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Panda S, Dhara S, Singh A, Dey S, Kumar Lahiri G. Metal-coordinated azoaromatics: Strategies for sequential azo-reduction, isomerization and application potential. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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2
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Seikh L, Dey S, Dhara S, Singh A, Lahiri GK. Inner-Sphere Electron Transfer Induced Reversible Electron Reservoir Feature of Azoheteroarene Bridged Diruthenium Frameworks. Inorg Chem 2022; 61:15735-15746. [PMID: 36129962 DOI: 10.1021/acs.inorgchem.2c02921] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This article demonstrates the stabilization of ground- and redox-induced metal-to-ligand charge transfer excited states on coordination of azo-coupled bmpd(L4) [bmpd = (E)-1,2-bis(1-methyl-1H-pyrazol-3-yl)diazene; L4 = -N═N-] to the electron-rich {Ru(acac)2} (acac = acetylacetonate) unit in mononuclear RuII(acac)2(L4) (1) and diastereomeric dinuclear (acac)2Ru2.5(μ-L4•-)Ru2.5(acac)2 [rac, ΔΔ/ΛΛ (2a)/meso, ΔΛ (2b)] complexes, respectively. It also develops further one-step intramolecular electron transfer induced L4•- bridged isovalent higher analogue [(acac)2RuIII(μ-L4•-)RuIII(acac)2]ClO4 in diastereomeric forms, rac-[2a]ClO4/meso-[2b]ClO4. On the contrary, under identical reaction conditions electronically and sterically permuted bimpd [L5, (E)-1,2-bis(4-iodo-1-methyl-1H-pyrazol-3-yl)diazene)] delivered mononuclear RuII(acac)2(L5) (3) as an exclusive product. Further, the generation of unprecedented heterotrinuclear complex [(acac)2RuII(μ-L4)AgI(μ-L4)RuII(acac)2]ClO4 ([4]ClO4) involving unreduced L4 via the reaction of 1 and AgClO4 revealed the absence of any inner-sphere electron transfer (IET) as in precursor 1, which in turn reaffirmed an IET (at the interface of electron-rich Ru(acac)2 and acceptor L4) mediated stabilization of 2. Structural authentication of the complexes with special reference to the tunable azo distance (N═N, N-N•-, N-N2-) of L and their spectro-electrochemical events in accessible redox states including the reversible electron reservoir feature of 2 → 2+/2+ → 2 were evaluated in conjunction with density functional theory/time-dependent density functional theory calculations. The varying extent of IET as a function of heteroaromatics appended to the azo group of L (L1 = abpy = 2,2'-azobipyridine, L2 = abbt = 2,2'-azobis(benzothiazole), L3 = abim = azobis(1-methylbenzimidazole), L4 and L5, Schemes 1 & 2) in the Ru(acac)2-derived respective molecular setup has been addressed.
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Affiliation(s)
- Liton Seikh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sanchaita Dey
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Suman Dhara
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Aditi Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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Nagarajan S, Srivastava AK, Ishtiyak M, Rani M, Pal S. Cycloruthenates(III) with CNO pincer-like ligands: Regioselective metallation of N-(4-R-benzoyl)-N′-(2-naphthylidene)hydrazines. J Organomet Chem 2022. [DOI: 10.1016/j.jorganchem.2022.122409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Jiang P, Yang X, Cao N, Zhu X, Zhang F, Liu SH, Ou YP. Tuning iron-amine electronic coupling by different aromatic bridges based on ferrocene-ethynyl-triarylamine systems. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2021.120743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Bavi M, Nabavizadeh SM, Hosseini FN, Niknam F, Hamidizadeh P, Hoseini SJ, Raoof F, Abu-Omar MM. Ligand-Mediated C-Br Oxidative Addition to Cycloplatinated(II) Complexes and Benzyl-Me C-C Bond Reductive Elimination from a Cycloplatinated(IV) Complex. ACS OMEGA 2020; 5:28621-28631. [PMID: 33195914 PMCID: PMC7658948 DOI: 10.1021/acsomega.0c03573] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Reaction of the Pt(II) complexes [PtMe2(pbt)], 1a, (pbt = 2-(2-pyridyl)benzothiazole) and [PtMe(C^N)(PPh2Me)] [C^N = deprotonated 2-phenylpyridine (ppy), 1b, or deprotonated benzo[h]quinoline (bhq), 1c] with benzyl bromide, PhCH2Br, is studied. The reaction of 1a with PhCH2Br gave the Pt(IV) product complex [PtBr(CH2Ph)Me2(pbt)]. The major trans isomer is formed in a trans oxidative addition (2a), while the minor cis products (2a' and 2a″) resulted from an isomerization process. A solution of Pt(II) complex 1a in the presence of benzyl bromide in toluene at 70 °C after 7 days gradually gave the dibromo Pt(IV) complex [Pt(Br)2Me2(pbt)], 4a, as determined by NMR spectroscopy and single-crystal XRD. The reaction of complexes 1b and 1c with PhCH2Br gave the Pt(IV) complexes [PtMeBr(CH2Ph)(C^N)(PPh2Me)] (C^N = ppy; 2b; C^N = bhq, 2c), in which the phosphine and benzyl ligands are trans. Multinuclear NMR spectroscopy ruled out other isomers. Attempts to grow crystals of the cycloplatinated(IV) complex 2b yielded a previously reported Pt(II) complex [PtBr(ppy)(PPh2Me)], 3b, presumably from reductive elimination of ethylbenzene. UV-vis spectroscopy was used to study the kinetics of reaction of Pt(II) complexes 1a-1c with benzyl bromide. The data are consistent with a second-order SN2 mechanism and the first order in both the Pt complex and PhCH2Br. The rate of reaction decreases along the series 1a ≫ 1c > 1b. Density functional theory calculations were carried out to support experimental findings and understand the formation of isomers.
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Affiliation(s)
- Marzieh Bavi
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - S. Masoud Nabavizadeh
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | | | - Fatemeh Niknam
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Peyman Hamidizadeh
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - S. Jafar Hoseini
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Fatemeh Raoof
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Mahdi M. Abu-Omar
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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6
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Li Z, Tang J, Shao J, Zhong Y. Near‐Infrared Electrochromism of Multilayer Films of an N C N‐Pincer Tri‐Ruthenium(II) Complex. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000400] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Zhi‐Juan Li
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Photochemistry CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences 100190 Beijing China
- School of Chemical Sciences University of Chinese Academy of Sciences 10049 Beijing China
| | - Jian‐Hong Tang
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Photochemistry CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences 100190 Beijing China
| | - Jiang‐Yang Shao
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Photochemistry CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences 100190 Beijing China
| | - Yu‐Wu Zhong
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Photochemistry CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences 100190 Beijing China
- School of Chemical Sciences University of Chinese Academy of Sciences 10049 Beijing China
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Hu YX, Zhang J, Zhang F, Wang X, Yin J, Hartl F, Liu SH. Electronic Properties of Oxidized Cyclometalated Diiridium Complexes: Spin Delocalization Controlled by the Mutual Position of the Iridium Centers. Chemistry 2020; 26:4567-4575. [PMID: 31891433 DOI: 10.1002/chem.201904894] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/20/2019] [Indexed: 11/10/2022]
Abstract
Four cyclometalated diiridium complexes, with IrCp*Cl (Cp*=η5 -C5 Me5 - ) termini bridged by 1,4- and 1,3-bis(p-tolyliminoethyl)benzene (1, 2), or 1,4- and 1,3-bis(2-pyridyl)benzene (3, 4), were prepared and characterized by nuclear magnetic resonance (NMR) spectroscopy and single-crystal X-ray diffraction (complexes 1, 2, and 4). The two iridium centers in complexes 1 and 3 are thus bound at the central benzene ring in the para-position (trans-Ir2), whereas those in complexes 2 and 4 are in the meta-position (cis-Ir2). Cyclic voltammograms of all four complexes show two consecutive one-electron oxidations. The potential difference between the two anodic steps in 1 and 3 is distinctly larger than that for 2 and 4. The visible-near-infrared (NIR)-short-wave infrared (SWIR) absorption spectra of trans-Ir2 monocations 1+ and 3+ are markedly different from those of cis-Ir2 monocations 2+ and 4+ . Notably, strong near-infrared electronic absorption appears only in the spectra of 1+ and 3+ whereas 2+ and 4+ absorb only weakly in the NIR-SWIR region. Combined DFT and TD-DFT calculations have revealed that (a) 1+ and 3+ (the diiridium-benzene trans-isomers) display the highest occupied spin-orbitals (HOSO) and the lowest unoccupied spin-orbital (LUSO) evenly delocalized over both molecule halves, and (b) their electronic absorptions in the NIR-SWIR region are attributed to mixed metal-to-ligand and ligand-to-ligand charge transfers (MLCT and LLCT). In contrast, cis-isomers 2+ and 4+ do not feature this stabilizing π-delocalization but a localized mixed-valence state showing a weak intervalence charge-transfer (IVCT) absorption in the SWIR region.
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Affiliation(s)
- Yu Xuan Hu
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Jing Zhang
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Fangfang Zhang
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Xiaoyan Wang
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Jun Yin
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - František Hartl
- Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK
| | - Sheng Hua Liu
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
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Li X, Du K, Xie C, Wu Y, Zhang B, Tang D. A highly sensitive and selective colorimetric probe based on a cycloruthenated complex: an Hg 2+-promoted switch of thiophene coordination. Dalton Trans 2020; 49:2024-2032. [PMID: 31993593 DOI: 10.1039/c9dt02934f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A cyclometalated ruthenium complex [Ru(pthb)(bpy)2]+ (1, bpy = 2,2'-bipyridine, Hpthb = 3,3-dimethyl-2-(5-pyridylthiophen-2-yl)vinyl-benzo[e]indolium-1-propylsulfonate) could be converted from a C-coordinated structure to non-metallated species with N,S-bonded Hpthb upon treatment with mercury(ii) ions in water. Strikingly, the switch in the coordination mode resulted in a great absorption change along with a change in the solution color of 1 from dark red to light yellow. Therefore, 1 can be used as a colorimetric probe to detect mercury(ii) ions by the naked eye. Although the emission was not observed for 1 in water, it still demonstrated an appreciably low detection limit of 21 nM by using UV-Vis absorption spectroscopy, which was comparable with those of some probes determined by ratiometric fluorescence spectroscopy.
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Affiliation(s)
- Xianghong Li
- Key Laboratory of Analytical Chemistry of State Ethnic Affairs Commission, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, PR China.
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Bhattacharjee S, Laru S, Samanta S, Singsardar M, Hajra A. Visible light-induced photocatalytic C–H ethoxycarbonylmethylation of imidazoheterocycles with ethyl diazoacetate. RSC Adv 2020; 10:27984-27988. [PMID: 35519122 PMCID: PMC9055643 DOI: 10.1039/d0ra05795a] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/21/2020] [Indexed: 12/30/2022] Open
Abstract
A visible-light-promoted regioselective ethoxycarbonylmethylation of imidazoheterocycles has been developed using an α-diazoester via a radical pathway.
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Affiliation(s)
- Suvam Bhattacharjee
- Department of Chemistry
- Visva-Bharati (A Central University)
- Santiniketan
- India
| | - Sudip Laru
- Department of Chemistry
- Visva-Bharati (A Central University)
- Santiniketan
- India
| | - Sadhanendu Samanta
- Department of Chemistry
- Visva-Bharati (A Central University)
- Santiniketan
- India
| | - Mukta Singsardar
- Department of Chemistry
- Visva-Bharati (A Central University)
- Santiniketan
- India
| | - Alakananda Hajra
- Department of Chemistry
- Visva-Bharati (A Central University)
- Santiniketan
- India
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Affiliation(s)
- Jean-Pierre Launay
- CEMES-CNRS; Université de Toulouse; 29 rue Jeanne Marvig 31055 Toulouse France
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11
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Haiduc I. Review. Inverse coordination. Organic nitrogen heterocycles as coordination centers. A survey of molecular topologies and systematization. Part 2. Six-membered rings. J COORD CHEM 2019. [DOI: 10.1080/00958972.2019.1670349] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Ionel Haiduc
- Facultatea de Chimie, Universitatea Babeş-Bolyai, Cluj-Napoca, Romania
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12
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Banasz R, Wałęsa-Chorab M. Polymeric complexes of transition metal ions as electrochromic materials: Synthesis and properties. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.03.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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13
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Yang T, Zhang CX, Li YJ, Fu YH, Yin ZH, Gao LH, Wang KZ. A 3D electropolymerized thin film based on a thiophene-functionalized Ru( ii) complex: electrochemical and photoelectrochemical insights. Inorg Chem Front 2019. [DOI: 10.1039/c9qi00863b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A 3D electropolymerized Ru(ii) complex film exhibited a rapid redox reaction and an oxygen reduction enhanced photocurrent which increased by 1.5 fold to 2.3 μA cm−2.
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Affiliation(s)
- Tong Yang
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875
- P.R. China
| | - Chen-Xing Zhang
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875
- P.R. China
| | - Yu-Jia Li
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875
- P.R. China
| | - Ying-Huan Fu
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875
- P.R. China
| | - Zhi-Han Yin
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875
- P.R. China
| | - Li-Hua Gao
- School of Science
- Beijing Technology and Business University
- Beijing 100048
- China
| | - Ke-Zhi Wang
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875
- P.R. China
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Zych D, Slodek A, Matuszczyk D, Golba S. Comprehensive Study of Mononuclear Osmium Complexes with Various Pyrene Ligands. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201801199] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Dawid Zych
- Physics and Chemistry; University of Silesia; Szkolna 9 40-007 Katowice Poland
| | - Aneta Slodek
- Physics and Chemistry; University of Silesia; Szkolna 9 40-007 Katowice Poland
| | - Daniel Matuszczyk
- Physics and Chemistry; University of Silesia; Szkolna 9 40-007 Katowice Poland
| | - Sylwia Golba
- Institute of Materials Science; University of Silesia; 75 Pulku Piechoty 1A, 41- 500 Chorzow Poland
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Klein J, Beerhues J, Schweinfurth D, van der Meer M, Gazvoda M, Lahiri GK, Košmrlj J, Sarkar B. Versatile Coordination of Azocarboxamides: Redox-Triggered Change of the Chelating Binding Pocket in Ruthenium Complexes. Chemistry 2018; 24:18020-18031. [PMID: 30136748 DOI: 10.1002/chem.201803606] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 08/22/2018] [Indexed: 11/09/2022]
Abstract
Azocarboxamides occupy a special place among azo ligands owing to their versatility for metal coordination. Herein ruthenium complexes with two different azocarboxamide ligands that differ in the presence (or not) of a coordinating pyridyl heterocycle are presented. By making full use of the O,N(amide), N(azo), and N(pyridyl) coordinating sites, the first diruthenium complex that is bridged by an azo ligand containing two different binding pockets was obtained. Moreover, it was conclusively proven that, in the mononuclear complexes, oxidation at the ruthenium center leads to a complete change of coordination at the chelating binding pocket. The complexes were characterized by NMR spectroscopy, mass spectrometry, and single-crystal X-ray diffraction. Additionally, the mechanism of the aforementioned redox-triggered change in the chelating binding pocket and the electronic structures of all the complexes were investigated by a combination of electrochemistry, UV/Vis/NIR/EPR spectroelectrochemistry, and DFT calculations. This is first instance in which a redox-driven change in the complete chelating binding pocket has been observed in a ruthenium complex as well as with azo-based ligands. These results thus show the potential of these versatile azocarboxamide ligands to act as redox-driven switches with possible relevance to electrocatalysis.
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Affiliation(s)
- Johannes Klein
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34-36, 14195, Berlin, Germany
| | - Julia Beerhues
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34-36, 14195, Berlin, Germany
| | - David Schweinfurth
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34-36, 14195, Berlin, Germany
| | - Margarethe van der Meer
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34-36, 14195, Berlin, Germany
| | - Martin Gazvoda
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Janez Košmrlj
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34-36, 14195, Berlin, Germany
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Aguirre-Araque JS, Rocha RC, Toma HE. Electrostatic bending and outer-sphere intervalence transfer in a flexible ligand-bridged ruthenium(III)-iron(II) complex. J COORD CHEM 2018. [DOI: 10.1080/00958972.2018.1493725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
| | | | - Henrique E. Toma
- Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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17
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Noss ME, Wieder NL, Carroll PJ, Zdilla MJ, Berry DH. Magnetism and EPR Studies of Binuclear Ruthenium Hydride Binuclear Species Bearing Redox-Active Ligands. Inorg Chem 2018; 57:7036-7043. [PMID: 29874060 DOI: 10.1021/acs.inorgchem.8b00735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The binuclear complex {[N3]Ru(H)}2(μ-η1:η1-N2) ([N3] = 2,6-(ArylN═CMe)2C5H3N and Aryl = mesityl or xylyl) contains two formally Ru(I), d7 centers linked by a bridging dinitrogen ligand, although the odd electrons are substantially delocalized onto the redox non-innocent pincer ligands. The complex exhibits paramagnetic behavior in solution, but is diamagnetic in the solid state. This difference is attributed to intermolecular "π-stacking" observed in the solid state, which essentially couples unpaired electrons on each half of the complex to form delocalized 22-center-2-electron covalent bonds. Introduction of a bulky t-butyl group on the ligand pyridine ring prevents this intermolecular association and allows further investigation of the magnetic behavior and electronic structure of the binuclear species. The interaction of the unpaired electrons in the two halves of the complex has been probed with magnetic susceptibility and perpendicular and parallel mode EPR measurements, revealing a weakly antiferromagnetically coupled system with a thermally accessible triplet excited state. In addition, the mixed valent, S = 1/2, {[N3]Ru(H)}(μ-η1:η1-N2){[N3]Ru} system has also been observed via perpendicular mode EPR and was used to quantify the growth of the thermally accessible triplet state of the dihydride complex using parallel mode EPR.
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Affiliation(s)
- Michael E Noss
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Noah L Wieder
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Patrick J Carroll
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Michael J Zdilla
- Department of Chemistry , Temple University , Philadelphia , Pennsylvania 19122 , United States
| | - Donald H Berry
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
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Arachchige PTK, Lee H, Yi CS. Synthesis of Symmetric and Unsymmetric Secondary Amines from the Ligand-Promoted Ruthenium-Catalyzed Deaminative Coupling Reaction of Primary Amines. J Org Chem 2018; 83:4932-4947. [PMID: 29665681 DOI: 10.1021/acs.joc.8b00649] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The catalytic system generated in situ from the tetranuclear Ru-H complex with a catechol ligand (1/L1) was found to be effective for the direct deaminative coupling of two primary amines to form secondary amines. The catalyst 1/L1 was highly chemoselective for promoting the coupling of two different primary amines to afford unsymmetric secondary amines. The analogous coupling of aniline with primary amines formed aryl-substituted secondary amines. The treatment of aniline- d7 with 4-methoxybenzylamine led to the coupling product with significant deuterium incorporation on CH2 (18% D). The most pronounced carbon isotope effect was observed on the α-carbon of the product isolated from the coupling reaction of 4-methoxybenzylamine (C(1) = 1.015(2)). A Hammett plot was constructed from measuring the rates of the coupling reaction of 4-methoxyaniline with a series of para-substituted benzylamines 4-X-C6H4CH2NH2 (X = OMe, Me, H, F, CF3) (ρ = -0.79 ± 0.1). A plausible mechanistic scheme has been proposed for the coupling reaction on the basis of these results. The catalytic coupling method provides an operationally simple and chemoselective synthesis of secondary amine products without using any reactive reagents or forming wasteful byproducts.
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Affiliation(s)
| | - Hanbin Lee
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201-1881 , United States
| | - Chae S Yi
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201-1881 , United States
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