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Noß C, Göttlich R, Schindler S. Photochemically Mediated Toluene Oxidation through a Copper Complex. Chemistry 2023; 29:e202301142. [PMID: 37194744 DOI: 10.1002/chem.202301142] [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: 04/11/2023] [Revised: 05/17/2023] [Accepted: 05/17/2023] [Indexed: 05/18/2023]
Abstract
A method is described to photochemically oxidize toluene selectively to benzaldehyde, an essential compound in the chemical industry. Copper(I) complexes with different ligands were applied in combination with [Ru(bipy)3 ](PF6 )2 and dioxygen as the oxidant. As a result, a "dioxygen adduct" copper complex, for example, a peroxido complex, is formed as the active species. The copper(II) complex obtained after oxidation can be photochemically reduced to the starting copper(I) species, and the process can be repeated continuously. The ligand tris(2-methylpyridyl)amine (tmpa) led to the highest conversion rates.
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Affiliation(s)
- Christian Noß
- Institute for Inorganic and Analytical Chemistry, Justus-Liebig-University Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
- Institute for Organic Chemistry, Justus-Liebig-University Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Richard Göttlich
- Institute for Organic Chemistry, Justus-Liebig-University Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Siegfried Schindler
- Institute for Inorganic and Analytical Chemistry, Justus-Liebig-University Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
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Parkatzidis K, Truong NP, Whitfield R, Campi CE, Grimm-Lebsanft B, Buchenau S, Rübhausen MA, Harrisson S, Konkolewicz D, Schindler S, Anastasaki A. Oxygen-Enhanced Atom Transfer Radical Polymerization through the Formation of a Copper Superoxido Complex. J Am Chem Soc 2023; 145:1906-1915. [PMID: 36626247 DOI: 10.1021/jacs.2c11757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In controlled radical polymerization, oxygen is typically regarded as an undesirable component resulting in terminated polymer chains, deactivated catalysts, and subsequent cessation of the polymerization. Here, we report an unusual atom transfer radical polymerization whereby oxygen favors the polymerization by triggering the in situ transformation of CuBr/L to reactive superoxido species at room temperature. Through a superoxido ARGET-ATRP mechanism, an order of magnitude faster polymerization rate and a rapid and complete initiator consumption can be achieved as opposed to when unoxidized CuBr/L was instead employed. Very high end-group fidelity has been demonstrated by mass-spectrometry and one-pot synthesis of block and multiblock copolymers while pushing the reactions to reach near-quantitative conversions in all steps. A high molecular weight polymer could also be targeted (DPn = 6400) without compromising the control over the molar mass distributions (Đ < 1.20), even at an extremely low copper concentration (4.5 ppm). The versatility of the technique was demonstrated by the polymerization of various monomers in a controlled fashion. Notably, the efficiency of our methodology is unaffected by the purity of the starting CuBr, and even a brown highly-oxidized 15-year-old CuBr reagent enabled a rapid and controlled polymerization with a final dispersity of 1.07, thus not only reducing associated costs but also omitting the need for rigorous catalyst purification prior to polymerization.
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Affiliation(s)
- Kostas Parkatzidis
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich 8093, Switzerland
| | - Nghia P Truong
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich 8093, Switzerland
| | - Richard Whitfield
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich 8093, Switzerland
| | - Chiara E Campi
- Institute of Inorganic and Analytical Chemistry, Justus-Liebig University of Gießen, Heinrich-Buff Ring 17, D-35392, Gießen, Hessen 35392, Germany
| | - Benjamin Grimm-Lebsanft
- Center For Free Electron Laser Science, University of Hamburg, Institut für Nanostruktur und Festkörperphysik, Gebäude 99, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Sören Buchenau
- Center For Free Electron Laser Science, University of Hamburg, Institut für Nanostruktur und Festkörperphysik, Gebäude 99, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Michael A Rübhausen
- Center For Free Electron Laser Science, University of Hamburg, Institut für Nanostruktur und Festkörperphysik, Gebäude 99, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Simon Harrisson
- Laboratoire de Chimie des Polymères Organiques, University of Bordeaux/ENSCBP/CNRS UMR5629, Pessac 33600, France
| | - Dominik Konkolewicz
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Siegfried Schindler
- Institute of Inorganic and Analytical Chemistry, Justus-Liebig University of Gießen, Heinrich-Buff Ring 17, D-35392, Gießen, Hessen 35392, Germany
| | - Athina Anastasaki
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich 8093, Switzerland
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Brückmann T, Becker J, Würtele C, Seuffert MT, Heuler D, Müller-Buschbaum K, Weiß M, Schindler S. Characterization of copper complexes with derivatives of the ligand (2-aminoethyl)bis(2-pyridylmethyl)amine (uns-penp) and their reactivity towards oxygen. J Inorg Biochem 2021; 223:111544. [PMID: 34333248 DOI: 10.1016/j.jinorgbio.2021.111544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 07/05/2021] [Accepted: 07/12/2021] [Indexed: 11/18/2022]
Abstract
A series of copper(I) complexes with ligands derived from the tripodal ligand (2-aminoethyl)bis(2-pyridylmethyl)amine (uns-penp) have been structurally characterized and their redox chemistry analyzed by cyclic voltammetry. While the redox potentials of most of the complexes were similar their reactivity towards dioxygen was quite different. While the complex with a ferrocene derived ligand of uns-penp reacted in solution at low temperatures in a two-step reaction from the preliminary formed mononuclear end-on superoxido complex to a quite stable dinuclear peroxido complex it did not react with dioxygen in the solid state. Other complexes also did not react with dioxygen in the solid state while some showed a reversible formation to a green compound, indicating formation of an end-on superoxido complex that unfortunately so far could not be characterized. In contrast, copper complexes with the Me2uns-penp and Et-iProp-uns-penp formed dinuclear peroxido complexes in a solid-state reaction. While the reaction of dioxygen with the [Cu(Me2uns-penp]BPh4 was quite slow an instant reaction took place for [Cu(Et-iProp-uns-penp]BPh. Very unusual, it turned out that crystals of the copper(I) complex that could be structurally characterized still were crystalline when reacted with dioxygen. Therefore, it was possible to solve the structure of the corresponding dinuclear peroxido complex directly from the same batch of crystals. The crystalline structures of the copper(I) and copper(II) complex revealed that the reason for this is the fact, that the copper(I) complex is kind of preorganized for the uptake of dioxygen and does not really change in its overall structure when being oxidized.
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Affiliation(s)
- Tim Brückmann
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Jonathan Becker
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Christian Würtele
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Marcel Thomas Seuffert
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Dominik Heuler
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Klaus Müller-Buschbaum
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Morten Weiß
- Fakultät für Biologie, Chemie und Geowissenschaften, Universität Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
| | - Siegfried Schindler
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany.
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