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Takemasa Y, Nozaki K. Hexakispyrazolylethane: New Strategy for Stabilization of Hexaarylethane. Chemistry 2023:e202303575. [PMID: 38095099 DOI: 10.1002/chem.202303575] [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: 10/28/2023] [Indexed: 01/25/2024]
Abstract
Hexakis(4-trimethylsilylpyrazol-1-yl)ethane was synthesized by the oxidative dimerization of tris(4-trimethylsilylpyrazol-1-yl)methane. Single-crystal X-ray structural analysis of hexakis(4-trimethylsilylpyrazol-1-yl)ethane showed that the ethane C-C bond (1.623(4) Å) is shorter than that in hexaphenylethane (1.67(3) Å). In solution, hexakis(4-trimethylsilylpyrazol-1-yl)ethane existed as a single species, contrastive that conventional hexaphenylethanes can keep the central C-C bond only by the aid of additional bridges between the two triarylmethyl units. Theoretical calculations indicated that the tris(pyrazol-1-yl)methyl radical, which is anticipated to be under equilibrium with hexakis(pyrazol-1-yl)ethane, is less stable than trityl radicals due to lack of delocalization of the radicals. Furthermore, introduction of pyrazole groups allowed additional bridging between the two triarylmethyl moieties through metal coordination to the adjacent N atoms: hexakis(4-trimethylsilylpyrazol-1-yl)ethane exhibited unique coordination to three Ag atoms affording a hexaarylethane analog bearing three N-Ag-N bridges.
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Affiliation(s)
- Yuta Takemasa
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Kyoko Nozaki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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Ishimoto M, Sakamaki D, Fujiwara H. A dicyanomethyl radical stabilized by ferrocene: a new building block for radical-based dynamic covalent chemistry with redox activity. Chem Commun (Camb) 2022; 58:3553-3556. [DOI: 10.1039/d1cc07253f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel dicyanomethyl radical conjugated with ferrocene as an electron donating unit through a benzene linker is firstly prepared. This radical is in equilibrium with the σ-dimer in solution, and...
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Ou YP, Zhang Q, Yang X, Cao N, Jiang P, Hua Liu S. Isomeric triarylamine-ferrocene mixed-valence systems: Syntheses, structural-(spectro)electrochemical analysis, and theoretical calculations. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Casper LA, Ebel V, Linseis M, Winter RF. Five shades of green: substituent influence on the (spectro-) electrochemical properties of diferrocenyl(phenyl)methylium dyes. Dalton Trans 2021; 50:15336-15351. [PMID: 34636831 DOI: 10.1039/d1dt03009d] [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
Five new, intensely green diferrocenylphenylmethylium complexes 1+-5+ with electron donating (EDG: 4-MeO, 4-Me, 4-Br) or withdrawing (EWG: 3,5-CF3, 4-nC6F13) substituents were synthesized and fully characterized. The substituent influence on their electrochemical and spectroscopic properties was investigated by cyclic voltammetry, UV/Vis/NIR and T-dependent EPR spectroscopy of the cationic as well as the oxidized (12+-52+) and reduced (1˙-5˙) species. The reduced forms equilibrate with their corresponding dimers (65-83%) with a clear substituent influence as expressed by their Hammett parameters in an ordering 4+ > 5+ > 3+ > 2+ > 1+. The structures of all five precursor carbinols 1-OH-5-OH and those of three of the diferrocenylphenylmethylium cations (1+, 4+-5+) were established by X-ray crystallography.
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Affiliation(s)
- Larissa A Casper
- Fachbereich Chemie, Universität Konstanz, 78457 Konstanz, Germany.
| | - Viktoria Ebel
- Fachbereich Chemie, Universität Konstanz, 78457 Konstanz, Germany.
| | - Michael Linseis
- Fachbereich Chemie, Universität Konstanz, 78457 Konstanz, Germany.
| | - Rainer F Winter
- Fachbereich Chemie, Universität Konstanz, 78457 Konstanz, Germany.
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Chen Z, Duan H, Gai Y, Xie W, Deng W, Jiang F. Separation of the host-guest system for ferrocene derivatives in octahedral nanocages by electrochemical ionization. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Casper LA, Linseis M, Demeshko S, Azarkh M, Drescher M, Winter RF. Tailoring Valence Tautomerism by Using Redox Potentials: Studies on Ferrocene-Based Triarylmethylium Dyes with Electron-Poor Fluorenylium and Thioxanthylium Acceptors. Chemistry 2021; 27:10854-10868. [PMID: 33901313 PMCID: PMC8361958 DOI: 10.1002/chem.202101032] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Indexed: 01/31/2023]
Abstract
Three new electrochromic ferrocenyl triarylmethylium dyes with fluorenylium (1 a+ , 1 b+ ) or thioxanthylium (1 c+ ) residues were selected in order to keep the intrinsic differences of redox potentials for ferrocene oxidation and triarylmethylium reduction small and to trigger valence tautomerism (VT). UV/Vis/NIR and quantitative EPR spectroscopy identified paramagnetic diradical isomers 1 a..+ -1 c..+ alongside diamagnetic forms 1 a+ -1 c+ , which renders these complexes magnetochemical switches. The diradical forms 1 a..+ -1 c..+ as well as the one-electron-reduced triarylmethyl forms of the complexes were found to dimerize in solution. For radical 1 a. , dimerization occurs on the timescale of cyclic voltammetry; this allowed us to determine the kinetics and equilibrium constant for this process by digital simulation. Mößbauer spectroscopy indicated that 1 a+ and 1 b+ retain VT even in the solid state. UV/Vis/NIR spectro-electrochemistry revealed the poly-electrochromic behaviour of these complexes by establishing the distinctly different electronic absorption profiles of the corresponding oxidized and reduced forms.
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Affiliation(s)
- Larissa A Casper
- Fachbereich Chemie, Universität Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
| | - Michael Linseis
- Fachbereich Chemie, Universität Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
| | - Serhiy Demeshko
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, 37077, Göttingen, Germany
| | - Mykhailo Azarkh
- Fachbereich Chemie, Universität Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
| | - Malte Drescher
- Fachbereich Chemie, Universität Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
| | - Rainer F Winter
- Fachbereich Chemie, Universität Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
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Casper LA, Wursthorn L, Geppert M, Roser P, Linseis M, Drescher M, Winter RF. 4-Ferrocenylphenyl-Substituted Tritylium Dyes with Open and Interlinked C +Ar 2 Entities: Redox Behavior, Electrochromism, and a Quantitative Study of the Dimerization of Their Neutral Radicals. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00486] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Larissa A. Casper
- Department of Chemistry, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Lukas Wursthorn
- Department of Chemistry, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Marcel Geppert
- Department of Chemistry, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Patrick Roser
- Department of Chemistry, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Michael Linseis
- Department of Chemistry, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Malte Drescher
- Department of Chemistry, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
| | - Rainer F. Winter
- Department of Chemistry, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
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Lange H, Schröder H, Oberem E, Villinger A, Rabeah J, Ludwig R, Neymeyr K, Seidel WW. Facile Synthesis of a Stable Side-on Phosphinyne Complex by Redox Driven Intramolecular Cyclisation. Chemistry 2020; 26:11492-11502. [PMID: 32181544 PMCID: PMC7540294 DOI: 10.1002/chem.201905750] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/08/2020] [Indexed: 11/23/2022]
Abstract
Alkyne complexes with vicinal substitution by a Lewis acid and a Lewis base at the coordinated alkyne are prospective frustrated Lewis pairs exhibiting a particular mutual distance and, hence, a specific activation potential. In this contribution, investigations on the generation of a WII alkyne complex bearing a phosphine as Lewis base and a carbenium group as Lewis acid are presented. Independently on potential substrates added, an intramolecular cyclisation product was always isolated. A subsequent deprotonation step led to an unprecedented side-on λ5 -phosphinyne complex, which is interpreted as highly zwitterionic according to visible absorption spectroscopy supported by TD-DFT. Low-temperature 31 P NMR and EPR spectroscopic measurements combined with time-dependent IR-spectroscopic monitoring provided insights in the mechanism of the cyclisation reaction. Decomposition of the multicomponent IR spectra by multivariate curve resolution and a kinetic hard-modelling approach allowed the derivation of kinetic parameters. Assignment of the individual IR spectra to potential intermediates was provided by DFT calculations.
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Affiliation(s)
- Helge Lange
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
| | - Henning Schröder
- Institut für MathematikUniversität RostockUlmenstraße 6918057RostockGermany
| | - Elisabeth Oberem
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
| | - Alexander Villinger
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
| | - Jabor Rabeah
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Straße 29a18059RostockGermany
| | - Ralf Ludwig
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Straße 29a18059RostockGermany
| | - Klaus Neymeyr
- Institut für MathematikUniversität RostockUlmenstraße 6918057RostockGermany
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Straße 29a18059RostockGermany
| | - Wolfram W. Seidel
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
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Casper LA, Oßwald S, Anders P, Rosenbaum L, Winter RF. Extremely Electron‐Poor Bis(diarylmethylium)‐Substituted Ferrocenes and the First Peroxoferrocenophane. Z Anorg Allg Chem 2020. [DOI: 10.1002/zaac.201900347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Larissa A. Casper
- Fachbereich Chemie Universität Konstanz Universitätsstraße 10 78453 Konstanz Germany
| | - Steffen Oßwald
- Fachbereich Chemie Universität Konstanz Universitätsstraße 10 78453 Konstanz Germany
| | - Patrick Anders
- Fachbereich Chemie Universität Konstanz Universitätsstraße 10 78453 Konstanz Germany
| | | | - Rainer F. Winter
- Fachbereich Chemie Universität Konstanz Universitätsstraße 10 78453 Konstanz Germany
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