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Redox-active ligands for chemical, electrochemical, and photochemical molecular conversions. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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2
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Singh K, Kundu A, Adhikari D. Ligand-Based Redox: Catalytic Applications and Mechanistic Aspects. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kirti Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar, Manauli 140306, India
| | - Abhishek Kundu
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar, Manauli 140306, India
| | - Debashis Adhikari
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar, Manauli 140306, India
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3
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Hanft A, Rottschäfer D, Müller V, Weinberger P, Radacki K, Xie X, Lichtenberg C. Sulfinyl-aminotroponiminates: alkali- (Li, Na, K) and heavy-metal (Bi) complexes. Dalton Trans 2022; 51:10809-10817. [PMID: 35818977 DOI: 10.1039/d2dt01802k] [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
The installation of electron-withdrawing functional groups at the carbocyclic backbone of aminotroponiminate (ATI) ligands is a versatile method for influencing the electronic properties of the resulting ATI complexes. We report here Li, Na, and K salts of an ATI ligand with a phenylsulfinyl substituent in the backbone. It is demonstrated that the sulfinyl group actively contributes to the coordination chemistry of these complexes, effectively competing with neutral donor ligands such as thf or pyridine in the solid state (XRD), in solution (DOSY NMR spectroscopy), and in the gas phase (DFT). The impact of the phenylsulfinyl group on the redox properties of the complexes have been investigated and access to sodium sodiate species through ligand-induced disproportionation has been studied. Transfer of the ATI ligand to the heavy p-block element bismuth has been demonstrated. Analytical techniques applied in this work include multinuclear and DOSY NMR spectroscopy, cyclic voltammetry, DFT calculations, and single-crystal X-ray diffraction analysis.
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Affiliation(s)
- Anna Hanft
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-98074 Würzburg, Germany
| | - Dennis Rottschäfer
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, D-35032 Marburg, Germany.
| | - Victoria Müller
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-98074 Würzburg, Germany
| | - Pascal Weinberger
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-98074 Würzburg, Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-98074 Würzburg, Germany
| | - Xiulan Xie
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, D-35032 Marburg, Germany.
| | - Crispin Lichtenberg
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, D-35032 Marburg, Germany.
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4
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Hanft A, Rottschäfer D, Wieprecht N, Geist F, Radacki K, Lichtenberg C. Aminotroponiminates: Impact of the NO 2 Functional Group on Coordination, Isomerisation, and Backbone Substitution. Chemistry 2021; 27:14250-14262. [PMID: 34314083 PMCID: PMC8597084 DOI: 10.1002/chem.202102324] [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: 06/28/2021] [Indexed: 01/17/2023]
Abstract
Aminotroponiminate (ATI) ligands are a versatile class of redox-active and potentially cooperative ligands with a rich coordination chemistry that have consequently found a wide range of applications in synthesis and catalysis. While backbone substitution of these ligands has been investigated in some detail, the impact of electron-withdrawing groups on the coordination chemistry and reactivity of ATIs has been little investigated. We report here Li, Na, and K salts of an ATI ligand with a nitro-substituent in the backbone. It is demonstrated that the NO2 group actively contributes to the coordination chemistry of these complexes, effectively competing with the N,N-binding pocket as a coordination site. This results in an unprecedented E/Z isomerisation of an ATI imino group and culminates in the isolation of the first "naked" (i. e., without directional bonding to a metal atom) ATI anion. Reactions of sodium ATIs with silver(I) and tritylium salts gave the first N,N-coordinated silver ATI complexes and unprecedented backbone substitution reactions. Analytical techniques applied in this work include multinuclear (VT-)NMR spectroscopy, single-crystal X-ray diffraction analysis, and DFT calculations.
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Affiliation(s)
- Anna Hanft
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Dennis Rottschäfer
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Nele Wieprecht
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Felix Geist
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Crispin Lichtenberg
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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5
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Hanft A, Radacki K, Lichtenberg C. Cationic Bismuth Aminotroponiminates: Charge Controls Redox Properties. Chemistry 2021; 27:6230-6239. [PMID: 33326650 PMCID: PMC8048980 DOI: 10.1002/chem.202005186] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Indexed: 01/03/2023]
Abstract
The behavior of the redox‐active aminotroponiminate (ATI) ligand in the coordination sphere of bismuth has been investigated in neutral and cationic compounds, [Bi(ATI)3] and [Bi(ATI)2Ln][A] (L=neutral ligand; n=0, 1; A=counteranion). Their coordination chemistry in solution and in the solid state has been analyzed through (variable‐temperature) NMR spectroscopy, line‐shape analysis, and single‐crystal X‐ray diffraction analyses, and their Lewis acidity has been evaluated by using the Gutmann–Beckett method (and modifications thereof). Cyclic voltammetry, in combination with DFT calculations, indicates that switching between ligand‐ and metal‐centered redox events is possible by altering the charge of the compounds from 0 in neutral species to +1 in cationic compounds. This adds important facets to the rich redox chemistry of ATIs and to the redox chemistry of bismuth compounds, which is, so far, largely unexplored.
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Affiliation(s)
- Anna Hanft
- Department of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Krzysztof Radacki
- Department of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Crispin Lichtenberg
- Department of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
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Lichtenberg C. Molecular bismuth(iii) monocations: structure, bonding, reactivity, and catalysis. Chem Commun (Camb) 2021; 57:4483-4495. [DOI: 10.1039/d1cc01284c] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Structurally defined, molecular bismuth(iii) cations show remarkable properties in coordination chemistry, Lewis acidity, and redox chemistry, allowing for unique applications in synthetic chemistry.
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Affiliation(s)
- Crispin Lichtenberg
- Julius-Maximilians-University Würzburg
- Institute of Inorganic Chemistry Am Hubland
- 97074 Würzburg
- Germany
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7
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Hanft A, Jürgensen M, Wolz L, Radacki K, Lichtenberg C. Salicylaldimines: Formation via Ring Contraction and Synthesis of Mono- and Heterobimetallic Alkali Metal Heterocubanes. Inorg Chem 2020; 59:17678-17688. [PMID: 33226783 DOI: 10.1021/acs.inorgchem.0c02920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The formation of salicylaldimine derivatives via ring contraction as byproducts in 2-aminotropone syntheses has been investigated. Salicylaldiminate (SAI) complexes of the alkali metals Li-K have been synthesized and transformed into heterobimetallic complexes. Important findings include an unusual double heterocubane structure of the homometallic sodium SAI, an unprecedented ligand-induced E/Z isomerization of the aldimine functional group in the homometallic potassium SAI, and the first example of a structurally authenticated mixed-metal SAI based on s-block central atoms. Rapid equilibria have been shown to play a crucial role in the solution phase chemistry of mixed-metal SAIs. Analytical techniques applied in this work include (heteronuclear) NMR spectroscopy, VT- and DOSY NMR spectroscopy, high-resolution mass spectrometry, single-crystal X-ray diffraction analysis, and DFT calculations.
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Affiliation(s)
- Anna Hanft
- Department of Inorganic Chemistry, Julius-Maximilians Universität, Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Malte Jürgensen
- Department of Inorganic Chemistry, Julius-Maximilians Universität, Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Laura Wolz
- Department of Inorganic Chemistry, Julius-Maximilians Universität, Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Krzysztof Radacki
- Department of Inorganic Chemistry, Julius-Maximilians Universität, Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Crispin Lichtenberg
- Department of Inorganic Chemistry, Julius-Maximilians Universität, Würzburg, Am Hubland, 97074 Würzburg, Germany
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8
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Lichtenberg C. Main-Group Metal Complexes in Selective Bond Formations Through Radical Pathways. Chemistry 2020; 26:9674-9687. [PMID: 32048770 PMCID: PMC7496981 DOI: 10.1002/chem.202000194] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/10/2020] [Indexed: 12/21/2022]
Abstract
Recent years have witnessed remarkable advances in radical reactions involving main-group metal complexes. This includes the isolation and detailed characterization of main-group metal radical compounds, but also the generation of highly reactive persistent or transient radical species. A rich arsenal of methods has been established that allows control over and exploitation of their unusual reactivity patterns. Thus, main-group metal compounds have entered the field of selective bond formations in controlled radical reactions. Transformations that used to be the domain of late transition-metal compounds have been realized, and unusual selectivities, high activities, as well as remarkable functional-group tolerances have been reported. Recent findings demonstrate the potential of main-group metal compounds to become standard tools of synthetic chemistry, catalysis, and materials science, when operating through radical pathways.
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Affiliation(s)
- Crispin Lichtenberg
- Institute of Inorganic ChemistryJulius-Maximilians-University WürzburgAm Hubland97074WürzburgGermany
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9
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Hanft A, Lichtenberg C. Dimerization of 2-[(2-((2-aminophenyl)thio)phenyl)amino]-cyclohepta-2,4,6-trien-1-one through hydrogen bonding, C 19H 16N 2OS. Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2020-0124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C19H16N2OS, triclinic, P1̄ (no. 2), a = 8.1510(3) Å, b = 8.8021(3) Å, c = 11.3953(5) Å, α = 72.546(2)°, β = 84.568(2)°, γ = 80.760(2)°, V = 768.86(5) Å3, Z = 2, R
gt(F) = 0.0491, wR
ref(F
2) = 0.1494, T = 100 K.
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Affiliation(s)
- Anna Hanft
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany
| | - Crispin Lichtenberg
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany
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10
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Yoshida J, Tateyama K, Yuge H. Tris(tropolonato) ruthenium as a hub for connecting π-conjugated systems. Dalton Trans 2020; 49:2102-2111. [PMID: 32025681 DOI: 10.1039/c9dt04860j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, the intramolecular electronic communication between π-conjugated moieties bridged by the tris-chelate [Ru(trop)3] (trop = tropolonate) framework has been investigated and compared with [Ru(acac)3] (acac = acetylacetonate) derivatives. Two types of π-conjugated groups, -C2SiMe3 and -C2Ph, which were each introduced at the 5-position of tropolonate, were found to behave almost independently in the resultant ruthenium complexes. In contrast, the cyclic voltammetry study of [Ru(trop)3] derivatives showed a clear decrease in ΔE, the difference in the potentials of the two redox couples, with an increase in the number of π-conjugated groups introduced into the [Ru(trop)3] framework. The lower ΔE values observed in [Ru(trop)3] derivatives compared to those in [Ru(acac)3] derivatives illustrated the non-innocent behavior of the tropolonate ligand, i.e., the mixing between the metal- and ligand-based frontier orbitals. This orbital mixing was exemplified in the oxidized [Ru(trop)3] derivatives, which showed a broad near-infrared (NIR) absorption. The increase in the red shift of the NIR absorption with the increasing number of terminal groups indicated intramolecular electronic communication between the terminal π-conjugated moieties. In contrast, no NIR absorption was observed upon oxidation of [Ru(acac)3] derivatives with -C2Ph groups. The lifetimes of the in situ formed [Ru(trop)3]+ and [Ru(acac)3]+ in acetonitrile solution were found to be several hours and minutes, respectively. Density functional theory calculations for [Ru(trop)3] and [Ru(acac)3] with terminal -C2Ph groups demonstrated that the spin densities in their mono-oxidized states were evenly distributed over the entire molecular framework and localized mainly on one ligand, respectively. These results confirmed that the mono-oxidized [Ru(trop)3]+ framework can behave as a hub and induce moderate intramolecular electronic communication between terminal π-conjugated groups.
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Affiliation(s)
- Jun Yoshida
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato Minami-ku, Sagamihara, 252-0373, Japan.
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11
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Hanft A, Krummenacher I, Lichtenberg C. Alkali‐Metal Aminotroponiminates: Selectivities and Equilibria in Reversible Radical Coupling of Delocalized π‐Electron Systems. Chemistry 2019; 25:11883-11891. [DOI: 10.1002/chem.201901962] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Anna Hanft
- Institute of Inorganic ChemistryJulius-Maximilians-University Würzburg Am Hubland 97074 Würzburg Germany
| | - Ivo Krummenacher
- Institute of Inorganic ChemistryJulius-Maximilians-University Würzburg Am Hubland 97074 Würzburg Germany
| | - Crispin Lichtenberg
- Institute of Inorganic ChemistryJulius-Maximilians-University Würzburg Am Hubland 97074 Würzburg Germany
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12
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van der Vlugt JI. Radical-Type Reactivity and Catalysis by Single-Electron Transfer to or from Redox-Active Ligands. Chemistry 2019; 25:2651-2662. [PMID: 30084211 PMCID: PMC6471147 DOI: 10.1002/chem.201802606] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Indexed: 12/12/2022]
Abstract
Controlled ligand-based redox-activity and chemical non-innocence are rapidly gaining importance for selective (catalytic) processes. This Concept aims to provide an overview of the progress regarding ligand-to-substrate single-electron transfer as a relatively new mode of operation to exploit ligand-centered reactivity and catalysis based thereon.
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Affiliation(s)
- Jarl Ivar van der Vlugt
- Bio-Inspired Homogeneous and Supramolecular Catalysis Groupvan ‘t Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098 XHAmsterdamNetherlands
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13
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Hanft A, Jürgensen M, Bertermann R, Lichtenberg C. Sodium Aminotroponiminates: Ligand-Induced Disproportionation, Mixed-Metal Compounds, and Exceptional Activity in Polymerization Catalysis. ChemCatChem 2018. [DOI: 10.1002/cctc.201800580] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Anna Hanft
- Department of Inorganic Chemistry; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Malte Jürgensen
- Department of Inorganic Chemistry; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Rüdiger Bertermann
- Department of Inorganic Chemistry; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Crispin Lichtenberg
- Department of Inorganic Chemistry; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
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14
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Hanft A, Lichtenberg C. New Perspectives for Aminotroponiminates: Coordination Chemistry, Redox Behavior, Cooperativity, and Catalysis. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800465] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anna Hanft
- Department of Inorganic Chemistry; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Crispin Lichtenberg
- Department of Inorganic Chemistry; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
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15
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Hanft A, Lichtenberg C. Rationalizing the Effect of Ligand Substitution Patterns on Coordination and Reactivity of Alkali Metal Aminotroponiminates. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00208] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anna Hanft
- Department of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Germany
| | - Crispin Lichtenberg
- Department of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Germany
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Hanft A, Lichtenberg C. Aminotroponiminates: ligand-centred, reversible redox events under oxidative conditions in sodium and bismuth complexes. Dalton Trans 2018; 47:10578-10589. [DOI: 10.1039/c8dt01019f] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Redox-active bismuth complexes based on a new aminotroponiminate ligand with ferrocenyl substituents have been synthesised and characterised.
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Affiliation(s)
- Anna Hanft
- Department of Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- D-97074 Würzburg
- Germany
| | - Crispin Lichtenberg
- Department of Inorganic Chemistry
- Julius-Maximilians-Universität Würzburg
- D-97074 Würzburg
- Germany
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Yoshida J, Kuwahara K, Suzuki K, Yuge H. Long-Range Intramolecular Electronic Communication in a Trinuclear Ruthenium Tropolonate Complex. Inorg Chem 2017; 56:1846-1856. [DOI: 10.1021/acs.inorgchem.6b02249] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jun Yoshida
- Department of Chemistry, School of Science, Kitasato University 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Kyohei Kuwahara
- Department of Chemistry, School of Science, Kitasato University 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Kota Suzuki
- Department of Chemistry, School of Science, Kitasato University 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Hidetaka Yuge
- Department of Chemistry, School of Science, Kitasato University 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
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