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Li F, He J, Song T, Gao W, Mu X, Mu Y. Zirconium Complexes with Bulkier Amine Bis(phenolate) Ligands and Their Catalytic Properties for Ethylene (Co)polymerization. Inorg Chem 2022; 61:6469-6479. [PMID: 35436094 DOI: 10.1021/acs.inorgchem.2c00061] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of new zirconium complexes bearing bulkier amine bis(phenolate) tetradentate ligands, Me2NCH2CH2N{CH2(2-O-3-R-5-tBu-C6H2)}2ZrCl2 [R = CPhMe2 (1); CMePh2 (2); CPh3 (3); Ph (4); 3,5-Me2C6H3 (5); 3,5-tBu2C6H3 (6); 4-tBuC6H4 (7)], were synthesized and characterized by 1H nuclear magnetic resonance (NMR), 13C NMR, and elemental analyses. The molecular structures of complexes 1 and 3 were determined by single-crystal X-ray diffraction analysis. The X-ray crystallography analysis reveals that these complexes display a slightly distorted octahedral geometry around their metal centers. Upon activation with methylaluminoxane (MAO), dry-MAO, MAO/butylated hydroxytoluene (BHT), or AliBu3/CPh3B(C6F5)4, these zirconium complexes exhibit high catalytic activity for ethylene polymerization [up to 1.07 × 107 g PE (mol Zr)-1 h-1] and ethylene/1-hexene copolymerization [up to 2.78 × 107 g polymer (mol Zr)-1 h-1], affording (co)polymers with moderate to high molecular weights and good comonomer incorporations. The zirconium complexes with bulkier R groups show higher catalytic activities and longer lifetimes and produce polymers with higher molecular weights, while the zirconium complexes with aryls as R groups demonstrate relatively good comonomer incorporation ability for the copolymerization reactions. These catalytic systems also show moderate catalytic activities for the polymerization reactions of propylene, 1-hexene, and 1-decene. Upon activation with MAO, the zirconium complexes also show moderate catalytic activities for the copolymerization reaction of ethylene with 3-buten-1-ol (treated with 1 equiv of AliBu3), affording copolymers with the incorporation of 3-buten-1-ol up to 1.05%.
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Affiliation(s)
- Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China
| | - Jianghao He
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China
| | - Tingting Song
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China
| | - Wei Gao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China
| | - Xiaoyue Mu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China
| | - Ying Mu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China
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2
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Polymetallic Group 4 Complexes: Catalysts for the Ring Opening Polymerisation of rac-Lactide. Catalysts 2021. [DOI: 10.3390/catal11050551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Five novel air- and moisture-stable polymetallic Ti and Zr amino acid-derived amine bis(phenolate) (ABP) complexes were synthesised and fully characterised, including X-ray crystallographic studies. The reaction of the ABP proligands with Ti or Zr alkoxides has resulted in the formation of polymetallic aggregates of different nuclearity. The steric bulk on the pendant arm of the ligand was found to play a critical role in establishing the nuclearity of the aggregated complex. Sterically, less-demanding groups, such as H or Me, facilitated the formation of tetrametallic Ti clusters, bridged by carboxylate groups, while increased steric bulk (tBu) led to the formation of binuclear μ-oxo-bridged species. The isolated complexes were employed as catalysts for the ring opening polymerisation (ROP) of rac-lactide. Overall, the Ti catalysts were all active with the smaller, bimetallic Ti aggregates exhibiting relatively faster rates. A monometallic, bis(ABP) Zr complex was found to exert remarkable ROP activity, albeit with limited control over the tacticity and molecular weight distribution of the polymer. A further oxo-bridged Zr cluster was shown to display a previously unprecedented trimetallic structure and achieved a moderate rate in the ROP of rac-lactide.
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Behm K, Fazekas E, Paterson MJ, Vilela F, McIntosh RD. Discrete Ti-O-Ti Complexes: Visible-Light-Activated, Homogeneous Alternative to TiO 2 Photosensitisers. Chemistry 2020; 26:9486-9494. [PMID: 32428304 PMCID: PMC7496837 DOI: 10.1002/chem.202001678] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/08/2020] [Indexed: 12/12/2022]
Abstract
A series of novel bimetallic TiIV amine bis(phenolate) complexes was synthesised and fully characterised. X-ray crystallography studies revealed distorted octahedral geometries around the Ti centres with single or double oxo-bridges connecting the two metals. These robust, air- and moisture-stable complexes were employed as photosensitisers generating singlet oxygen following irradiation with visible light (420 nm) LED module in a commercial flow reactor. All five complexes showed high activity in the photo-oxygenation of α-terpinene and achieved complete conversion to ascaridole in four hours at ambient temperature. The excellent selectivity of these photosensitisers towards ascaridole (vs. transformation to p-cymene) was demonstrated with control experiments using a traditional TiO2 catalyst. Further comparative studies employing the free pro-ligands as well as a monometallic analogue highlighted the importance of the 'TiO2 -like' moiety in the polymetallic catalysts. Computational studies were used to determine the nature of the ligand to metal charge transfer (LMCT) states and singlet-triplet gaps for each complex, the calculated trends in the UV-vis absorption spectra across the series agreed well with the experimental results.
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Affiliation(s)
- Kira Behm
- Institute of Chemical SciencesHeriot-Watt UniversityEdinburghEH14 4ASUK
| | - Eszter Fazekas
- Institute of Chemical SciencesHeriot-Watt UniversityEdinburghEH14 4ASUK
| | | | - Filipe Vilela
- Institute of Chemical SciencesHeriot-Watt UniversityEdinburghEH14 4ASUK
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Gurung RK, McMillen CD, Jarrett WL, Holder AA. Synthesis, characterization, NMR spectroscopic, and X-ray crystallographic studies of new titanium(IV) Schiff base salen complexes: Formation of intriguing titanium(IV) species. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Maru MS, Barroso S, Adão P, Alves LG, Martins AM. New salan and salen vanadium complexes: Syntheses and application in sulfoxidation catalysis. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2018.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Barroso S, Coelho AM, Adão P, Calhorda MJ, Martins AM. Radical reactions of diamine bis(phenolate) vanadium(iii) complexes. Solid state binding of O 2 to form a vanadium(v) peroxo complex. Dalton Trans 2017; 46:9692-9704. [PMID: 28714510 DOI: 10.1039/c7dt01699a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
[VCl3(THF)3] reacted with the sodium salt of a tripodal diamine bisphenolate ligand precursor Na2L2 to give a paramagnetic d2 complex [V(L2)Cl] (2). The reaction of 2 with oxygen is strongly dependent on the experimental conditions, affording [VO(L2)Cl] (6) or [V(η2-O2)(L2)Cl] (7). The formation of 7 involves the direct addition of O2 to V(iii) in the solid state with oxidation to V(v) without significantly disturbing the structure of 2. DFT calculations showed that compound 7 is an intermediate in the formation of 6 from 2. The reaction involves the cleavage of the η1-O-O bond in a proposed dimeric species. The overall reaction of 2 moles of vanadium(iii), complex 2, and one mole of O2 to yield two moles of product 6 is a favourable process with ΔG298 = -38.3 kcal mol-1. 7 is the first non-oxido peroxidovanadium(v) complex obtained directly from the reaction of a crystal and the second example of a structurally characterized complex of that type. Reactions of V(L1)Cl (1) and V(L2)Cl (2) with one equivalent of the nitroxyl radical TEMPO in toluene also result in the formation of oxido V(v) complexes, VO(L1)Cl (5) and VO(L2)Cl (6). The reaction of VO(OiPr)3 with Na2L2 afforded [VO(L2)(OiPr)] (8) in high yield. A major isomer having the V[double bond, length as m-dash]O moiety in the equatorial plane was characterised by X-ray diffraction although solution NMR data showed the presence of a minor species with the oxido ligand trans to the tripodal nitrogen, as in 6. Complexes 6 and 8 are very active and selective sulfoxidation catalysts of thioanisole, but no enantiomeric excess was obtained.
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Affiliation(s)
- Sónia Barroso
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
| | - Ana M Coelho
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
| | - Pedro Adão
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
| | - Maria José Calhorda
- Centro de Química e Bioquímica, DQB, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa, Portugal
| | - Ana M Martins
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
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Cols JMEP, Taylor CE, Gagnon KJ, Teat SJ, McIntosh RD. Well-defined Ti 4 pre-catalysts for the ring-opening polymerisation of lactide. Dalton Trans 2016; 45:17729-17738. [PMID: 27766320 DOI: 10.1039/c6dt03842e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The synthesis and full characterisation of four discrete tetrametallic titanium complexes is reported. These well-defined compounds are isostructural in the solid state and share the same general formula: Ti4(μ-O)2L4 (L = 1, 2, 3 or 4). Using a combination of NMR techniques the complexes are found to be stable in solution, even at elevated temperatures. Further studies show that the carboxylate moieties of the supporting amine bis(phenolate) ligands can be displaced by a more strongly coordinating solvent. This reversible process causes the coordinatively saturated Ti4(μ-O)2L4 complexes to separate into two Ti2(μ-O)L2 subunits which we envisaged would be catalytically active. Proof-of-concept experiments establish that all four of these complexes display catalytic activity in the ring-opening polymerisation of rac-lactide. These aggregates can therefore be viewed as air and moisture stable pre-catalysts for a range of reactions.
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Affiliation(s)
- Jean-Marie E P Cols
- Institute of Chemical Sciences Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK.
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8
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Oliveira RL, Nijholt T, Shakeri M, de Jongh PE, Gebbink RJMK, de Jong KP. Encapsulation of chiral Fe(salen) in mesoporous silica structures for use as catalysts to produce optically active sulfoxides. Catal Sci Technol 2016. [DOI: 10.1039/c6cy00113k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solid catalysts which are heterogeneous at the macroscopic scale but homogeneous at the microscopic level were prepared by the encapsulation of Fe(salen) by a “ship in a bottle” approach.
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Affiliation(s)
- Rafael L. Oliveira
- Inorganic Chemistry and Catalysis
- Debye Institute for Nanomaterials Science
- Utrecht University
- Netherlands
- Institute of Chemistry
| | - Tom Nijholt
- Inorganic Chemistry and Catalysis
- Debye Institute for Nanomaterials Science
- Utrecht University
- Netherlands
| | - Mozaffar Shakeri
- Inorganic Chemistry and Catalysis
- Debye Institute for Nanomaterials Science
- Utrecht University
- Netherlands
| | - Petra E. de Jongh
- Inorganic Chemistry and Catalysis
- Debye Institute for Nanomaterials Science
- Utrecht University
- Netherlands
| | | | - Krijn P. de Jong
- Inorganic Chemistry and Catalysis
- Debye Institute for Nanomaterials Science
- Utrecht University
- Netherlands
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Boreen MA, Bogart JA, Carroll PJ, Schelter EJ. Rearrangement in a Tripodal Nitroxide Ligand To Modulate the Reactivity of a Ti–F Bond. Inorg Chem 2015; 54:9588-93. [DOI: 10.1021/acs.inorgchem.5b01687] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael A. Boreen
- P. Roy
and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Justin A. Bogart
- P. Roy
and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Patrick J. Carroll
- P. Roy
and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Eric J. Schelter
- P. Roy
and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
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Su CK, Chuang HJ, Li CY, Yu CY, Ko BT, Chen JD, Chen MJ. Oxo-Bridged Bimetallic Group 4 Complexes Bearing Amine-Bis(benzotriazole phenolate) Derivatives as Bifunctional Catalysts for Ring-Opening Polymerization of Lactide and Copolymerization of Carbon Dioxide with Cyclohexene Oxide. Organometallics 2014. [DOI: 10.1021/om500784a] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Ching-Kai Su
- Department
of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
- Department
of Chemistry, Chung Yuan Christian University, Chung-Li 320, Taiwan
| | - Hui-Ju Chuang
- Department
of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Chen-Yu Li
- Department
of Chemistry, Chung Yuan Christian University, Chung-Li 320, Taiwan
| | - Chun-Yue Yu
- Department
of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Bao-Tsan Ko
- Department
of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Jhy-Der Chen
- Department
of Chemistry, Chung Yuan Christian University, Chung-Li 320, Taiwan
| | - Ming-Jen Chen
- Department
of Applied Cosmetology and Graduate Institute of Cosmetic Science, Hungkuang University, Taichung City 43302, Taiwan
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11
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Barroso S, de Aguiar SR, Munhá RF, Martins AM. New zirconium complexes supported by N-heterocyclic carbene (NHC) ligands: Synthesis and assessment of hydroamination catalytic properties. J Organomet Chem 2014. [DOI: 10.1016/j.jorganchem.2013.11.041] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Barroso S, Coelho AM, Gómez-Ruiz S, Calhorda MJ, Žižak Ž, Kaluđerović GN, Martins AM. Synthesis, cytotoxic and hydrolytic studies of titanium complexes anchored by a tripodal diamine bis(phenolate) ligand. Dalton Trans 2014; 43:17422-33. [DOI: 10.1039/c4dt00975d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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