1
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Porte V, Milunovic MNM, Knof U, Leischner T, Danzl T, Kaiser D, Gruene T, Zalibera M, Jelemenska I, Bucinsky L, Jannuzzi SAV, DeBeer S, Novitchi G, Maulide N, Arion VB. Chemical and Redox Noninnocence of Pentane-2,4-dione Bis( S-methylisothiosemicarbazone) in Cobalt Complexes and Their Application in Wacker-Type Oxidation. JACS AU 2024; 4:1166-1183. [PMID: 38559722 PMCID: PMC10976605 DOI: 10.1021/jacsau.4c00005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/09/2024] [Accepted: 02/15/2024] [Indexed: 04/04/2024]
Abstract
Cobalt complexes with multiproton- and multielectron-responsive ligands are of interest for challenging catalytic transformations. The chemical and redox noninnocence of pentane-2,4-dione bis(S-methylisothiosemicarbazone) (PBIT) in a series of cobalt complexes has been studied by a range of methods, including spectroscopy [UV-vis, NMR, electron paramagnetic resonance (EPR), X-ray absorption spectroscopy (XAS)], cyclic voltammetry, X-ray diffraction, and density functional theory (DFT) calculations. Two complexes [CoIII(H2LSMe)I]I and [CoIII(LSMe)I2] were found to act as precatalysts in a Wacker-type oxidation of olefins using phenylsilane, the role of which was elucidated through isotopic labeling. Insights into the mechanism of the catalytic transformation as well as the substrate scope of this selective reaction are described, and the essential role of phenylsilane and the noninnocence of PBIT are disclosed. Among the several relevant species characterized was an unprecedented Co(III) complex with a dianionic diradical PBIT ligand ([CoIII(LSMe••)I]).
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Affiliation(s)
- Vincent Porte
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Miljan N. M. Milunovic
- University
of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
| | - Ulrich Knof
- Novartis
Pharma AG, CH-4056 Basel, Switzerland
| | - Thomas Leischner
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Tobias Danzl
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Daniel Kaiser
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Tim Gruene
- University
of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
| | - Michal Zalibera
- Institute
of Physical Chemistry and Chemical Physics, Faculty of Chemical and
Food Technology, Slovak University of Technology
in Bratislava, Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Ingrid Jelemenska
- Institute
of Physical Chemistry and Chemical Physics, Faculty of Chemical and
Food Technology, Slovak University of Technology
in Bratislava, Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Lukas Bucinsky
- Institute
of Physical Chemistry and Chemical Physics, Faculty of Chemical and
Food Technology, Slovak University of Technology
in Bratislava, Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Sergio A. V. Jannuzzi
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | | | - Nuno Maulide
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Vladimir B. Arion
- University
of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
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2
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Kayser AK, Wolczanski PT, Cundari TR, MacMillan SN, Bollmeyer MM. Benzimidazole-diamide (bida) Pincer Chromium Complexes: Structures and Reactivity. Inorg Chem 2023; 62:15450-15464. [PMID: 37707794 DOI: 10.1021/acs.inorgchem.3c01771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Serendipitous discovery of bida (i.e., N1-Ar-N2-((1-Ar-1-benzo[d]imidazol-2-yl)methyl)benzene-1,2-diamide; Ar = 2,6-iPr-C6H3), a potentially redox noninnocent, hemilabile pincer ligand with a methylene group that may facilitate proton/H atom reactivity, prompted its investigation. Chromium was chosen for study due to its multiple stable oxidation states. Disodium salt (bida)Na2(THF)n was prepared by thermal rearrangement of (dadi)Na2(THF)4 (i.e., (N,N'-di-2-(2,6-diisopropylphenylamine)phenylglyoxaldiimine)-Na2(THF)4). Salt metathesis of (bida)Na2(THF)n (generated in situ) with CrCl3(THF)3 or Cl3V═NAr (Ar = 2,6-iPr2C6H3) afforded (bida)CrCl(THF) (1-THF) and (bida)ClV═NAr, respectively. Substitutions provided (bida)CrCl(PMe2Ph) (1-PMe2Ph) and (bida)CrR(THF) (2-R, where R = Me, CH2CMe2Ph (Nph)). Oxidation of 1-THF with ArN3 (Ar = 2,6-iPr2C6H3) or AdN3 (Ad = 1-adamantyl) generated (bida)ClCr═NAr (3═NAr) and (bida)ClCr═NAd (3═NAd) and subsequent alkylation converted these to (bida)R'Cr═NR (R' = Me, R = Ad, Ar, 5═NR; R' = CH2CMe2Ph (Nph), R = Ad, Ar, 6═NR). In contrast, the addition of AdN3 to 2-Nph gave the insertion product (bida)Cr(κ2-N,N-ArN3Nph) (7). Addition of N-chlorosuccinimide to 1-THF produced (bia)CrCl2(THF) (8), where bia is the pincer derived via hydrogen atom loss from bida methylene. A similar HAT afforded (bia)ClCr(CNAr')2 (9, Ar' = 2,6-Me2C6H3) when 3═NAd was exposed to Ar'NC. An empirical equation of charge was applied to each bida species, whose metric parameters are unchanging despite formal oxidation state conversions from Cr(III) to Cr(V). Calculations and Mulliken spin density assessments reveal several situations in which antiferromagnetic (AF) coupling and admixtures of integer ground states (GSs) describe a complicated electronic structure.
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Affiliation(s)
- Ann K Kayser
- Department of Chemistry and Chemical Biology, Baker Laboratory Cornell University, Ithaca, New York 14853, United States
| | - Peter T Wolczanski
- Department of Chemistry and Chemical Biology, Baker Laboratory Cornell University, Ithaca, New York 14853, United States
| | - Thomas R Cundari
- Department of Chemistry, CASCam University of North Texas Denton, Denton, Texas 76201, United States
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology, Baker Laboratory Cornell University, Ithaca, New York 14853, United States
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3
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Bartholomew AK, Musgrave RA, Anderton KJ, Juda CE, Dong Y, Bu W, Wang SY, Chen YS, Betley TA. Revealing redox isomerism in trichromium imides by anomalous diffraction. Chem Sci 2021; 12:15739-15749. [PMID: 35003606 PMCID: PMC8654065 DOI: 10.1039/d1sc04819h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/02/2021] [Indexed: 12/02/2022] Open
Abstract
In polynuclear biological active sites, multiple electrons are needed for turnover, and the distribution of these electrons among the metal sites is affected by the structure of the active site. However, the study of the interplay between structure and redox distribution is difficult not only in biological systems but also in synthetic polynuclear clusters since most redox changes produce only one thermodynamically stable product. Here, the unusual chemistry of a sterically hindered trichromium complex allowed us to probe the relationship between structural and redox isomerism. Two structurally isomeric trichromium imides were isolated: asymmetric terminal imide (tbsL)Cr3(NDipp) and symmetric, μ3-bridging imide (tbsL)Cr3(μ3–NBn) ((tbsL)6− = (1,3,5-C6H9(NC6H4-o-NSitBuMe2)3)6−). Along with the homovalent isocyanide adduct (tbsL)Cr3(CNBn) and the bisimide (tbsL)Cr3(μ3–NPh)(NPh), both imide isomers were examined by multiple-wavelength anomalous diffraction (MAD) to determine the redox load distribution by the free refinement of atomic scattering factors. Despite their compositional similarities, the bridging imide shows uniform oxidation of all three Cr sites while the terminal imide shows oxidation at only two Cr sites. Further oxidation from the bridging imide to the bisimide is only borne at the Cr site bound to the second, terminal imido fragment. Thus, depending on the structural motifs present in each [Cr3] complex, MAD revealed complete localization of oxidation, partial localization, and complete delocalization, all supported by the same hexadentate ligand scaffold. Application of high-resolution Multiwavelength Anomalous Diffraction (MAD) allows the assignment of localized, partly delocalized, and fully delocalized oxidation in a series of trichromium imide isomers.![]()
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Affiliation(s)
| | - Rebecca A Musgrave
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Kevin J Anderton
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Cristin E Juda
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Yuyang Dong
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Wei Bu
- ChemMatCARS, The University of Chicago Argonne Illinois 60439 USA
| | - Su-Yin Wang
- ChemMatCARS, The University of Chicago Argonne Illinois 60439 USA
| | - Yu-Sheng Chen
- ChemMatCARS, The University of Chicago Argonne Illinois 60439 USA
| | - Theodore A Betley
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
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4
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Lu YL, Lan WL, Shi W, Jin QH, Cheng P. Photo-induced variation of magnetism in coordination polymers with ligand-based electron transfer. Dalton Trans 2021; 50:13124-13137. [PMID: 34581367 DOI: 10.1039/d1dt01963e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photo-induced variation of magnetism from ligand-based electron transfer has been extensively studied because of its potential applications in magneto-optical memory devices, light-responsive switches, and high-density information storage materials. In this review, we discussed the progress in the photo-induced variation of magnetism in coordination polymers with ligand-to-metal charge transfer (LMCT), ligand-to-ligand charge transfer (LLCT) and internal ligand charge transfer (ILCT), which provides fundamentals for the rational design of multi-functional materials. We also discussed the design and synthetic strategy of such molecule-based materials and gave views on the current challenges and growth trends in this field.
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Affiliation(s)
- Yan-Lei Lu
- Department of Chemistry, Capital Normal University, Beijing 100048, China.
| | - Wen-Long Lan
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071, China.
| | - Wei Shi
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071, China.
| | - Qiong-Hua Jin
- Department of Chemistry, Capital Normal University, Beijing 100048, China.
| | - Peng Cheng
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071, China.
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5
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Liu R, Yang S, Ding Y. Study on the Structure, Thermodynamic property, and Fluorescence of Pyridin‐2‐ylmethyl‐tert‐butylamine Dimethyl aluminum complex. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202000478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ruiyuan Liu
- The Key Laboratory of synthetic and biological colloids, Ministry of Education, School of Chemical and Material Engineering Jiangnan University Wuxi 214122 Jiangsu Province China
| | - Shuyan Yang
- The Key Laboratory of synthetic and biological colloids, Ministry of Education, School of Chemical and Material Engineering Jiangnan University Wuxi 214122 Jiangsu Province China
| | - Yuqiang Ding
- The Key Laboratory of synthetic and biological colloids, Ministry of Education, School of Chemical and Material Engineering Jiangnan University Wuxi 214122 Jiangsu Province China
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6
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So J, Kim S, Cho KB, Lee Y. Metal-ligand cooperative transformation of alkyl azide to isocyanate occurring at a Co-Si moiety. Chem Commun (Camb) 2021; 57:3219-3222. [PMID: 33645611 DOI: 10.1039/d0cc08012h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A cobalt-silyl moiety reveals metal-ligand cooperative group transfer to generate isocyanate from the reaction of alkyl azide and CO. This reaction involves the reversible insertion of a nitrene group into a Co-Si bond. Photolysis leads to ligand substitution of a Co(CO)2 species, allowing the successful catalytic conversion of AdN3 to AdNCO under CO(g).
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Affiliation(s)
- Jongho So
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
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7
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Müller I, Werncke CG. Reductive Coupling of (Fluoro)pyridines by Linear 3d-Metal(I) Silylamides of Cr-Co: A Tale of C-C Bond Formation, C-F Bond Cleavage and a Pyridyl Radical Anion. Chemistry 2021; 27:4932-4938. [PMID: 33453071 PMCID: PMC7986091 DOI: 10.1002/chem.202004852] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/21/2020] [Indexed: 01/10/2023]
Abstract
Herein, we disclose the facile reduction of pyridine (and its derivatives) by linear 3d-metal(I) silylamides (M=Cr-Co). This reaction resulted in intermolecular C-C coupling to give dinuclear metal(II) complexes bearing a bridging 4,4'-dihydrobipyridyl ligand. For iron, we demonstrated that the C-C coupling is reversible in solution, either directly or by reaction with substrates, via a presumed monomeric metal(II) complex bearing a pyridyl radical anion. In the course of this investigation, we also observed that the dinuclear metal(II) complex incorporating iron facilitated the isomerisation of 1,4-cyclohexadiene to 1,3-cyclohexadiene as well as equimolar amounts of benzene and cyclohexene. Furthermore, we synthesised and structurally characterised a non-3d-metal-bound pyridyl radical anion. The reactions of the silylamides with perfluoropyridine led to C-F bond cleavage with the formation of metal(II) fluoride complexes of manganese, iron and cobalt along with the homocoupling or reductive degradation of the substrate. In the case of cobalt, the use of lesser fluorinated pyridines led to C-F bond cleavage but no homocoupling. Overall, in this paper we provide insights into the multifaceted behaviour of simple (fluoro)pyridines in the presence of moderately to highly reducing metal complexes.
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Affiliation(s)
- Igor Müller
- Fachbereich Chemie/Department of ChemistryPhilipps-Universität MarburgHans-Meerwein-Strasse 435037MarburgGermany
| | - Christian Gunnar Werncke
- Fachbereich Chemie/Department of ChemistryPhilipps-Universität MarburgHans-Meerwein-Strasse 435037MarburgGermany
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8
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Sarkar P, Sarmah A, Mukherjee C. Synthesis, crystallographic and spectroscopic characterization, and theoretical elucidation of an elusive aminyl radical containing a Cu II-aminyl-iminosemiquinone complex. Chem Commun (Camb) 2021; 57:1352-1355. [PMID: 33432948 DOI: 10.1039/d0cc07378d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An elusive aminyl radical and an iminosemiquinone radical-coordinated square pyramidal Cu(ii) complex (1) have been isolated by the reaction between the noninnocent ligand H4LPy(AP) and Cu(ClO4)2·6H2O in the presence of Et3N and air as the sole oxidant. The geometry and electronic structure of the complex were concluded by X-ray crystallography, magnetic and EPR measurements, and density functional theory (DFT) calculations. This work reports the first crystallographic example of the two different types of radicals co-existing in a stable complex.
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Affiliation(s)
- Prasenjit Sarkar
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
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9
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Stüker T, Hohmann T, Beckers H, Riedel S. Fluoro Nitrenoid Complexes FN=MF
2
(M=Co, Rh, Ir): Electronic Structure Dichotomy and Formation of Nitrido Fluorides N≡MF
3. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202010950] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tony Stüker
- Anorganische Chemie Institut für Chemie und Biochemie Freie Universität Berlin 14195 Berlin Germany
| | - Thomas Hohmann
- Anorganische Chemie Institut für Chemie und Biochemie Freie Universität Berlin 14195 Berlin Germany
| | - Helmut Beckers
- Anorganische Chemie Institut für Chemie und Biochemie Freie Universität Berlin 14195 Berlin Germany
| | - Sebastian Riedel
- Anorganische Chemie Institut für Chemie und Biochemie Freie Universität Berlin 14195 Berlin Germany
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10
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Stüker T, Hohmann T, Beckers H, Riedel S. Fluoro Nitrenoid Complexes FN=MF 2 (M=Co, Rh, Ir): Electronic Structure Dichotomy and Formation of Nitrido Fluorides N≡MF 3. Angew Chem Int Ed Engl 2020; 59:23174-23179. [PMID: 32886443 PMCID: PMC7756499 DOI: 10.1002/anie.202010950] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 08/30/2020] [Indexed: 11/10/2022]
Abstract
The fluoronitrenoid metal complexes FNCoF2 and FNRhF2 as well as the first ternary RhVI and IrVI complexes NIrF3 and NRhF3 are described. They were obtained by the reaction of excited Group-9 metal atoms with NF3 and their IR spectra, isolated in solid rare gases (neon and argon), were recorded. Aided by the observed 14/15 N isotope shifts and quantum-chemical predictions, all four stretching fundamentals of the novel complexes were safely assigned. The F-N stretching frequencies of the fluoronitrenoid complexes FNCoF2 (1056.8 cm-1 ) and FNRhF2 (872.6 cm-1 ) are very different and their N-M bonds vary greatly. In FNCoF2 , the FN ligand is singly bonded to Co and bears considerable iminyl/nitrene radical character, while the N-Rh bond in FNRhF2 is a strong double bond with comparatively strong σ- and π-bonds. The anticipated rearrangement of FNCoF2 to the nitrido CoVI complex is predicted to be endothermic and was not observed.
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Affiliation(s)
- Tony Stüker
- Anorganische ChemieInstitut für Chemie und BiochemieFreie Universität Berlin14195BerlinGermany
| | - Thomas Hohmann
- Anorganische ChemieInstitut für Chemie und BiochemieFreie Universität Berlin14195BerlinGermany
| | - Helmut Beckers
- Anorganische ChemieInstitut für Chemie und BiochemieFreie Universität Berlin14195BerlinGermany
| | - Sebastian Riedel
- Anorganische ChemieInstitut für Chemie und BiochemieFreie Universität Berlin14195BerlinGermany
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11
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Zhang X, Zhou S, Fang X, Zhang L, Tao G, Wei Y, Zhu X, Cui P, Wang S. Syntheses of Dianionic α-Iminopyridine Rare-Earth Metal Complexes and Their Catalytic Acitivities toward Dehydrogenative Coupling of Amines with Hydrosilanes. Inorg Chem 2020; 59:9683-9692. [PMID: 32602707 DOI: 10.1021/acs.inorgchem.0c00907] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions of [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 with aminomethylene-substituted pyridine 2-[O(CH2CH2)2NCH2CH2NCH2]C5H4N (1) gave the dianionic α-iminopyridine rare-earth metal amido complexes {μ-η2:σ1:κ1:κ1-2-[O(CH2CH2)2NCH2CH2NCH]C5H4N}2RE2[N(SiMe3)2]2 (RE = Y(2a), La(2b), Pr(2c), Nd(2d), Sm(2e), Dy(2f), Er(2g), and Lu (2h)). However, reaction of [(Me3Si)2N]3Y(μ-Cl)Li(THF)3 with pyridin-2-ylmethyl-substituted amines such as 2-(RNHCH2)C5H4N (R = tBu (3a) and 2,6-iPr2Ph (3b)) or benzyl-substituted amine O(CH2CH2)2NCH2CH2NHCH2C6H5 (5) afforded the corresponding yttrium complexes containing monoanionic ligands [2-(RNCH2)C5H4N]2YN(SiMe3)2 (R = tBu (4a) and 2,6-iPr2Ph (4b)) or [O(CH2CH2)2NCH2CH2NCH2C6H5][(Me3Si)2N)]Y(μ-Cl)(μ-η3-O(CH2CH2)2NCH2CH2NCH2C6H5)Li(THF) (6). Dianionic α-iminopyridine rare-earth metal amido complexes showed high catalytic activities for the dehydrogenation coupling reaction of hydrosilanes and amines providing a variety of silylamines in high yields.
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Affiliation(s)
- Xiuli Zhang
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Shuangliu Zhou
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Xiaofei Fang
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Lijun Zhang
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Guide Tao
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Yun Wei
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Xiancui Zhu
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Peng Cui
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Shaowu Wang
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China.,Anhui Laboratory of Clean Catalytic Engineering, Anhui Laboratory of Functional Complexes for Materials Chemistry and Application, College of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu, Anhui 241000, PR China
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12
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Ternes VA, Morgan HA, Lanquist AP, Murray MJ, Wile BM. Ruthenium (II) complexes bearing thioether‐appended α‐iminopyridine ligands: Arene precursors permit access to κ
2
‐N,N and κ
3
‐N,N,S complexes. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Victoria A. Ternes
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
| | - Hannah A. Morgan
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
| | - Austin P. Lanquist
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
| | - Michael J. Murray
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
| | - Bradley M. Wile
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
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13
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Dong Y, Clarke RM, Zheng SL, Betley TA. Synthesis and electronic structure studies of a Cr-imido redox series. Chem Commun (Camb) 2020; 56:3163-3166. [PMID: 32065193 PMCID: PMC7132162 DOI: 10.1039/d0cc00108b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effect of metal identity, d-electron count, and coordination geometry on the electronic structure of a metal-ligand multiple bond (MLMB) is an area of active exploration. Although high oxidation state Cr imidos have been extensively studied, very few reports on low-valent Cr imidos or the interconversion of redox isomers exist. Herein, we report the synthesis and characterization of a family of dipyrrinato Cr imido complexes in oxidation states ranging from CrIII to CrV, showcasing the influence of the weak-field dipyrromethene scaffold on the electronic structure and coordination geometries of these Cr imides.
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Affiliation(s)
- Yuyang Dong
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
| | - Ryan M Clarke
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
| | - Shao-Liang Zheng
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
| | - Theodore A Betley
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
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14
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Regenauer NI, Settele S, Bill E, Wadepohl H, Roşca DA. Bis(imino)pyrazine-Supported Iron Complexes: Ligand-Based Redox Chemistry, Dearomatization, and Reversible C-C Bond Formation. Inorg Chem 2020; 59:2604-2612. [PMID: 31990534 DOI: 10.1021/acs.inorgchem.9b03665] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Iron complexes supported by novel π-acidic bis(imino)pyrazine (PPzDI) ligands can be functionalized at the nonligated nitrogen atom, and this has a marked effect on the redox properties of the resulting complexes. Dearomatization is observed in the presence of cobaltocene, which reversibly reduces the pyrazine core and not the imine functionality, as observed in the case of the pyridinediimine-ligated iron analogues. The resulting ligand-based radical is prone to dimerization through the formation of a long carbon-carbon bond, which can be subsequently cleaved under mild oxidative conditions.
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Affiliation(s)
- Nicolas I Regenauer
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
| | - Simon Settele
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
| | - Eckhard Bill
- Max-Planck-Institut für Chemische Energiekonversion , Stiftstraße 24-36 , 45470 Mülheim/Ruhr , Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
| | - Dragoş-Adrian Roşca
- Anorganisch-Chemisches Institut , Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
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15
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Sabenya G, Gamba I, Gómez L, Clémancey M, Frisch JR, Klinker EJ, Blondin G, Torelli S, Que L, Martin-Diaconescu V, Latour JM, Lloret-Fillol J, Costas M. Octahedral iron(iv)-tosylimido complexes exhibiting single electron-oxidation reactivity. Chem Sci 2019; 10:9513-9529. [PMID: 32055323 PMCID: PMC6979323 DOI: 10.1039/c9sc02526j] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/17/2019] [Indexed: 11/28/2022] Open
Abstract
High valent iron species are very reactive molecules involved in oxidation reactions of relevance to biology and chemical synthesis. Herein we describe iron(iv)-tosylimido complexes [FeIV(NTs)(MePy2tacn)](OTf)2 (1(IV)[double bond, length as m-dash]NTs) and [FeIV(NTs)(Me2(CHPy2)tacn)](OTf)2 (2(IV)[double bond, length as m-dash]NTs), (MePy2tacn = N-methyl-N,N-bis(2-picolyl)-1,4,7-triazacyclononane, and Me2(CHPy2)tacn = 1-(di(2-pyridyl)methyl)-4,7-dimethyl-1,4,7-triazacyclononane, Ts = Tosyl). 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs are rare examples of octahedral iron(iv)-imido complexes and are isoelectronic analogues of the recently described iron(iv)-oxo complexes [FeIV(O)(L)]2+ (L = MePy2tacn and Me2(CHPy2)tacn, respectively). 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs are metastable and have been spectroscopically characterized by HR-MS, UV-vis, 1H-NMR, resonance Raman, Mössbauer, and X-ray absorption (XAS) spectroscopy as well as by DFT computational methods. Ferric complexes [FeIII(HNTs)(L)]2+, 1(III)-NHTs (L = MePy2tacn) and 2(III)-NHTs (L = Me2(CHPy2)tacn) have been isolated after the decay of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs in solution, spectroscopically characterized, and the molecular structure of [FeIII(HNTs)(MePy2tacn)](SbF6)2 determined by single crystal X-ray diffraction. Reaction of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs with different p-substituted thioanisoles results in the transfer of the tosylimido moiety to the sulphur atom producing sulfilimine products. In these reactions, 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs behave as single electron oxidants and Hammett analyses of reaction rates evidence that tosylimido transfer is more sensitive than oxo transfer to charge effects. In addition, reaction of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs with hydrocarbons containing weak C-H bonds results in the formation of 1(III)-NHTs and 2(III)-NHTs respectively, along with the oxidized substrate. Kinetic analyses indicate that reactions proceed via a mechanistically unusual HAT reaction, where an association complex precedes hydrogen abstraction.
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Affiliation(s)
- Gerard Sabenya
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Ilaria Gamba
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Laura Gómez
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Martin Clémancey
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Jonathan R Frisch
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Eric J Klinker
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Geneviève Blondin
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Stéphane Torelli
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Lawrence Que
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Vlad Martin-Diaconescu
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avinguda Països Catalans 16 , 43007 Tarragona , Spain .
| | - Jean-Marc Latour
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Julio Lloret-Fillol
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avinguda Països Catalans 16 , 43007 Tarragona , Spain .
- Catalan Institution for Research and Advanced Studies (ICREA) , Passeig Lluïs Companys, 23 , 08010 , Barcelona , Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
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16
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Safaei E, Balaghi SE, Chiang L, Clarke RM, Martelino D, Webb MI, Wong EWY, Savard D, Walsby CJ, Storr T. Stabilization of different redox levels of a tridentate benzoxazole amidophenoxide ligand when bound to Co(iii) or V(v). Dalton Trans 2019; 48:13326-13336. [DOI: 10.1039/c9dt02865j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The electronic structure of Co and V complexes of a tridentate benzoxazole-containing aminophenol ligand NNOH2 were characterized by both experimental and theoretical methods.
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Affiliation(s)
- Elham Safaei
- Department of Chemistry
- College of Science
- Shiraz University
- Shiraz
- Iran
| | | | - Linus Chiang
- Department of Chemistry
- Simon Fraser University
- 8888 University Drive
- Burnaby
- Canada
| | - Ryan M. Clarke
- Department of Chemistry
- Simon Fraser University
- 8888 University Drive
- Burnaby
- Canada
| | - Diego Martelino
- Department of Chemistry
- Simon Fraser University
- 8888 University Drive
- Burnaby
- Canada
| | - Michael I. Webb
- Department of Chemistry
- Simon Fraser University
- 8888 University Drive
- Burnaby
- Canada
| | - Edwin W. Y. Wong
- Department of Chemistry
- Simon Fraser University
- 8888 University Drive
- Burnaby
- Canada
| | - Didier Savard
- Department of Chemistry
- Simon Fraser University
- 8888 University Drive
- Burnaby
- Canada
| | - Charles J. Walsby
- Department of Chemistry
- Simon Fraser University
- 8888 University Drive
- Burnaby
- Canada
| | - Tim Storr
- Department of Chemistry
- Simon Fraser University
- 8888 University Drive
- Burnaby
- Canada
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17
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Popov IA, Mehio N, Chu T, Davis BL, Mukundan R, Yang P, Batista ER. Impact of Ligand Substitutions on Multielectron Redox Properties of Fe Complexes Supported by Nitrogenous Chelates. ACS OMEGA 2018; 3:14766-14778. [PMID: 31458151 PMCID: PMC6643937 DOI: 10.1021/acsomega.8b01921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 08/17/2018] [Indexed: 06/10/2023]
Abstract
Redox flow batteries (RFBs) have recently been recognized as a potentially viable technology for scalable energy storage. To take full advantage of RFBs, one possible approach for achieving high energy densities is to maximize a number of redox events by utilizing charge carriers capable of multiple one-electron transfers within the electrochemical window of solvent. However, past efforts to develop more efficient electrolytes for nonaqueous RFBs have mostly been empirical. In this manuscript, we shed light on design principles by theoretically investigating the effects of systematically substituting pyridyl moieties with imine ligands within a series of Fe complexes with some experimental validation. We found that such replacement is an effective strategy for reducing the molecular weight-to-charge ratios of these complexes. Simultaneously, calculations suggest that the reduction potentials and ligand-based redox activity of such substituted N-heterocyclic Fe compounds might be maintained within their +4 → -1 charge states. Additionally, by theoretically examining the role of coordination geometry, vis-à-vis reducing the number of redox noninnocent ligands within the first coordination sphere, we have demonstrated that Fe complexes with one such ligand were also capable of supporting multielectron reduction events and exhibited reduction potentials similar to their parent analogs supported by two or three of the same multidentate ligands. However, some differences in redox nature within the lower (+2 → -1) charge states were also noticed. Specifically, complexes containing two bidentate ligands, or one tridentate ligand, exhibited ligand-based reductions, whereas compounds with one bidentate ligand exhibited metal-centered reductions. The current results pave the way toward the design of the next-generation of Fe complexes with lower molecular weights and greater stored energy for redox flow batteries.
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Affiliation(s)
- Ivan A. Popov
- Theoretical
Division, , and Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Nada Mehio
- Theoretical
Division, , and Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Terry Chu
- Theoretical
Division, , and Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Benjamin L. Davis
- Theoretical
Division, , and Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Rangachary Mukundan
- Theoretical
Division, , and Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Ping Yang
- Theoretical
Division, , and Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Enrique R. Batista
- Theoretical
Division, , and Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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18
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Zheng Y, Wang X, Bai Y, Wang X, Ru C, Chen W, Lv X, Pan X, Wu J. Diradical Anion of Potassium Aggregate: Reduction of Dimer Boroxide Complex. Inorg Chem 2018; 57:13544-13551. [PMID: 30351066 DOI: 10.1021/acs.inorgchem.8b02157] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Crystalline aggregates containing metal cation clusters "wrapped" by reduced hydrocarbon anions have been presented. Initially, a dimeric complex (2) possessing a bimetallic K2O2 core was synthesized from the reaction between an anthracene substituted boronic acid (2-(anthracen-9-yl)phenyl)(hydroxy)(mesityl)borane (1-H) and KN(SiMe3)2 in THF solution. The B-O bond length (1.281(4) Å) in complex 2 is comparable to those observed in oxoboranes, indicating this may be a double bond, which is supported by its Wiberg bond order (1.9) predicted by density functional theory calculations. Subsequently, potassium aggregate complexes, diradical 3 and dihydro anion 4, were obtained through the reduction reactions of dimeric complex 2 and 1-H, respectively. They exhibit similar K3O2B2 aggregate structures, but differ significantly in the geometry of the anthracene units. Complex 3 features a triplet diradical character with planar anthracene units that carry the unpaired electrons, while the anthracene groups in complex 4 display a puckered structure due to the addition of hydrogen atoms.
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Affiliation(s)
- Yang Zheng
- State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , P. R. China
| | - Xi Wang
- State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , P. R. China
| | - Yunfei Bai
- State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , P. R. China
| | - Xingyong Wang
- School of Chemistry , University of Wollongong , Wollongong , New South Wales 2522 , Australia
| | - Chenglong Ru
- State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , P. R. China
| | - Wenhao Chen
- State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , P. R. China
| | - Xiaoxia Lv
- School of Chemistry and Chemical Engineering , Qufu Normal University , Qufu , China
| | - Xiaobo Pan
- State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , P. R. China
| | - Jincai Wu
- State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , P. R. China
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19
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Synthesis, structure, and magnetic properties of a YbIII complex with the iminopyridine radical-anionic ligand. Russ Chem Bull 2018. [DOI: 10.1007/s11172-018-2036-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Du HY, Chen SC, Su XJ, Jiao L, Zhang MT. Redox-Active Ligand Assisted Multielectron Catalysis: A Case of Co III Complex as Water Oxidation Catalyst. J Am Chem Soc 2018; 140:1557-1565. [PMID: 29309165 DOI: 10.1021/jacs.8b00032] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Water oxidation is the key step in both natural and artificial photosynthesis to capture solar energy for fuel production. The design of highly efficient and stable molecular catalysts for water oxidation based on nonprecious metals is still a great challenge. In this article, the electrocatalytic oxidation of water by Na[(L4-)CoIII], where L is a substituted tetraamido macrocyclic ligand, was investigated in aqueous solution (pH 7.0). We found that Na[(L4-)CoIII] is a stable and efficient homogeneous catalyst for electrocatalytic water oxidation with 380 mV onset overpotential in 0.1 M phosphate buffer (pH 7.0). Both ligand- and metal-centered redox features are involved in the catalytic cycle. In this cycle, Na[(L4-)CoIII] was first oxidized to [(L2-)CoIIIOH] via a ligand-centered proton-coupled electron transfer process in the presence of water. After further losing an electron and a proton, the resting state, [(L2-)CoIIIOH], was converted to [(L2-)CoIV═O]. Density functional theory (DFT) calculations at the B3LYP-D3(BJ)/6-311++G(2df,2p)//B3LYP/6-31+G(d,p) level of theory confirmed the proposed catalytic cycle. According to both experimental and DFT results, phosphate-assisted water nucleophilic attack to [(L2-)CoIV═O] played a key role in O-O bond formation.
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Affiliation(s)
- Hao-Yi Du
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University , Beijing 100084, China
| | - Si-Cong Chen
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University , Beijing 100084, China
| | - Xiao-Jun Su
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University , Beijing 100084, China
| | - Lei Jiao
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University , Beijing 100084, China
| | - Ming-Tian Zhang
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University , Beijing 100084, China
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21
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Trifonov AA, Mahrova TV, Luconi L, Giambastiani G, Lyubov DM, Cherkasov AV, Sorace L, Louyriac E, Maron L, Lyssenko KA. Steric control in the metal–ligand electron transfer of iminopyridine–ytterbocene complexes. Dalton Trans 2018; 47:1566-1576. [DOI: 10.1039/c7dt04299j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A systematic study of reactions between Cp*2Yb(THF) and iminopyridine ligands featuring similar electron accepting properties but variable denticity and steric demand, has provided a new example of steric control on the redox chemistry of ytterbocenes.
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Affiliation(s)
- Alexander A. Trifonov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences
- 603950 Nizhny Novgorod
- Russia
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences
- Moscow
| | - Tatyana V. Mahrova
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences
- 603950 Nizhny Novgorod
- Russia
| | - Lapo Luconi
- Istituto di ChimicadeiCompostiOrganometallici (ICCOM - CNR)
- Sesto Fiorentino
- Italy
| | - Giuliano Giambastiani
- Istituto di ChimicadeiCompostiOrganometallici (ICCOM - CNR)
- Sesto Fiorentino
- Italy
- Kazan Federal University
- 420008 Kazan
| | - Dmitry M. Lyubov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences
- 603950 Nizhny Novgorod
- Russia
| | - Anton V. Cherkasov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences
- 603950 Nizhny Novgorod
- Russia
| | - Lorenzo Sorace
- Dipartimento di Chimica “U. Schiff” and UdR INSTM
- Università di Firenze
- 50019 Sesto Fiorentino
- Italy
| | | | - Laurent Maron
- Université de Toulouse
- INSA
- UPS
- CNRS-UMR5215
- 31077 Toulouse
| | - Konstantin A. Lyssenko
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences
- Moscow
- Russia
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22
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Elpitiya GR, Malbrecht BJ, Jenkins DM. A Chromium(II) Tetracarbene Complex Allows Unprecedented Oxidative Group Transfer. Inorg Chem 2017; 56:14101-14110. [DOI: 10.1021/acs.inorgchem.7b02253] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Gaya R. Elpitiya
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Brian J. Malbrecht
- Department
of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - David M. Jenkins
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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23
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Wilding MJT, Iovan DA, Wrobel AT, Lukens JT, MacMillan SN, Lancaster KM, Betley TA. Direct Comparison of C-H Bond Amination Efficacy through Manipulation of Nitrogen-Valence Centered Redox: Imido versus Iminyl. J Am Chem Soc 2017; 139:14757-14766. [PMID: 28937756 PMCID: PMC5821126 DOI: 10.1021/jacs.7b08714] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reduction of previously reported iminyl radical (ArL)FeCl(•N(C6H4-p-tBu)) (2) with potassium graphite furnished the corresponding high-spin (S = 5/2) imido (ArL)Fe(N(C6H4-p-tBu)) (3) (ArL = 5-mesityl-1,9-(2,4,6-Ph3C6H2)dipyrrin). Oxidation of the three-coordinate imido (ArL)Fe(NAd) (5) with chlorotriphenylmethane afforded (ArL)FeCl(•NAd) (6) with concomitant expulsion of Ph3C(C6H5)CPh2. The respective aryl/alkyl imido/iminyl pairs (3, 2; 5, 6) have been characterized by EPR, zero-field 57Fe Mössbauer, magnetometry, single crystal X-ray diffraction, XAS, and EXAFS for 6. The high-spin (S = 5/2) imidos exhibit characteristically short Fe-N bonds (3: 1.708(4) Å; 5: 1.674(11) Å), whereas the corresponding iminyls exhibit elongated Fe-N bonds (2: 1.768(2) Å; 6: 1.761(6) Å). Comparison of the pre-edge absorption feature (1s → 3d) in the X-ray absorption spectra reveals that the four imido/iminyl complexes share a common iron oxidation level consistent with a ferric formulation (3: 7111.5 eV, 2: 7111.5 eV; 5: 7112.2 eV, 6: 7112.4 eV) as compared with a ferrous amine adduct (ArL)FeCl(NH2Ad) (7: 7110.3 eV). N K-edge X-ray absorption spectra reveal a common low-energy absorption present only for the iminyl species 2 (394.5 eV) and 6 (394.8 eV) that was assigned as a N 1s promotion into a N-localized, singly occupied iminyl orbital. Kinetic analysis of the reaction between the respective iron imido and iminyl complexes with toluene yielded the following activation parameters: Ea (kcal/mol) 3: 12.1, 2: 9.2; 5: 11.5, 6: 7.1. The attenuation of the Fe-N bond interaction on oxidation from an imido to an iminyl complex leads to a reduced enthalpic barrier [Δ(ΔH‡) ≈ 5 kcal/mol]; the alkyl iminyl 6 has a reduced enthalpic barrier (1.84 kcal/mol) as compared with the aryl iminyl 2 (3.84 kcal/mol), consistent with iminyl radical delocalization into the aryl substituent in 2 as compared with 6.
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Affiliation(s)
- Matthew J. T. Wilding
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Diana A. Iovan
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Alexandra T. Wrobel
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - James T. Lukens
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Samantha N. MacMillan
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Kyle M. Lancaster
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Theodore A. Betley
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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24
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Rodríguez-Lugo RE, de Bruin B, Trincado M, Grützmacher H. A Stable Aminyl Radical Coordinated to Cobalt. Chemistry 2017; 23:6795-6802. [PMID: 28164405 DOI: 10.1002/chem.201605624] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Indexed: 11/09/2022]
Abstract
A family of cobalt complexes bearing the trop2 NH [bis(5-H-dibenzo[a,d]cyclohepten-5-yl)-amine] and 2,2'-bpy (2,2'-bipyridine) chelate ligands were prepared and fully characterized. The compounds [Co(trop2 N)(bpy)], [Co(trop2 NH)(bpy)]+ , and [Co(trop2 N)(bpy)]+ are cobalt complexes interrelated by one-electron redox processes and/or proton transfer. Two limiting resonance structures can be used to describe the paramagnetic complex [Co(trop2 N)(bpy)]+ : [CoII (trop2 N- )(bpy)]+ (CoII amido) and [CoI (trop2 N⋅ )(bpy)]+ (CoI -aminyl radical). Structural data, DFT calculations, and reactivity toward H-abstraction indicate a slightly higher contribution of the aminyl radical form to the ground state of [Co(trop2 N)(bpy)]+ . The results described here complete the series of Group 9 metal aminyl radical complexes bearing the diolefin amine ligand trop2 NH.
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Affiliation(s)
- Rafael E Rodríguez-Lugo
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 1-5/10, 8093, Zürich, Switzerland.,Current address: Centro de Química, Instituto Venezolano de Investigaciones Científicas (IVIC), Altos de Pipe, 1020-A, Caracas, Venezuela.,Current address: Departamento de Química, Universidad Simón Bolívar (USB), Valle de Sartenejas, 1080-A, Caracas, Venezuela
| | - Bas de Bruin
- Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Monica Trincado
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 1-5/10, 8093, Zürich, Switzerland
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 1-5/10, 8093, Zürich, Switzerland
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25
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Sherbow TJ, Fettinger JC, Berben LA. Control of Ligand pK a Values Tunes the Electrocatalytic Dihydrogen Evolution Mechanism in a Redox-Active Aluminum(III) Complex. Inorg Chem 2017; 56:8651-8660. [PMID: 28402654 DOI: 10.1021/acs.inorgchem.7b00230] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Redox-active ligands bring electron- and proton-transfer reactions to main-group coordination chemistry. In this Forum Article, we demonstrate how ligand pKa values can be used in the design of a reaction mechanism for a ligand-based electron- and proton-transfer pathway, where the ligand retains a negative charge and enables dihydrogen evolution. A bis(pyrazolyl)pyridine ligand, iPrPz2P, reacts with 2 equiv of AlCl3 to afford [(iPrPz2P)AlCl2(THF)][AlCl4] (1). A reaction involving two-electron reduction and single-ligand protonation of 1 affords [(iPrHPz2P-)AlCl2] (2), where each of the electron- and proton-transfer events is ligand-centered. Protonation of 2 would formally close a catalytic cycle for dihydrogen production. At -1.26 V versus SCE, in a 0.3 M Bu4NPF6/tetrahydrofuran solution with salicylic acid or (HNEt3)+ as the source of H+, 1 produced dihydrogen electrocatalytically, according to cyclic voltammetry and controlled potential electrolysis experiments. The mechanism for the reaction is most likely two electron-transfer steps followed by two chemical steps based on the available reactivity information. A comparison of this work with our previously reported aluminum complexes of the phenyl-substituted bis(imino)pyridine system (PhI2P) reveals that the pKa values of the N-donor atoms in iPrPz2P are lower, which facilitates reduction before ligand protonation. In contrast, the PhI2P ligand complexes of aluminum are protonated twice before reduction liberates dihydrogen.
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Affiliation(s)
- Tobias J Sherbow
- Department of Chemistry, University of California , Davis, California 95616, United States
| | - James C Fettinger
- Department of Chemistry, University of California , Davis, California 95616, United States
| | - Louise A Berben
- Department of Chemistry, University of California , Davis, California 95616, United States
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26
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Stichauer R, Helmers A, Bremer J, Rohdenburg M, Wark A, Lork E, Vogt M. Rhenium(I) Triscarbonyl Complexes with Redox-Active Amino- and Iminopyridine Ligands: Metal–Ligand Cooperation as Trigger for the Reversible Binding of CO2 via a Dearmomatization/Rearomatization Reaction Sequence. Organometallics 2017. [DOI: 10.1021/acs.organomet.6b00897] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rasmus Stichauer
- Institut für Anorganische
Chemie und Kristallographie, Universität Bremen, Leobener Strasse
NW2 − C Block, 28359 Bremen, Germany
| | - Arne Helmers
- Institut für Anorganische
Chemie und Kristallographie, Universität Bremen, Leobener Strasse
NW2 − C Block, 28359 Bremen, Germany
| | - Jennifer Bremer
- Institut für Anorganische
Chemie und Kristallographie, Universität Bremen, Leobener Strasse
NW2 − C Block, 28359 Bremen, Germany
| | - Markus Rohdenburg
- Institut für Anorganische
Chemie und Kristallographie, Universität Bremen, Leobener Strasse
NW2 − C Block, 28359 Bremen, Germany
| | - André Wark
- Institut für Anorganische
Chemie und Kristallographie, Universität Bremen, Leobener Strasse
NW2 − C Block, 28359 Bremen, Germany
| | - Enno Lork
- Institut für Anorganische
Chemie und Kristallographie, Universität Bremen, Leobener Strasse
NW2 − C Block, 28359 Bremen, Germany
| | - Matthias Vogt
- Institut für Anorganische
Chemie und Kristallographie, Universität Bremen, Leobener Strasse
NW2 − C Block, 28359 Bremen, Germany
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27
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Saha P, Samanta D, Ghosh P. Glyoxalbis(2-methylmercaptoanil) complexes of nickel and ruthenium: radical versus non-radical states. NEW J CHEM 2017. [DOI: 10.1039/c6nj02903e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The molecular and electronic structures of nickel(ii) and ruthenium(ii) complexes of glyoxalbis(2-methylmercaptoanil) and their reduced and oxidized analogues are reported.
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Affiliation(s)
- Pinaki Saha
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-103
- India
| | - Debasish Samanta
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-103
- India
| | - Prasanta Ghosh
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-103
- India
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28
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Simler T, Danopoulos AA, Braunstein P. Non-symmetrical, potentially redox non-innocent imino NHC pyridine ‘pincers’ via a zinc ion template-assisted synthesis. Dalton Trans 2017; 46:5955-5964. [DOI: 10.1039/c7dt01014a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A ZnII-promoted modular synthesis allows access to new non-symmetrical, redox-active imino NHC pyridine pincer ligands. Radical anionic and dianionic redox states of the ligand are involved in its FeII complexes obtained from FeBr2/KC8.
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Affiliation(s)
- Thomas Simler
- Université de Strasbourg
- CNRS
- CHIMIE UMR 7177
- Laboratoire de Chimie de Coordination
- 67081 Strasbourg Cedex
| | - Andreas A. Danopoulos
- Université de Strasbourg
- CNRS
- CHIMIE UMR 7177
- Laboratoire de Chimie de Coordination
- 67081 Strasbourg Cedex
| | - Pierre Braunstein
- Université de Strasbourg
- CNRS
- CHIMIE UMR 7177
- Laboratoire de Chimie de Coordination
- 67081 Strasbourg Cedex
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29
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Kikuchi T, Kobayashi K, Tsuge K, Kitagawa S, Tanaka K. Asymmetric dimerization of aniline-ruthenium-dioxolene complex driven by stepwise PCET. Dalton Trans 2016; 45:14030-4. [PMID: 27535700 DOI: 10.1039/c6dt02573k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The base-assisted oxidation of an aniline-Ru-quinone complex produced an anilinyl radical-Ru-semiquinone. Furthermore, base-assisted oxidation of the radical complex resulted in selective C-N bond formation through an intermolecular coupling between nitrogen and carbon atoms at the para-position of the anilinyl ligand.
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Affiliation(s)
- T Kikuchi
- Institute for Integrated Cell-Material Sciences, Kyoto University, 105 Jibu-cho, Fushimi-ku, Kyoto 612-8374, ACT Kyoto #507, Japan.
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30
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Broere DLJ, Plessius R, Tory J, Demeshko S, de Bruin B, Siegler MA, Hartl F, van der Vlugt JI. Localized Mixed-Valence and Redox Activity within a Triazole-Bridged Dinucleating Ligand upon Coordination to Palladium. Chemistry 2016; 22:13965-13975. [PMID: 27531163 DOI: 10.1002/chem.201601900] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Indexed: 12/31/2022]
Abstract
The new dinucleating redox-active ligand (LH4 ), bearing two redox-active NNO-binding pockets linked by a 1,2,3-triazole unit, is synthetically readily accessible. Coordination to two equivalents of PdII resulted in the formation of paramagnetic (S=1/2 ) dinuclear Pd complexes with a κ2 -N,N'-bridging triazole and a single bridging chlorido or azido ligand. A combined spectroscopic, spectroelectrochemical, and computational study confirmed Robin-Day Class II mixed-valence within the redox-active ligand, with little influence of the secondary bridging anionic ligand. Intervalence charge transfer was observed between the two ligand binding pockets. Selective one-electron oxidation allowed for isolation of the corresponding cationic ligand-based diradical species. SQUID (super-conducting quantum interference device) measurements of these compounds revealed weak anti-ferromagnetic spin coupling between the two ligand-centered radicals and an overall singlet ground state in the solid state, which is supported by DFT calculations. The rigid and conjugated dinucleating redox-active ligand framework thus allows for efficient electronic communication between the two binding pockets.
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Affiliation(s)
- Daniël L J Broere
- Homogeneous, Bioinspired and Supramolecular Catalysis, van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Raoul Plessius
- Homogeneous, Bioinspired and Supramolecular Catalysis, van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Joanne Tory
- Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK
| | - Serhiy Demeshko
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammanstrasse 4, 37077, Göttingen, Germany
| | - Bas de Bruin
- Homogeneous, Bioinspired and Supramolecular Catalysis, van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Maxime A Siegler
- Department of Chemistry, John Hopkins University, 3400 N. Charles St., Baltimore, MD, 21218, USA
| | - Frantisek Hartl
- Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK
| | - Jarl Ivar van der Vlugt
- Homogeneous, Bioinspired and Supramolecular Catalysis, van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
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31
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Iovan DA, Betley TA. Characterization of Iron-Imido Species Relevant for N-Group Transfer Chemistry. J Am Chem Soc 2016; 138:1983-93. [PMID: 26788747 DOI: 10.1021/jacs.5b12582] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A sterically accessible tert-butyl-substituted dipyrrinato di-iron(II) complex [((tBu)L)FeCl]2 possessing two bridging chloride atoms was synthesized from the previously reported solvento adduct. Upon treatment with aryl azides, the formation of high-spin Fe(III) species was confirmed by (57)Fe Mössbauer spectroscopy. Crystallographic characterization revealed two possible oxidation products: (1) a terminal iron iminyl from aryl azides bearing ortho isopropyl substituents, ((tBu)L)FeCl((•)NC6H3-2,6-(i)Pr2); or (2) a bridging di-iron imido arising from reaction with 3,5-bis(trifluoromethyl)aryl azide, [((tBu)L)FeCl]2(μ-NC6H3-3,5-(CF3)2). Similar to the previously reported ((Ar)L)FeCl((•)NC6H4-4-(t)Bu), the monomeric iron imido is best described as a high-spin Fe(III) antiferromagnetically coupled to an iminyl radical, affording an S = 2 spin state as confirmed by SQUID magnetometry. The di-iron imido possesses an S = 0 ground state, arising from two high-spin Fe(III) centers weakly antiferromagnetically coupled through the bridging imido ligand. The terminal iron iminyl complex undergoes facile decomposition via intra- or intermolecular hydrogen-atom abstraction (HAA) from an imido aryl ortho isopropyl group, or from 1,4-cyclohexadiene, respectively. The bridging di-iron imido is a competent N-group transfer reagent to cyclic internal olefins as well as styrene. Although solid-state magnetometry indicates an antiferromagnetic interaction between the two iron centers (J = -108.7 cm(-1)) in [((tBu)L)FeCl]2(μ-NC6H3-3,5-(CF3)2), we demonstrate that in solution the bridging imido can facilitate HAA as well as dissociate into a terminal iminyl species, which then can promote HAA. In situ monitoring reveals the di-iron bridging imido is a catalytically competent intermediate, one of several iron complexes observed in the amination of C-H bond substrates or styrene aziridination.
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Affiliation(s)
- Diana A Iovan
- Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Theodore A Betley
- Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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32
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Heins SP, Morris WD, Wolczanski PT, Lobkovsky EB, Cundari TR. Nitrene Insertion into CC and CH Bonds of Diamide Diimine Ligands Ligated to Chromium and Iron. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507463] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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33
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Heins SP, Morris WD, Wolczanski PT, Lobkovsky EB, Cundari TR. Nitrene Insertion into CC and CH Bonds of Diamide Diimine Ligands Ligated to Chromium and Iron. Angew Chem Int Ed Engl 2015; 54:14407-11. [DOI: 10.1002/anie.201507463] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Spencer P. Heins
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14850 (USA)
| | - Wesley D. Morris
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14850 (USA)
| | - Peter T. Wolczanski
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14850 (USA)
| | - Emil B. Lobkovsky
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14850 (USA)
| | - Thomas R. Cundari
- Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Box 305070, Denton, TX 76203‐5070 (USA)
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34
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Chiang L, Herasymchuk K, Thomas F, Storr T. Influence of Electron-Withdrawing Substituents on the Electronic Structure of Oxidized Ni and Cu Salen Complexes. Inorg Chem 2015; 54:5970-80. [DOI: 10.1021/acs.inorgchem.5b00783] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Linus Chiang
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Khrystyna Herasymchuk
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Fabrice Thomas
- Département de Chimie Moléculaire,
Chimie Inorganique Redox (CIRE), UMR-5250, Université Grenoble Alpes, BP 53, 38041 Grenoble
Cedex 9, France
| | - Tim Storr
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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35
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Butschke B, Fillman KL, Bendikov T, Shimon LJW, Diskin-Posner Y, Leitus G, Gorelsky SI, Neidig ML, Milstein D. How Innocent are Potentially Redox Non-Innocent Ligands? Electronic Structure and Metal Oxidation States in Iron-PNN Complexes as a Representative Case Study. Inorg Chem 2015; 54:4909-26. [DOI: 10.1021/acs.inorgchem.5b00509] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Kathlyn L. Fillman
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | | | | | | | | | - Serge I. Gorelsky
- Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Michael L. Neidig
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
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36
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Zhou XT, Ji HB. Highly efficient selective oxidation of sulfides to sulfoxides by montmorillonite-immobilized metalloporphyrins in the presence of molecular oxygen. CATAL COMMUN 2014. [DOI: 10.1016/j.catcom.2014.04.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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37
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Shen J, Yap GPA, Barker IV WE, Geiger WE, Theopold KH. An electron transfer series of octahedral chromium complexes containing a redox non-innocent α-diimine ligand. Chem Commun (Camb) 2014; 50:10626-9. [DOI: 10.1039/c4cc03332a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Zhou W, Patrick BO, Smith KM. Influence of redox non-innocent phenylenediamido ligands on chromium imido hydrogen-atom abstraction reactivity. Chem Commun (Camb) 2014; 50:9958-60. [DOI: 10.1039/c4cc04545a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Reaction of new CpCr[(RN)2C6H4] complexes (R = SiMe3, CH2CMe3, Ph) with organic azides generates chromium imido complexes.
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Affiliation(s)
- Wen Zhou
- Department of Chemistry
- University of British Columbia Okanagan
- Kelowna, Canada
| | - Brian O. Patrick
- Department of Chemistry
- University of British Columbia
- Vancouver, Canada
| | - Kevin M. Smith
- Department of Chemistry
- University of British Columbia Okanagan
- Kelowna, Canada
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39
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Sazama GT, Betley TA. Multiple, disparate redox pathways exhibited by a tris(pyrrolido)ethane iron complex. Inorg Chem 2013; 53:269-81. [PMID: 24320208 DOI: 10.1021/ic402210j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Iron(III) complexes of the tris(pyrrolide)ethane trianion have been synthesized by reaction of one- and two-electron oxidants with [(tpe)Fe(THF)][Li(THF)4] (tpe = tris(5-mesitylpyrrolyl)ethane). X-ray crystallography, (57)Fe Mössbauer, (1)H NMR and EPR spectroscopy, SQUID magnetometry, and density functional theory calculations were employed to rigorously establish the iron 3+ oxidation state. All oxidants employed are proposed to operate via an inner-sphere electron transfer mechanism. Dialkyl peroxides and dibenzyldisulfide served to oxidize iron by one electron, and group transfer of an aryl nitrene unit to the Fe(2+) starting material resulted in formation of Fe(3+) amido species following H-atom abstraction by a presumed nitrenoid intermediate. Single electron transfer to and from diphenyldiazoalkane was also observed to yield a diphenyldiazomethanyl radical anion antiferromagnetically coupled to the S = 5/2 Fe(3+). Isolation of Fe(3+) complexes of tpe, in comparison with previous results wherein the tpe ligand was the redox active moiety, presents an unusual juxtaposition of two noncommunicating redox reservoirs, each accessible via different reaction pathways (namely, inner- and outer-sphere electron transfer).
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Affiliation(s)
- Graham T Sazama
- Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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40
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Olivos Suarez AI, Lyaskovskyy V, Reek JNH, van der Vlugt JI, de Bruin B. Komplexe mit Stickstoffradikalliganden: Einteilung, spektroskopische Eigenschaften, Reaktivität und katalytische Anwendungen. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301487] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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41
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Suarez AIO, Lyaskovskyy V, Reek JNH, van der Vlugt JI, de Bruin B. Complexes with Nitrogen-Centered Radical Ligands: Classification, Spectroscopic Features, Reactivity, and Catalytic Applications. Angew Chem Int Ed Engl 2013; 52:12510-29. [DOI: 10.1002/anie.201301487] [Citation(s) in RCA: 208] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Indexed: 01/07/2023]
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42
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Hänninen MM, Paturi P, Tuononen HM, Sillanpää R, Lehtonen A. Heptacoordinated Molybdenum(VI) Complexes of Phenylenediamine Bis(phenolate): A Stable Molybdenum Amidophenoxide Radical. Inorg Chem 2013; 52:5714-21. [DOI: 10.1021/ic302355b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mikko M. Hänninen
- Department of Chemistry, P.O. Box 35, University of Jyväskylä, FI-40014 Jyväskylä,
Finland
| | - Petriina Paturi
- Wihuri Physical
Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
| | - Heikki M. Tuononen
- Department of Chemistry, P.O. Box 35, University of Jyväskylä, FI-40014 Jyväskylä,
Finland
| | - Reijo Sillanpää
- Department of Chemistry, P.O. Box 35, University of Jyväskylä, FI-40014 Jyväskylä,
Finland
| | - Ari Lehtonen
- Department of Chemistry, University of Turku, FI-20014 Turku,
Finland
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43
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McDaniel AM, Tseng HW, Hill EA, Damrauer NH, Rappé AK, Shores MP. Syntheses and Photophysical Investigations of Cr(III) Hexadentate Iminopyridine Complexes and Their Tris(Bidentate) Analogues. Inorg Chem 2013; 52:1368-78. [DOI: 10.1021/ic302055r] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Ashley M. McDaniel
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
| | - Huan-Wei Tseng
- Department
of Chemistry and
Biochemistry, University of Colorado, Boulder,
Colorado 80309-0215, United States
| | - Ethan A. Hill
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
| | - Niels H. Damrauer
- Department
of Chemistry and
Biochemistry, University of Colorado, Boulder,
Colorado 80309-0215, United States
| | - Anthony K. Rappé
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
| | - Matthew P. Shores
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
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44
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Kundu S, Miceli E, Farquhar E, Pfaff FF, Kuhlmann U, Hildebrandt P, Braun B, Greco C, Ray K. Lewis acid trapping of an elusive copper-tosylnitrene intermediate using scandium triflate. J Am Chem Soc 2012; 134:14710-3. [PMID: 22928636 PMCID: PMC3743661 DOI: 10.1021/ja306674h] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
High-valent copper-nitrene intermediates have long been proposed to play a role in copper-catalyzed aziridination and amination reactions. However, such intermediates have eluded detection for decades, preventing the unambiguous assignments of mechanisms. Moreover, the electronic structure of the proposed copper-nitrene intermediates has also been controversially discussed in the literature. These mechanistic questions and controversy have provided tremendous motivation to probe the accessibility and reactivity of Cu(III)-NR/Cu(II)N(•)R species. In this paper, we report a breakthrough in this field that was achieved by trapping a transient copper-tosylnitrene species, 3-Sc, in the presence of scandium triflate. The sufficient stability of 3-Sc at -90 °C enabled its characterization with optical, resonance Raman, NMR, and X-ray absorption near-edge spectroscopies, which helped to establish its electronic structure as Cu(II)N(•)Ts (Ts = tosyl group) and not Cu(III)NTs. 3-Sc can initiate tosylamination of cyclohexane, thereby suggesting Cu(II)N(•)Ts cores as viable reactants in oxidation catalysis.
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Affiliation(s)
- Subrata Kundu
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, D-12489 Berlin, Germany
| | - Enrico Miceli
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, D-12489 Berlin, Germany
| | - Erik Farquhar
- Case Western Reserve University Center for Synchrotron Biosciences and Center for Proteomics and Bioinformatics, National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY-11973, USA
| | - Florian Felix Pfaff
- Case Western Reserve University Center for Synchrotron Biosciences and Center for Proteomics and Bioinformatics, National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY-11973, USA
| | - Uwe Kuhlmann
- Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Straße des 17 Juni 135, D-10623 Berlin, Germany
| | - Peter Hildebrandt
- Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Straße des 17 Juni 135, D-10623 Berlin, Germany
| | - Beatrice Braun
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, D-12489 Berlin, Germany
| | - Claudio Greco
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, D-12489 Berlin, Germany
| | - Kallol Ray
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, D-12489 Berlin, Germany
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Closed-shell and open-shell square-planar iridium nitrido complexes. Nat Chem 2012; 4:552-8. [DOI: 10.1038/nchem.1368] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 04/25/2012] [Indexed: 12/25/2022]
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Summerscales OT, Myers TW, Berben LA. Mild Reduction Route to a Redox-Active Silicon Complex: Structure and Properties of (IP2–)2Si and (IP–)2Mg(THF) (IP = α-Iminopyridine). Organometallics 2012. [DOI: 10.1021/om300242q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Owen T. Summerscales
- Department of Chemistry, University of California, Davis, California
95616, United States
| | - Thomas W. Myers
- Department of Chemistry, University of California, Davis, California
95616, United States
| | - Louise A. Berben
- Department of Chemistry, University of California, Davis, California
95616, United States
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Takaoka A, Moret ME, Peters JC. A Ru(I) Metalloradical That Catalyzes Nitrene Coupling to Azoarenes from Arylazides. J Am Chem Soc 2012; 134:6695-706. [DOI: 10.1021/ja211603f] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ayumi Takaoka
- California Institute of Technology, Division of Chemistry and Chemical Engineering, Pasadena, California
91125, United States
| | - Marc-Etienne Moret
- California Institute of Technology, Division of Chemistry and Chemical Engineering, Pasadena, California
91125, United States
| | - Jonas C. Peters
- California Institute of Technology, Division of Chemistry and Chemical Engineering, Pasadena, California
91125, United States
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Samanta S, Ghosh P, Goswami S. Recent advances on the chemistry of transition metal complexes of 2-(arylazo)pyridines and its arylamino derivatives. Dalton Trans 2012; 41:2213-26. [PMID: 22218724 DOI: 10.1039/c2dt10986g] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent advancement on the redox properties of a selection of transition metal complexes of the azoaromatic ligands: bidentate L(1) [2-(arylazo)pyridine] and tridentate HL(2) [2-(aminoarylphenylazo)pyridine] are described and compared. Due to the presence of a low lying azo-centered π*-orbital, these azoaromatic ligands may exist in multiple valent states. The coordination chemistry of the L(1) ligands was thoroughly studied during the 1980s. These complexes undergo facile reduction in solution at low accessible potentials. One electron reduced azo-complexes, though known for a long time to occur in solution, have only recently been isolated in a crystalline state. New synthetic protocols for the synthesis of metal-bound azo-radical complexes have been developed. Low-valent metal complexes such as metal carbonyls have been found to be excellent starting materials for this purpose. In a few selected cases, syntheses of these complexes were also achieved from very high valent metal oxides using triphenylphosphine as both a reducing and oxo-abstracting agent. Issues related to the ambiguities of the electronic structures in the azo-metal complexes have been discussed considering bond parameters, redox and spectral properties. Unusual redox events such as RIET (Redox-Induced Electron Transfer) phenomena in a few systems have been elaborated and compared with the known example. Novel examples of N=N bond cleavage reactions via four-electron reduction and subsequent C-N bond formation in metal-bound coordinated ligands have been noted.
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Affiliation(s)
- Subhas Samanta
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
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Zhou W, Chiang L, Patrick BO, Storr T, Smith KM. Cyclopentadienyl chromium diimine and pyridine-imine complexes: ligand-based radicals and metal-based redox chemistry. Dalton Trans 2012; 41:7920-30. [DOI: 10.1039/c2dt30160a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Bowman AC, Milsmann C, Bill E, Turner ZR, Lobkovsky E, DeBeer S, Wieghardt K, Chirik PJ. Synthesis and electronic structure determination of N-alkyl-substituted bis(imino)pyridine iron imides exhibiting spin crossover behavior. J Am Chem Soc 2011; 133:17353-69. [PMID: 21985461 DOI: 10.1021/ja205736m] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three new N-alkyl substituted bis(imino)pyridine iron imide complexes, ((iPr)PDI)FeNR ((iPr)PDI = 2,6-(2,6-(i)Pr(2)-C(6)H(3)-N═CMe)(2)C(5)H(3)N; R = 1-adamantyl ((1)Ad), cyclooctyl ((Cy)Oct), and 2-adamantyl ((2)Ad)) were synthesized by addition of the appropriate alkyl azide to the iron bis(dinitrogen) complex, ((iPr)PDI)Fe(N(2))(2). SQUID magnetic measurements on the isomeric iron imides, ((iPr)PDI)FeN(1)Ad and ((iPr)PDI)FeN(2)Ad, established spin crossover behavior with the latter example having a more complete spin transition in the experimentally accessible temperature range. X-ray diffraction on all three alkyl-substituted bis(imino)pyridine iron imides established essentially planar compounds with relatively short Fe-N(imide) bond lengths and two-electron reduction of the redox-active bis(imino)pyridine chelate. Zero- and applied-field Mössbauer spectroscopic measurements indicate diamagnetic ground states at cryogenic temperatures and established low isomer shifts consistent with highly covalent molecules. For ((iPr)PDI)FeN(2)Ad, Mössbauer spectroscopy also supports spin crossover behavior and allowed extraction of thermodynamic parameters for the S = 0 to S = 1 transition. X-ray absorption spectroscopy and computational studies were also performed to explore the electronic structure of the bis(imino)pyridine alkyl-substituted imides. An electronic structure description with a low spin ferric center (S = 1/2) antiferromagnetically coupled to an imidyl radical (S(imide) = 1/2) and a closed-shell, dianionic bis(imino)pyridine chelate (S(PDI) = 0) is favored for the S = 0 state. An iron-centered spin transition to an intermediate spin ferric ion (S(Fe) = 3/2) accounts for the S = 1 state observed at higher temperatures. Other possibilities based on the computational and experimental data are also evaluated and compared to the electronic structure of the bis(imino)pyridine iron N-aryl imide counterparts.
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Affiliation(s)
- Amanda C Bowman
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
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