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Goswami B, Khatua M, Devi A, Hans S, Chatterjee R, Samanta S. Ligand redox controlled amine dehydrogenation and imine hemilability in singlet diradical azo-aromatic Ni(II) complexes: characterization of the electron transfer series of azo-imine complexes of Ni(II). Dalton Trans 2024; 53:10250-10260. [PMID: 38829194 DOI: 10.1039/d3dt03414c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Herein, using azo-amine (H2L) and azo-imine (L1-3) ligands, singlet diradical Ni(II) complexes [1] and [2] were synthesized from Ni(0)(COD)2 in THF. In separate reactions, homoleptic NiII complexes, [3a]2+-[3c]2+, were synthesized from [NiII(H2O)6](ClO4)2 and L1-3, respectively. All these complexes were characterized thoroughly. The X-ray structures of [1] and [2] showed that the amine side arm in [1] and the imine side arm in [2] are de-coordinated. The dN-N lengths in these two complexes were found to be ∼1.32 Å, which corresponds to the one-electron reduced azo-bond length. These complexes, [1] and [2], showed 1H NMR signals characteristic of diamagnetic compounds. These studies, along with DFT calculations, indicated that the unpaired spins on ligands coupled antiferromagnetically with the two unpaired spins on NiII to result in s = 0 ground states. Complex [1] showed ligand-based redox-induced dehydrogenation of the distal amine side arm to result in L1. Complexes [3a]2+-[3c]2+ have dN-N lengths of ∼1.27 Å and dC-N lengths of ∼1.28 Å. In cyclic voltammetry, complex [3a]2+ showed four well-resolved reversible reductive waves at 0.5 V to -1.6 V in dichloromethane. The first two waves became irreversible when they were measured in acetonitrile solution. The electron transfer series of [3a]2+ was further characterized by spectro-electrochemistry, EPR, and DFT calculations. These showed that all the reductions were associated with the ligand. It was further probed by redox events in complexes [3b]2+ and [3c]2+. While the electron donor -OMe group on the phenyl ring of the azo moiety in [3b]2+ showed a prominent cathodic shift of the potentials, the -F substitution on the phenyl group on the imine side arm of [3c]2+ has almost no effect. It has to be noted here that the oxidation of [2] by two electrons returns it back to complex [3a]2+. Reduction of [3a]2+ by two electrons also resulted in complex [2], indicating reversible ligand redox-induced hemilability of the imine moiety between [3a]2+ and [2]. Moreover, characterization of the electron transfer series of [3a]2+ and [2] has shown superior redox non-innocent behaviour and coordination ability of the azo-pyridine moiety in nickel(II) complexes over the imino-pyridine moiety of the ligand.
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Affiliation(s)
- Bappaditya Goswami
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal 741246, India
| | - Manas Khatua
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal 741246, India
| | - Ambika Devi
- Department of Chemistry, Indian Institute of Technology Jammu, Jagti, Jammu, Jammu and Kashmir 181221, India.
| | - Shivali Hans
- Department of Chemistry, Indian Institute of Technology Jammu, Jagti, Jammu, Jammu and Kashmir 181221, India.
| | - Robindo Chatterjee
- Department of Chemistry, Indian Institute of Technology Jammu, Jagti, Jammu, Jammu and Kashmir 181221, India.
| | - Subhas Samanta
- Department of Chemistry, Indian Institute of Technology Jammu, Jagti, Jammu, Jammu and Kashmir 181221, India.
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Pahar S, Sharma V, Raj KV, Sangole MP, George CP, Singh K, Vanka K, Gonnade RG, Sen SS. Tridentate NacNac Tames T-Shaped Nickel(I) Radical. Chemistry 2024; 30:e202303957. [PMID: 38051591 DOI: 10.1002/chem.202303957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
The reaction of a nickel(II) chloride complex containing a tridentate β-diketiminato ligand with a picolyl group [2,6-iPr2 -C6 H3 NC(Me)CHC(Me)NH(CH2 py)]Ni(II)Cl (1)] with KSi(SiMe3 )3 conveniently afforded a nickel(I) radical with a T-shaped geometry (2). The compound's metalloradical nature was confirmed through electron paramagnetic resonance (EPR) studies and its reaction with TEMPO, resulting in the formation of a highly unusual three-membered nickeloxaziridine complex (3). When reacted with disulfide and diselenide, the S-S and Se-Se bonds were cleaved, and a coupled product was formed through carbon atom of the pyridine-imine group. The nickel(I) radical activates dihydrogen at room temperature and atmospheric pressure to give the monomeric nickel hydride.
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Affiliation(s)
- Sanjukta Pahar
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Vishal Sharma
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - K Vipin Raj
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Mayur P Sangole
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Christy P George
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Kirandeep Singh
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Rajesh G Gonnade
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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Mangin LP, Albkuri YM, Ovens JS, Al Shehimy S, Khrouz L, Steinmann S, Bucher C, Baker RT. Electron-Triggered Imine Coupling: Synthesis and Characterization of Three Redox States (0,-1,-2) of a Ni(N 2 S 2 ) Complex. Chemistry 2024; 30:e202302714. [PMID: 37983723 DOI: 10.1002/chem.202302714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Indexed: 11/22/2023]
Abstract
Metal imine-thiolate complexes, M(NS)2 are known to undergo imine C-C bond formation to give M(N2 S2 ) complexes (M=Co, Ni) containing a redox-active ligand. Although these transfor-mations are not typically quantitative, we demonstrate here that the one-electron reduction of a related Ni bis(imine-thiolate) complex affords the corresponding paramagnetic [Ni(N2 S2 )]- anion (2⋅- ) exclusively; subsequent oxidation with [Cp2 Fe]BF4 then affords a high yield of neutral 2 (Cp=η5 -cyclopentadienyl). Moreover, electrochemical studies indicate that a second one-electron reduction affords the diamagnetic dianion. Both anionic products were isolated and characterized by SC-XRD and their electronic structures were investigated by UV-vis spectro-electrochemistry, EPR and NMR spectroscopy, and DFT studies. These studies show that reduction proceeds primarily on the ligand, with (N2 S2 )4- containing both thiolate and ring-delocalized anions.
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Affiliation(s)
- Loïc P Mangin
- Department of Chemistry and Biomolecular Sciences and, Centre for Catalysis Research and Innovation, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Yahya M Albkuri
- Department of Chemistry and Biomolecular Sciences and, Centre for Catalysis Research and Innovation, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Jeffrey S Ovens
- Faculty of Science, University of Ottawa, 150 Louis Pasteur Pvt., Ottawa, Ontario, K1N 6N5, Canada
| | - Shaymaa Al Shehimy
- ENSL, CNRS, Laboratoire de Chimie UMR 5182, 46 allée d'Italie, 69342, Lyon, France
| | - Lhoussain Khrouz
- ENSL, CNRS, Laboratoire de Chimie UMR 5182, 46 allée d'Italie, 69342, Lyon, France
| | - Stephan Steinmann
- ENSL, CNRS, Laboratoire de Chimie UMR 5182, 46 allée d'Italie, 69342, Lyon, France
| | - Christophe Bucher
- ENSL, CNRS, Laboratoire de Chimie UMR 5182, 46 allée d'Italie, 69342, Lyon, France
| | - R Tom Baker
- Department of Chemistry and Biomolecular Sciences and, Centre for Catalysis Research and Innovation, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
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Huang P, Yoshida Y, Komatsu T, Nakamura Y, Sugimoto K, Kitagawa H. Isomerization-Controlled Proton-Electron Coupling in a π-Planar Metal Complex. Inorg Chem 2023; 62:1135-1140. [PMID: 36632676 DOI: 10.1021/acs.inorgchem.2c03417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Proton-coupled electron transfer (PCET) is a ubiquitous and fundamental process in biochemistry and electrochemistry performed by transition-metal complexes. Most synthetic efforts have been devoted to selecting the components, that is, metal ions and ligands, to control the proton-electron coupling. Here, we show the first example of controlling the proton-electron coupling using the cis-trans metal-ligand isomerization in a π-planar platinum complex, Pt(itsq)2 (itsq1-: o-iminothiosemiquinonate). Both the isomers, which were obtained separately, were characterized by single-crystal X-ray diffraction, and the cis-to-trans isomerization was achieved by immersing in organic solvents. Theoretical calculations predicted that the proton-electron coupling evaluated from the energetic stabilization of the lowest unoccupied molecular orbital by protonation varies greatly depending on the geometrical configuration compared to the metal substitution.
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Affiliation(s)
- Pingping Huang
- Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto606-8502, Japan
| | - Yukihiro Yoshida
- Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto606-8502, Japan
| | - Tokutaro Komatsu
- School of Medicine, Nihon University, 30-1 Oyaguchi-Kamicho, Itabashi-ku, Tokyo173-8610, Japan
| | - Yuiga Nakamura
- Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo679-5198, Japan
| | - Kunihisa Sugimoto
- Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo679-5198, Japan
| | - Hiroshi Kitagawa
- Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto606-8502, Japan
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Wojnar M, Ziller JW, Heyduk AF. Two-Electron Mixed Valency in a Heterotrimetallic Nickel-Vanadium-Nickel Complex. Inorg Chem 2023; 62:1405-1413. [PMID: 36633592 PMCID: PMC9890480 DOI: 10.1021/acs.inorgchem.2c03381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Mixed-valence complexes represent an enticing class of coordination compounds to interrogate electron transfer confined within a molecular framework. The diamagnetic heterotrimetallic anion, [V(SNS)2{Ni(dppe)}2]-, was prepared by reducing (dppe)NiCl2 in the presence of the chelating metalloligand [V(SNS)2]- [dppe = bis(diphenylphosphino)ethane; (SNS)3- = bis(2-thiolato-4-methylphenyl)amide]. Vanadium-nickel bonds span the heterotrimetallic core in the structure of [V(SNS)2{Ni(dppe)}2]-, with V-Ni bond lengths of 2.78 and 2.79 Å. One-electron oxidation of monoanionic [V(SNS)2{Ni(dppe)}2]- yielded neutral, paramagnetic V(SNS)2{Ni(dppe)}2. The solid-state structure of V(SNS)2{Ni(dppe)}2 revealed that the two nickel ions occupy unique coordination environments: one nickel is in a square-planar S2P2 coordination environment (τ4 = 0.19), with a long Ni···V distance of 3.45 Å; the other nickel is in a tetrahedral S2P2 coordination environment (τ4 = 0.84) with a short Ni-V distance of 2.60 Å, consistent with a formal metal-metal bond. Continuous-wave X-band electron paramagnetic resonance spectroscopy, electrochemical investigations, and density functional theory computations indicated that the unpaired electron in the neutral V(SNS)2{Ni(dppe)}2 cluster is localized on the bridging [V(SNS)2] metalloligand, and as a result, V(SNS)2{Ni(dppe)}2 is best described as a two-electron mixed-valence complex. These results demonstrate the important role that metal-metal interactions and flexible coordination geometries play in enabling multiple, reversible electron transfer processes in small cluster complexes.
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Kumar P, Devkota L, Casey MC, Fischer AA, Lindeman SV, Fiedler AT. Reversible Dioxygen Binding to Co(II) Complexes with Noninnocent Ligands. Inorg Chem 2022; 61:16664-16677. [PMID: 36206536 PMCID: PMC11218047 DOI: 10.1021/acs.inorgchem.2c02246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of mononuclear Co(II) complexes with noninnocent (redox-active) ligands are prepared that exhibit metal-ligand cooperativity during the reversible binding of O2. The complexes have the general formula, [CoII(LS,N)(TpR2)] (R = Me, Ph), where LS,N is a bidentate o-aminothiophenolate and TpR2 is a hydrotris(pyrazol-1-yl)borate scorpionate with R-substituents at the 3- and 5-positions. Exposure to O2 at room temperature results in one-electron oxidation and deprotonation of LS,N. The oxidized derivatives possess substantial "singlet diradical" character arising from antiferromagnetic coupling between an iminothiosemiquinonate (ITSQ•-) ligand radical and a low-spin Co(II) ion. The [CoII(TpMe2)(X2ITSQ)] complexes, where X = H or tBu, coordinate O2 reversibly at reduced temperatures to provide Co/O2 adducts. The O2 binding reactions closely resemble those previously reported by our group (Kumar et al., J. Am. Chem. Soc. 2019,141, 10984-10987) for the related complexes [CoII(TpMe2)(tBu2SQ)] and [CoII(TpMe2)(tBu2ISQ)], where tBu2(I)SQ represents 4,6-di-tert-butyl-(2-imino)semiquinonate radicals. In each case, the oxygenation reaction proceeds via the addition of O2 to both the cobalt ion and the ligand radical, generating metallocyclic cobalt(III)-alkylperoxo structures. Thermodynamic measurements elucidate the relationship between O2 affinity and redox potentials of the (imino)(thio)semiquinonate radicals, as well as energetic differences between these reactions and conventional metal-based oxygenations. The results highlight the utility and versatility of noninnocent ligands in the design of O2-absorbing compounds.
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Affiliation(s)
- Praveen Kumar
- Department of Chemistry, Marquette University, 1414 W. Clybourn Street, Milwaukee, Wisconsin53233, United States
| | - Laxmi Devkota
- Department of Chemistry, Marquette University, 1414 W. Clybourn Street, Milwaukee, Wisconsin53233, United States
| | - Maximilian C Casey
- Department of Chemistry, Marquette University, 1414 W. Clybourn Street, Milwaukee, Wisconsin53233, United States
| | - Anne A Fischer
- Department of Chemistry, Marquette University, 1414 W. Clybourn Street, Milwaukee, Wisconsin53233, United States
| | - Sergey V Lindeman
- Department of Chemistry, Marquette University, 1414 W. Clybourn Street, Milwaukee, Wisconsin53233, United States
| | - Adam T Fiedler
- Department of Chemistry, Marquette University, 1414 W. Clybourn Street, Milwaukee, Wisconsin53233, United States
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Arya Y, Bera SK, Priego JL, Jiménez-Aparicio R, Lahiri GK. Bidirectional noninnocence of hinge-like deprotonated bis-lawsone on selective ruthenium platform: a function of varying ancillary ligands. Dalton Trans 2022; 51:10441-10456. [PMID: 35762823 DOI: 10.1039/d2dt01466a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The present work aimed to obtain discrete heavier metal complexes of unperturbed deprotonated bis-lawsone (hinge-like H2L = 2,2'-bis(3-hydroxy-1,4-napthoquinone). This is primarily due to its limited examples with lighter metal ions (Co, Zn, and Ga) and the fact that our earlier approach with the osmium ion facilitated its functionalisation. Herein, we demonstrated the successful synthesis and structural characterisation of L2--derived diruthenium [(bpy)2RuII(μ-L2-)RuII(bpy)2](ClO4)2 [1](ClO4)2 (S = 0), (acac)2RuIII(μ-L2-)RuIII(acac)22 (S = 1) and monoruthenium (pap)2Ru(L2-) 3 (S = 0) derivatives (bpy = 2,2'-bipyridine, acac = acetylacetonate, and pap = 2-phenylazopyridine). The crystal structures established that (i) O,O-/O,O- donating five-membered bis-bidentate and O-,O- donating seven-membered bidentate chelating modes of deprotonated L2- in rac (ΔΔ/ΛΛ) diastereomeric [1](ClO4)2, 2 and 3, respectively. (ii) The L2- bridging unit in [1](ClO4)2, 2 and 3 underwent twisting its two naphthoquinone rings with respect to the ring connecting C-C bond by 73.01°, 62.15° and 59.12°, respectively. (iii) Intermolecular π-π interactions (∼3.5 Å) between the neighbouring molecules. The paramagnetic complex 2 (S = 1) with two non-interacting Ru(III) (S = 1/2) ions exhibited weak antiferromagnetic coupling only at very low temperatures. In agreement with the magnetic results, 2 displayed typical RuIII-based anisotropic EPR in CH3CN (<g>/Δg: 2.314/0.564) but without any forbidden g1/2 signal at 120 K. The complexes exhibited multiple redox processes in CH3CN in the experimental potential window of ± 2.0 V versus SCE. The analysis of the redox steps via a combined experimental and theoretical (DFT/TD-DFT) approach revealed the involvement of L2- to varying extents in both the oxidative and reductive processes as a consequence of its bidirectional redox non-innocent feature. The mixing of the frontier orbitals of the metal ion and L2- due to their closeness in energy indeed led to the resonating electronic form in certain redox states instead of any precise electronic structural state.
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Affiliation(s)
- Yogita Arya
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Sudip Kumar Bera
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - José Luis Priego
- Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria, E-28040 Madrid, Spain
| | - Reyes Jiménez-Aparicio
- Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria, E-28040 Madrid, Spain
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
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Huang P, Yoshida Y, Nakano Y, Yamochi H, Hayashi M, Kitagawa H. Strong Proton‐Electron Coupling in π‐Planar Metal Complex with Redox‐Active Ligands. Angew Chem Int Ed Engl 2022; 61:e202204521. [DOI: 10.1002/anie.202204521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Pingping Huang
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
| | - Yukihiro Yoshida
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
| | - Yoshiaki Nakano
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
- Division of Chemistry, Graduate School of Science Kyoto University Yoshida Honmachi Sakyo-ku Kyoto 606–8501 Japan
| | - Hideki Yamochi
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
- Division of Chemistry, Graduate School of Science Kyoto University Yoshida Honmachi Sakyo-ku Kyoto 606–8501 Japan
| | - Mikihiro Hayashi
- Faculty of Education Nagasaki University 1-14 Bunkyo-machi Nagasaki 852-8521 Japan
| | - Hiroshi Kitagawa
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
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Huang P, Yoshida Y, Nakano Y, Yamochi H, Hayashi M, Kitagawa H. Strong Proton‐Electron Coupling in π‐Planar Metal Complex with Redox‐Active Ligands. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Pingping Huang
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
| | - Yukihiro Yoshida
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
| | - Yoshiaki Nakano
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
- Division of Chemistry, Graduate School of Science Kyoto University Yoshida Honmachi Sakyo-ku Kyoto 606–8501 Japan
| | - Hideki Yamochi
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
- Division of Chemistry, Graduate School of Science Kyoto University Yoshida Honmachi Sakyo-ku Kyoto 606–8501 Japan
| | - Mikihiro Hayashi
- Faculty of Education Nagasaki University 1-14 Bunkyo-machi Nagasaki 852-8521 Japan
| | - Hiroshi Kitagawa
- Division of Chemistry, Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto 606-8502 Japan
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Hogarth G, Al-Jibori SA, Al-Janabi A, Ghosh S, Basak-Modi S, Irzoqi AA, Wagner C, Al-Nassiry AI. Synthesis, structure and reactivity with phosphines of Hg(II) ortho-cyano-aminothiophenolate complexes formed via C-S bond cleavage and dehydrogenation of 2-aminobenzothiazoles. Dalton Trans 2022; 51:7889-7898. [DOI: 10.1039/d2dt00391k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Addition of 2-aminobenzothiazole (abt) and substituted derivatives to Hg(OAc)2 leads to the high yield formation of ortho-cyano-aminothiophenolate (ocap) complexes [Hg{SC6H3XN(C≡N)}]n (X = H, Me, Cl, Br, NO2) resulting from dehydrogenation...
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Bera SK, Lahiri GK. Structural and electronic forms of doubly oxido/Pz and triply oxido/(Pz) 2 bridged mixed valent and isovalent diruthenium complexes (Pz = pyrazolate). Dalton Trans 2021; 50:17653-17664. [PMID: 34806731 DOI: 10.1039/d1dt03076k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The article reported on the diastereomeric dinuclear mixed-valent complexes [(acac)2Ru(III)(μ-O)(μ-PzR)Ru(IV)(acac)2] (R = H, Me, meso: ΔΛ, 1a-1c; rac: ΔΔ/ΛΛ, 2a-2c) and rac-[(acac)2Ru(III)(μ-O)(μ-Iz)Ru(IV)(acac)2], (2d) (HPz = pyrazole, HIz = indazole, acac = acetylacetonate). Moreover, the diruthenium(II,II) complexes [(HPz)3Ru(II)(μ-O)(μ-Pz)2 Ru(II)(HPz)3] (3a) and [(HIz)3Ru(II)(μ-O)(μ-Iz)2Ru(II)(HIz)3] (3d) were presented. The analogous form of 3a, i.e., [(HPz)2(Pz)Ru(III)(μ-O)(μ-Pz)2Ru(III)(Pz)(HPz)2], was previously reported. Single crystal X-ray structures of 1a-1c/2a-2d and representative 3a showed their molecular forms, including the diastereomeric nature of the former. The Ru-O-Ru angle decreased appreciably on switching from doubly bridged 1 and 2 (128-135°) to triply bridged 3a (114°). Both series of complexes displayed rhombic symmetry in their EPR spectra, with g1 and g2 being very similar for 1a-1c with an almost axial look. The mixed-valence complex with a Ru(III)Ru(IV) (S = 1/2) state of 1 and 2 would lead to iso-valence complexes of Ru(III)Ru(III) and Ru(IV)Ru(IV) with an EPR inactive state by one electron redox reaction. On the other hand, metal based {Ru(II)Ru(II)/Ru(II)Ru(III), 3a/3a+} and terminal ligand (HPz/HPz-, 3a/3a-) based redox processes displayed anisotropic and free radical EPR, respectively. An IVCT (intervalence charge transfer) band was found for the delocalised mixed valent 1 and 2 {Ru(III)Ru(IV)} or 3a+ {Ru(II)Ru(III)} in the NIR region. The intense metal-to-ligand charge transfer (MLCT) transitions of 1-3 in the visible region varied systematically as a function of the metal oxidation state.
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Affiliation(s)
- Sudip Kumar Bera
- 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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12
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Gordon JB, McGale JP, Siegler MA, Goldberg DP. Proton-Coupled Electron-Transfer Reactivity Controls Iron versus Sulfur Oxidation in Nonheme Iron-Thiolate Complexes. Inorg Chem 2021; 60:6255-6265. [PMID: 33872005 DOI: 10.1021/acs.inorgchem.0c03779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reaction of the five-coordinate FeII(N4S) complexes, [FeII(iPr3TACN)(abtX)](OTf) (abt = aminobenzenethiolate, X = H, CF3), with a one-electron oxidant and an appropriate base leads to net H atom loss, generating new FeIII(iminobenzenethiolate) complexes that were characterized by single-crystal X-ray diffraction (XRD), as well as UV-vis, EPR, and Mössbauer spectroscopies. The spectroscopic data indicate that the iminobenzenethiolate complexes have S = 3/2 ground states. In the absence of a base, oxidation of the FeII(abt) complexes leads to disulfide formation instead of oxidation at the metal center. Bracketing studies with separated proton-coupled electron-transfer (PCET) reagents show that the FeII(aminobenzenethiolate) and FeIII(iminobenzenethiolate) forms are readily interconvertible by H+/e- transfer and provide a measure of the bond dissociation free energy (BDFE) for the coordinated N-H bond between 64 and 69 kcal mol-1. This work shows that coordination to the iron center causes a dramatic weakening of the N-H bond and that Fe- versus S-oxidation in a nonheme iron complex can be controlled by the protonation state of an ancillary amino donor.
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Affiliation(s)
- Jesse B Gordon
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Jeremy P McGale
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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13
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Synthesis of Novel Heteroleptic Oxothiolate Ni(II) Complexes and Evaluation of Their Catalytic Activity for Hydrogen Evolution. Catalysts 2021. [DOI: 10.3390/catal11030401] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Two heteroleptic nickel oxothiolate complexes, namely [Ni(bpy)(mp)] (1) and [Ni(dmbpy)(mp)] (2), where mp = 2-hydroxythiophenol, bpy = 2,2′-bipyridine and dmbpy = 4,4′-dimethyl-2,2′-bipyridine were synthesized and characterized with various physical and spectroscopic methods. Complex 2 was further characterized by single crystal X-ray diffraction data. The complex crystallizes in the monoclinic P 21/c system and in its neutral form. The catalytic properties of both complexes for proton reduction were evaluated with photochemical and electrochemical studies. Two different in their nature photosensitizers, namely fluorescein and CdTe-TGA-coated quantum dots, were tested under various conditions. The role of the electron donating character of the methyl substituents was revealed in the light of the studies. Thus, catalyst 2 performs better than 1, reaching 39.1 TONs vs. 4.63 TONs in 3 h, respectively, in electrochemical experiments. In contrast, complex 1 is more photocatalytically active than 2, achieving a TON of over 6700 in 120 h of irradiation. This observed reverse catalytic activity suggests that HER mechanism follows different pathways in electrocatalysis and photocatalysis.
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14
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Huang Y, Jian Y, Li L, Li D, Fang Z, Dong W, Lu Y, Luo B, Chen R, Yang Y, Chen M, Shi W. A NIR-Responsive Phytic Acid Nickel Biomimetic Complex Anchored on Carbon Nitride for Highly Efficient Solar Hydrogen Production. Angew Chem Int Ed Engl 2021; 60:5245-5249. [PMID: 33247495 DOI: 10.1002/anie.202014317] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Indexed: 01/25/2023]
Abstract
A challenge in photocatalysis consists in improving the efficiency by harnessing a large portion of the solar spectrum. We report the design and realization of a robust molecular-semiconductor photocatalytic system (MSPS) consisting of an earth-abundant phytic acid nickel (PA-Ni) biomimetic complex and polymeric carbon nitride (PCN). The MSPS exhibits an outstanding activity at λ=940 nm with high apparent quantum efficiency (AQE) of 2.8 %, particularly λ>900 nm, as it outperforms all reported state-of-the-art near-infrared (NIR) hybrid photocatalysts without adding any noble metals. The optimum hydrogen (H2 ) production activity was about 52 and 64 times higher with respect to its pristine counterpart under the AM 1.5 G and visible irradiation, respectively, being equivalent to the platinum-assisted PCN. This work sheds light on feasible avenues to prepare highly active, stable, cheap NIR-harvesting photosystems toward sustainable and scalable solar-to-H2 production.
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Affiliation(s)
- Yuanyong Huang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Yaping Jian
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Longhua Li
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Di Li
- Institute for Energy Research, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Zhenyuan Fang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Weixuan Dong
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Yahui Lu
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Bifu Luo
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Ruijie Chen
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Yingchen Yang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Min Chen
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Weidong Shi
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
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15
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Charette BJ, Ziller JW, Heyduk AF. Metal-Ion Influence on Ligand-Centered Hydrogen-Atom Transfer. Inorg Chem 2021; 60:1579-1589. [PMID: 33434022 DOI: 10.1021/acs.inorgchem.0c02981] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ligand-centered hydrogen-atom-transfer (HAT) reactivity was examined for a family of group 10 metal complexes containing a tridentate pincer ligand derived from bis(2-mercapto-p-tolyl)amine, [SNS]H3. Six new metal complexes of palladium and platinum were synthesized with the [SNS] ligand platform in different redox and protonation states to complete the group 10 series previously reported with nickel. The HAT reactivity was examined for this family of nickel, palladium, and platinum complexes to determine the impact of a metal ion on the ligand-centered reactivity. Thermodynamic measurements revealed that N-H bond dissociation free energies increased by approximately 10 kcal mol-1 along the series Ni < Pd < Pt driven by changes to both the redox potential and pKa of the ligand. Kinetic analyses for all three metal complexes suggest that the barrier to the HAT reactivity is primarily entropic rather than enthalpic for this system.
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Affiliation(s)
- Bronte J Charette
- Department of Chemistry, University of California at Irvine (UCI), Irvine, California 92677-2025, United States
| | - Joseph W Ziller
- Department of Chemistry, University of California at Irvine (UCI), Irvine, California 92677-2025, United States
| | - Alan F Heyduk
- Department of Chemistry, University of California at Irvine (UCI), Irvine, California 92677-2025, United States
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16
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Huang Y, Jian Y, Li L, Li D, Fang Z, Dong W, Lu Y, Luo B, Chen R, Yang Y, Chen M, Shi W. A NIR‐Responsive Phytic Acid Nickel Biomimetic Complex Anchored on Carbon Nitride for Highly Efficient Solar Hydrogen Production. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202014317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yuanyong Huang
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Yaping Jian
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Longhua Li
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Di Li
- Institute for Energy Research Jiangsu University Zhenjiang 212013 P. R. China
| | - Zhenyuan Fang
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Weixuan Dong
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Yahui Lu
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Bifu Luo
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Ruijie Chen
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Yingchen Yang
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Min Chen
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
| | - Weidong Shi
- School of Chemistry and Chemical Engineering Jiangsu University Zhenjiang 212013 P. R. China
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17
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Kumari M, Bera SK, Lahiri GK. Noninnocence of the deprotonated 1,2-bis((1 H-pyrrol-2-yl)methylene)hydrazine bridge in diruthenium frameworks - a function of co-ligands. Dalton Trans 2021; 50:9891-9903. [PMID: 34196336 DOI: 10.1039/d1dt01488a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The article deals with the sensitive electronic forms in accessible redox states of structurally and spectroscopically authenticated deprotonated 1,2-bis((1H-pyrrol-2-yl)methylene)hydrazine (H2LR, R = H) or 1,2-bis((3,5-dimethyl-1H-pyrrol-2-yl)methylene)hydrazine (H2LR, R = Me), a BODIPY analogue bridged diruthenium complex as a function of varying ancillary ligands. It involved rac-(acac)2RuIII(μ-LR 2-)RuIII(acac)21a, R = H; 1b, R = Me (S = 1, acac = acetylacetonate), rac-[(bpy)2RuII(μ-L2-)RuII(bpy)2](ClO4)2 [2](ClO4)2 (S = 0, bpy = 2,2'-bipyridine) and diastereomeric [(pap)2RuII(μ-L2-)RuII(pap)2](ClO4)2meso-[3a](ClO4)2/rac-[3b](ClO4)2 (S = 0, pap = phenylazopyridine). The crystal structure established the linkage of the conjugated -C5[double bond, length as m-dash]N2-N3[double bond, length as m-dash]C6- central unit with the two terminal deprotonated pyrrole units of coordinated L2-. The bridging L2- in 1a, 1b, [2](ClO4)2, [3b](ClO4)2 and [3a](ClO4)2 was slightly twisted and planar with torsional angles of 41.54°, 42.91°, 37.38°, 35.33° and 0°, respectively, with regard to the central N2-N3 bond. The extent of twisting of the bridge followed an inverse relationship with the RuRu separation: 4.935/4.934 Å 1a/1b < 5.141 Å [2](ClO4)2 < 5.201 Å [3b](ClO4)2 < 5.351 Å [3a](ClO4)2. This is also attributed to the intermolecular ππ/CHπ interactions between the nearby aromatic rings of L and bpy or pap in [2](ClO4)2 or [3](ClO4)2, respectively. The multiple redox steps of the complexes varied appreciably based on the σ-donating (acac) and π-acidic (bpy, pap) characteristics of the ancillary ligands. Experimental (structure, EPR) and theoretical (DFT) evaluation pertaining to the electronic forms of 1n, 2n and 3n demonstrated the preferential involvement of L based frontier orbitals in electron transfer processes even in combination with the redox facile ruthenium ion. This in turn highlighted its redox non-innocent feature as in the case of well-documented metal coordinated quinonoid, formazanate, diimine (bpy), azo (pap) and β-diketiminate functions.
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Affiliation(s)
- Maya Kumari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Sudip Kumar Bera
- 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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18
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Kumar P, SantaLucia DJ, Kaniewska-Laskowska K, Lindeman SV, Ozarowski A, Krzystek J, Ozerov M, Telser J, Berry JF, Fiedler AT. Probing the Magnetic Anisotropy of Co(II) Complexes Featuring Redox-Active Ligands. Inorg Chem 2020; 59:16178-16193. [DOI: 10.1021/acs.inorgchem.0c01812] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Praveen Kumar
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Daniel J. SantaLucia
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Kinga Kaniewska-Laskowska
- Department of Inorganic Chemistry, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk PL-80-233, Poland
| | - Sergey V. Lindeman
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - J. Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - John F. Berry
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Adam T. Fiedler
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
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19
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Sengupta D, Goswami S, Banerjee R, Guberman-Pfeffer MJ, Patra A, Dutta A, Pramanick R, Narasimhan S, Pradhan N, Batista V, Venkatesan T, Goswami S. Size-selective Pt siderophores based on redox active azo-aromatic ligands. Chem Sci 2020; 11:9226-9236. [PMID: 34123171 PMCID: PMC8163438 DOI: 10.1039/d0sc02683b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We demonstrate a strategy inspired by natural siderophores for the dissolution of platinum nanoparticles that could enable their size-selective synthesis, toxicological assessment, and the recycling of this precious metal. From the fabrication of electronics to biomedical diagnosis and therapy, PtNPs find increasing use. Mitigating concerns over potential human toxicity and the need to recover precious metal from industrial debris motivates the study of bio-friendly reagents to replace traditional harsh etchants. Herein, we report a family of redox-active siderophore-viz. π-acceptor azo aromatic ligands (L) that spontaneously ionize and chelate Pt atoms selectively from nanoparticles of size ≤6 nm. The reaction produces a monometallic diradical complex, PtII(L˙-)2, isolated as a pure crystalline compound. Density functional theory provides fundamental insights on the size dependent PtNP chemical reactivity. The reported findings reveal a generalized platform for designing π-acceptor ligands to adjust the size threshold for dissolution of Pt or other noble metals NPs. Our approach may, for example, be used for the generation of Pt-based therapeutics or for reclamation of Pt nano debris formed in catalytic converters or electronic fabrication industries.
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Affiliation(s)
- Debabrata Sengupta
- School of Chemical Sciences, Indian Association for the Cultivation of Science Jadavpur Kolkata 700032 India
| | - Sreetosh Goswami
- NUSNNI-NanoCore, National University of Singapore Singapore 117411 Singapore .,NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore Singapore 117456 Singapore.,Department of Physics, National University of Singapore Singapore 117542 Singapore
| | - Rajdeep Banerjee
- Theoretical Sciences Unit, School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur Bangalore 560064 India
| | | | - Abhijeet Patra
- NUSNNI-NanoCore, National University of Singapore Singapore 117411 Singapore
| | - Anirban Dutta
- School of Materials Sciences, Indian Association for the Cultivation of Science Jadavpur Kolkata 700032 India
| | - Rajib Pramanick
- School of Chemical Sciences, Indian Association for the Cultivation of Science Jadavpur Kolkata 700032 India
| | - Shobhana Narasimhan
- Theoretical Sciences Unit, School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur Bangalore 560064 India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science Jadavpur Kolkata 700032 India
| | - Victor Batista
- Department of Chemistry, Yale University 225 Prospect Street New Haven Connecticut 06520 USA .,Energy Sciences Institute, Yale University 810 West Campus Drive West Haven Connecticut 06516 USA
| | - T Venkatesan
- NUSNNI-NanoCore, National University of Singapore Singapore 117411 Singapore .,NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore Singapore 117456 Singapore.,Department of Physics, National University of Singapore Singapore 117542 Singapore.,Department of Electrical and Computer Engineering, National University of Singapore Singapore 117583 Singapore.,Department of Materials Science and Engineering, National University of Singapore Singapore 117575 Singapore
| | - Sreebrata Goswami
- School of Chemical Sciences, Indian Association for the Cultivation of Science Jadavpur Kolkata 700032 India
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20
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Nickel(II)‐Mediated Reversible Thiolate/Disulfide Conversion as a Mimic for a Key Step of the Catalytic Cycle of Methyl‐Coenzyme M Reductase. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202001363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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21
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Bhandari A, Mishra S, Maji RC, Kumar A, Olmstead MM, Patra AK. Nickel(II)‐Mediated Reversible Thiolate/Disulfide Conversion as a Mimic for a Key Step of the Catalytic Cycle of Methyl‐Coenzyme M Reductase. Angew Chem Int Ed Engl 2020; 59:9177-9185. [DOI: 10.1002/anie.202001363] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Indexed: 01/22/2023]
Affiliation(s)
- Anirban Bhandari
- Department of Chemistry National Institute of Technology Durgapur Mahatma Gandhi Avenue Durgapur 713 209 (WB) India
| | - Saikat Mishra
- Department of Chemistry National Institute of Technology Durgapur Mahatma Gandhi Avenue Durgapur 713 209 (WB) India
| | - Ram Chandra Maji
- Department of Chemistry National Institute of Technology Durgapur Mahatma Gandhi Avenue Durgapur 713 209 (WB) India
| | - Akhilesh Kumar
- Department of Chemistry Indian Institute of Technology Kanpur Kanpur 208016 India
| | | | - Apurba K. Patra
- Department of Chemistry National Institute of Technology Durgapur Mahatma Gandhi Avenue Durgapur 713 209 (WB) India
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22
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Banerjee S, Sheet D, Sarkar S, Halder P, Paine TK. Nickel complexes of ligands derived from (o-hydroxyphenyl) dichalcogenide: delocalised redox states of nickel and o-chalcogenophenolate ligands. Dalton Trans 2019; 48:17355-17363. [PMID: 31730150 DOI: 10.1039/c9dt03413g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Two monoanionic nickel complexes Bu4N[Ni(LSeO)2] (1) and Bu4N[Ni(LSO)2] (2) (H2LSeO = 3,5-di-tert-butyl-2-hydroxyselenophenol and H2LSO = 3,5-di-tert-butyl-2-hydroxythiophenol) were synthesised by reductive cleavage of the respective 2,2'-dichalcogenobis(4,6-di-tert-butylphenol) (H2LX-X; X = Se, S) with nickel(ii) salts. The crystal structures of 1 and 2 confirm the reductive X-X bond cleavage with the concomitant formation of the corresponding monoanionic square planar complex, where quinoidal distortions of the aromatic rings are observed. The monoanionic complexes (1 and 2) are paramagnetic (S = 1/2), exhibiting rhombic EPR signals, and the g anisotropies are well correlated with the spin-orbit coupling of chalcogenides. The spectral data indicate that the ligands H2LXO in 1 and 2 are redox non-innocent and stabilise the square planar S = 1/2 nickel complexes with a highly delocalised unpaired electron. DFT calculations further support the delocalised electronic structures of the nickel complexes.
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Affiliation(s)
- Sridhar Banerjee
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A&2B Raja S. C. Mullick Road, Jadavpur, Kolkata-700032, India.
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23
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Sanz CA, Patrick BO, Hicks RG. Synthesis and redox chemistry of Pd(ii) complexes of a pincer verdazyl ligand. Dalton Trans 2019; 48:12674-12683. [PMID: 31384845 DOI: 10.1039/c9dt02549a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of palladium(ii) complexes containing a redox-active, tridentate verdazyl ligand of general formula (verdazyl)PdL (L = Cl, CH3CN) are synthesized. The tetrazine core of tridentate verdazyl ligand 5 is flanked by two pyridyl groups, creating a geometry in which the ancillary ligand L is bound trans to the verdazyl ring in the square planar metal complexes. Pd(ii) complexes were isolated with the verdazyl ligand in either its neutral radical charge state (6: L = CH3CN, 12: L = Cl) or its closed-shell monoanionic charge state (10: L = CH3CN, 9: L = Cl). The charge state of the ligand was determined using X-ray crystallography and NMR, EPR, and IR spectroscopy. The cyclic voltammograms of radical complexes 6 and 12 each contain a reversible one-electron reduction wave and an irreversible one-electron oxidation wave. The complexes can be chemically interconverted between radical ligand (6, 12) and reduced, closed-shell anion (9, 10) using decamethylferrocene as the reductant and a mixture of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and fluoroboric acid as the oxidant.
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Affiliation(s)
- Corey A Sanz
- Department of Chemistry, University of Victoria, PO Box 3065 STN CSC, Victoria, B.C. V8W3V6, Canada.
| | - Brian O Patrick
- Crystallography Laboratory, Department of Chemistry, University of British Columbia, Vancouver, BC V6T1Z1, Canada
| | - Robin G Hicks
- Department of Chemistry, University of Victoria, PO Box 3065 STN CSC, Victoria, B.C. V8W3V6, Canada.
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24
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Saeedi R, Safaei E, Lee YI, Lužnik J. Oxidation of sulfides including DBT using a new vanadyl complex of a non-innocent o
-aminophenol benzoxazole based ligand. Appl Organomet Chem 2019. [DOI: 10.1002/aoc.4781] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Roonak Saeedi
- Institute for Advanced Studies in Basic Sciences (IASBS); 45137-66731 Zanjan Iran
| | - Elham Safaei
- Department of Chemistry, College of Sciences; Shiraz University; Shiraz 71454 Iran
| | - Yong-Ill Lee
- Department of Chemistry; Changwon National University; Changwon 641-773 South Korea
| | - Janez Lužnik
- J. Stefan Institute and University of Ljubljana, Faculty of Mathematics and Physics; Jamova 39, SI-1000 Ljubljana Slovenia SI-1000 Ljubljana Slovenia
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25
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Dalle K, Warnan J, Leung JJ, Reuillard B, Karmel IS, Reisner E. Electro- and Solar-Driven Fuel Synthesis with First Row Transition Metal Complexes. Chem Rev 2019; 119:2752-2875. [PMID: 30767519 PMCID: PMC6396143 DOI: 10.1021/acs.chemrev.8b00392] [Citation(s) in RCA: 419] [Impact Index Per Article: 83.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Indexed: 12/31/2022]
Abstract
The synthesis of renewable fuels from abundant water or the greenhouse gas CO2 is a major step toward creating sustainable and scalable energy storage technologies. In the last few decades, much attention has focused on the development of nonprecious metal-based catalysts and, in more recent years, their integration in solid-state support materials and devices that operate in water. This review surveys the literature on 3d metal-based molecular catalysts and focuses on their immobilization on heterogeneous solid-state supports for electro-, photo-, and photoelectrocatalytic synthesis of fuels in aqueous media. The first sections highlight benchmark homogeneous systems using proton and CO2 reducing 3d transition metal catalysts as well as commonly employed methods for catalyst immobilization, including a discussion of supporting materials and anchoring groups. The subsequent sections elaborate on productive associations between molecular catalysts and a wide range of substrates based on carbon, quantum dots, metal oxide surfaces, and semiconductors. The molecule-material hybrid systems are organized as "dark" cathodes, colloidal photocatalysts, and photocathodes, and their figures of merit are discussed alongside system stability and catalyst integrity. The final section extends the scope of this review to prospects and challenges in targeting catalysis beyond "classical" H2 evolution and CO2 reduction to C1 products, by summarizing cases for higher-value products from N2 reduction, C x>1 products from CO2 utilization, and other reductive organic transformations.
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Affiliation(s)
| | | | - Jane J. Leung
- Christian Doppler Laboratory
for Sustainable SynGas Chemistry, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Bertrand Reuillard
- Christian Doppler Laboratory
for Sustainable SynGas Chemistry, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Isabell S. Karmel
- Christian Doppler Laboratory
for Sustainable SynGas Chemistry, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Erwin Reisner
- Christian Doppler Laboratory
for Sustainable SynGas Chemistry, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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26
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Patra SC, Saha Roy A, Banerjee S, Banerjee A, Das Saha K, Bhadra R, Pramanik K, Ghosh P. Palladium(ii) and platinum(ii) complexes of glyoxalbis(N-aryl)osazone: molecular and electronic structures, anti-microbial activities and DNA-binding study. NEW J CHEM 2019. [DOI: 10.1039/c9nj00223e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A new family of palladium(ii) and platinum(ii) complexes of redox non-innocent osazone ligands that exhibit moderate antileishmanial activity were isolated.
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Affiliation(s)
- Sarat Chandra Patra
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-700103
- India
- Department of Chemistry
| | - Amit Saha Roy
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-700103
- India
- Department of Chemistry
| | - Saswati Banerjee
- Cancer Biology & Inflammatory Disorder
- Indian Institute of Chemical Biology
- Kolkata 700032
- India
| | - Ananya Banerjee
- Department of Chemistry
- Bijaygarh Jyotish Roy College
- Kolkata-700032
- India
| | - Krishna Das Saha
- Cancer Biology & Inflammatory Disorder
- Indian Institute of Chemical Biology
- Kolkata 700032
- India
| | - Ranjan Bhadra
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-700103
- India
| | | | - Prasanta Ghosh
- Department of Chemistry
- R. K. Mission Residential College
- Kolkata-700103
- India
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27
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Truong PT, Broering EP, Dzul SP, Chakraborty I, Stemmler TL, Harrop TC. Simultaneous nitrosylation and N-nitrosation of a Ni-thiolate model complex of Ni-containing SOD. Chem Sci 2018; 9:8567-8574. [PMID: 30568781 PMCID: PMC6253683 DOI: 10.1039/c8sc03321h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/17/2018] [Indexed: 11/21/2022] Open
Abstract
Nitric oxide (NO) is used as a substrate analogue/spectroscopic probe of metal sites that bind and activate oxygen and its derivatives. To assess the interaction of superoxide with the Ni center in Ni-containing superoxide dismutase (NiSOD), we studied the reaction of NO+ and NO with the model complex, Et4N[Ni(nmp)(SPh-o-NH2-p-CF3)] (1; nmp2- = dianion of N-(2-mercaptoethyl)picolinamide; -SPh-o-NH2-p-CF3 = 2-amino-4-(trifluoromethyl)benzenethiolate) and its oxidized analogue 1ox , respectively. The ultimate products of these reactions are the disulfide of -SPh-o-NH2-p-CF3 and the S,S-bridged tetrameric complex [Ni4(nmp)4], a result of S-based redox activity. However, introduction of NO to 1 affords the green dimeric {NiNO}10 complex (Et4N)2[{Ni(κ2-SPh-o-NNO-p-CF3)(NO)}2] (2) via NO-induced loss of nmp2- as the disulfide and N-nitrosation of the aromatic thiolate. Complex 2 was characterized by X-ray crystallography and several spectroscopies. These measurements are in-line with other tetrahedral complexes in the {NiNO}10 classification. In contrast to the established stability of this metal-nitrosyl class, the Ni-NO bond of 2 is labile and release of NO from this unit was quantified by trapping the NO with a CoII-porphyrin (70-80% yield). In the process, the Ni ends up coordinated by two o-nitrosaminobenzenethiolato ligands to result in the structurally characterized trans-(Et4N)2[Ni(SPh-o-NNO-p-CF3)2] (3), likely by a disproportionation mechanism. The isolation and characterization of 2 and 3 suggest that: (i) the strongly donating thiolates dominate the electronic structure of Ni-nitrosyls that result in less covalent Ni-NO bonds, and (ii) superoxide undergoes disproportionation via an outer-sphere mechanism in NiSOD as complexes in the {NiNO}9/8 state have yet to be isolated.
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Affiliation(s)
- Phan T Truong
- Department of Chemistry , Center for Metalloenzyme Studies , The University of Georgia , Athens , Georgia 30602 , USA .
| | - Ellen P Broering
- Department of Chemistry , Center for Metalloenzyme Studies , The University of Georgia , Athens , Georgia 30602 , USA .
| | - Stephen P Dzul
- Departments of Pharmaceutical Sciences, Biochemistry, and Molecular Biology , Wayne State University , Detroit , Michigan 48201 , USA
| | - Indranil Chakraborty
- Department of Chemistry and Biochemistry , Florida International University , Miami , Florida 33199 , USA
| | - Timothy L Stemmler
- Departments of Pharmaceutical Sciences, Biochemistry, and Molecular Biology , Wayne State University , Detroit , Michigan 48201 , USA
| | - Todd C Harrop
- Department of Chemistry , Center for Metalloenzyme Studies , The University of Georgia , Athens , Georgia 30602 , USA .
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28
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Sarkar P, Mukherjee C. A non-innocent pincer H 3L ONS ligand and its corresponding octahedral low-spin Fe(iii) complex formation via ligand-centric homolytic S-S bond scission. Dalton Trans 2018; 47:13337-13341. [PMID: 30207350 DOI: 10.1039/c8dt02763c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the presence of FeCl3 and Et3N, a ligand H4Ldtda(AP) underwent S-S bond cleavage and generated a pincer non-innocent H3LONS ligand, which formed a homoleptic, six-coordinate, low-spin Fe(iii) complex (1). The complex comprised two 2-iminobenzosemiquinone (1-) π-radicals and one thiyl π-radical.
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Affiliation(s)
- Prasenjit Sarkar
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
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29
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Cross ED, Ang MTC, Richards DD, Clemens AC, Muthukumar H, McDonald R, Woodfolk L, Ckless K, Bierenstiel M. Synthesis, characterization, cytotoxicity and antimicrobial activity of copper complexes of N-imine pendant derivatives of 2-(methylthio)aniline. Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2017.09.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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30
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Inoue S, Mitsuhashi M, Ono T, Yan YN, Kataoka Y, Handa M, Kawamoto T. Photo- and Electrocatalytic Hydrogen Production Using Valence Isomers of N2S2-Type Nickel Complexes. Inorg Chem 2017; 56:12129-12138. [DOI: 10.1021/acs.inorgchem.7b01244] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Satoshi Inoue
- Department of Chemistry,
Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan
| | - Manabu Mitsuhashi
- Department of Chemistry,
Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan
| | - Takeshi Ono
- Department of Chemistry,
Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan
| | - Yin-Nan Yan
- Department of Chemistry,
Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan
| | - Yusuke Kataoka
- Department of Material Science, Interdisciplinary Graduate School
of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan
| | - Makoto Handa
- Department of Material Science, Interdisciplinary Graduate School
of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan
| | - Tatsuya Kawamoto
- Department of Chemistry,
Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan
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31
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Function of 7,7,8,8-tetracyanoquinodimethane (TCNQ) on electrocatalytic hydrogen generation catalyzed by N,N′-benzene bis(salicylideniminato)nickel(II). Polyhedron 2016. [DOI: 10.1016/j.poly.2016.05.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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Cameron LA, Ziller JW, Heyduk AF. Near-IR absorbing donor-acceptor ligand-to-ligand charge-transfer complexes of nickel(ii). Chem Sci 2016; 7:1807-1814. [PMID: 28959392 PMCID: PMC5604403 DOI: 10.1039/c5sc02703a] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/25/2015] [Indexed: 02/05/2023] Open
Abstract
A new series of square-planar nickel(ii) donor-acceptor complexes exhibiting ligand-to-ligand charge-transfer (LL'CT) transitions have been prepared. Whereas the use of a catecholate donor ligand in conjunction with a bipyridyl acceptor ligand affords a complex that absorbs throughout the visible region, the use of a azanidophenolate donor ligands in conjunction with a bipyridyl acceptor ligand affords complexes that absorbs well into the near-IR region of the solar spectrum. Three new complexes, (cat)Ni(bpy t Bu2) (1; (cat)2- = 3,5-di-tert-butyl-1,2-catecholate; bpy t Bu2 = 4,4'-di-tert-butyl-2,2'-bipyridine), (ap)Ni(bpy t Bu2) (2; (ap)2- = 4,6-di-tert-butyl-2-(2,6-diisopropylphenylazanido)phenolate), and (apPh)Ni(bpy t Bu2) (3; (apPh)2- = 10-(2,6-diisopropylphenylazanido)-9-phenanthrolate), have been prepared and characterized by structural, electrochemical, and spectroscopic methods. Whereas all three square-planar complexes show multiple reversible one-electron redox-processes and strong LL'CT absorption bands, in azanidophenolate complexes 2 and 3, the LL'CT absorption covers the near-IR region from 700-1200 nm. The electronic absorption spectra and ground state electrochemical data for 2 and 3 provide an estimate of their excited-state reduction potentials, E+/*, of -1.3 V vs. SCE, making them as potent as the singlet excited state of [Ru(bpy)3]2+.
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Affiliation(s)
- Lindsay A Cameron
- Department of Chemistry , University of California , Irvine , California 92697 , USA .
| | - Joseph W Ziller
- Department of Chemistry , University of California , Irvine , California 92697 , USA .
| | - Alan F Heyduk
- Department of Chemistry , University of California , Irvine , California 92697 , USA .
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33
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Skara G, Gimferrer M, De Proft F, Salvador P, Pinter B. Scrutinizing the Noninnocence of Quinone Ligands in Ruthenium Complexes: Insights from Structural, Electronic, Energy, and Effective Oxidation State Analyses. Inorg Chem 2016; 55:2185-99. [DOI: 10.1021/acs.inorgchem.5b02543] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Gabriella Skara
- Eenheid Algemene Chemie (ALGC), Member
of the QCMM VUB-UGent Alliance Research Group, Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050 Brussels, Belgium
| | - Marti Gimferrer
- Institut de Química
Computacional i Catàlisi (IQCC) i Department de Química, Universitat de Girona, 17071 Girona, Spain
| | - Frank De Proft
- Eenheid Algemene Chemie (ALGC), Member
of the QCMM VUB-UGent Alliance Research Group, Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050 Brussels, Belgium
| | - Pedro Salvador
- Institut de Química
Computacional i Catàlisi (IQCC) i Department de Química, Universitat de Girona, 17071 Girona, Spain
| | - Balazs Pinter
- Eenheid Algemene Chemie (ALGC), Member
of the QCMM VUB-UGent Alliance Research Group, Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050 Brussels, Belgium
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34
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Kennedy SR, Goyal P, Kozar MN, Yennawar HP, Hammes-Schiffer S, Lear BJ. Effect of Protonation upon Electronic Coupling in the Mixed Valence and Mixed Protonated Complex, [Ni(2,3-pyrazinedithiol)2]. Inorg Chem 2016; 55:1433-45. [DOI: 10.1021/acs.inorgchem.5b02035] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Steven R. Kennedy
- Department
of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Puja Goyal
- Department
of Chemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Morgan N. Kozar
- Department
of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Hemant P. Yennawar
- Department
of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Sharon Hammes-Schiffer
- Department
of Chemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Benjamin J. Lear
- Department
of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
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35
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Synthesis and crystal structures of a series of (μ-thiophenolato)(μ-pyrazolato-N,N′) double bridged dipalladium(II) complexes and their application in Mizoroki–Heck reaction as highly efficient catalysts. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2015.10.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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36
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Ghosh P, Mandal S, Chatterjee I, Mondal TK, Goswami S. Comparison of Redox Activity between 2-Aminothioether and 2-Aminothiophenol: Redox-Induced Dimerization of 2-Aminothioether via C-C Coupling. Inorg Chem 2015; 54:6235-44. [PMID: 26107050 DOI: 10.1021/acs.inorgchem.5b00457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Three chemical reactions of two 2-aminothioethers and 2-aminothiophenol with CpRu(II)Cl(PPh3)2 (Cp(-) = cyclopentadienyl anion), under identical reaction conditions, are reported. While 2-(methylthio)aniline, H2L(1) and an analogous substrate, 2-(phenylthio)aniline yielded dicationic dinuclear complexes [(PPh3)CpRu(II)(L(3/)L(4))Ru(II)Cp(PPh3)]Cl2 (where L(3) = (4E)-4-(4-imino-3-(methylthio)cyclohexa-2,5-dienylidene)-2-(methylthio)cyclohexa-2,5-dienimine ([1a]Cl2) and L(4) = (4E)-4-(4-imino-3-(phenylthio)cyclohexa-2,5-dienylidene)-2-(phenylthio)cyclohexa-2,5-dienimine ([1b]Cl2)), the reaction with 2-aminothiophenol (H2L(2)) produced a mononuclear complex [(PPh3)CpRu(II)(L(2))]Cl (where L(2) = 6-iminocyclohexa-2,4-dienethione) ([2]Cl). All these complexes are obtained in high yields (65%-75%). Formations of the products from the above reactions involve a similar level of oxidation of the respective substrate, although their courses are completely different. A comparison between the above two chemical transformations are scrutinized thoroughly. Characterizations of these complexes were made using a host of physical methods: X-ray crystallography, nuclear magnetic resonance (NMR), cyclic voltammetry, ultraviolet-visible (UV-vis), electron paramagnetic resonance (EPR) spectroscopy, and density functional theory (DFT). The complexes [1a]Cl2 and [1b]Cl2 showed intense metal-to-ligand charge transfer transition in the long wavelength region of the spectrum, at 860 and 895 nm, respectively, and displayed two reversible electron transfer (ET) processes at [1a](2+): -0.28 and -0.52 V; [1b](2+): -0.13 and -0.47 V, along with an irreversible ET process at 0.76 and 0.54 V, respectively. The ET processes at negative potentials are due to successive reductions of the bridging ligand, which are characterized by EPR and UV-vis spectroscopy. The one-electron reduced compound, [1a](+), showed a intraligand charge transfer transition (ILCT) at 1530 nm. The complex [2](+) showed a reversible ET process at -0.36 V and two irreversible ET processes at -1.04 and 1.18 V, respectively. DFT calculations were used to support the spectral and redox properties of the complexes and also to throw light on the difference of redox behavior between thioether and thiophenol substrates.
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Affiliation(s)
- Pradip Ghosh
- †Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India
| | - Sutanuva Mandal
- †Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India
| | - Ipsita Chatterjee
- †Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India
| | | | - Sreebrata Goswami
- †Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India
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37
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Koley MK, Chatterjee A, Chattopadhyay A, Manoharan PT, Koley AP. Spectroscopic studies for the changes of a Cr(II) compound in solution triggered by the deprotonation of an aqua ligand. J COORD CHEM 2015. [DOI: 10.1080/00958972.2015.1033412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Manjuri K. Koley
- Department of Chemical Engineering, Birla Institute of Technology and Science-Pilani, Zuarinagar, Goa, India
| | - Amrita Chatterjee
- Department of Chemistry, Birla Institute of Technology and Science-Pilani, Zuarinagar, Goa, India
| | - Anjan Chattopadhyay
- Department of Chemistry, Birla Institute of Technology and Science-Pilani, Zuarinagar, Goa, India
| | | | - Aditya P. Koley
- Department of Chemistry, Birla Institute of Technology and Science-Pilani, Zuarinagar, Goa, India
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38
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Cazacu M, Shova S, Soroceanu A, Machata P, Bucinsky L, Breza M, Rapta P, Telser J, Krzystek J, Arion VB. Charge and Spin States in Schiff Base Metal Complexes with a Disiloxane Unit Exhibiting a Strong Noninnocent Ligand Character: Synthesis, Structure, Spectroelectrochemistry, and Theoretical Calculations. Inorg Chem 2015; 54:5691-706. [DOI: 10.1021/acs.inorgchem.5b00229] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Maria Cazacu
- “Petru Poni” Institute of Macromolecular Chemistry, Alea Gr. Ghica Voda 41A, 700487 Iasi, Romania
| | - Sergiu Shova
- “Petru Poni” Institute of Macromolecular Chemistry, Alea Gr. Ghica Voda 41A, 700487 Iasi, Romania
| | - Alina Soroceanu
- “Petru Poni” Institute of Macromolecular Chemistry, Alea Gr. Ghica Voda 41A, 700487 Iasi, Romania
| | - Peter Machata
- Institute of Physical Chemistry and Chemical Physics, Faculty of
Chemical and Food Technology, Slovak University of Technology, Radlinského
9, SK-81237 Bratislava, Slovak Republic
| | - Lukas Bucinsky
- Institute of Physical Chemistry and Chemical Physics, Faculty of
Chemical and Food Technology, Slovak University of Technology, 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, 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, Radlinského
9, SK-81237 Bratislava, Slovak Republic
| | - Joshua Telser
- Department of Biological, Chemical and
Physical Sciences, Roosevelt University, 430 South Michigan Avenue, Chicago, Illinois 60605 United States
| | - J. Krzystek
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 United States
| | - Vladimir B. Arion
- Faculty of Chemistry, Institute of Inorganic
Chemistry, University of Vienna, Währinger Strasse 42, A-1090 Vienna, Austria
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39
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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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40
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Denny JA, Darensbourg MY. Metallodithiolates as ligands in coordination, bioinorganic, and organometallic chemistry. Chem Rev 2015; 115:5248-73. [PMID: 25948147 DOI: 10.1021/cr500659u] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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41
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Skara G, Pinter B, Geerlings P, De Proft F. Revealing the thermodynamic driving force for ligand-based reductions in quinoids; conceptual rules for designing redox active and non-innocent ligands. Chem Sci 2015; 6:4109-4117. [PMID: 29218177 PMCID: PMC5707504 DOI: 10.1039/c5sc01140j] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 04/30/2015] [Indexed: 12/18/2022] Open
Abstract
Metal and ligand-based reductions have been modeled in octahedral ruthenium complexes revealing metal-ligand interactions as the profound driving force for the redox-active behaviour of orthoquinoid-type ligands. Through an extensive investigation of redox-active ligands we revealed the most critical factors that facilitate or suppress redox-activity of ligands in metal complexes, from which basic rules for designing non-innocent/redox-active ligands can be put forward. These rules also allow rational redox-leveling, i.e. the moderation of redox potentials of ligand-centred electron transfer processes, potentially leading to catalysts with low overpotential in multielectron activation processes.
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Affiliation(s)
- G Skara
- Eenheid Algemene Chemie (ALGC) , Vrije Universiteit Brussel (VUB) , Pleinlaan 2 , 1050 , Brussels , Belgium .
| | - B Pinter
- Eenheid Algemene Chemie (ALGC) , Vrije Universiteit Brussel (VUB) , Pleinlaan 2 , 1050 , Brussels , Belgium .
| | - P Geerlings
- Eenheid Algemene Chemie (ALGC) , Vrije Universiteit Brussel (VUB) , Pleinlaan 2 , 1050 , Brussels , Belgium .
| | - F De Proft
- Eenheid Algemene Chemie (ALGC) , Vrije Universiteit Brussel (VUB) , Pleinlaan 2 , 1050 , Brussels , Belgium .
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42
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Broering EP, Dillon S, Gale EM, Steiner RA, Telser J, Brunold TC, Harrop TC. Accessing Ni(III)-thiolate versus Ni(II)-thiyl bonding in a family of Ni-N2S2 synthetic models of NiSOD. Inorg Chem 2015; 54:3815-28. [PMID: 25835183 PMCID: PMC4630978 DOI: 10.1021/ic503124f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Superoxide dismutase (SOD) catalyzes the disproportionation of superoxide (O2(• -)) into H2O2 and O2(g) by toggling through different oxidation states of a first-row transition metal ion at its active site. Ni-containing SODs (NiSODs) are a distinct class of this family of metalloenzymes due to the unusual coordination sphere that is comprised of mixed N/S-ligands from peptide-N and cysteine-S donor atoms. A central goal of our research is to understand the factors that govern reactive oxygen species (ROS) stability of the Ni-S(Cys) bond in NiSOD utilizing a synthetic model approach. In light of the reactivity of metal-coordinated thiolates to ROS, several hypotheses have been proffered and include the coordination of His1-Nδ to the Ni(II) and Ni(III) forms of NiSOD, as well as hydrogen bonding or full protonation of a coordinated S(Cys). In this work, we present NiSOD analogues of the general formula [Ni(N2S)(SR')](-), providing a variable location (SR' = aryl thiolate) in the N2S2 basal plane coordination sphere where we have introduced o-amino and/or electron-withdrawing groups to intercept an oxidized Ni species. The synthesis, structure, and properties of the NiSOD model complexes (Et4N)[Ni(nmp)(SPh-o-NH2)] (2), (Et4N)[Ni(nmp)(SPh-o-NH2-p-CF3)] (3), (Et4N)[Ni(nmp)(SPh-p-NH2)] (4), and (Et4N)[Ni(nmp)(SPh-p-CF3)] (5) (nmp(2-) = dianion of N-(2-mercaptoethyl)picolinamide) are reported. NiSOD model complexes with amino groups positioned ortho to the aryl-S in SR' (2 and 3) afford oxidized species (2(ox) and 3(ox)) that are best described as a resonance hybrid between Ni(III)-SR and Ni(II)-(•)SR based on ultraviolet-visible (UV-vis), magnetic circular dichroism (MCD), and electron paramagnetic resonance (EPR) spectroscopies, as well as density functional theory (DFT) calculations. The results presented here, demonstrating the high percentage of S(3p) character in the highest occupied molecular orbital (HOMO) of the four-coordinate reduced form of NiSOD (NiSODred), suggest that the transition from NiSODred to the five-coordinate oxidized form of NiSOD (NiSODox) may go through a four-coordinate Ni-(•)S(Cys) (NiSODox-Hisoff) that is stabilized by coordination to Ni(II).
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Affiliation(s)
- Ellen P. Broering
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Stephanie Dillon
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Eric M. Gale
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Ramsey A. Steiner
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 South Michigan Avenue, Chicago, Illinois 60605, United States
| | - Thomas C. Brunold
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Todd C. Harrop
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
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Maity S, Kundu S, Weyhermüller T, Ghosh P. Tris(2,2'-azobispyridine) complexes of copper(II): X-ray structures, reactivities, and the radical nonradical bis(ligand) analogues. Inorg Chem 2015; 54:1300-13. [PMID: 25650719 DOI: 10.1021/ic502750u] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Tris(abpy) complexes of types mer-[Cu(II)(abpy)3][PF6]2 (mer-1(2+)[PF6(–)]2) and ctc-[Cu(II)(abpy)2(bpy)][PF6]2 (ctc-2(2+)[PF6(–)]2) were successfully isolated and characterized by spectra and single-crystal X-ray structure determinations (abpy = 2,2′-azobispyridine; bpy = 2,2′-bipyridine). Reactions of mer-1(2+) and ctc-2(2+) ions with catechol, o-aminophenol, p-phenylenediamine, and diphenylamine (Ph–NH–Ph) in 2:1 molar ratio afford [CuI(abpy)2](+) (3(+)) and corresponding quinone derivatives. The similar reactions of [Cu(II)(bpy)3](2+) and [Cu(II)(phen)3](2+) with these substrates yielding [Cu(I)(bpy)2](+) and [Cu(I)(phen)2](+) imply that these complexes undergo reduction-induced ligand dissociation reactions (phen = 1,10-phenanthroline). The average −N═N– lengths in mer-1(2+)[PF6(–)]2 and ctc-2(2+)[PF6(–)]2 are 1.248(4), while that in 3(+)[PF6(–)]·2CH2Cl2 is relatively longer, 1.275(2) Å, due to dCu → πazo* back bonding. In cyclic voltammetry, mer-1(2+) exhibits one quasi-reversible wave at −0.42 V due to Cu(II)/Cu(I) and abpy/abpy(•–) couples and two reversible waves at −0.90 and −1.28 V due to abpy/abpy(•–) couple, while those of ctc-2(2+) ion appear at −0.44, −0.86, and −1.10 V versus Fc(+)/Fc couple. The anodic 3(2+)/3(+) and the cathodic 3(+)/3 redox waves at +0.33 and −0.40 V are reversible. The electron paramagnetic resonance spectra and density functional theory (DFT) calculations authenticated the existence of abpy anion radical (abpy(•–)) in 3, which is defined as a hybrid state of [Cu(I)(abpy(0.5•–))(abpy(0.5•–))] and [Cu(II)(abpy(•–))(abpy(•–))] states. 3(2+) ion is a neutral abpy complex of copper(II) of type [Cu(II)(abpy)2](2+). 3 exhibits a near-IR absorption band at 2400–3000 nm because of the intervalence ligand-to-ligand charge transfer, elucidated by time-dependent DFT calculations in CH2Cl2.
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Affiliation(s)
- Suvendu Maity
- Department of Chemistry, R. K. Mission Residential College , Narendrapur, Kolkata-103, India
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Das A, Han Z, Brennessel WW, Holland PL, Eisenberg R. Nickel Complexes for Robust Light-Driven and Electrocatalytic Hydrogen Production from Water. ACS Catal 2015. [DOI: 10.1021/acscatal.5b00045] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Amit Das
- Department
of Chemistry, University of Rochester, RC Box 270216, Rochester, New York 14627, United States
| | - Zhiji Han
- Department
of Chemistry, University of Rochester, RC Box 270216, Rochester, New York 14627, United States
| | - William W. Brennessel
- Department
of Chemistry, University of Rochester, RC Box 270216, Rochester, New York 14627, United States
| | - Patrick L. Holland
- Department
of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06511, United States
| | - Richard Eisenberg
- Department
of Chemistry, University of Rochester, RC Box 270216, Rochester, New York 14627, United States
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45
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Bimetallic nickel complexes supported by 2,5-bis(phosphine)-1,4-hydroquinonate ligands. Structural, electrochemical and theoretical investigations. Inorganica Chim Acta 2015. [DOI: 10.1016/j.ica.2014.08.049] [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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46
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Hananouchi S, Krull BT, Ziller JW, Furche F, Heyduk AF. Metal effects on ligand non-innocence in Group 5 complexes of the redox-active [ONO] pincer ligand. Dalton Trans 2014; 43:17991-8000. [DOI: 10.1039/c4dt02259a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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Kawai M, Yamaguchi T, Masaoka S, Tani F, Kohzuma T, Chiang L, Storr T, Mieda K, Ogura T, Szilagyi RK, Shimazaki Y. Influence of ligand flexibility on the electronic structure of oxidized Ni(III)-phenoxide complexes. Inorg Chem 2014; 53:10195-202. [PMID: 25254603 DOI: 10.1021/ic501181k] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
One-electron-oxidized Ni(III)-phenoxide complexes with salen-type ligands, [Ni(salen)py2](2+) ([1(en)-py](2+)) and [Ni(1,2-salcn)py2](2+) ([1(cn)-py](2+)), with a five-membered chelate dinitrogen backbone and [Ni(salpn)py2](2+) ([2(pn)-py](2+)), with a six-membered chelate backbone, have been characterized with a combination of experimental and theoretical methods. The five-membered chelate complexes [1(en)-py](2+) and [1(cn)-py](2+) were assigned as Ni(III)-phenoxyl radical species, while the six-membered chelate complex [2(pn)-py](2+) was concluded to be a Ni(II)-bis(phenoxyl radical) species with metal-centered reduction in the course of the one-electron oxidation of the Ni(III)-phenoxide complex [2(pn)-py](+). Thus, the oxidation state of the one-electron-oxidized Ni(III) salen-type complexes depends on the chelate ring size of the dinitrogen backbone.
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Affiliation(s)
- Minoru Kawai
- College of Science and ‡Graduate School of Science and Engineering, Ibaraki University , Bunkyo, Mito 310-8512, Japan
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Kramer WW, Cameron LA, Zarkesh RA, Ziller JW, Heyduk AF. Donor-acceptor ligand-to-ligand charge-transfer coordination complexes of nickel(II). Inorg Chem 2014; 53:8825-37. [PMID: 25100175 DOI: 10.1021/ic5017214] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A family of charge-transfer chromophores comprising square-planar nickel(II) complexes with one catecholate donor ligand and one α-diimine acceptor ligand is reported. The nine new chromophores were prepared using three different catecholate ligands and three different α-diimine ligands. Single-crystal X-ray diffraction studies on all members of the series confirm a catecholate donor-nickel(II)-α-diimine acceptor electronic structure. The coplanar arrangement of donor and acceptor ligands manifests an intense ligand-to-ligand charge-transfer (LL'CT) absorption band that can be tuned incrementally from 650 nm (1.9 eV) to 1370 nm (0.9 eV). Electrochemical studies of all nine complexes reveal rich redox chemistry with two one-electron reduction processes and two one-electron oxidation processes. For one dye, both the singly reduced anion and the singly oxidized cation were prepared, isolated, and characterized by EPR spectroscopy to confirm ligand-localization of the redox processes. The optical and electrochemical properties of these new complexes identify them as attractive candidates for charge-transfer photochemistry and solar-energy conversion applications.
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Affiliation(s)
- Wesley W Kramer
- Department of Chemistry, University of California , Irvine, California 92697, United States
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Witt A, Heinemann FW, Sproules S, Khusniyarov MM. Modulation of Magnetic Properties at Room Temperature: Coordination-Induced Valence Tautomerism in a Cobalt Dioxolene Complex. Chemistry 2014; 20:11149-62. [DOI: 10.1002/chem.201402129] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Indexed: 11/06/2022]
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50
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Feldscher B, Stammler A, Bögge H, Glaser T. Aromatic Versus Heteroradialene Character in Extended Thiophloroglucinol Ligands and their Trinuclear Nickel(II) Complexes. Chem Asian J 2014; 9:2205-18. [DOI: 10.1002/asia.201402272] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Indexed: 11/11/2022]
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