our transition-state selectivity model was based on our DFT mechanistic calculations, and studies by Britovsek and McGuinness, Cheon, Liu and others.…”

Section: Resultsmentioning

confidence: 99%

Quantum-mechanical transition-state model combined with machine learning provides catalyst design features for selective Cr olefin oligomerization

et al. 2020

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Section: Resultsmentioning

confidence: 99%

Quantum-mechanical transition-state model combined with machine learning provides catalyst design features for selective Cr olefin oligomerization

et al. 2020

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“…[125] Am etallacycle mechanism is accepted for these systems and supported by theoretical investigations. [126][127][128] However,t he nature of the active sites is still very much under debate,w ith several possible redox couples such as Cr I /Cr III or Cr II /Cr IV proposed. [105,129] Very active and selective homogeneous Cr trimerization catalysts based on PNP ligands (Scheme 7e)w ere developed by BP [130] and Sasol [125,131] (up to 10 6 g hexenes g Cr À1 h À1 and > 90 % 1-hexene selectivities).…”

Section: Selected Homogeneous Systemsmentioning

confidence: 99%

“…The selective trimerization of ethylene to 1‐hexene using homogeneous Cr catalysts was discovered by Union Carbide and commercialized by Chevron Phillips (Phillips trimerization system, Scheme d) . A metallacycle mechanism is accepted for these systems and supported by theoretical investigations . However, the nature of the active sites is still very much under debate, with several possible redox couples such as Cr I /Cr III or Cr II /Cr IV proposed .…”

Section: Alkene Oligomerizationmentioning

confidence: 99%

Bridging the Gap between Industrial and Well‐Defined Supported Catalysts

et al. 2018

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Many industrial catalysts contain isolated metal sites on the surface of oxide supports. Although such catalysts have been used in a broad range of processes for more than 40 years, there is often a very limited understanding about the structure of the catalytically active sites. This Review discusses how surface organometallic chemistry (SOMC) engineers surface sites with well-defined structures and provides insight into the nature of the active sites of industrial catalysts; the Review focuses in particular on olefin production and conversion processes.

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“…[Cr] 1-octene Elsewhere, a number of computational investigations have been performed to shed light on the valence state of the active chromium species [132,164,[168][169][170][171]. Indeed, Cr(II)/Cr(IV) and Cr(I)/Cr(III) redox processes have been proposed for selective oligomerization which are largely dependent on the ligand structure.…”

Section: Cr N+2mentioning

confidence: 99%

Recent advances in homogeneous chromium catalyst design for ethylene tri-, tetra-, oligo- and polymerization

Bariashir

Huang

Solan

et al. 2019

Coordination Chemistry Reviews

115

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This review focuses on recent progress made using well-defined molecular chromium complexes that, upon suitable activation, can catalyze the tri-, tetra, oligo-and/or polymerization of ethylene. In particular, emphasis will be placed on the tuning of the performance characteristics of these homogeneous catalysts through structural modifications made to the multidentate ligand manifold (e.g., donor atoms, charge, backbone and strain) and the effects these changes have on the resulting ethylene derivatives. While the ability of these catalysts to mediate the formation of high molecular weight linear polyethylene continues to see many developments, their capacity to form polyethylene waxes and oligomers has witnessed some major advances. Moreover, the impressive selectivity of some chromium systems to generate commercially important 1-hexene and more recently 1-octene has seen the implementation of this technology at the industrial level. The types of precatalysts to be discussed will be divided broadly on the basis of their ability to generate either polymers/oligomers or short chain αolefins; the effects of co-catalyst and reaction conditions (e.g., temperature, pressure, solvent) on catalytic activity and selectivity, will be also developed. In addition, current proposals as to the mechanistic details displayed by these versatile chromium catalysts will be highlighted.

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Density functional studies on chromium catalyzed ethylene trimerization

Cited by 42 publications

References 60 publications

Quantum-mechanical transition-state model combined with machine learning provides catalyst design features for selective Cr olefin oligomerization

Quantum-mechanical transition-state model combined with machine learning provides catalyst design features for selective Cr olefin oligomerization

Bridging the Gap between Industrial and Well‐Defined Supported Catalysts

Recent advances in homogeneous chromium catalyst design for ethylene tri-, tetra-, oligo- and polymerization

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