1
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Miller JD, Walsh MM, Lee K, Moore CE, Thomas CM. Hydrogen atom abstraction as a synthetic route to a square planar Co II complex with a redox-active tetradentate PNNP ligand. Chem Sci 2024:d4sc03364g. [PMID: 39220158 PMCID: PMC11362828 DOI: 10.1039/d4sc03364g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 08/16/2024] [Indexed: 09/04/2024] Open
Abstract
Redox-active ligands improve the reactivity of transition metal complexes by facilitating redox processes independent of the transition metal center. A tetradentate square planar (PNCH2CH2NP)CoII (1) complex was synthesized and the ethylene backbone was dehydrogenated through hydrogen atom abstraction to afford (PNCHCHNP)CoII (2), which now contains a redox-active ligand. The ligand backbone of 2 can be readily hydrogenated with H2 to regenerate 1. Reduction of 1 and 2 with KC8 in the presence of 18-crown-6 results in cobalt-based reductions to afford [(PNCH2CH2NP)CoI][K(18-crown-6)] (3) and [(PNCHCHNP)CoI][K(18-crown-6)] (4), respectively. Cyclic voltammetry revealed two reversible oxidation processes for 2, presumed to be ligand-based. Following treatment of 2 with one equivalent of FcPF6, the one-electron oxidation product {[(PNCHCHNP)CoII(THF)][PF6]}·THF (5) was obtained. Treating 5 with an additional equivalent of FcPF6 affords the two-electron oxidation product [(PNCHCHNP)CoII][PF6]2 (6). Addition of PMe3 to 5 produced [(PNCHCHNP)CoII(PMe3)][PF6] (7). A host of characterization methods including nuclear magnetic resonance (NMR) spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, cyclic voltammetry, magnetic susceptibility measurements using SQUID magnetometry, single-crystal X-ray diffraction, and density functional theory calculations were used to assign 5 and 6 as ligand-based oxidation products of 2.
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Affiliation(s)
- Justin D Miller
- Department of Chemistry and Biochemistry, The Ohio State University 100 W. 18th Ave Columbus OH 43210 USA
| | - Mitchell M Walsh
- Department of Chemistry and Biochemistry, The Ohio State University 100 W. 18th Ave Columbus OH 43210 USA
| | - Kyounghoon Lee
- Department of Chemistry and Biochemistry, The Ohio State University 100 W. 18th Ave Columbus OH 43210 USA
- Department of Chemical Education and Research Institute of Natural Sciences, Gyeongsang National University Gyeongnam 52828 Republic of Korea
| | - Curtis E Moore
- Department of Chemistry and Biochemistry, The Ohio State University 100 W. 18th Ave Columbus OH 43210 USA
| | - Christine M Thomas
- Department of Chemistry and Biochemistry, The Ohio State University 100 W. 18th Ave Columbus OH 43210 USA
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2
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Jelemenska I, Zalibera M, Rapta P, Dobrov AA, Arion VB, Bucinsky L. Isomerization pathway of a C-C sigma bond in a bis(octaazamacrocycle)dinickel(II) complex activated by deprotonation: a DFT study. Theor Chem Acc 2024; 143:26. [PMID: 38495857 PMCID: PMC10937780 DOI: 10.1007/s00214-024-03100-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 02/07/2024] [Indexed: 03/19/2024]
Abstract
The anti (a) to syn (s) isomerization pathway of the deprotonated form of the dimer with two nickel(II) 15-membered octaazamacrocyclic units connected via a carbon-carbon (C-C) σ bond was investigated. For the initial anti (a) structure, a deprotonation of one of the bridging (sp3 hybridized) carbon atoms is suggested to allow for an a to s geometry twist. A 360° scan around the bridging C-C dihedral angle was performed first to find an intermediate geometry. Subsequently, the isomerization pathway was explored via individual steps using a series of mode redundant geometry optimizations (internal coordinates potential energy surface scans) and geometry relaxations leading to the s structure. The prominent geometries (intermediates) of the isomerization pathway are chosen and compared to the a and s structures, and geometry relaxations of the protonated forms of selected intermediates are considered. Supplementary Information The online version contains supplementary material available at 10.1007/s00214-024-03100-5.
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Affiliation(s)
- Ingrid Jelemenska
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovak Republic
| | - Michal Zalibera
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovak Republic
| | - Peter Rapta
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovak Republic
| | - Anatoly A. Dobrov
- Faculty of Chemistry, Institute of Biophysical Chemistry, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Vladimir B. Arion
- Institute of Inorganic Chemistry, University of Vienna, Währinger Strasse 42, 1090 Vienna, Austria
| | - Lukas Bucinsky
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovak Republic
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3
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Dobrov A, Darvasiová D, Zalibera M, Bučinský L, Jelemenská I, Rapta P, Shova S, Dumitrescu DG, Andrade MA, Martins LMDRS, Pombeiro AJL, Arion VB. Diastereomeric dinickel(II) complexes with non-innocent bis(octaazamacrocyclic) ligands: isomerization, spectroelectrochemistry, DFT calculations and use in catalytic oxidation of cyclohexane. Dalton Trans 2022; 51:5151-5167. [PMID: 35266945 PMCID: PMC8962992 DOI: 10.1039/d2dt00154c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/28/2022] [Indexed: 11/21/2022]
Abstract
Diastereomeric dinickel(II) complexes with bis-octaazamacrocyclic 15-membered ligands [Ni(L1-3-L1-3)Ni] (4-6) have been prepared by oxidative dehydrogenation of nickel(II) complexes NiL1-3 (1-3) derived from 1,2- and 1,3-diketones and S-methylisothiocarbohydrazide. The compounds were characterized by elemental analysis, ESI mass spectrometry, and IR, UV-vis, 1H NMR, and 13C NMR spectroscopy. Single crystal X-ray diffraction (SC-XRD) confirmed the isolation of the anti and syn isomers of bis-octaazamacrocyclic dinickel(II) complexes 4a and 4s, the syn-configuration of 5s and the anti-configuration of the dinickel(II) complex 6a. Dimerization of prochiral nickel(II) complexes 1-3 generates two chiral centers at the bridging carbon atoms. The anti-complexes were isolated as meso-isomers (4a and 6a) and the syn-compounds as racemic mixtures of R,R/S,S-enantiomers (4s and 5s). The syn-anti isomerization (epimerization) of the isolated complexes in chloroform was disclosed. The isomerization kinetics of 5a was monitored at five different temperatures ranging from 20 °C to 50 °C by 1H NMR spectroscopy indicating the clean conversion of 5a into 5s. The activation barrier determined from the temperature dependence of the rate constants via the Eyring equation was found to be ΔH‡ = 114 ± 1 kJ mol-1 with activation entropy ΔS‡ = 13 ± 3 J K-1 mol-1. The complexes contain two low-spin nickel(II) ions in a square-planar coordination environment. The electrochemical behavior of 4a, 4s, 5s and 6a and the electronic structure of the oxidized species were studied by UV-vis-NIR-spectroelectrochemistry (SEC) and DFT calculations indicating the redox non-innocent behavior of the complexes. The dinickel(II) complexes 4a, 4s, 5s and 6a/6s were investigated as catalysts for microwave-assisted solvent-free oxidation of cyclohexane by tert-butyl hydroperoxide to produce a mixture of cyclohexanone and cyclohexanol (KA oil). The best value for KA oil yield (16%) was obtained with a mixture of 6a/6s after 2 h of microwave irradiation at 100 °C.
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Affiliation(s)
- Anatolie Dobrov
- University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria.
- Universität Wien, Fakultät für Chemie, Institut für Biophysikalische Chemie, 1090 Wien, Austria
| | - Denisa Darvasiová
- 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.
| | - 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.
| | - Lukáš Bučinský
- 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 Jelemenská
- 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.
- Department of Chemistry, Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, 949 74 Nitra, Slovak Republic
| | - Peter Rapta
- 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.
| | - Sergiu Shova
- Inorganic Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41 A, Iasi 700487, Romania
| | - Dan G Dumitrescu
- Elettra - Sincrotrone Trieste S.C.p.A., Strada Statale 14 - km 163, 5 in AREA Science Park 34149 Basovizza, Trieste, Italy
| | - Marta A Andrade
- Centro de Química Estrutural, Institute of Molecular Sciences, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
| | - Luísa M D R S Martins
- Centro de Química Estrutural, Institute of Molecular Sciences, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
| | - Armando J L Pombeiro
- Centro de Química Estrutural, Institute of Molecular Sciences, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
- Peoples' Friendship University of Russia (RUDN University), Research Institute of Chemistry, 6 Miklukho-Maklaya Street, Moscow 117198, Russian Federation
| | - Vladimir B Arion
- University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria.
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4
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Synthesis, electronic structures, and reactivity of mononuclear and dinuclear low-valent molybdenum complexes in iminopyridine and bis(imino)pyridine ligand environments. J Inorg Biochem 2022; 230:111744. [DOI: 10.1016/j.jinorgbio.2022.111744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/18/2022] [Accepted: 01/22/2022] [Indexed: 11/22/2022]
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5
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Mondal R, Guin AK, Chakraborty G, Paul ND. Metal-ligand cooperative approaches in homogeneous catalysis using transition metal complex catalysts of redox noninnocent ligands. Org Biomol Chem 2022; 20:296-328. [PMID: 34904619 DOI: 10.1039/d1ob01153g] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Catalysis offers a straightforward route to prepare various value-added molecules starting from readily available raw materials. The catalytic reactions mostly involve multi-electron transformations. Hence, compared to the inexpensive and readily available 3d-metals, the 4d and 5d-transition metals get an extra advantage for performing multi-electron catalytic reactions as the heavier transition metals prefer two-electron redox events. However, for sustainable development, these expensive and scarce heavy metal-based catalysts need to be replaced by inexpensive, environmentally benign, and economically affordable 3d-metal catalysts. In this regard, a metal-ligand cooperative approach involving transition metal complexes of redox noninnocent ligands offers an attractive alternative. The synergistic participation of redox-active ligands during electron transfer events allows multi-electron transformations using 3d-metal catalysts and allows interesting chemical transformations using 4d and 5d-metals as well. Herein we summarize an up-to-date literature report on the metal-ligand cooperative approaches using transition metal complexes of redox noninnocent ligands as catalysts for a few selected types of catalytic reactions.
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Affiliation(s)
- Rakesh Mondal
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur Botanic Garden, Howrah 711103, India.
| | - Amit Kumar Guin
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur Botanic Garden, Howrah 711103, India.
| | - Gargi Chakraborty
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur Botanic Garden, Howrah 711103, India.
| | - Nanda D Paul
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur Botanic Garden, Howrah 711103, India.
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6
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Thenarukandiyil R, Paenurk E, Wong A, Fridman N, Karton A, Carmieli R, Ménard G, Gershoni-Poranne R, de Ruiter G. Extensive Redox Non-Innocence in Iron Bipyridine-Diimine Complexes: a Combined Spectroscopic and Computational Study. Inorg Chem 2021; 60:18296-18306. [PMID: 34787414 PMCID: PMC8653161 DOI: 10.1021/acs.inorgchem.1c02925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Indexed: 11/28/2022]
Abstract
Metal-ligand cooperation is an important aspect in earth-abundant metal catalysis. Utilizing ligands as electron reservoirs to supplement the redox chemistry of the metal has resulted in many new exciting discoveries. Here, we demonstrate that iron bipyridine-diimine (BDI) complexes exhibit an extensive electron-transfer series that spans a total of five oxidation states, ranging from the trication [Fe(BDI)]3+ to the monoanion [Fe(BDI]-1. Structural characterization by X-ray crystallography revealed the multifaceted redox noninnocence of the BDI ligand, while spectroscopic (e.g., 57Fe Mössbauer and EPR spectroscopy) and computational studies were employed to elucidate the electronic structure of the isolated complexes, which are further discussed in this report.
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Affiliation(s)
- Ranjeesh Thenarukandiyil
- Schulich
Faculty of Chemistry, Technion −
Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
| | - Eno Paenurk
- Laboratorium
für Organische Chemie, ETH Zurich, Vladimir-Prelog-Weg 2, Zurich 8093, Switzerland
| | - Anthony Wong
- Department
of Chemistry and Biochemistry, University
of California, Santa
Barbara, California 93106, United States
| | - Natalia Fridman
- Schulich
Faculty of Chemistry, Technion −
Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
| | - Amir Karton
- School
of Molecular Science, The University of
Western Australia, 35 Stirling Highway, 6009 Perth, Australia
| | - Raanan Carmieli
- Department
of Chemical Research Support, Weizmann Institute
of Science, Rehovot 761000, Israel
| | - Gabriel Ménard
- Department
of Chemistry and Biochemistry, University
of California, Santa
Barbara, California 93106, United States
| | - Renana Gershoni-Poranne
- Schulich
Faculty of Chemistry, Technion −
Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
- Laboratorium
für Organische Chemie, ETH Zurich, Vladimir-Prelog-Weg 2, Zurich 8093, Switzerland
| | - Graham de Ruiter
- Schulich
Faculty of Chemistry, Technion −
Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
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7
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Sieg G, Pessemesse Q, Reith S, Yelin S, Limberg C, Munz D, Werncke CG. Cobalt and Iron Stabilized Ketyl, Ketiminyl and Aldiminyl Radical Anions. Chemistry 2021; 27:16760-16767. [PMID: 34569676 PMCID: PMC9298351 DOI: 10.1002/chem.202103096] [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: 08/25/2021] [Indexed: 01/02/2023]
Abstract
Carbonyl and iminyl based radical anions are reactive intermediates in a variety of transformations in organic synthesis. Herein, the isolation of ketyl, and more importantly unprecedented ketiminyl and aldiminyl radical anions coordinated to cobalt and iron complexes is presented. Insights into the electronic structure of these unusual metal bound radical anions is provided by X-Ray diffraction analysis, NMR, IR, UV/Vis and Mössbauer spectroscopy, solid and solution state magnetometry, as well as a by a detailed computational analysis. The metal bound radical anions are very reactive and facilitate the activation of intra- and intermolecular C-H bonds.
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Affiliation(s)
- Grégoire Sieg
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Straße 435043MarburgGermany
| | - Quentin Pessemesse
- Univ. Lyon, ENS de Lyon, CNRS UMR 5182 Université Claude Bernard Lyon 1, Laboratoire de Chimie69342LyonFrance
- Anorganische Chemie: Koordinationschemie Campus C4.1Universität des Saarlandes66123SaarbrückenGermany
| | - Sascha Reith
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Straße 435043MarburgGermany
| | - Stefan Yelin
- Institut für ChemieHumboldt-Universität zu BerlinBrook-Taylor-Str. 212489BerlinGermany
| | - Christian Limberg
- Institut für ChemieHumboldt-Universität zu BerlinBrook-Taylor-Str. 212489BerlinGermany
| | - Dominik Munz
- Anorganische Chemie: Koordinationschemie Campus C4.1Universität des Saarlandes66123SaarbrückenGermany
- Department Chemie und PharmazieFriedrich-Alexander Universität (FAU) Erlangen-NürnbergEgerlandstr. 1D-91058ErlangenGermany
| | - C. Gunnar Werncke
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Straße 435043MarburgGermany
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8
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Zhang X, Zhou S, Wang D, Zhang L, Wei Y, Zhu X, Cui P, Luo G, Wang S. Syntheses of Rare-Earth Metal Alkyl Complexes Bearing a Dianionic α-Iminopyridyl Ligand and Their Catalytic Activities toward Polymerization of 2-Vinylpyridine. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00470] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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
| | - Donghan 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
| | - 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
| | - 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
| | - Gen Luo
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, 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 Functional Complexes for Materials Chemistry and Application, College of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, Anhui 241000, China
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9
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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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10
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A hydrophilic olefin Pt(0) complex containing a glucoconjugated 2-iminopyridine ligand: Synthesis, characterization, stereochemistry and biological activity. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.120092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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11
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Garhwal S, Kroeger AA, Thenarukandiyil R, Fridman N, Karton A, de Ruiter G. Manganese-Catalyzed Hydroboration of Terminal Olefins and Metal-Dependent Selectivity in Internal Olefin Isomerization-Hydroboration. Inorg Chem 2021; 60:494-504. [PMID: 33325695 DOI: 10.1021/acs.inorgchem.0c03451] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the past decade, the use of earth-abundant metals in homogeneous catalysis has flourished. In particular, metals such as cobalt and iron have been used extensively in reductive transformations including hydrogenation, hydroboration, and hydrosilylation. Manganese, on the other hand, has been considerably less explored in these reductive transformations. Here, we report a well-defined manganese complex, [Mn(iPrBDI)(OTf)2] (2a; BDI = bipyridinediimine), that is an active precatalyst in the hydroboration of a variety of electronically differentiated alkenes (>20 examples). The hydroboration is specifically selective for terminal alkenes and occurs with exclusive anti-Markovnikov selectivity. In contrast, when using the analogous cobalt complex [Co(iPrBDI)(OTf)2] (3a), internal alkenes are hydroborated efficiently, where a sequence of isomerization steps ultimately leads to their hydroboration. The contrasting terminal versus internal alkene selectivity for manganese and cobalt was investigated computationally and is further discussed in the herein-reported study.
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Affiliation(s)
- Subhash Garhwal
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
| | - Asja A Kroeger
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, 6009 Perth, WA Australia
| | - Ranjeesh Thenarukandiyil
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
| | - Amir Karton
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, 6009 Perth, WA Australia
| | - Graham de Ruiter
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
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12
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Bondi R, Dalla Via L, Hyeraci M, Pagot G, Labella L, Marchetti F, Samaritani S. Cytotoxicity and DNA interaction in a series of aryl terminated iminopyridine Pt(II) complexes. J Inorg Biochem 2020; 216:111335. [PMID: 33360320 DOI: 10.1016/j.jinorgbio.2020.111335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/15/2020] [Accepted: 12/05/2020] [Indexed: 01/01/2023]
Abstract
A series of iminopyridine complexes of platinum(II), bearing a flexible diethereal, aryl terminated residue, where the size of aryl group is varied from phenyl to 9-anthracenyl, was synthesized. The new complexes are soluble and stable in DMSO/H2O mixtures. Besides the metal center, aryl groups are available for further interactions with DNA, due to the good side chain flexibility. The new aryl functionalized iminopyridine dichlorido platinum(II) complexes show a significant antiproliferative activity on ovarian carcinoma cells and notably, complex 13 is able to overcome cisplatin resistance. The study of the interaction mode of 13 with DNA highlighted the ability to form a molecular complex characterized by a dual (intercalative and groove binding) geometry. The complex is also able to covalently add to DNA even though interstrand cross-links appear significantly hampered with respect to cisplatin. The interactions with the macromolecule are discussed in view of the observed cell effect.
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Affiliation(s)
- Riccardo Bondi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy
| | - Lisa Dalla Via
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (C.I.R.C.M.S.B.), Bari, Italy; Dipartimento di Scienze del Farmaco, Università degli Studi di Padova, Via F. Marzolo 5, Padova I-35131, Italy.
| | - Mariafrancesca Hyeraci
- Dipartimento di Scienze del Farmaco, Università degli Studi di Padova, Via F. Marzolo 5, Padova I-35131, Italy
| | - Gioele Pagot
- Dipartimento di Ingegneria Industriale, Università degli Studi di Padova, Via F. Marzolo 9, Padova I-35131, Italy
| | - Luca Labella
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy; Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (C.I.R.C.M.S.B.), Bari, Italy
| | - Fabio Marchetti
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy
| | - Simona Samaritani
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy; Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (C.I.R.C.M.S.B.), Bari, Italy.
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13
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Ershova IV, Piskunov AV, Cherkasov VK. Complexes of diamagnetic cations with radical anion ligands. RUSSIAN CHEMICAL REVIEWS 2020. [DOI: 10.1070/rcr4957] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Dobrov A, Fesenko A, Yankov A, Stepanenko I, Darvasiová D, Breza M, Rapta P, Martins LMDRS, Pombeiro AJL, Shutalev A, Arion VB. Nickel(II), Copper(II) and Palladium(II) Complexes with Bis-Semicarbazide Hexaazamacrocycles: Redox-Noninnocent Behavior and Catalytic Activity in Oxidation and C-C Coupling Reactions. Inorg Chem 2020; 59:10650-10664. [PMID: 32649194 DOI: 10.1021/acs.inorgchem.0c01119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nickel(II), copper(II), and palladium(II) complexes MLH, where M = Ni (1), Cu (2), Pd (3), and MLOMe, where M = Ni (4), Cu (5), Pd (6), have been prepared by reactions of NiCl2·6H2O, Cu(OAc)2·H2O, and PdCl2(MeCN)2 with 14-membered bis-semicarbazide hexaazamacrocycles H2LH and H2LOMe in dimethylformamide (DMF). The compounds were characterized by elemental analysis, ESI mass spectrometry, IR, UV-vis, and 1D (1H, 13C) and 2D (1H-1H COSY, 1H-1H TOCSY, 1H-1H NOESY, 1H-13C HSQC, 1H-13C HMBC) NMR spectra (1, 3, 4, and 6), and X-ray diffraction (2, 4-6). The complexes with MIIN4 coordination environment have S = 0, 1/2, 0 ground states for Ni, Cu, and Pd, respectively. The electrochemical behavior of 1-6 was investigated in detail. The electronic structures of 1e-oxidized species were studied by EPR, UV-vis-NIR spectroelectrochemistry, and DFT calculations, indicating the redox-noninnocent behavior of the ligands. Compounds 1-6 were tested in the oxidation of styrene and C-C coupling (Henry and Knoevenagel condensations). Compounds 2 and 5 selectively catalyze the microwave-assisted oxidation of neat styrene to benzaldehyde (up to 88% yield), whereas the 1 and 4 catalytic systems afforded up to 99% β-nitroethanol yield with an appreciable diastereoselectivity toward the formation of the anti isomer.
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Affiliation(s)
- Anatolie Dobrov
- University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria.,Universität Wien, Fakultät für Chemie, Institut für Biophysikalische Chemie, Altanstraße 14, 1090 Wien, Austria
| | - Anastasia Fesenko
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Ave., 119991 Moscow, Russian Federation
| | - Alexander Yankov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Ave., 119991 Moscow, Russian Federation
| | - Iryna Stepanenko
- University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
| | - Denisa Darvasiová
- 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
| | - Martin Breza
- 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
| | - Peter Rapta
- 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
| | - Luísa M D R S Martins
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Armando J L Pombeiro
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Anatoly Shutalev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Ave., 119991 Moscow, Russian Federation
| | - Vladimir B Arion
- University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
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15
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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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16
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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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17
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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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18
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Ghosh C, Kim S, Mena MR, Kim JH, Pal R, Rock CL, Groy TL, Baik MH, Trovitch RJ. Efficient Cobalt Catalyst for Ambient-Temperature Nitrile Dihydroboration, the Elucidation of a Chelate-Assisted Borylation Mechanism, and a New Synthetic Route to Amides. J Am Chem Soc 2019; 141:15327-15337. [PMID: 31462037 DOI: 10.1021/jacs.9b07529] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
N,N-Diborylamines have emerged as promising reagents in organic synthesis; however, their efficient preparation and full synthetic utility have yet to be realized. To address both shortcomings, an effective catalyst for nitrile dihydroboration was sought. Heating CoCl2 in the presence of PyEtPDI afforded the six-coordinate Co(II) salt, [(PyEtPDI)CoCl][Cl]. Upon adding 2 equiv of NaEt3BH, hydride transfer to one chelate imine functionality was observed, resulting in the formation of (κ4-N,N,N,N-PyEtIPCHMeNEtPy)Co. Single-crystal X-ray diffraction and density functional theory calculations revealed that this compound possesses a low-spin Co(II) ground state featuring antiferromagnetic coupling to a singly reduced imino(pyridine) moiety. Importantly, (κ4-N,N,N,N-PyEtIPCHMeNEtPy)Co was found to catalyze the dihydroboration of nitriles using HBPin with turnover frequencies of up to 380 h-1 at ambient temperature. Stoichiometric addition experiments revealed that HBPin adds across the Co-Namide bond to generate a hydride intermediate that can react with additional HBPin or nitriles. Computational evaluation of the reaction coordinate revealed that the B-H addition and nitrile insertion steps occur on the antiferromagnetically coupled triplet spin manifold. Interestingly, formation of the borylimine intermediate was found to occur following BPin transfer from the borylated chelate arm to regenerate (κ4-N,N,N,N-PyEtIPCHMeNEtPy)Co. Borylimine reduction is in turn facile and follows the same ligand-assisted borylation pathway. The independent hydroboration of alkyl and aryl imines was also demonstrated at 25 °C. With a series of N,N-diborylamines in hand, their addition to carboxylic acids allowed for the direct synthesis of amides at 120 °C, without the need for an exogenous coupling reagent.
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Affiliation(s)
- Chandrani Ghosh
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
| | - Suyeon Kim
- Department of Chemistry , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations , Institute for Basic Science (IBS) , Daejeon 34141 , Republic of Korea
| | - Matthew R Mena
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
| | - Jun-Hyeong Kim
- Department of Chemistry , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations , Institute for Basic Science (IBS) , Daejeon 34141 , Republic of Korea
| | - Raja Pal
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
| | - Christopher L Rock
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
| | - Thomas L Groy
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
| | - Mu-Hyun Baik
- Department of Chemistry , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations , Institute for Basic Science (IBS) , Daejeon 34141 , Republic of Korea
| | - Ryan J Trovitch
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
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19
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Dobrov A, Darvasiová D, Zalibera M, Bučinský L, Puškárová I, Rapta P, Shova S, Dumitrescu D, Martins LMDRS, Pombeiro AJL, Arion VB. Nickel(II) Complexes with Redox Noninnocent Octaazamacrocycles as Catalysts in Oxidation Reactions. Inorg Chem 2019; 58:11133-11145. [PMID: 31373487 DOI: 10.1021/acs.inorgchem.9b01700] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nickel(II) complexes with 15-membered (1-5) and 14-membered (6) octaazamacrocyclic ligands derived from 1,2- and 1,3-diketones and S-methylisothiocarbohydrazide were prepared by template synthesis. The compounds were characterized by elemental analysis, electrospray ionization mass spectrometry, IR, UV-vis, 1H NMR spectroscopies, and X-ray diffraction. The complexes contain a low-spin nickel(II) ion in a square-planar coordination environment. The electrochemical behavior of 1-6 was investigated in detail, and the electronic structure of 1e-oxidized and 1e-reduced species was studied by electron paramagnetic resonance, UV-vis-near-IR spectroelectrochemistry, and density functional theory calculations indicating redox noninnocent behavior of the ligands. Compounds 1-6 were tested in the microwave-assisted solvent-free oxidation of cyclohexane by tert-butyl hydroperoxide to produce the industrially significant mixture of cyclohexanol and cyclohexanone (i.e., A/K oil). The results showed that the catalytic activity was affected by several factors, namely, reaction time and temperature or amount and type of catalyst. The best values for A/K oil yield (23%, turnover number of 1.1 × 102) were obtained with compound 6 after 2 h of microwave irradiation at 100 °C.
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Affiliation(s)
- Anatolie Dobrov
- Institute of Inorganic Chemistry , University of Vienna , Währinger Strasse 42 , A-1090 Vienna , Austria
| | - Denisa Darvasiová
- 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
| | - 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
| | - Lukáš Bučinský
- 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 Puškárová
- 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
| | - Peter Rapta
- 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
| | - Sergiu Shova
- Inorganic Polymers Department , "Petru Poni" Institute of Macromolecular Chemistry , Aleea Gr. Ghica Voda 41 A , 700487 Iasi , Romania
| | - Dan Dumitrescu
- Elettra-Sincrotrone Trieste S.C.p.A. , Strada Statale 14-km 163,5 in AREA Science Park , 34149 Basovizza, Trieste , Italy
| | - Luísa M D R S Martins
- Centro de Química Estrutural, Instituto Superior Técnico , Universidade de Lisboa , Av. Rovisco Pais , 1049-001 Lisboa , Portugal
| | - Armando J L Pombeiro
- Centro de Química Estrutural, Instituto Superior Técnico , Universidade de Lisboa , Av. Rovisco Pais , 1049-001 Lisboa , Portugal
| | - Vladimir B Arion
- Institute of Inorganic Chemistry , University of Vienna , Währinger Strasse 42 , A-1090 Vienna , Austria
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20
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Kennedy CR, Zhong H, Macaulay RL, Chirik PJ. Regio- and Diastereoselective Iron-Catalyzed [4+4]-Cycloaddition of 1,3-Dienes. J Am Chem Soc 2019; 141:8557-8573. [PMID: 31060353 DOI: 10.1021/jacs.9b02443] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A family of single-component iron precatalysts for the [4+4]-cyclodimerization and intermolecular cross-[4+4]-cycloaddition of monosubstituted 1,3-dienes is described. Cyclooctadiene products were obtained with high regioselectivity, and catalyst-controlled access to either cis- or trans-diastereomers was achieved using 4-substituted diene substrates. Reactions conducted either with single-component precatalysts or with iron dihalide complexes activated in situ proved compatible with common organic functional groups and were applied on multigram scale (up to >100 g). Catalytically relevant, S = 1 iron complexes bearing 2-(imino)pyridine ligands, (RPI)FeL2 (RPI = [2-(2,6-R2-C6H3-N═CMe)-C5H4N] where R = iPr or Me, L2 = bis-olefin), were characterized by single-crystal X-ray diffraction, Mößbauer spectroscopy, magnetic measurements, and DFT calculations. The structural and spectroscopic parameters are consistent with an electronic structure description comprised of a high spin iron(I) center ( SFe = 3/2) engaged in antiferromagnetically coupling with a ligand radical anion ( SPI = -1/2). Mechanistic studies conducted with these single-component precatalysts, including kinetic analyses, 12C/13C isotope effect measurements, and in situ Mößbauer spectroscopy, support a mechanism involving oxidative cyclization of two dienes that determines regio- and diastereoselectivity. Topographic steric maps derived from crystallographic data provided insights into the basis for the catalyst control through stereoselective oxidative cyclization and subsequent, stereospecific allyl-isomerization and C-C bond-forming reductive elimination.
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Affiliation(s)
- C Rose Kennedy
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Hongyu Zhong
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Rachel L Macaulay
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Paul J Chirik
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
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21
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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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22
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Das C, Upadhyay A, Shanmugam M. Influence of Radicals on Magnetization Relaxation Dynamics of Pseudo-Octahedral Lanthanide Iminopyridyl Complexes. Inorg Chem 2018; 57:9002-9011. [DOI: 10.1021/acs.inorgchem.8b00979] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chinmoy Das
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India
| | - Apoorva Upadhyay
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India
| | - Maheswaran Shanmugam
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India
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23
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Luconi L, Rossin A, Tuci G, Gafurov Z, Lyubov DM, Trifonov AA, Cicchi S, Ba H, Pham‐Huu C, Yakhvarov D, Giambastiani G. Benzoimidazole‐Pyridylamido Zirconium and Hafnium Alkyl Complexes as Homogeneous Catalysts for Tandem Carbon Dioxide Hydrosilylation to Methane. ChemCatChem 2018. [DOI: 10.1002/cctc.201800077] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lapo Luconi
- Institute of Chemistry of OrganoMetallic Compounds, ICCOM-CNR Via Madonna del Piano, 10 50019 Sesto Fiorentino (Florence) Italy
| | - Andrea Rossin
- Institute of Chemistry of OrganoMetallic Compounds, ICCOM-CNR Via Madonna del Piano, 10 50019 Sesto Fiorentino (Florence) Italy
| | - Giulia Tuci
- Institute of Chemistry of OrganoMetallic Compounds, ICCOM-CNR Via Madonna del Piano, 10 50019 Sesto Fiorentino (Florence) Italy
- Department of Chemistry “Ugo Schiff”University of Florence 50019 Sesto Fiorentino Italy
| | - Zufar Gafurov
- A.E.Arbuzov Institute of Organic and Physical ChemistryRussian Academy of Sciences Arbuzov str. 8 420088 Kazan Russian Federation
- Kazan Federal University 420008 Kazan Russian Federation
| | - Dmitrii M. Lyubov
- G. A. Razuvaev Institute of Organometallic Chemistry of theRussian Academy of Sciences Tropinina 49, GSP-445 603950 Nizhny Novgorod Russia
| | - Alexander A. Trifonov
- G. A. Razuvaev Institute of Organometallic Chemistry of theRussian Academy of Sciences Tropinina 49, GSP-445 603950 Nizhny Novgorod Russia
| | - Stefano Cicchi
- Department of Chemistry “Ugo Schiff”University of Florence 50019 Sesto Fiorentino Italy
| | - Housseinou Ba
- Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé (ICPEES-CNRS)UMR 7515 CNRS-University of Strasbourg (UdS) France
| | - Cuong Pham‐Huu
- Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé (ICPEES-CNRS)UMR 7515 CNRS-University of Strasbourg (UdS) France
| | - Dmitry Yakhvarov
- A.E.Arbuzov Institute of Organic and Physical ChemistryRussian Academy of Sciences Arbuzov str. 8 420088 Kazan Russian Federation
- Kazan Federal University 420008 Kazan Russian Federation
| | - Giuliano Giambastiani
- Institute of Chemistry of OrganoMetallic Compounds, ICCOM-CNR Via Madonna del Piano, 10 50019 Sesto Fiorentino (Florence) Italy
- Kazan Federal University 420008 Kazan Russian Federation
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24
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Leipzig BK, Rees JA, Kowalska JK, Theisen RM, Kavčič M, Poon PCY, Kaminsky W, DeBeer S, Bill E, Kovacs JA. How Do Ring Size and π-Donating Thiolate Ligands Affect Redox-Active, α-Imino-N-heterocycle Ligand Activation? Inorg Chem 2018; 57:1935-1949. [PMID: 29411979 PMCID: PMC8312276 DOI: 10.1021/acs.inorgchem.7b02748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Considerable effort has been devoted to the development of first-row transition-metal catalysts containing redox-active imino-pyridine ligands that are capable of storing multiple reducing equivalents. This property allows abundant and inexpensive first-row transition metals, which favor sequential one-electron redox processes, to function as competent catalysts in the concerted two-electron reduction of substrates. Herein we report the syntheses and characterization of a series of iron complexes that contain both π-donating thiolate and π-accepting (α-imino)-N-heterocycle redox-active ligands, with progressively larger N-heterocycle rings (imidazole, pyridine, and quinoline). A cooperative interaction between these complementary redox-active ligands is shown to dictate the properties of these complexes. Unusually intense charge-transfer (CT) bands, and intraligand metrical parameters, reminiscent of a reduced (α-imino)-N-heterocycle ligand (L•-), initially suggested that the electron-donating thiolate had reduced the N-heterocycle. Sulfur K-edge X-ray absorption spectroscopic (XAS) data, however, provides evidence for direct communication, via backbonding, between the thiolate sulfur and the formally orthogonal (α-imino)-N-heterocycle ligand π*-orbitals. DFT calculations provide evidence for extensive delocalization of bonds over the sulfur, iron, and (α-imino)-N-heterocycle, and TD-DFT shows that the intense optical CT bands involve transitions between a mixed Fe/S donor, and (α-imino)-N-heterocycle π*-acceptor orbital. The energies and intensities of the optical and S K-edge pre-edge XAS transitions are shown to correlate with N-heterocycle ring size, as do the redox potentials. When the thiolate is replaced with a thioether, or when the low-spin S = 0 Fe(II) is replaced with a high-spin S = 3/2 Co(II), the N-heterocycle ligand metrical parameters and electronic structure do not change relative to the neutral L0 ligand. With respect to the development of future catalysts containing redox-active ligands, the energy cost of storing reducing equivalents is shown to be lowest when a quinoline, as opposed to imidazole or pyridine, is incorporated into the ligand backbone of the corresponding Fe complex.
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Affiliation(s)
- Benjamin K. Leipzig
- The Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States
| | - Julian A. Rees
- The Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States
| | - Joanna K. Kowalska
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34–36, D–45470 Mülheim an der Ruhr, Germany
| | - Roslyn M. Theisen
- The Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States
| | | | | | - Werner Kaminsky
- The Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34–36, D–45470 Mülheim an der Ruhr, Germany
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34–36, D–45470 Mülheim an der Ruhr, Germany
| | - Julie A. Kovacs
- The Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States
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25
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Huang W, Li Y, Yong J, Liu Y, Wu D. Hydrazone-based cobalt complexes toward multielectron redox and spin crossover. RSC Adv 2018; 8:17159-17167. [PMID: 35539225 PMCID: PMC9081832 DOI: 10.1039/c8ra02963f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 04/19/2018] [Indexed: 01/14/2023] Open
Abstract
Hydrazone-based derivatives modified by substitution at different positions were utilized to prepare a series of bis-homoleptic cobalt complexes. One species, [CoIII(L1)2]+ (1), which incorporated deprotonated ligands, adopted a Co(iii) diamagnetic ground state. However, the substituent of a hydrogen atom with a methyl group precluded the possibility of deprotonation upon metal coordination, which led to two species, [CoII(L2Me)2]2+ (2) and [CoII(L3NO2)2]2+, (3) which underwent a gradual spin crossover with an adjustable substituent effect and a mixed character of low-spin (doublet) and high-spin (quartet) populations in wide temperature ranges. Depending on the electronic effects of the substituents on the ligand, the multielectron redox behavior of the cobalt center was systematically modulated as well. This result demonstrates redox-switchable spin crossover in a new hydrazone-based Co(ii) system, in which the deprotonation of the coordination pocket and substituent groups in aromatic ligands can have a profound effect on the redox potential and spin state of the metal center. Hydrazone-based derivatives modified by substitution at different positions were utilized to prepare a series of bis-homoleptic cobalt complexes toward multielectron redox and spin crossover.![]()
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Affiliation(s)
- Wei Huang
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Collaborative Innovation Center of Advanced Catalysis & Green Manufacturing
- School of Petrochemical Engineering
- Changzhou University
- Changzhou
| | - Yujie Li
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Collaborative Innovation Center of Advanced Catalysis & Green Manufacturing
- School of Petrochemical Engineering
- Changzhou University
- Changzhou
| | - Juan Yong
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Collaborative Innovation Center of Advanced Catalysis & Green Manufacturing
- School of Petrochemical Engineering
- Changzhou University
- Changzhou
| | - Yang Liu
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Collaborative Innovation Center of Advanced Catalysis & Green Manufacturing
- School of Petrochemical Engineering
- Changzhou University
- Changzhou
| | - Dayu Wu
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Collaborative Innovation Center of Advanced Catalysis & Green Manufacturing
- School of Petrochemical Engineering
- Changzhou University
- Changzhou
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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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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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28
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Sieh D, Kubiak CP. A Series of Diamagnetic Pyridine Monoimine Rhenium Complexes with Different Degrees of Metal-to-Ligand Charge Transfer: Correlating 13
C NMR Chemical Shifts with Bond Lengths in Redox-Active Ligands. Chemistry 2016; 22:10638-50. [DOI: 10.1002/chem.201600679] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Indexed: 12/30/2022]
Affiliation(s)
- Daniel Sieh
- Joint Center for Artificial Photosynthesis; Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 East California Boulevard Pasadena CA 91125 USA
| | - Clifford P. Kubiak
- Joint Center for Artificial Photosynthesis; Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 East California Boulevard Pasadena CA 91125 USA
- Department of Chemistry and Biochemistry; University of California, San Diego; 9500 Gilman Drive MC 0358 La Jolla California 92093 USA
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29
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Starikov AG, Starikova AA, Minkin VI. Adducts of tetracoordinate cobalt(II) complexes and 1-(pyridin-2-yl)methanimine: Computational search for valence tautomeric systems. RUSS J GEN CHEM+ 2016. [DOI: 10.1134/s1070363216040174] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Reiß F, Altenburger K, Becker L, Schubert K, Jiao H, Spannenberg A, Hollmann D, Arndt P, Rosenthal U. Reactions of 2-Substituted Pyridines with Titanocenes and Zirconocenes: Coupling versus Dearomatisation. Chemistry 2016; 22:3361-3369. [DOI: 10.1002/chem.201504411] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Fabian Reiß
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
| | - Kai Altenburger
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
| | - Lisanne Becker
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
| | - Kathleen Schubert
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
| | - Haijun Jiao
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
| | - Dirk Hollmann
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
| | - Perdita Arndt
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
| | - Uwe Rosenthal
- Leibniz-Institut für Katalyse e.V. an der; Universität Rostock; Albert-Einstein-Strasse 29a 18059 Rostock Germany
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31
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Tomaschun G, Altenburger K, Reiß F, Becker L, Spannenberg A, Arndt P, Jiao H, Rosenthal U. Group 4 Metallocene Complexes and Cyanopyridines: Coordination or Coupling to Metallacycles. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201501235] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Gabriele Tomaschun
- Leibniz‐Institut für Katalyse e.V. an der Universität Rostock, Albert‐Einstein‐Str. 29a, 18059 Rostock, Germany www.catalysis.de
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl‐von‐Ossietzky‐Str. 9–11, 26129 Oldenburg, Germany
| | - Kai Altenburger
- Leibniz‐Institut für Katalyse e.V. an der Universität Rostock, Albert‐Einstein‐Str. 29a, 18059 Rostock, Germany www.catalysis.de
| | - Fabian Reiß
- Leibniz‐Institut für Katalyse e.V. an der Universität Rostock, Albert‐Einstein‐Str. 29a, 18059 Rostock, Germany www.catalysis.de
| | - Lisanne Becker
- Leibniz‐Institut für Katalyse e.V. an der Universität Rostock, Albert‐Einstein‐Str. 29a, 18059 Rostock, Germany www.catalysis.de
| | - Anke Spannenberg
- Leibniz‐Institut für Katalyse e.V. an der Universität Rostock, Albert‐Einstein‐Str. 29a, 18059 Rostock, Germany www.catalysis.de
| | - Perdita Arndt
- Leibniz‐Institut für Katalyse e.V. an der Universität Rostock, Albert‐Einstein‐Str. 29a, 18059 Rostock, Germany www.catalysis.de
| | - Haijun Jiao
- Leibniz‐Institut für Katalyse e.V. an der Universität Rostock, Albert‐Einstein‐Str. 29a, 18059 Rostock, Germany www.catalysis.de
| | - Uwe Rosenthal
- Leibniz‐Institut für Katalyse e.V. an der Universität Rostock, Albert‐Einstein‐Str. 29a, 18059 Rostock, Germany www.catalysis.de
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32
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Schaefer BA, Margulieux GW, Tiedemann MA, Small BL, Chirik PJ. Synthesis and Electronic Structure of Iron Borate Betaine Complexes as a Route to Single-Component Iron Ethylene Oligomerization and Polymerization Catalysts. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00839] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brian A. Schaefer
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Grant W. Margulieux
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Margaret A. Tiedemann
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Brooke L. Small
- Chevron Phillips Chemical Company, 1862 Kingwood Drive, Kingwood, Texas 77339, United States
| | - Paul J. Chirik
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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33
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Lindley BM, Wolczanski PT, Cundari TR, Lobkovsky EB. First-Row Transition Metal and Lithium Pyridine-ene-amide Complexes Exhibiting N- and C-Isomers and Ligand-Based Activation of Benzylic C–H Bonds. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00385] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brian M. Lindley
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Peter T. Wolczanski
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Thomas R. Cundari
- Department of Chemistry, Center for Advanced
Scientific Computing and Modeling (CASCaM), University of North Texas, Box 305070, Denton, Texas 76203-5070, United States
| | - Emil B. Lobkovsky
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
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34
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Machan CW, Chabolla SA, Kubiak CP. Reductive Disproportionation of Carbon Dioxide by an Alkyl-Functionalized Pyridine Monoimine Re(I) fac-Tricarbonyl Electrocatalyst. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00406] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Charles W. Machan
- Department of Chemistry and
Biochemistry, University of California−San Diego, 9500 Gilman Drive
0358, La Jolla, California 92023, United States
| | - Steven A. Chabolla
- Department of Chemistry and
Biochemistry, University of California−San Diego, 9500 Gilman Drive
0358, La Jolla, California 92023, United States
| | - Clifford P. Kubiak
- Department of Chemistry and
Biochemistry, University of California−San Diego, 9500 Gilman Drive
0358, La Jolla, California 92023, United States
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35
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Sieh D, Lacy DC, Peters JC, Kubiak CP. Reduction of CO2 by Pyridine Monoimine Molybdenum Carbonyl Complexes: Cooperative Metal-Ligand Binding of CO2. Chemistry 2015; 21:8497-503. [PMID: 25924730 PMCID: PMC4523092 DOI: 10.1002/chem.201500463] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Indexed: 12/22/2022]
Abstract
[((Ar) PMI)Mo(CO)4 ] complexes (PMI=pyridine monoimine; Ar=Ph, 2,6-di-iso-propylphenyl) were synthesized and their electrochemical properties were probed with cyclic voltammetry and infrared spectroelectrochemistry (IR-SEC). The complexes undergo a reduction at more positive potentials than the related [(bipyridine)Mo(CO)4 ] complex, which is ligand based according to IR-SEC and DFT data. To probe the reaction product in more detail, stoichiometric chemical reduction and subsequent treatment with CO2 resulted in the formation of a new product that is assigned as a ligand-bound carboxylate, [( iPr 2PhPMI)Mo(CO)3 (CO2 )](2-) , by NMR spectroscopic methods. The CO2 adduct [( iPr 2PhPMI)Mo(CO)3 (CO2 )](2-) could not be isolated and fully characterized. However, the C-C coupling between the CO2 molecule and the PDI ligand was confirmed by X-ray crystallographic characterization of one of the decomposition products of [( iPr 2PhPMI)Mo(CO)3 (CO2 )](2-) .
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Affiliation(s)
- Daniel Sieh
- Joint Center for Artificial Photosynthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (USA)
| | - David C Lacy
- Joint Center for Artificial Photosynthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (USA)
| | - Jonas C Peters
- Joint Center for Artificial Photosynthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (USA)
| | - Clifford P Kubiak
- Joint Center for Artificial Photosynthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (USA).
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive MC 0358, La Jolla, California 92093 (USA).
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36
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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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37
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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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38
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Synthesis, characterization and crystal structure of cationic bis(pyridinylimine)cobalt(II) complexes. Inorganica Chim Acta 2015. [DOI: 10.1016/j.ica.2014.12.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Palmer WN, Diao T, Pappas I, Chirik PJ. High-Activity Cobalt Catalysts for Alkene Hydroboration with Electronically Responsive Terpyridine and α-Diimine Ligands. ACS Catal 2014. [DOI: 10.1021/cs501639r] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- W. Neil Palmer
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Tianning Diao
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Iraklis Pappas
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Paul J. Chirik
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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40
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Hulley EB, Williams VA, Morris WD, Wolczanski PT, Hernández-Burgos K, Lobkovsky EB, Cundari TR. Disparate reactivity from isomeric {Me 2 C(CH 2 N CHpy) 2 } and {Me 2 C(CH NCH 2 py) 2 } chelates in iron complexation. Polyhedron 2014. [DOI: 10.1016/j.poly.2014.07.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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41
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Mukhopadhyay TK, Flores M, Feller RK, Scott BL, Taylor RD, Paz-Pasternak M, Henson NJ, Rein FN, Smythe NC, Trovitch RJ, Gordon JC. A New Spin on Cyclooctatetraene (COT) Redox Activity: Low-Spin Iron(I) Complexes That Exhibit Antiferromagnetic Coupling to a Singly Reduced η4-COT Ligand. Organometallics 2014. [DOI: 10.1021/om500909h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Tufan K. Mukhopadhyay
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, Arizona 85287, United States
| | - Marco Flores
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, Arizona 85287, United States
| | - Russell K. Feller
- Materials
Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Brian L. Scott
- Materials
Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - R. Dean Taylor
- Materials
Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Moshe Paz-Pasternak
- School
of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Neil J. Henson
- Theoretical
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Francisca N. Rein
- Chemistry
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Nathan C. Smythe
- Chemistry
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Ryan J. Trovitch
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, Arizona 85287, United States
| | - John C. Gordon
- Chemistry
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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42
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Sengupta D, Ghosh P, Chatterjee T, Datta H, Paul ND, Goswami S. Ligand-Centered Redox in Nickel(II) Complexes of 2-(Arylazo)pyridine and Isolation of 2-Pyridyl-Substituted Triaryl Hydrazines via Catalytic N-Arylation of Azo-Function. Inorg Chem 2014; 53:12002-13. [DOI: 10.1021/ic501656s] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Debabrata Sengupta
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Pradip Ghosh
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Tanmay Chatterjee
- Department
of Organic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Harashit Datta
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Nanda D. Paul
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Sreebrata Goswami
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
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43
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Pal R, Groy TL, Bowman AC, Trovitch RJ. Preparation and Hydrosilylation Activity of a Molybdenum Carbonyl Complex That Features a Pentadentate Bis(imino)pyridine Ligand. Inorg Chem 2014; 53:9357-65. [DOI: 10.1021/ic501465v] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Raja Pal
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, Arizona 85287, United States
| | - Thomas L. Groy
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, Arizona 85287, United States
| | - Amanda C. Bowman
- Department
of Chemistry, Transylvania University, Lexington, Kentucky 40508, United States
| | - Ryan J. Trovitch
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, Arizona 85287, United States
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44
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Morris WD, Wolczanski PT, Sutter J, Meyer K, Cundari TR, Lobkovsky EB. Iron and chromium complexes containing tridentate chelates based on nacnac and imino- and methyl-pyridine components: triggering C-X bond formation. Inorg Chem 2014; 53:7467-84. [PMID: 25010819 DOI: 10.1021/ic500807y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Nacnac-based tridentate ligands containing a pyridyl-methyl and a 2,6-dialkyl-phenylamine (i.e., (2,6-R2-C6H3N═C(Me)CH═C(Me)NH(CH2py); R = Et, {Et(nn)PM}H; R = (i)Pr, {(i)Pr(nn)PM}H) were synthesized by condensation routes. Treatment of M{N(TMS)2}THFn (M = Cr, n = 2; M = Fe, Co, n = 1; TMS = trimethylsilane; THF = tetrahydrofuran) with {(i)Pr(nn)PM}H) afforded {(i)Pr(nn)PM}MN(TMS)2 (1-M(iPr); M = Cr, Fe); {Et(nn)PM}MN(TMS)2 (1-M(Et); M = Fe, Co) was similarly obtained. {R(nn)PM}FeBr (R = (i)Pr, Et; 2-Fe(R)) were prepared from FeBr2 and {R(nn)PM}Li, and alkylated to generate {R(nn)PM}Fe(neo)Pe (R = (i)Pr, Et; 3-Fe(R)). Carbonylation of 3-Fe(R) provided {(i)Pr(nn)PM}Fe(CO(neo)Pe)CO (4-Fe(iPr)), and carbonylations of 1-Fe(R) (R = Et, (i)Pr) and 1-Cr(iPr) induced deamination to afford {R(nn)PI}Fe(CO)2 (R = (i)Pr, 5-Fe(iPr); Et, 5-Fe(Et)), where PI is pyridine-imine, and {κ(2)-N,N-pyrim-pyr}Cr(CO)4 (6-Cr(iPr)), in which the aryl-amide side of the nacnac attacked the incipient PI group. Carbon-carbon bonds were formed at the imine carbon of the {R(nn)PI} ligand. Addition of [{(i)Pr(nn)PI}(2-)](K(+)(THF)x)2 to FeCl3 generated {(i)Pr(nn)CHpy}2Fe2Cl2 (7-Fe(iPr)), and TMSN3 induced the deamination of 1-Fe(Et), but with disproportionation to provide {[Et(nn)CHpy]2}Fe (8-Fe(Et)). Ph2CN2 induced C-C bond formation with 1-Fe(iPr) via its thermal degradation to ultimately afford {(i)Pr(nn)CHpy}2(FeN═CPh2)2 (9-Fe(iPr)). The compounds were examined by X-ray crystallography (1-M(iPr), M = Cr, Fe; 1-Co(Et); 2-Fe(iPr); 4-Fe(iPr); 5-Fe(iPr); 6-Cr(iPr); 7-Fe(iPr); 8-Fe(Et); 9-Fe(iPr)), Mössbauer spectroscopy, and NMR spectroscopy. Structural parameters assessing redox noninnocence are discussed, as are structural and mechanistic consequences of the various electronic environments.
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Affiliation(s)
- Wesley D Morris
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853, United States
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45
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Takaichi J, Morimoto Y, Ohkubo K, Shimokawa C, Hojo T, Mori S, Asahara H, Sugimoto H, Fujieda N, Nishiwaki N, Fukuzumi S, Itoh S. Redox chemistry of nickel(II) complexes supported by a series of noninnocent β-diketiminate ligands. Inorg Chem 2014; 53:6159-69. [PMID: 24884152 DOI: 10.1021/ic5006693] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Nickel complexes of a series of β-diketiminate ligands ((R)L(-), deprotonated form of 2-substituted N-[3-(phenylamino)allylidene]aniline derivatives (R)LH, R = Me, H, Br, CN, and NO2) have been synthesized and structurally characterized. One-electron oxidation of the neutral complexes [Ni(II)((R)L(-))2] by AgSbF6 or [Ru(III)(bpy)3](PF6)3 (bpy = 2,2'-bipyridine) gave the corresponding metastable cationic complexes, which exhibit an EPR spectrum due to a doublet species (S = 1/2) and a characteristic absorption band in near IR region ascribable to a ligand-to-ligand intervalence charge-transfer (LLIVCT) transition. DFT calculations have indicated that the divalent oxidation state of nickel ion (Ni(II)) is retained, whereas one of the β-diketiminate ligands is oxidized to give formally a mixed-valence complex, [Ni(II)((R)L(-))((R)L(•))](+). Thus, the doublet spin state of the oxidized cationic complex can be explained by taking account of the antiferromagnetic interaction between the high-spin nickel(II) ion (S = 1) and the organic radical (S = 1/2) of supporting ligand. A single-crystal structure of one of the cationic complexes (R = H) has been successfully determined to show that both ligands in the cationic complex are structurally equivalent. On the basis of theoretical analysis of the LLIVCT band and DFT calculations as well as the crystal structure, the mixed-valence complexes have been assigned to Robin-Day class III species, where the radical spin is equally delocalized between the two ligands to give the cationic complex, which is best described as [Ni(II)((R)L(0.5•-))2](+). One-electron reduction of the neutral complexes with decamethylcobaltocene gave the anionic complexes when the ligand has the electron-withdrawing substituent (R = CN, NO2, Br). The generated anionic complexes exhibited EPR spectra due to a doublet species (S = 1/2) but showed no LLIVCT band in the near-IR region. Thus, the reduced complexes are best described as the d(9) nickel(I) complexes supported by two anionic β-diketiminate ligands, [Ni(I)((R)L(-))2](-). This conclusion was also supported by DFT calculations. Substituent effects on the electronic structures of the three oxidation states (neutral, cationic, and anionic) of the complexes are systematically evaluated on the basis of DFT calculations.
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Affiliation(s)
- June Takaichi
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University , 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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46
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Lacy DC, McCrory CCL, Peters JC. Studies of cobalt-mediated electrocatalytic CO2 reduction using a redox-active ligand. Inorg Chem 2014; 53:4980-8. [PMID: 24773584 PMCID: PMC4033636 DOI: 10.1021/ic403122j] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Indexed: 01/04/2023]
Abstract
The cobalt complex [Co(III)N4H(Br)2](+) (N4H = 2,12-dimethyl-3,7,11,17-tetraazabicyclo-[11.3.1]-heptadeca-1(7),2,11,13,15-pentaene) was used for electrocatalytic CO2 reduction in wet MeCN with a glassy carbon working electrode. When water was employed as the proton source (10 M in MeCN), CO was produced (fCO= 45% ± 6.4) near the Co(I/0) redox couple for [Co(III)N4H(Br)2](+) (E1/2 = -1.88 V FeCp2(+/0)) with simultaneous H2 evolution (fH2= 30% ± 7.8). Moreover, we successfully demonstrated that the catalytically active species is homogeneous through the use of control experiments and XPS studies of the working glassy-carbon electrodes. As determined by cyclic voltammetry, CO2 catalysis occurred near the formal Co(I/0)redox couple, and attempts were made to isolate the triply reduced compound ("[Co(0)N4H]"). Instead, the doubly reduced ("Co(I)") compounds [CoN4] and [CoN4H(MeCN)](+) were isolated and characterized by X-ray crystallography. Their molecular structures prompted DFT studies to illuminate details regarding their electronic structure. The results indicate that reducing equivalents are stored on the ligand, implicating redox noninnocence in the ligands for H2 evolution and CO2 reduction electrocatalysis.
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Affiliation(s)
- David C. Lacy
- Joint Center
for Artificial Photosynthesis, Division of Chemistry and Chemical
Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Charles C. L. McCrory
- Joint Center
for Artificial Photosynthesis, Division of Chemistry and Chemical
Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Jonas C. Peters
- Joint Center
for Artificial Photosynthesis, Division of Chemistry and Chemical
Engineering, California Institute of Technology, Pasadena, California 91125, United States
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47
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Williams VA, Wolczanski PT, Sutter J, Meyer K, Lobkovsky EB, Cundari TR. Iron complexes derived from {nacnac-(CH2py)2}- and {nacnac-(CH2py)(CHpy)}n ligands: stabilization of iron(II) via redox noninnocence. Inorg Chem 2014; 53:4459-74. [PMID: 24762120 DOI: 10.1021/ic5001123] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nacnac-based tetradentate chelates, {nacnac-(CH2py)2}(-) ({nn(PM)2}(-)) and {nacnac-(CH2py)(CHpy)}(n) ({nn(PM)(PI)}(n)) have been investigated in iron complexes. Treatment of Fe{N(TMS)2}2(THF) with {nn(PM)2}H afforded {nn(PM)2}FeN(TMS)2 [1-N(TMS)2], which led to {nn(PM)2}FeCl (1-Cl) from HCl and to {nn(PM)2}FeN3 (1-N3) upon salt metathesis. Dehydroamination of 1-N(TMS)2 was induced by L (L = PMe3, CO) to afford {nn(PM)(PI)}Fe(PMe3)2 [2-(PMe3)2] and {nn(PM)(PI)}FeCO (3-CO). Substitution of 2-(PMe3)2 led to {nn(PM)(PI)}Fe(PMe3)CO [2-(PMe3)CO], and exposure to a vacuum provided {nn(PM)(PI)}Fe(PMe3) (3-PMe3). Metathesis routes to {nn(PM)(PI)}FeL2 (2-L2; L = PMe3, PMe2Ph) and {nn(PM)(PI)}FeL (3-L; L = PMePh2, PPh3) from [{nn(PM)(PI)}(2-)]Li2 and FeBr2(THF)2 in the presence of L proved feasible, and 1e(-) and 2e(-) oxidation of 2-(PMe3)2 afforded 2(+)-(PMe3)2 and 2(2+)-(PMe3)2 salts. Mössbauer spectroscopy, structural studies, and calculational assessments revealed the dominance of iron(II) in both high-spin (1-X) and low-spin (2-L2 and 3-L) environments, and the redox noninnocence (RNI) of {nn(PM)(PI)}(n) [2-L2, 3-L, n = 2-; 2(+)-(PMe3)2, n = 1-; 2(2+)-(PMe3)2, n = 0]. A discussion regarding the utility of RNI in chemical reactivity is proffered.
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Affiliation(s)
- Valerie A Williams
- Baker Laboratory, Department of Chemistry & Chemical Biology, Cornell University , Ithaca, New York 14853, United States
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48
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Peng D, Zhang Y, Du X, Zhang L, Leng X, Walter MD, Huang Z. Phosphinite-Iminopyridine Iron Catalysts for Chemoselective Alkene Hydrosilylation. J Am Chem Soc 2013; 135:19154-66. [DOI: 10.1021/ja404963f] [Citation(s) in RCA: 180] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Dongjie Peng
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, P.R. China
| | - Yanlu Zhang
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, P.R. China
| | - Xiaoyong Du
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, P.R. China
| | - Lei Zhang
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, P.R. China
| | - Xuebing Leng
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, P.R. China
| | - Marc D. Walter
- Institut
für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Zheng Huang
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, P.R. China
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49
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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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50
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Tahsini L, Specht SE, Lum JS, Nelson JJM, Long AF, Golen JA, Rheingold AL, Doerrer LH. Structural and Electronic Properties of Old and New A2[M(pinF)2] Complexes. Inorg Chem 2013; 52:14050-63. [DOI: 10.1021/ic401837y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Laleh Tahsini
- Chemistry Department, Boston University, 590
Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Sarah E. Specht
- Chemistry Department, Boston University, 590
Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - June S. Lum
- Chemistry Department, Boston University, 590
Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Joshua J. M. Nelson
- Chemistry Department, Boston University, 590
Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Alexandra F. Long
- Chemistry Department, Boston University, 590
Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - James A. Golen
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Arnold L. Rheingold
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Linda H. Doerrer
- Chemistry Department, Boston University, 590
Commonwealth Avenue, Boston, Massachusetts 02215, United States
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