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Collins S, Linnolahti M. Sheet Models for Methylaluminoxane (MAO) Activators? A Theoretical Case Study involving rac-Me 2Si(η 5-C 9H 6) 2Zr (SBIZr) Complexes. Chemphyschem 2024; 25:e202300856. [PMID: 38469662 DOI: 10.1002/cphc.202300856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/09/2024] [Accepted: 03/10/2024] [Indexed: 03/13/2024]
Abstract
Activation of SBIZrMe2 or SBIZrMeCl and a sheet model for an active component of hydrolytic MAO, (MeAlO)16(Me3Al)6, (16,6) has been studied by DFT. Contact ion-pair formation occurs through the intermediacy of SBIZrMe(Cl) or SBIZrMe2 reacting with sheet 16,6 to furnish SBIZrMe-μ-X(MeAlO)16(Me3Al)6 (2, X=Me, Cl). Contact ion-pairs 2 would be in equilibrium with heterodinuclear catalyst precursors [SBIZrMe2AlMe2][(MeAlO)16(Me3Al)6X] (3 (X=Me, Cl) through reversible binding of Me3Al at higher Al : Zr ratios. Calculations show that formation of ion-pairs 3 from contact ion-pairs 2 is more favourable for the SBIZr compared with the parent Cp2Zr complexes. TD-DFT calculations were conducted on relevant SBIZr complexes to relate the results to earlier spectroscopic studies of catalyst activation using UV-Vis spectroscopy. Finally, propene insertion into ion-pairs 2, SBIZrMe-μ-MeB(C6F5)3 (6) and [SBIZrMe][B(C6F5)4] (7) was studied at M06-2X/TZVP level of theory. These studies suggest that contact ion-pairs 2 are significantly less reactive towards insertion than 6 or 7, in disagreement with experiment.
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Affiliation(s)
- Scott Collins
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, FI-80100, Joensuu, Finland
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, FI-80100, Joensuu, Finland
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2
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Collins S, Linnolahti M. Cages versus Sheets: A Critical Comparison in the Size Range Expected for Methylaluminoxane (MAO). Chemphyschem 2023; 24:e202300342. [PMID: 37314040 DOI: 10.1002/cphc.202300342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/14/2023] [Accepted: 06/14/2023] [Indexed: 06/15/2023]
Abstract
New cage models (MeAlO)n (Me3 Al)m (n=16, m=6 or 7) isomeric with previously reported sheet models for the principle activator found in hydrolytic MAO (h-MAO) are compared at M06-2X and MN15 levels of theory using density functional theory with respect to their thermodynamic stability. Reactivity of the neutrals or corresponding anions with formula [(MeAlO)16 (Me3 Al)6 Me]- towards chlorination, and loss of Me3 Al is explored while reactivity of the neutrals towards formation of contact- and outer-sphere ion pairs from Cp2 ZrMe2 and Cp2 ZrMeCl is examined. The results suggest on balance that a cage model for this activator is less consistent with experiment than an isomeric sheet model, although the latter are more stable based on free energy.
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Affiliation(s)
- Scott Collins
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, 80100, Joensuu, Finland
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, 80100, Joensuu, Finland
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3
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Nifant'ev IE, Vinogradov AA, Vinogradov AA, Minyaev ME, Bagrov VV, Salakhov II, Shaidullin NM, Chalykh AE, Shapagin AV, Ivchenko PV. Heterocene-catalyzed ethylene/oct-1-ene copolymerization under MAO-free and low-MAO conditions: The synthesis of highly statistical copolymers and their use in blending with HDPE. POLYMER 2023. [DOI: 10.1016/j.polymer.2023.125836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
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4
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Collins S, Linnolahti M. Ionization of Cp 2 ZrMe 2 and Lewis Bases by Methylaluminoxane: Computational Insights. Chemphyschem 2023; 24:e202200759. [PMID: 36321588 DOI: 10.1002/cphc.202200759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 10/20/2022] [Indexed: 11/06/2022]
Abstract
The interactions of the Lewis bases CO, octamethyltrisiloxane (OMTS) and 2,2'-bipyridine (bipy) with a sheet model for the principal activator (MeAlO)16 (Me3 Al)6 (16,6) in hydrolytic methylaluminoxane (MAO) were investigated by DFT. These studies reveal that OMTS and bipy form adducts with Me3 Al prior to methide abstraction by 16,6 to form the ion-pairs [Me2 Al(κ2 -L)][16,6] (5: L=OMTS, 6: L=bipy, [16,6]- =[(MeAlO)16 (Me3 Al)6 Me]- ) while CO simply binds to a reactive edge site without ionization. The binding and activation of Cp2 ZrMe2 with 16,6 to form both neutral adducts 1 Cp2 ZrMe2 ⋅16,6 and contact ion-pairs 4 and 7, both with formula [Cp2 ZrMe][μ-Me(MeAlO)16 (Me3 Al)6 ], featuring terminal and chelated MAO-anions, respectively was studied by DFT. The displacement of the anion with either excess Cp2 ZrMe2 or Me3 Al was also studied, forming outer-sphere ion-pairs [(Cp2 ZrMe)2 μ-Me][16,6] (2) and [Cp2 Zr(μ-Me)2 AlMe2 ][16,6] (3). The theoretical NMR spectra of these species were compared to experimental spectra of MAO and Cp2 ZrMe2 and found to be in good agreement with the reported data and assignments. These studies confirm that 16,6 is a very suitable model for the activators present in MAO but highlight the difficulty in accurately calculating thermodynamic quantities for molecules in this size regime.
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Affiliation(s)
- Scott Collins
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, F80100, Joensuu, Finland.,Former address: Department of Chemistry, University of Victoria, 3800 Finnerty Rd., Victoria, BC, Canada
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, F80100, Joensuu, Finland
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5
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Tanaka R, Sogo K, Komaguchi K, Ae K, Nakayama Y, Shiono T. Impact of Methylaluminoxane Oxidation on Ethylene Polymerization Using Ni Catalysts. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ryo Tanaka
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527, Japan
| | - Kenji Sogo
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527, Japan
| | - Kenji Komaguchi
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527, Japan
| | - Kazuki Ae
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527, Japan
| | - Yuushou Nakayama
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527, Japan
| | - Takeshi Shiono
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527, Japan
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Kitphaitun S, Fujimoto T, Ochi Y, Nomura K. Effect of Borate Cocatalysts toward Activity and Comonomer Incorporation in Ethylene Copolymerization by Half-Titanocene Catalysts in Methylcyclohexane. ACS ORGANIC & INORGANIC AU 2022; 2:386-391. [PMID: 36855669 PMCID: PMC9955119 DOI: 10.1021/acsorginorgau.2c00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/15/2022] [Accepted: 07/22/2022] [Indexed: 11/30/2022]
Abstract
Ethylene copolymerizations with 2-methyl-1-pentene, 1-dodecene (DD), vinylcyclohexane (VCH), [Me2Si(C5Me4)(N t Bu)]TiCl2 (1), Cp*TiMe2(O-2,6- i Pr2-4-RC6H2) [R = H (2), SiEt3 (3)]-borate, and [A(H)]+[BAr4]- [Ar = C6F5; A(H)+ = N+(H)Me(n-C18H37)2, N+(H)(CH2CF3)(n-C18H37)2, HO+(n-C14H29)2·O(n-C14H29)2, HO+(n-C16H33)2·O(n-C16H33)2; Ar = C10F7, A(H)+ = HO+(n-C14H29)2·O(n-C14H29)2 (B5), N+(H)(CH2CF3)(n-C18H37)2] catalyst systems conducted in methylcyclohexane (MCH) exhibited better comonomer incorporation than those conducted in toluene (in the presence of methylaluminoxane (MAO) or borate cocatalysts). The activity was affected by the borate cocatalyst and 1,3-B5 catalyst systems in MCH and showed the highest activity in the ethylene copolymerizations with VCH and DD.
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Affiliation(s)
- Suphitchaya Kitphaitun
- Department
of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami Osawa, Hachioji,
Tokyo 192-0376, Japan
| | - Takuya Fujimoto
- AGC
Inc., Yokohama Technical Center, 1-1, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Yosuke Ochi
- AGC
Inc., Yokohama Technical Center, 1-1, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Kotohiro Nomura
- Department
of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami Osawa, Hachioji,
Tokyo 192-0376, Japan,
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Linnolahti M, Collins S. Thermodynamics of metallocene catalyst activation: alignment of theory and experiment. Dalton Trans 2022; 51:11152-11162. [PMID: 35801522 DOI: 10.1039/d2dt01711c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three equilibria involved in metallocene catalyst activation, including dissociation of R6Al2 (R = Me, Et or i-Bu) and related species such as [L2ZrMe2AlMe2][B(C6F5)4] (L2 = Cp2, 1,2-ethylenebis(η5-indenyl), Me2C(η5-C5H4)2) or [(L2ZrMe)2μ-Me][MePBB] (L2 = (h5-1,2-Me2C5H3)2, [MePBB]- = [MeB(ArF)3]- with ArF = o-C6F5-C6F4) are studied by DFT using various approaches to account for the enthalpy and entropy changes in gas and condensed phases. These studies reveal that both low energy vibrations and translational entropy conspire to cause significant deviations between theory and experiment when it comes to the free energy change in condensed or even gas phase. Alignment of theory with experiment requires in addition, consideration of specific solvation of reactants and products.
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Affiliation(s)
- Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, FI-80100, Joensuu, Finland.
| | - Scott Collins
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, FI-80100, Joensuu, Finland.
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8
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Collins S, Linnolahti M. Activation of Substituted Metallocene Catalysts using Methylaluminoxane. ChemCatChem 2022. [DOI: 10.1002/cctc.202101918] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Scott Collins
- University of Victoria Faculty of Science chemistry CANADA
| | - Mikko Linnolahti
- University of Eastern Finland Department of Chermistry Yliopistokatu 7 80100 Joensuu FINLAND
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9
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Piovano A, Groppo E. Flexible ligands in heterogeneous catalysts for olefin polymerization: Insights from spectroscopy. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214258] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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le Roux WH, Matthews M, Lederer A, van Reenen AJ, Malgas-Enus R. First report of Schiff-base nickel nanoparticle-catalyzed oligomerization and polymerization of norbornene. J Catal 2022. [DOI: 10.1016/j.jcat.2021.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Collins S, Joshi A, Linnolahti M. Formation and Structure of Hydrolytic Methylaluminoxane Activators. Chemistry 2021; 27:15460-15471. [PMID: 34436806 PMCID: PMC8596698 DOI: 10.1002/chem.202102463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Indexed: 01/14/2023]
Abstract
Methylaluminoxane (MAO) activators have sheet structures which form ion-pairs on reaction of neutral donors such as octamethyltrisiloxane (OMTS). The ion-pairs can be detected by electrospray ionization mass spectrometry (ESI-MS) in polar media. The growth of these reactive precursors during hydrolysis of Me3 Al can be monitored using ESI-MS. Density functional theory, combined with numerical simulation of growth, indicates that this process involves rapid formation of low MW oligomers, followed by assembly of these species into low MW sheets. These can grow through further addition of low MW oligomers or by fusion into larger sheets. The mechanism of these growth processes leads to the prediction that even-numbered sheets should be favored, and this surprising result is confirmed by ESI-MS monitoring experiments of both activator growth and MAO aging.
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Affiliation(s)
- Scott Collins
- Former affiliation: Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada)
| | - Anuj Joshi
- UVic Genome BC Proteomics Research Centre sup, 4464 Markham St #3101, Victoria, BC V8Z 5N3, Canada
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, 80100, Joensuu, Finland
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12
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Removal of mononuclear alkylaluminum species in aluminoxane using a crosslinked polymer bearing bulky phenoxy groups. Polym J 2021. [DOI: 10.1038/s41428-021-00507-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Kenyon P, Leung DJ, Lyu M, Chen C, Turner ZR, Buffet JC, O'Hare D. Controlling the activity of an immobilised molecular catalyst by Lewis acidity tuning of the support. J Catal 2021. [DOI: 10.1016/j.jcat.2021.08.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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14
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Tyumkina TV, Islamov DN, Kovyazin PV, Parfenova LV. Chain and cluster models of methylaluminoxane as activators of zirconocene hydride, alkyl and metallacyclopropane intermediates in alkene transformations. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111768] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Collins S, Hasan G, Joshi A, McIndoe JS, Linnolahti M. Are Methylaluminoxane Activators Sheets? Chemphyschem 2021; 22:1326-1335. [PMID: 33971081 PMCID: PMC8362195 DOI: 10.1002/cphc.202100268] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/07/2021] [Indexed: 11/14/2022]
Abstract
Density functional theory calculations on neutral sheet models for methylaluminoxane (MAO) indicate that these structures, containing 5‐coordinate and 4‐coordinate Al, are likely precursors to ion‐pairs seen during the hydrolysis of trimethylaluminum (Me3Al) in the presence of donors such as octamethyltrisiloxane (OMTS). Ionization by both methide ([Me]−) and [Me2Al]+ abstraction, involving this donor, were studied by polarizable continuum model calculations in fluorobenzene (PhF) and o‐difluorobenzene (DFB) media. These studies suggest that low MW, 5‐coordinate sheets ionize by [Me2Al]+ abstraction, while [Me]− abstraction from Me3Al‐OMTS is the likely process for higher MW 4‐coordinate sheets. Further, comparison of anion stabilities per mole of aluminoxane repeat unit (MeAlO)n, suggest that anions such as [(MeAlO)7(Me3Al)4Me]−=[7,4]− are especially stable compared to higher homologues, even though their neutral precursors are unstable.
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Affiliation(s)
- Scott Collins
- Department of Chemistry, University of Victoria, 3800, Finnerty Road, Victoria, BC, V8P 5 C2, Canada
| | - Galib Hasan
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, 80100, Joensuu, Finland.,Institute for Atmospheric and Earth System Research (INAR) c/o Department of Chemistry, University of Helsinki, A.I Virtasen Aukio 1, 00014, Helsinki, Finland
| | - Anuj Joshi
- Department of Chemistry, University of Victoria, 3800, Finnerty Road, Victoria, BC, V8P 5 C2, Canada.,UVic Genome BC Proteomics Research Centre, 4464, Markham St #3101, Victoria, BC V8Z 5N3, Canada
| | - J Scott McIndoe
- Department of Chemistry, University of Victoria, 3800, Finnerty Road, Victoria, BC, V8P 5 C2, Canada
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, 80100, Joensuu, Finland
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Nifant'ev IE, Vinogradov AA, Vinogradov AA, Ivchenko PV. Alternative mechanistic interpretation for unconventional catalytic behaviour of triisobutylaluminium-activated heterocenes in ethylene polymerization. MENDELEEV COMMUNICATIONS 2021. [DOI: 10.1016/j.mencom.2021.07.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Joshi A, Collins S, Linnolahti M, Zijlstra HS, Liles E, McIndoe JS. Spectroscopic Studies of Synthetic Methylaluminoxane: Structure of Methylaluminoxane Activators. Chemistry 2021; 27:8753-8763. [PMID: 33780574 DOI: 10.1002/chem.202100271] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Indexed: 11/06/2022]
Abstract
Hydrolysis of trimethylaluminum (Me3 Al) in polar solvents can be monitored by electrospray ionization mass spectrometry (ESI-MS) using the donor additive octamethyltrisiloxane [(Me3 SiO)2 SiMe2 , OMTS]. Using hydrated salts, hydrolytic methylaluminoxane (h-MAO) features different anion distributions, depending on the conditions of synthesis, and different activator contents as measured by NMR spectroscopy. Non-hydrolytic MAO was prepared using trimethylboroxine. The properties of this material, which contains incorporated boron, differ significantly from h-MAO. In the case of MAO prepared by direct hydrolysis, oligomeric anions are observed to rapidly form, and then more slowly evolve into a mixture dominated by an anion with m/z 1375 with formula [(MeAlO)16 (Me3 Al)6 Me]- . Theoretical calculations predict that sheet structures with composition (MeAlO)n (Me3 Al)m are favoured over other motifs for MAO in the size range suggested by the ESI-MS experiments. A possible precursor to the m/z 1375 anion is a local minimum based on the free energy released upon hydrolysis of Me3 Al.
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Affiliation(s)
- Anuj Joshi
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada
| | - Scott Collins
- C/o Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, 80100, Joensuu, Finland
| | - Harmen S Zijlstra
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada
| | - Elena Liles
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada
| | - J Scott McIndoe
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada
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Zaccaria F, Zuccaccia C, Cipullo R, Budzelaar PHM, Vittoria A, Macchioni A, Busico V, Ehm C. Methylaluminoxane’s Molecular Cousin: A Well-defined and “Complete” Al-Activator for Molecular Olefin Polymerization Catalysts. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05696] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Francesco Zaccaria
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
- Dipartimento di Chimica, Biologia e Biotecnologie and CIRCC, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Cristiano Zuccaccia
- Dipartimento di Chimica, Biologia e Biotecnologie and CIRCC, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Roberta Cipullo
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
| | - Peter H. M. Budzelaar
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
| | - Antonio Vittoria
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
| | - Alceo Macchioni
- Dipartimento di Chimica, Biologia e Biotecnologie and CIRCC, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Vincenzo Busico
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
| | - Christian Ehm
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
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Zanchin G, Piovano A, Amodio A, De Stefano F, Di Girolamo R, Groppo E, Leone G. NEt 3-Triggered Synthesis of UHMWPE Using Chromium Complexes Bearing Non-innocent Iminopyridine Ligands. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02475] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Giorgia Zanchin
- CNR, Istituto di Scienze e Tecnologie Chimiche “Giulio Natta” (SCITEC), via A. Corti 12, I-20133 Milano, Italy
| | - Alessandro Piovano
- Dipartimento di Chimica, NIS Interdepartmental Research Center and INSTM Reference Center, Università degli Studi di Torino, Via G. Quarello 15A, I-10135 Torino, Italy
| | - Alessia Amodio
- Dipartimento di Chimica, NIS Interdepartmental Research Center and INSTM Reference Center, Università degli Studi di Torino, Via G. Quarello 15A, I-10135 Torino, Italy
| | - Fabio De Stefano
- Dipartimento di Scienze Chimiche, Università di Napoli “Federico II”, Complesso Monte S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Rocco Di Girolamo
- Dipartimento di Scienze Chimiche, Università di Napoli “Federico II”, Complesso Monte S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Elena Groppo
- Dipartimento di Chimica, NIS Interdepartmental Research Center and INSTM Reference Center, Università degli Studi di Torino, Via G. Quarello 15A, I-10135 Torino, Italy
| | - Giuseppe Leone
- CNR, Istituto di Scienze e Tecnologie Chimiche “Giulio Natta” (SCITEC), via A. Corti 12, I-20133 Milano, Italy
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20
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Nakashima T, Nakayama Y, Shiono T, Tanaka R. Neutral, Noncoordinating, and Hydrocarbon-Soluble Protic Cocatalyst for Olefin Polymerization. ACS Catal 2021. [DOI: 10.1021/acscatal.0c04758] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tomoya Nakashima
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
| | - Yuushou Nakayama
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
| | - Takeshi Shiono
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
| | - Ryo Tanaka
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
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Kilpatrick AFR, Geddes HS, Turner ZR, Buffet JC, Goodwin AL, O'Hare D. Polymethylaluminoxane organic frameworks (sMAOF) – highly active supports for slurry phase ethylene polymerisation. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00767j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A series of modified solid polymethylaluminoxane (sMAO) catalyst supports have been developed for slurry phase ethylene polymerisation, using aryl di-ol modifier groups.
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Affiliation(s)
| | | | - Zoë R. Turner
- Chemistry Research Laboratory
- Department of Chemistry
- University of Oxford
- Oxford
- UK
| | - Jean-Charles Buffet
- Chemistry Research Laboratory
- Department of Chemistry
- University of Oxford
- Oxford
- UK
| | | | - Dermot O'Hare
- Chemistry Research Laboratory
- Department of Chemistry
- University of Oxford
- Oxford
- UK
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Joshi A, Zijlstra HS, Liles E, Concepcion C, Linnolahti M, McIndoe JS. Real-time analysis of methylalumoxane formation. Chem Sci 2020; 12:546-551. [PMID: 34163784 PMCID: PMC8178985 DOI: 10.1039/d0sc05075j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Methylalumoxane (MAO), a perennially useful activator for olefin polymerization precatalysts, is famously intractable to structural elucidation, consisting as it does of a complex mixture of oligomers generated from hydrolysis of pyrophoric trimethylaluminum (TMA). Electrospray ionization mass spectrometry (ESI-MS) is capable of studying those oligomers that become charged during the activation process. We have exploited that ability to probe the synthesis of MAO in real time, starting less than a minute after the mixing of H2O and TMA and tracking the first half hour of reactivity. We find that the process does not involve an incremental build-up of oligomers; instead, oligomerization to species containing 12–15 aluminum atoms happens within a minute, with slower aggregation to higher molecular weight ions. The principal activated product of the benchtop synthesis is the same as that observed in industrial samples, namely [(MeAlO)16(Me3Al)6Me]−, and we have computationally located a new sheet structure for this ion 94 kJ mol−1 lower in Gibbs free energy than any previously calculated. The activator methylaluminoxane is made by hydrolysis of trimethylaluminum. Analysis using ESI-MS reveals rapid formation of small oligomers is followed by slower aggregation to the larger precursors most capable of releasing [Me2Al]+.![]()
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Affiliation(s)
- Anuj Joshi
- Department of Chemistry, University of Victoria PO Box 1700 STN CSC, Victoria BC V8W 2Y2 Canada
| | - Harmen S Zijlstra
- Department of Chemistry, University of Victoria PO Box 1700 STN CSC, Victoria BC V8W 2Y2 Canada
| | - Elena Liles
- Department of Chemistry, University of Victoria PO Box 1700 STN CSC, Victoria BC V8W 2Y2 Canada
| | - Carina Concepcion
- Department of Chemistry, University of Victoria PO Box 1700 STN CSC, Victoria BC V8W 2Y2 Canada
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland P.O. Box 111 FI-80101 Joensuu Finland
| | - J Scott McIndoe
- Department of Chemistry, University of Victoria PO Box 1700 STN CSC, Victoria BC V8W 2Y2 Canada
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