1
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Haaf S, Engels E, Kaifer E, Himmel HJ. Hexaguanidino-Triptycenes and Triphenylenes: Electronic Coupling in Molecules Containing Three Redox-Active o-Diguanidinobenzene Units Connected either Directly or Interacting Through Homoconjugation. Chemistry 2024; 30:e202301903. [PMID: 37815019 DOI: 10.1002/chem.202301903] [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: 06/15/2023] [Revised: 09/22/2023] [Accepted: 10/10/2023] [Indexed: 10/11/2023]
Abstract
Novel redox-active hexaguanidine molecules with multiple redox states were synthesized by connecting three o-diguanidinobenzene units. In 2,3,6,7,14,15-hexaguanidino-triptycenes, the three redox-active o-diguanidinobenzene units are connected through C-C bonds to the sp3 -hybridized bridgehead C atoms, and in 2,3,6,7,10,11-hexaguanidino-triphenylenes they are directly connected. The connectivity difference leads to different electronic coupling between the three redox-active o-diguanidinobenzene units, with homoconjugation being present in the triptycene, but not in the triphenylene compounds. Motivated by the appearance of an intense low-energy electronic transition, we especially analysed the effect of homoconjugation on the electronic structure and charge delocalization in the dicationic redox state of the triptycene derivatives. Then, several trinuclear high-spin cobalt (and copper) complexes were synthesized with the triphenylene and triptycene ligands, and the magnetic coupling and redox properties analysed. By choice of the coligands (hexafluoroacetylacetonate, trifluoroacetylacetonate and acetylacetonate), oxidation could be switched between metal- and ligand-centered redox events, leading to drastic changes in the magnetic or optical properties, especially as a consequence of homoconjugation in the triptycene derivatives.
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Affiliation(s)
- Sebastian Haaf
- Inorganic Chemistry, Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Eliane Engels
- Inorganic Chemistry, Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Inorganic Chemistry, Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Inorganic Chemistry, Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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2
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Lohmeyer L, Werr M, Kaifer E, Himmel H. Interplay and Competition Between Two Different Types of Redox-Active Ligands in Cobalt Complexes: How to Allocate the Electrons? Chemistry 2022; 28:e202201789. [PMID: 35894809 PMCID: PMC9804828 DOI: 10.1002/chem.202201789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Indexed: 01/09/2023]
Abstract
The field of molecular transition metal complexes with redox-active ligands is dominated by compounds with one or two units of the same redox-active ligand; complexes in which different redox-active ligands are bound to the same metal are uncommon. This work reports the first molecular coordination compounds in which redox-active bisguanidine or urea azine (biguanidine) ligands as well as oxolene ligands are bound to the same cobalt atom. The combination of two different redox-active ligands leads to mono- as well as unprecedented dinuclear cobalt complexes, being multiple (four or six) center redox systems with intriguing electronic structures, all exhibiting radical ligands. By changing the redox potential of the ligands through derivatisation, the electronic structure of the complexes could be altered in a rational way.
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Affiliation(s)
- Lukas Lohmeyer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Marco Werr
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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3
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Lohmeyer L, Kaifer E, Himmel HJ. Solvent-Induced Redox Isomerism of Cobalt Complexes with Redox-Active Bisguanidine Ligands. Inorg Chem 2022; 61:8440-8454. [PMID: 35612530 DOI: 10.1021/acs.inorgchem.1c03983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Redox-isomeric coordination compounds, in which the magnetic and optical properties could be varied by a stimulated intramolecular electron transfer between the metal and a redox-active ligand, are of interest for several applications in catalysis and materials science. In this work, the redox chemistry of cobalt complexes with redox-active bisguanidine ligands is studied; systematic modifications at the redox-active bisguanidine and the co-ligand units allow for fine-tuning of the electronic structure, which eventually leads to the first observation of redox isomerism for cobalt complexes with redox-active guanidine ligands. Redox isomerism is triggered by a change in the solvent properties.
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Affiliation(s)
- Lukas Lohmeyer
- Anorganisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
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4
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Wild U, Hübner O, Enders M, Kaifer E, Himmel HJ. Connecting Organic Redox‐Active Building Blocks Through Mild Non‐Catalytic C‐H Activation. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ute Wild
- Ruprecht Karls Universitat Heidelberg Fakultat fur Chemie und Geowissenschaften Chemistry GERMANY
| | - Olaf Hübner
- Ruprecht Karls Universitat Heidelberg Fakultat fur Chemie und Geowissenschaften Chemistry GERMANY
| | - Markus Enders
- Ruprecht Karls Universitat Heidelberg Fakultat fur Chemie und Geowissenschaften Chemistry GERMANY
| | - Elisabeth Kaifer
- Ruprecht Karls Universitat Heidelberg Fakultat fur Chemie und Geowissenschaften Chemistry GERMANY
| | - Hans-Jörg Himmel
- Ruprecht-Karls-Universität Heidelberg Institut für Anorganische Chemie Im Neuenheimer Feld 270 69120 Heidelberg GERMANY
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5
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Steuer L, Kaifer E, Himmel HJ. Redox‐Active Dendrimer‐Like Oligoguanidines and Their Use in a Proton‐Coupled Electron Transfer Reaction. European J Org Chem 2022. [DOI: 10.1002/ejoc.202101360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lena Steuer
- Ruprecht Karls Universitat Heidelberg Fakultat fur Chemie und Geowissenschaften Chemistry GERMANY
| | - Elisabeth Kaifer
- Ruprecht Karls Universitat Heidelberg Fakultat fur Chemie und Geowissenschaften Chemistry GERMANY
| | - Hans-Jörg Himmel
- Ruprecht-Karls-Universität Heidelberg Institut für Anorganische Chemie Im Neuenheimer Feld 270 69120 Heidelberg GERMANY
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6
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Werr M, Kaifer E, Enders M, Asyuda A, Zharnikov M, Himmel H. Synthese eines Kupfer(I)‐Komplexes mit zwei ungepaarten Elektronen durch Oxidation eines Kupfer(II)‐Komplexes mit zwei redoxaktiven Liganden. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202109367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Marco Werr
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Markus Enders
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Andika Asyuda
- Angewandte Physikalische Chemie Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Deutschland
| | - Michael Zharnikov
- Angewandte Physikalische Chemie Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Deutschland
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
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7
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Werr M, Kaifer E, Enders M, Asyuda A, Zharnikov M, Himmel H. A Copper(I) Complex with Two Unpaired Electrons, Synthesised by Oxidation of a Copper(II) Complex with Two Redox-Active Ligands. Angew Chem Int Ed Engl 2021; 60:23451-23462. [PMID: 34423532 PMCID: PMC8596453 DOI: 10.1002/anie.202109367] [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: 07/14/2021] [Revised: 07/30/2021] [Indexed: 01/10/2023]
Abstract
Two homoleptic copper(II) complexes [Cu(L1)2 ] and [Cu(L2)2 ] with anionic redox-active ligands were synthesised, one with urea azine (L1) and the other with thio-urea azine (L2) ligands. One-electron oxidation of the complexes initiates an unprecedented redox-induced electron transfer process, leading to monocationic copper(I) complexes [Cu(L1)2 ]+ and [Cu(L2)2 ]+ with two oxidised ligands. While [Cu(L1)2 ]+ is best described as a CuI complex with two neutral radical ligands that couple antiferromagnetically, [Cu(L2)2 ]+ is a CuI complex with two clearly different ligand units in the solid state and with a magnetic susceptibility close to a diamagnetic compound. Further one-electron oxidation of the complex with L1 ligands results in a dication [Cu(L1)2 ]2+ , best described as a CuI complex with a twofold oxidised, monocationic ligand and a neutral radical ligand. The stability in at least three redox states, the accumulation of spin density at the ligands and the facile ligand-metal electron transfer make these complexes highly attractive for a variety of applications; here the catalytic aerobic oxidation of alcohols to aldehydes is tested.
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Affiliation(s)
- Marco Werr
- Anorganisch-Chemisches InstitutRuprecht-Karls Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches InstitutRuprecht-Karls Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Markus Enders
- Anorganisch-Chemisches InstitutRuprecht-Karls Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Andika Asyuda
- Angewandte Physikalische ChemieRuprecht-Karls Universität HeidelbergIm Neuenheimer Feld 25369120HeidelbergGermany
| | - Michael Zharnikov
- Angewandte Physikalische ChemieRuprecht-Karls Universität HeidelbergIm Neuenheimer Feld 25369120HeidelbergGermany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches InstitutRuprecht-Karls Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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8
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Steuer L, Kaifer E, Himmel HJ. On the metal-ligand bonding in dinuclear complexes with redox-active guanidine ligands. Dalton Trans 2021; 50:9467-9482. [PMID: 34136887 DOI: 10.1039/d1dt01354h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Coordination compounds with redox-active ligands are currently intensively studied. Within this research theme, redox-active guanidines have been established as a new, eminent class of redox-active ligands. In this work the variation of metal-guanidine bonding in dinuclear transition metal complexes with bridging redox-active tetrakisguanidine ligands is analysed. A series of dinuclear complexes with different metals (Mn, Fe, Co, Ni, Cu and Zn) is synthesized, using either newly prepared redox-active tetrakisguanidino-dioxine or previously reported tetrakisguanidino-benzene ligands. The discussion of the bond properties in this work is predominantly based on the trends of structural parameters, derived from determination of single-crystal structures by X-ray diffraction and quantum chemical calculations. In addition, the trends in the redox potentials and magnetometric (SQUID) measurements on some of the complexes are included. Due to their combined σ- and π-electron donor capability, redox-active guanidine ligands are weak-field ligands; the σ- and π-bonding contributions vary with the metal. The results highlight the peculiarity of copper-guanidine bonding with a high π-bond contribution to metal-guanidine bonding, enabled by structural distortion of the coordination mode from tetrahedral in the direction of square-planar, short copper-guanidine bonds and minor displacement of the copper atoms from the ligand aromatic plane.
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Affiliation(s)
- Lena Steuer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
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Lohmeyer L, Kaifer E, Enders M, Himmel H. Switching from Metal- to Ligand-Based Oxidation in Cobalt Complexes with Redox-Active Bisguanidine Ligands. Chemistry 2021; 27:11852-11867. [PMID: 34101917 PMCID: PMC8457109 DOI: 10.1002/chem.202101364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Indexed: 11/19/2022]
Abstract
The control of the redox reactivity, magnetic and optical properties of the different redox states of complexes with redox‐active ligands permits their rational use in catalysis and materials science. The redox‐chemistry of octahedrally coordinated high‐spin CoII complexes (three unpaired electrons) with one redox‐active bisguanidine ligand and two acetylacetonato (acac) co‐ligands is completely changed by replacing the acac by hexafluoro‐acetylacetonato (hfacac) co‐ligands. The first one‐electron oxidation is metal‐centered in the case of the complexes with acac co‐ligands, giving diamagnetic CoIII complexes. By contrast, in the case of the less Lewis‐basic hfacac co‐ligands, the first one‐electron oxidation becomes ligand‐centered, leading to high‐spin CoII complexes with a radical monocationic guanidine ligand unit (four unpaired electrons). Ferromagnetic coupling between the spins on the metal and the organic radical in solution is evidenced by temperature‐dependent paramagnetic NMR studies, allowing to estimate the isotropic exchange coupling constant in solution. Second one‐electron oxidation leads to high‐spin CoII complexes with dicationic guanidine ligand units (three unpaired electrons) in the presence of hfacac co‐ligands, but to low‐spin CoIII complexes with radical monocationic, peralkylated guanidine ligand (one unpaired electron) in the presence of acac co‐ligands. The analysis of the electronic structures is complemented by quantum‐chemical calculations on the spin density distributions and relative energies of the possible redox isomers.
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Affiliation(s)
- Lukas Lohmeyer
- Inorganic ChemistryRuprecht-Karls University of HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Elisabeth Kaifer
- Inorganic ChemistryRuprecht-Karls University of HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Markus Enders
- Inorganic ChemistryRuprecht-Karls University of HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Hans‐Jörg Himmel
- Inorganic ChemistryRuprecht-Karls University of HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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10
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Lohmeyer L, Schön F, Kaifer E, Himmel H. Stimulierung eines redoxinduzierten Elektronentransfers durch Interligand‐Wasserstoffbrücken in einem Cobaltkomplex mit redoxaktivem Guanidin‐Liganden. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101423] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Lukas Lohmeyer
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Florian Schön
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
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11
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Lohmeyer L, Schön F, Kaifer E, Himmel HJ. Stimulation of Redox-Induced Electron Transfer by Interligand Hydrogen Bonding in a Cobalt Complex with Redox-Active Guanidine Ligand. Angew Chem Int Ed Engl 2021; 60:10415-10422. [PMID: 33616266 PMCID: PMC8252010 DOI: 10.1002/anie.202101423] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Indexed: 12/27/2022]
Abstract
Octahedrally coordinated cobalt(II) complexes with a redox‐active bisguanidine ligand and acac co‐ligands were synthesized and their redox chemistry analysed in detail. The N−H functions in a bisguanidine ligand with partially alkylated guanidino groups form N−H⋅⋅⋅O hydrogen bonds with the acac co‐ligands, thereby massively influencing the redox chemistry. For all complexes, the first one‐electron oxidation is metal‐centred, leading to CoIII complexes with neutral bisguanidine ligand units. Further one‐electron oxidation is ligand‐centred in the case of Co–bisguanidine complexes with fully alkylated guanidino groups, giving CoIII complexes with radical monocationic bisguanidine ligands. On the other hand, the hydrogen‐bond strengthening upon oxidation of the Co–bisguanidine complex with partially alkylated guanidino groups initiates metal reduction (CoIII→CoII) and two‐electron oxidation of the guanidine ligand, providing the first example for the stimulation of redox‐induced electron transfer by interligand hydrogen bonding.
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Affiliation(s)
- Lukas Lohmeyer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Florian Schön
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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12
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Haaf S, Kaifer E, Wadepohl H, Himmel H. Use of Crown Ether Functions as Secondary Coordination Spheres for the Manipulation of Ligand-Metal Intramolecular Electron Transfer in Copper-Guanidine Complexes. Chemistry 2021; 27:959-970. [PMID: 32833269 PMCID: PMC7839521 DOI: 10.1002/chem.202003469] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Indexed: 01/16/2023]
Abstract
Intramolecular electron transfer (IET) between a redox-active organic ligand and a metal in a complex is of fundamental interest and used in a variety of applications. In this work it is demonstrated that secondary coordination sphere motifs can be applied to trigger a radical change in the electronic structure of copper complexes with a redox-active guanidine ligand through ligand-metal IET. Hence, crown ether functions attached to the ligand allow the manipulation of the degree of IET between the guanidine ligand and the copper atom through metal encapsulation.
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Affiliation(s)
- Sebastian Haaf
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Hubert Wadepohl
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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13
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Nadurata VL, Boskovic C. Switching metal complexes via intramolecular electron transfer: connections with solvatochromism. Inorg Chem Front 2021. [DOI: 10.1039/d0qi01490g] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Solvent-induced color-changing phenomena exhibited by some metal complexes can illuminate key aspects of their switchable behavior.
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14
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Kang XM, Tang MH, Yang GL, Zhao B. Cluster/cage-based coordination polymers with tetrazole derivatives. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213424] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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15
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Lohmeyer L, Kaifer E, Wadepohl H, Himmel H. 1,2,5,6-Tetrakis(guanidino)-Naphthalenes: Electron Donors, Fluorescent Probes and Redox-Active Ligands. Chemistry 2020; 26:5834-5845. [PMID: 32017282 PMCID: PMC7318682 DOI: 10.1002/chem.201905471] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/23/2020] [Indexed: 01/07/2023]
Abstract
New redox-active 1,2,5,6-tetrakis(guanidino)-naphthalene compounds, isolable and storable in the neutral and deep-green dicationic redox states and oxidisable further in two one-electron steps to the tetracations, are reported. Protonation switches on blue fluorescence, with the fluorescence intensity (quantum yield) increasing with the degree of protonation. Reactions with N-halogenosuccinimides or N-halogenophthalimides led to a series of new redox-active halogeno- and succinimido-/phthalimido-substituted derivatives. These highly selective reactions are proposed to proceed via the tri- or tetracationic state as the intermediate. The derivatives are oxidised reversibly at slightly higher potentials than that of the unsubstituted compounds to dications and further to tri- and tetracations. The integration of redox-active ligands in the transition-metal complexes shifts the redox potentials to higher values and also allows reversible oxidation in two potentially separated one-electron steps.
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Affiliation(s)
- Lukas Lohmeyer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Hubert Wadepohl
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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16
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Werr M, Kaifer E, Wadepohl H, Himmel HJ. Tuneable Redox Chemistry and Electrochromism of Persistent Symmetric and Asymmetric Azine Radical Cations. Chemistry 2019; 25:12981-12990. [PMID: 31306523 DOI: 10.1002/chem.201902216] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/21/2019] [Indexed: 12/16/2022]
Abstract
Molecular organic radicals have been intensively studied in the last decades, due to their interesting optical, magnetic and redox properties. Here we report the synthesis and characterisation of persistent organic radicals from one-electron oxidation of redox-active azines (RAAs), composed of two guanidinyl or related groups. By connecting two different groups together, asymmetric compounds result. In this way a series of compounds with varying redox potential is obtained that could be oxidised reversibly to the mono- and the dicationic charge states. The accessible redox states were fully determined by chemical redox reactions. The standard Gibbs free energy change for disproportionation of the radical monocation into the dication and the neutral molecule in solution, estimated from cyclovoltammetric measurements, varies between 43 and 71 kJ mol-1 . While the neutral RAAs absorb predominately UV light, the radical monocations display strong absorptions covering almost the entire visible region and extending for some compounds into the NIR region. A detailed analysis of this highly reversible electrochromism is presented, and the fast switching characteristics are demonstrated in an electrochromic test device.
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Affiliation(s)
- Marco Werr
- Anorganisch Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Anorganisch Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hubert Wadepohl
- Anorganisch Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Anorganisch Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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17
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Schön F, Biebl F, Greb L, Leingang S, Grimm‐Lebsanft B, Teubner M, Buchenau S, Kaifer E, Rübhausen MA, Himmel H. On the Metal Cooperativity in a Dinuclear Copper–Guanidine Complex for Aliphatic C−H Bond Cleavage by Dioxygen. Chemistry 2019; 25:11257-11268. [DOI: 10.1002/chem.201901906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Florian Schön
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Florian Biebl
- Institut für Nanostruktur- und FestkörperphysikUniversität Hamburg and Center for Free Electron Laser Science Luruper Chaussee 149 22761 Hamburg Germany
| | - Lutz Greb
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Simone Leingang
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Benjamin Grimm‐Lebsanft
- Institut für Nanostruktur- und FestkörperphysikUniversität Hamburg and Center for Free Electron Laser Science Luruper Chaussee 149 22761 Hamburg Germany
| | - Melissa Teubner
- Institut für Nanostruktur- und FestkörperphysikUniversität Hamburg and Center for Free Electron Laser Science Luruper Chaussee 149 22761 Hamburg Germany
| | - Sören Buchenau
- Institut für Nanostruktur- und FestkörperphysikUniversität Hamburg and Center for Free Electron Laser Science Luruper Chaussee 149 22761 Hamburg Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Michael A. Rübhausen
- Institut für Nanostruktur- und FestkörperphysikUniversität Hamburg and Center for Free Electron Laser Science Luruper Chaussee 149 22761 Hamburg Germany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
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18
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Schön F, Kaifer E, Himmel H. Catalytic Aerobic Phenol Homo‐ and Cross‐Coupling Reactions with Copper Complexes Bearing Redox‐Active Guanidine Ligands. Chemistry 2019; 25:8279-8288. [DOI: 10.1002/chem.201900583] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Indexed: 01/12/2023]
Affiliation(s)
- Florian Schön
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
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19
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Doddi A, Peters M, Tamm M. N-Heterocyclic Carbene Adducts of Main Group Elements and Their Use as Ligands in Transition Metal Chemistry. Chem Rev 2019; 119:6994-7112. [PMID: 30983327 DOI: 10.1021/acs.chemrev.8b00791] [Citation(s) in RCA: 309] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
N-Heterocyclic carbenes (NHC) are nowadays ubiquitous and indispensable in many research fields, and it is not possible to imagine modern transition metal and main group element chemistry without the plethora of available NHCs with tailor-made electronic and steric properties. While their suitability to act as strong ligands toward transition metals has led to numerous applications of NHC complexes in homogeneous catalysis, their strong σ-donating and adaptable π-accepting abilities have also contributed to an impressive vitalization of main group chemistry with the isolation and characterization of NHC adducts of almost any element. Formally, NHC coordination to Lewis acids affords a transfer of nucleophilicity from the carbene carbon atom to the attached exocyclic moiety, and low-valent and low-coordinate adducts of the p-block elements with available lone pairs and/or polarized carbon-element π-bonds are able to act themselves as Lewis basic donor ligands toward transition metals. Accordingly, the availability of a large number of novel NHC adducts has not only produced new varieties of already existing ligand classes but has also allowed establishment of numerous complexes with unusual and often unprecedented element-metal bonds. This review aims at summarizing this development comprehensively and covers the usage of N-heterocyclic carbene adducts of the p-block elements as ligands in transition metal chemistry.
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Affiliation(s)
- Adinarayana Doddi
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
| | - Marius Peters
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
| | - Matthias Tamm
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
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20
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Gransbury GK, Boulon ME, Petrie S, Gable RW, Mulder RJ, Sorace L, Stranger R, Boskovic C. DFT Prediction and Experimental Investigation of Valence Tautomerism in Cobalt-Dioxolene Complexes. Inorg Chem 2019; 58:4230-4243. [DOI: 10.1021/acs.inorgchem.8b03291] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Gemma K. Gransbury
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Marie-Emmanuelle Boulon
- UdR INSTM and Department of Chemistry “U. Schiff”, University of Florence, 50019 Sesto Fiorentino, FI, Italy
| | - Simon Petrie
- Research School of Chemistry, College of Physical & Mathematical Sciences, Australian National University, Canberra, ACT 2601, Australia
| | - Robert W. Gable
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
| | | | - Lorenzo Sorace
- UdR INSTM and Department of Chemistry “U. Schiff”, University of Florence, 50019 Sesto Fiorentino, FI, Italy
| | - Robert Stranger
- Research School of Chemistry, College of Physical & Mathematical Sciences, Australian National University, Canberra, ACT 2601, Australia
| | - Colette Boskovic
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
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21
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Rajput A, Saha A, Barman SK, Lloret F, Mukherjee R. [Cu II{(L ISQ)˙ -} 2] (H 2L: thioether-appended o-aminophenol ligand) monocation triggers change in donor site from N 2O 2 to N 2O (2)S and valence-tautomerism. Dalton Trans 2019; 48:1795-1813. [PMID: 30644480 DOI: 10.1039/c8dt03778g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Using a potentially tridentate o-aminophenol-based redox-active ligand H2L1 (2-[2-(benzylthio)phenylamino]-4,6-di-tert-butylphenol) in its deprotonated form, [Cu(L1)2] has been synthesized and crystallized as [CuII(L1)2]·CH2Cl2 (1·CH2Cl2). A cyclic voltammetry experiment (in CH2Cl2; V vs. SCE (saturated calomel electrode)) on 1·CH2Cl2 exhibits two oxidative (E = 0.20 V (peak-to-peak separation, ΔEp = 100 mV) and E = 0.90 V (ΔEp = 140 mV)) and two reductive (E = -0.52 V (ΔEp = 110 mV) and E = -0.92 V (ΔEp = 120 mV)) responses. Upon oxidation using a stoichiometric amount of [FeIII(η5-C5H5)2](PF6), 1·CH2Cl2 yielded [Cu(L1)2](PF6) (2). Structural analysis (100 K) reveals that 1·CH2Cl2 is a four-coordinate bis(iminosemiquinonato)copper(ii) complex (CuN2O2 coordination), and that the thioethers remain uncoordinated. The twisted geometry of 1 (distorted tetrahedral) results in considerable changes in the electronic structure, compared to well-known square-planar analogues. Crystallographic analysis of 2 both at 100 K and at 293 K reveals that it is effectively a four-coordinate complex with a CuN2OS coordination; however, a substantial interaction with the other phenolate O is observed. The metal-ligand bond distances and metric parameters associated with the o-aminophenolate rings indicate a valence-tautomeric (VT) equilibrium involving monocationic (iminosemiquinonato)(iminoquinone)copper(ii) and bis(iminoquinone)copper(i). Complex 1·CH2Cl2 is a three-spin system and a magnetic study (4-300 K) established that it has a S = 1/2 ground-state, owing to the strong antiferromagnetic coupling between the unpaired spin of the copper(ii) and the iminosemiquinonate(1-) π-radical anion. Electron paramagnetic resonance (EPR) spectral studies corroborate this result. Complex 2 is diamagnetic and the existence of VT in 2 was probed using variable-temperature (248-328 K) 1H NMR and EPR (100-298 K) spectral measurements and X-ray photoelectron spectroscopic studies at 298 K. Remarkably, modification of the well-studied 2-anilino-4,6-di-tert-butylphenol by incorporation of a benzylthioether arm leads to the occurrence of VT in 2. The electronic structure of 1·CH2Cl2 and 2 has been assigned using density functional theory (DFT) calculations at the B3LYP-D3 level of theory. Time-dependent (TD)-DFT calculations have been performed to elucidate the origin of the observed UV-VIS-NIR absorptions.
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Affiliation(s)
- Amit Rajput
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India. and Department of Basic and Applied Sciences, School of Engineering, G. D. Goenka University, Sohna Road, Gurugram 122 103, Haryana, India
| | - Anannya Saha
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India
| | - Suman K Barman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India.
| | - Francesc Lloret
- Departament de Quımíca, Inorgànica/Instituto de Ciencia Molecular (ICMOL), Universitat de Valeńcia, Polígono de la Coma, s/n, 46980-Paterna, València, Spain
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22
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Ortmeyer J, Vukadinovic Y, Neuba A, Flörke U, Henkel G. Combining a Phenanthroline Moiety with Peralkylated Guanidine Residues: Homometallic Cu
II
, Ni
II
and Zn
II
Halide Complexes with Site‐Differentiating Janus Head Ligands. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Jochen Ortmeyer
- Fakultät für Naturwissenschaften Department Chemie Universität Paderborn Warburger Strasse 100 33098 Paderborn Germany
| | - Yannik Vukadinovic
- Fakultät für Naturwissenschaften Department Chemie Universität Paderborn Warburger Strasse 100 33098 Paderborn Germany
| | - Adam Neuba
- Fakultät für Naturwissenschaften Department Chemie Universität Paderborn Warburger Strasse 100 33098 Paderborn Germany
| | - Ulrich Flörke
- Fakultät für Naturwissenschaften Department Chemie Universität Paderborn Warburger Strasse 100 33098 Paderborn Germany
| | - Gerald Henkel
- Fakultät für Naturwissenschaften Department Chemie Universität Paderborn Warburger Strasse 100 33098 Paderborn Germany
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23
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Alaji Z, Safaei E, Yi H, Cong H, Wojtczak A, Lei A. Redox active ligand and metal cooperation for C(sp 2)-H oxidation: extension of the galactose oxidase mechanism in water-mediated amide formation. Dalton Trans 2018; 47:15293-15297. [PMID: 30325380 DOI: 10.1039/c8dt03477j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Redox interplay between a ligand and a metal can provide a profound driving force for the promotion of unprecedented reactions. This work presents an intriguing water-assisted oxidative transformation of imine to amide with no formal change in the metal oxidation state in the copper and nickel complexes of an aminophenol ligand versus a zinc analogue.
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Affiliation(s)
- Zahra Alaji
- Institute for Advanced Studies in Basic Sciences (IASBS), 45137-66731, Zanjan, Iran
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24
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25
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Schrempp DF, Kaifer E, Himmel HJ. Solvent Control of Ligand-Metal Electron Transfer in Mononuclear Copper Complexes with Redox-Active Bisguanidine Ligands. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800525] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- David F. Schrempp
- Anorganisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
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26
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Lorenz R, Kaifer E, Wadepohl H, Himmel HJ. Di- and tetranuclear transition metal complexes of a tetrakisguanidino-substituted phenazine dye by stepwise coordination. Dalton Trans 2018; 47:11016-11029. [DOI: 10.1039/c8dt02176g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Coordination of a tetrakisguanidino-substituted phenazine dye in two steps provides rational access to tetranuclear homo- and heterobimetallic complexes.
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Affiliation(s)
- Roxana Lorenz
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
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27
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Kang XM, Wang WM, Yao LH, Ren HX, Zhao B. Solvent-dependent variations of both structure and catalytic performance in three manganese coordination polymers. Dalton Trans 2018; 47:6986-6994. [DOI: 10.1039/c8dt01103f] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three new Mn-based MOFs have been prepared, and a 3D framework can act as an efficient and recycled catalyst in CO2 cycloaddition with different epoxides.
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Affiliation(s)
- Xiao-Min Kang
- College of Chemistry and Key Laboratory of Advanced Energy Material Chemistry
- Nankai University
- Tianjin
- China
| | - Wen-Min Wang
- College of Chemistry and Key Laboratory of Advanced Energy Material Chemistry
- Nankai University
- Tianjin
- China
| | - Lin-Hong Yao
- College of Chemistry and Key Laboratory of Advanced Energy Material Chemistry
- Nankai University
- Tianjin
- China
| | - Hong-Xia Ren
- College of Chemistry and Key Laboratory of Advanced Energy Material Chemistry
- Nankai University
- Tianjin
- China
| | - Bin Zhao
- College of Chemistry and Key Laboratory of Advanced Energy Material Chemistry
- Nankai University
- Tianjin
- China
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28
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Ziesak A, Steuer L, Kaifer E, Wagner N, Beck J, Wadepohl H, Himmel HJ. Intramolecular metal–ligand electron transfer triggered by co-ligand substitution. Dalton Trans 2018; 47:9430-9441. [DOI: 10.1039/c8dt01234b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Labile co-ligands are attached to a dinuclear copper(i) complex with a redox-active bridging guanidine ligand. Their substitution triggers electron-transfer from the copper atoms to the guanidine.
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Affiliation(s)
- Alexandra Ziesak
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Lena Steuer
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Norbert Wagner
- Institut für Anorganische Chemie
- Universität Bonn
- 53121 Bonn
- Germany
| | - Johannes Beck
- Institut für Anorganische Chemie
- Universität Bonn
- 53121 Bonn
- Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
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29
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Stanek J, Sackers N, Fink F, Paul M, Peters L, Grunzke R, Hoffmann A, Herres-Pawlis S. Copper Guanidinoquinoline Complexes as Entatic State Models of Electron-Transfer Proteins. Chemistry 2017; 23:15738-15745. [DOI: 10.1002/chem.201703261] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Julia Stanek
- Institut für Anorganische Chemie; RWTH Aachen University; Landoltweg 1 52074 Aachen Germany
| | - Nina Sackers
- Institut für Anorganische Chemie; RWTH Aachen University; Landoltweg 1 52074 Aachen Germany
| | - Fabian Fink
- Institut für Anorganische Chemie; RWTH Aachen University; Landoltweg 1 52074 Aachen Germany
| | - Melanie Paul
- Institut für Anorganische Chemie; RWTH Aachen University; Landoltweg 1 52074 Aachen Germany
| | - Laurens Peters
- Department Chemie; Ludwig-Maximilians Universität München; Butenandtstraße 5-13 81377 München Germany
| | - Richard Grunzke
- Zentrum für Informationsdienste und Hochleistungsrechnen; Technische Universität Dresden; Zellescher Weg 12-14 01062 Dresden Germany
| | - Alexander Hoffmann
- Institut für Anorganische Chemie; RWTH Aachen University; Landoltweg 1 52074 Aachen Germany
| | - Sonja Herres-Pawlis
- Institut für Anorganische Chemie; RWTH Aachen University; Landoltweg 1 52074 Aachen Germany
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30
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Schrempp DF, Leingang S, Schnurr M, Kaifer E, Wadepohl H, Himmel HJ. Inter- and Intramolecular Electron Transfer in Copper Complexes: Electronic Entatic State with Redox-Active Guanidine Ligands. Chemistry 2017; 23:13607-13611. [PMID: 28771843 DOI: 10.1002/chem.201703611] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Indexed: 02/01/2023]
Abstract
Fast and efficient electron transfer in blue copper proteins is realized by a structural harmonization between the CuI and CuII complex pair ("entatic state" model). Herein, we present now a CuI /CuII complex pair with redox-active guanidine ligands showing almost perfect match between both redox states. By modifying the ligand electron donor strength, the redox chemistry of the copper complex can be controlled to be either metal-centered or to cross the borderline to ligand-centered. This work is the first systematic study of complexes with redox-active ligands within the concept of the entatic state.
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Affiliation(s)
- David F Schrempp
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Simone Leingang
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Martin Schnurr
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
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31
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Schrempp DF, Schneider E, Kaifer E, Wadepohl H, Himmel HJ. Homo- and Heterobinuclear Cu and Pd Complexes with a Bridging Redox-Active Bisguanidino-Substituted Dioxolene Ligand: Electronic Structure and Metal-Ligand Electron-Transfer. Chemistry 2017; 23:11636-11648. [DOI: 10.1002/chem.201702053] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Indexed: 12/17/2022]
Affiliation(s)
- David Fridolin Schrempp
- Anorganisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 275 69120 Heidelberg Germany
| | - Elisa Schneider
- Anorganisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 275 69120 Heidelberg Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 275 69120 Heidelberg Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 275 69120 Heidelberg Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 275 69120 Heidelberg Germany
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32
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Herrmann H, Kaifer E, Himmel H. Hydrogen‐Atom Transfer (HAT) Initiated by Intramolecular Ligand–Metal Electron Transfer. Chemistry 2017; 23:5520-5528. [DOI: 10.1002/chem.201605971] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Indexed: 01/02/2023]
Affiliation(s)
- Hendrik Herrmann
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
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