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Kröckert KW, Garg F, Heck J, Heinz MV, Lange J, Schmidt R, Hoffmann A, Herres-Pawlis S. ATRP catalysts of tetradentate guanidine ligands - do guanidine donors induce a faster atom transfer? Dalton Trans 2024. [PMID: 38258473 DOI: 10.1039/d3dt03392a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Tripodal tetradentate N donor ligands stabilise the most active ATRP catalyst systems. Here, we set out to synthesise the new guanidine ligand TMG-4NMe2uns-penp, inspired by p-substituted tris(2-pyridylmethyl)amine (TPMA) ligands. The impact of changing pyridine against guanidine donors was examined through solid state and solution experiments and density functional theory (DFT) calculations. In the solid state, the molecular structures of copper complexes based on the ligands TMG-4NMe2uns-penp, TMG-uns-penp and TMG3tren were discussed concerning the influence of a NMe2 substituent at the pyridines and the guanidine donors. In solution, the TMG-4NMe2uns-penp system was investigated by several methods, including UV/Vis, EPR and NMR spectroscopy indicating similar properties to that of the highly active TPMANMe2 system. The redox potentials were determined and related to the catalytic activity. Besides the expected trends between these and the ligand structures, there is evidence that guanidine donors in tripodal ligand systems lead to a better deactivation and possibly a faster exchange within the ATRP equilibrium than TPMA systems. Supported by DFT calculations, it derives from an easier cleavable Cu-Br bond of the copper(II) deactivator species. The high activity was stated by a controlled initiator for continuous activator regeneration (ICAR) ATRP of styrene.
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Affiliation(s)
- Konstantin W Kröckert
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
| | - Felix Garg
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
| | - Joshua Heck
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
| | - Michel V Heinz
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
| | - Justin Lange
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
| | - Regina Schmidt
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
| | - Alexander Hoffmann
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
| | - Sonja Herres-Pawlis
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
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Koch A, Engesser TA, Tuczek F. Copper Complexes Supported by Iminotriazole Ligands: Effective Catalysts for the Monooxygenation of Phenols. Organometallics 2023. [DOI: 10.1021/acs.organomet.3c00014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Affiliation(s)
- Alexander Koch
- Institute of Inorganic Chemistry, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany
| | - Tobias A. Engesser
- Institute of Inorganic Chemistry, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany
| | - Felix Tuczek
- Institute of Inorganic Chemistry, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany
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Raßpe-Lange L, Hoffmann A, Gertig C, Heck J, Leonhard K, Herres-Pawlis S. Geometrical benchmarking and analysis of redox potentials of copper(I/II) guanidine-quinoline complexes: Comparison of semi-empirical tight-binding and DFT methods and the challenge of describing the entatic state (part III). J Comput Chem 2023; 44:319-328. [PMID: 35640228 DOI: 10.1002/jcc.26927] [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: 02/16/2022] [Revised: 04/14/2022] [Accepted: 04/20/2022] [Indexed: 01/03/2023]
Abstract
Copper guanidine-quinoline complexes are an important class of bioinorganic complexes that find utilization in electron and atom transfer processes. By substitution of functional groups on the quinoline moiety the electron transfer abilities of these complexes can be tuned. In order to explore the full substitution space by simulations, the accurate theoretical description of the effect of functional groups is essential. In this study, we compare three different methods for the theoretical description of the structures. We use the semi-empirical tight-binding method GFN2-xTB, the density functional TPSSh and the double-hybrid functional B2PLYP. We evaluate the methods on five different complex pairs (Cu(I) and Cu(II) complexes), and compare how well calculated energies can predict the redox potentials. We find even though B2PLYP and TPSSh yield better accordance with the experimental structures. GFN2-xTB performs surprisingly well in the geometry optimization at a fraction of the computational cost. TPSSh offers a good compromise between computational cost and accuracy of the redox potential for real-life complexes.
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Affiliation(s)
- Lukas Raßpe-Lange
- Institute of Technical Thermodynamics, RWTH Aachen University, Aachen, Germany
| | - Alexander Hoffmann
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Christoph Gertig
- Institute of Technical Thermodynamics, RWTH Aachen University, Aachen, Germany.,Pharmaplan AG, Basel, Switzerland
| | - Joshua Heck
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Kai Leonhard
- Institute of Technical Thermodynamics, RWTH Aachen University, Aachen, Germany
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