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Takeyama T, Shimazaki Y. Diversity of oxidation state in copper complexes with phenolate ligands. Dalton Trans 2024; 53:3911-3929. [PMID: 38319292 DOI: 10.1039/d3dt04230h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
The phenoxyl radical binding copper complexes have been widely developed and their detailed geometric and electronic structures have been clarified. While many one-electron oxidized CuII-phenolate complexes have been reported previously, recent studies of the Cu-phenolate complexes proceed toward elucidation of the complexes with other oxidation states, such as the phenoxyl radical binding CuI complexes and CuIV-phenolate complexes in the formal oxidation state. This Perspective focuses on new aspects of the properties and reactivities of various Cu-phenolate and Cu-phenoxyl radical complexes with emphasis on the relationship between geometric and electronic structures.
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Affiliation(s)
- Tomoyuki Takeyama
- Department of Applied Chemistry, Sanyo-Onoda City University, 1-1-1, Daigakudori, Sanyo-Onoda, 756-0884 Yamaguchi, Japan.
| | - Yuichi Shimazaki
- College of Science, Ibaraki University, Bunkyo, Mito 310-8512, Japan.
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2
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Mahato S, VandeVen W, MacNeil GA, Pulfer JM, Storr T. Untangling ancillary ligand donation versus locus of oxidation effects on metal nitride reactivity. Chem Sci 2024; 15:2211-2220. [PMID: 38332824 PMCID: PMC10848731 DOI: 10.1039/d3sc05403a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 01/01/2024] [Indexed: 02/10/2024] Open
Abstract
We detail the relative role of ancillary ligand electron-donating ability in comparison to the locus of oxidation (either metal or ligand) on the electrophilic reactivity of a series of oxidized Mn salen nitride complexes. The electron-donating ability of the ancillary salen ligand was tuned via the para-phenolate substituent (R = CF3, H, tBu, OiPr, NMe2, NEt2) in order to have minimal effect on the geometry at the metal center. Through a suite of experimental (electrochemistry, electron paramagnetic resonance spectroscopy, UV-vis-NIR spectroscopy) and theoretical (density functional theory) techniques, we have demonstrated that metal-based oxidation to [MnVI(SalR)N]+ occurs for R = CF3, H, tBu, OiPr, while ligand radical formation to [MnV(SalR)N]+˙ occurs with the more electron-donating substituents R = NMe2, NEt2. We next investigated the reactivity of the electrophilic nitride with triarylphosphines to form a MnIV phosphoraneiminato adduct and determined that the rate of reaction decreases as the electron-donating ability of the salen para-phenolate substituent is increased. Using a Hammett plot, we find a break in the Hammett relation between R = OiPr and R = NMe2, without a change in mechanism, consistent with the locus of oxidation exhibiting a dominant effect on nitride reactivity, and not the overall donating ability of the ancillary salen ligand. This work differentiates between the subtle and interconnected effects of ancillary ligand electron-donating ability, and locus of oxidation, on electrophilic nitride reactivity.
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Affiliation(s)
- Samyadeb Mahato
- Department of Chemistry, Simon Fraser University Burnaby British Columbia V5A 1S6 Canada
| | - Warren VandeVen
- Department of Chemistry, Simon Fraser University Burnaby British Columbia V5A 1S6 Canada
| | - Gregory A MacNeil
- Department of Chemistry, Simon Fraser University Burnaby British Columbia V5A 1S6 Canada
| | - Jason M Pulfer
- Department of Chemistry, Simon Fraser University Burnaby British Columbia V5A 1S6 Canada
| | - Tim Storr
- Department of Chemistry, Simon Fraser University Burnaby British Columbia V5A 1S6 Canada
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3
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Nguyen BX, VandeVen W, MacNeil GA, Zhou W, Paterson AR, Walsby CJ, Chiang L. High-Valent Ni and Cu Complexes of a Tetraanionic Bis(amidateanilido) Ligand. Inorg Chem 2023; 62:15180-15194. [PMID: 37676794 DOI: 10.1021/acs.inorgchem.3c02358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
High-valent metal species are often invoked as intermediates during enzymatic and synthetic catalytic cycles. Anionic donors are often required to stabilize such high-valent states by forming strong bonds with the Lewis acidic metal centers while decreasing their oxidation potentials. In this report, we discuss the synthesis of two high-valent metal complexes [ML]+ in which the NiIII and CuIII centers are ligated by a new tetradentate, tetraanionic bis(amidateanilido) ligand. [ML]+, obtained via chemical oxidation of ML, exhibits UV-vis-NIR, EPR, and XANES spectra characteristic of square planar, high-valent MIII species, suggesting the locus of oxidation for both [ML]+ is predominantly metal-based. This is supported by theoretical analyses, which also support the observed visible transitions as ligand-to-metal charge transfer transitions characteristic of square planar, high-valent MIII species. Notably, [ML]+ can also be obtained via O2 oxidation of ML due to its remarkably negative oxidation potentials (CuL/[CuL]+: -1.16 V, NiL/[NiL]+: -1.01 V vs Fc/Fc+ in MeCN). This demonstrates the exceptionally strong donating nature of the tetraanionic bis(amidateanilido) ligation and its ability to stabilize high-valent metal centers..
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Affiliation(s)
- Bach X Nguyen
- Department of Chemistry, University of the Fraser Valley, Abbotsford, British Columbia V2S 7M8, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, British Columba V5A 1S6, Canada
| | - Warren VandeVen
- Department of Chemistry, Simon Fraser University, Burnaby, British Columba V5A 1S6, Canada
| | - Gregory A MacNeil
- Department of Chemistry, Simon Fraser University, Burnaby, British Columba V5A 1S6, Canada
| | - Wen Zhou
- Department of Chemistry, Simon Fraser University, Burnaby, British Columba V5A 1S6, Canada
| | - Alisa R Paterson
- Canadian Light Source, 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2 V3, Canada
| | - Charles J Walsby
- Department of Chemistry, Simon Fraser University, Burnaby, British Columba V5A 1S6, Canada
| | - Linus Chiang
- Department of Chemistry, University of the Fraser Valley, Abbotsford, British Columbia V2S 7M8, Canada
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4
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Kessler BJO, Mansoor IF, Wozniak DI, Emge TJ, Lipke MC. Controlling Intramolecular and Intermolecular Electronic Coupling of Radical Ligands in a Series of Cobaltoviologen Complexes. J Am Chem Soc 2023; 145:15924-15935. [PMID: 37460450 DOI: 10.1021/jacs.3c03725] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Controlling electronic coupling between multiple redox sites is of interest for tuning the electronic properties of molecules and materials. While classic mixed-valence (MV) systems are highly tunable, e.g., via the organic bridges connecting the redox sites, metal-bridged MV systems are difficult to control because the electronics of the metal cannot usually be altered independently of redox-active moieties embedded in its ligands. Herein, this limitation was overcome by varying the donor strengths of ancillary ligands in a series of cobalt complexes without directly perturbing the electronics of viologen-like redox sites bridged by the cobalt ions. The cobaltoviologens [1X-Co]n+ feature four 4-X-pyridyl donor groups (X = CO2Me, Cl, H, Me, OMe, NMe2) that provide gradual electronic tuning of the bridging CoII centers, while a related complex [2-Co]n+ with NHC donors supports exclusively CoIII states even upon reduction of the viologen units. Electrochemistry and IVCT band analysis indicate that the MV states of these complexes have electronic structures ranging from fully localized ([2-Co]4+; Robin-Day Class I) to fully delocalized ([1CO2Me-Co]3+; Class III) descriptions, demonstrating unprecedented control over electronic coupling without changing the identity of the redox sites or bridging metal. Additionally, single-crystal XRD characterization of the homovalent complexes [1H-Co]2+ and [1H-Zn]2+ revealed radical-pairing interactions between the viologen ligands of adjacent complexes, representing a type of through-space electronic coupling commonly observed for organic viologen radicals but never before seen in metalloviologens. The extended solid-state packing of these complexes produces 3D networks of radical π-stacking interactions that impart unexpected mechanical flexibility to these crystals.
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Affiliation(s)
- Brice J O Kessler
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, New Jersey 08854, United States
| | - Iram F Mansoor
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, New Jersey 08854, United States
| | - Derek I Wozniak
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, New Jersey 08854, United States
| | - Thomas J Emge
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, New Jersey 08854, United States
| | - Mark C Lipke
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, New Jersey 08854, United States
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5
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Chongdar S, Mondal U, Chakraborty T, Banerjee P, Bhaumik A. A Ni-MOF as Fluorescent/Electrochemical Dual Probe for Ultrasensitive Detection of Picric Acid from Aqueous Media. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 36893380 DOI: 10.1021/acsami.3c00604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
A water-stable, microporous, luminescent Ni(II)-based metal-organic framework (MOF) (Ni-OBA-Bpy-18) with a 4-c uninodal sql topology was solvothermally synthesized using mixed N-, O-donor-directed π-conjugated co-ligands. The extraordinary performance of this MOF toward rapid monitoring of mutagenic explosive trinitrophenol (TNP) in aqueous and vapor phases by the fluorescence "Turn-off" technique with an ultralow detection limit of 66.43 ppb (Ksv: 3.45 × 105 M-1) was governed by a synchronous occurrence of photoinduced electron transfer-resonance energy transfer-intermolecular charge transfer (PET-RET-ICT) and non-covalent π···π weak interactions, as revealed from density functional theory studies. The recyclable nature of the MOF, detection from complex environmental matrices, and fabrication of a handy MOF@cotton-swab detection kit certainly escalated the on-field viability of the probe. Interestingly, the presence of electron-withdrawing TNP decisively facilitated the redox events of the reversible NiIII/II and NiIV/III couples under an applied voltage based on which electrochemical recognition of TNP was realized by the Ni-OBA-Bpy-18 MOF/glassy carbon electrode, with an excellent detection limit of ∼0.6 ppm. Such detection of a specific analyte by MOF-based probe via two divergent yet coherent techniques is unprecedented and yet to be explored in relevant literature.
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Affiliation(s)
- Sayantan Chongdar
- School of Materials Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Udayan Mondal
- Surface Engineering & Tribology Division, CSIR-Central Mechanical Engineering Research Institute, M. G. Avenue, Durgapur 713209, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
| | - Tonmoy Chakraborty
- School of Materials Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Priyabrata Banerjee
- Surface Engineering & Tribology Division, CSIR-Central Mechanical Engineering Research Institute, M. G. Avenue, Durgapur 713209, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
| | - Asim Bhaumik
- School of Materials Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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6
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Essien NB, Galvácsi A, Kállay C, Al-Hilaly Y, González-Méndez R, Akien GR, Tizzard GJ, Coles SJ, Besora M, Kostakis GE. Fluorine-based Zn salan complexes. Dalton Trans 2023; 52:4044-4057. [PMID: 36880418 DOI: 10.1039/d2dt04082d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
We synthesised and characterised the racemic and chiral versions of two Zn salan fluorine-based complexes from commercially available materials. The complexes are susceptible to absorbing H2O from the atmosphere. In solution (DMSO-H2O) and at the millimolar level, experimental and theoretical studies identify that these complexes exist in a dimeric-monomeric equilibrium. We also investigated their ability to sense amines via19F NMR. In CDCl3 or d6-DMSO, strongly coordinating molecules (H2O or DMSO) are the limiting factor in using these easy-to-make complexes as chemosensory platforms since their exchange with analytes requires an extreme excess of the latter.
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Affiliation(s)
- Nsikak B Essien
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, UK.
| | - Antal Galvácsi
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4032 Debrecen, Hungary
| | - Csilla Kállay
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4032 Debrecen, Hungary
| | - Youssra Al-Hilaly
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.,Chemistry Department, College of Science, Mustansiriyah University, Baghdad, Iraq
| | - Ramón González-Méndez
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, UK.
| | - Geoffrey R Akien
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, UK
| | - Graham J Tizzard
- UK National Crystallography Service, Chemistry, University of Southampton, Southampton SO1 71BJ, UK
| | - Simon J Coles
- UK National Crystallography Service, Chemistry, University of Southampton, Southampton SO1 71BJ, UK
| | - Maria Besora
- Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, C/Marcel lí Domingo, 1, 43007 Tarragona, Spain.
| | - George E Kostakis
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, UK.
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7
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Sailer R, VandeVen W, Teindl K, Chiang L. Ni II and Cu II complexes of a salen ligand bearing ferrocenes in its secondary coordination sphere. RSC Adv 2023; 13:7293-7299. [PMID: 36891492 PMCID: PMC9986886 DOI: 10.1039/d2ra07671c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 02/24/2023] [Indexed: 03/08/2023] Open
Abstract
Herein, we report the synthesis, spectroscopic characterization and electrochemical investigation of the NiII and CuII complexes of a novel Sal ligand bearing two ferrocene moieties attached at its diimine linker, M(Sal)Fc. The electronic spectra of M(Sal)Fc are near identical to its phenyl-substituted counterpart, M(Sal)Ph, indicating the ferrocene moieties exist in the secondary coordination sphere of M(Sal)Fc. The cyclic voltammograms of M(Sal)Fc exhibit an additional two-electron wave in comparison to M(Sal)Ph, which is assigned to the sequential oxidation of the two ferrocene moieties. The chemical oxidation of M(Sal)Fc, monitored by low temperature UV-vis spectroscopy, supports the formation of a mixed valent FeIIFeIII species followed by a bis(ferrocenium) species upon sequential addition of one and two equivalents of chemical oxidant. The addition of a third equivalent of oxidant to Ni(Sal)Fc yielded intense near-IR transitions that are indicative of the formation of a fully delocalized Sal-ligand radical (Sal˙), while the same addition to Cu(Sal)Fc yielded a species that is currently under further spectroscopic investigation. These results suggest the oxidation of the ferrocene moieties of M(Sal)Fc does not affect the electronic structure of the M(Sal) core, and these are thus in the secondary coordination sphere of the overall complex.
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Affiliation(s)
- Rachel Sailer
- Department of Chemistry, University of the Fraser Valley Abbotsford V2S 7M8 British Columbia Canada
| | - Warren VandeVen
- Department of Chemistry, Simon Fraser University Burnaby V5A 1S6 British Columbia Canada
| | - Kaeden Teindl
- Department of Chemistry, University of the Fraser Valley Abbotsford V2S 7M8 British Columbia Canada
| | - Linus Chiang
- Department of Chemistry, University of the Fraser Valley Abbotsford V2S 7M8 British Columbia Canada
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8
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Novozhilova M, Polozhentseva J, Karushev M. Asymmetric Monomer Design Enables Structural Control of M(Salen)-Type Polymers. Polymers (Basel) 2023; 15:polym15051127. [PMID: 36904368 PMCID: PMC10007425 DOI: 10.3390/polym15051127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 02/05/2023] [Accepted: 02/21/2023] [Indexed: 03/12/2023] Open
Abstract
Conductive and electrochemically active polymers consisting of Salen-type metal complexes as building blocks are of interest for energy storage and conversion applications. Asymmetric monomer design is a powerful tool for fine-tuning the practical properties of conductive electrochemically active polymers but has never been employed for polymers of M(Salen)]. In this work, we synthesize a series of novel conducting polymers composed of a nonsymmetrical electropolymerizable copper Salen-type complex (Cu(3-MeOSal-Sal)en). We show that asymmetrical monomer design provides easy control of the coupling site via polymerization potential control. With in-situ electrochemical methods such as UV-vis-NIR (ultraviolet-visible-near infrared) spectroscopy, EQCM (electrochemical quartz crystal microbalance), and electrochemical conductivity measurements, we elucidate how the properties of these polymers are defined by chain length, order, and cross-linking. We found that the highest conductivity in the series has a polymer with the shortest chain length, which emphasizes the importance of intermolecular iterations in polymers of [M(Salen)].
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Affiliation(s)
- Maria Novozhilova
- Ioffe Physical-Technical Institute of the Russian Academy of Sciences (Ioffe Institute), 26 Polytekhnicheskaya Str., 194021 St. Petersburg, Russia
| | - Julia Polozhentseva
- Ioffe Physical-Technical Institute of the Russian Academy of Sciences (Ioffe Institute), 26 Polytekhnicheskaya Str., 194021 St. Petersburg, Russia
| | - Mikhail Karushev
- Ioffe Physical-Technical Institute of the Russian Academy of Sciences (Ioffe Institute), 26 Polytekhnicheskaya Str., 194021 St. Petersburg, Russia
- Independent Researcher, Astana 020000, Kazakhstan
- Correspondence:
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9
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Sharma A, Mejia K, Ueno H, Zhou W, Chiang L. Copper complexes of strongly electron rich and deficient salen ligands. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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McKee ML. Exploring the Reaction Mechanism of C-H Oxidation by Copper-Salen Complexes. J Phys Chem A 2022; 126:4969-4980. [PMID: 35861503 DOI: 10.1021/acs.jpca.2c03344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mechanism of C-H oxidation of propylene (C3H6) and 1-phenyl-1-pentyne (C3H7-C≡C-Ph) by HOOR (R═Me, tBu) and 3O2 by a copper-salen complex was explored by computations. The most noteworthy step is the complexation of two Cu salens to the peroxide to form either the LCuOH/LCuOR pair or an OH-bridged complex LCu(μ-OH)CuL plus OR. The latter pathway involves an avoided crossing of two triplet electronic states. The LCuOH complex can abstract a hydrogen atom from C3H6 and the C3H5 radical plus 3O2 forms the complex LCuOOC3H5. Migration of a hydrogen to the proximal oxygen atom reforms LCuOH and acrolein HC(O)CH═CH2.
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Affiliation(s)
- Michael L McKee
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849, United States
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11
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Ding YF, La YT, Li WD, Yao GX, Wang L, Dong WK. Experimental and Theoretical Studies of Two New Trinuclear Ni(II) Asymmetric Salamo-Based Complexes. RUSS J GEN CHEM+ 2022. [DOI: 10.1134/s1070363222020220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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12
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Reversible Redox Processes in Polymer of Unmetalated Salen-Type Ligand: Combined Electrochemical in Situ Studies and Direct Comparison with Corresponding Nickel Metallopolymer. Int J Mol Sci 2022; 23:ijms23031795. [PMID: 35163715 PMCID: PMC8836782 DOI: 10.3390/ijms23031795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 11/17/2022] Open
Abstract
Most non-metalized Salen-type ligands form passivation thin films on electrode surfaces upon electrochemical oxidation. In contrast, the H2(3-MeOSalen) forms electroactive polymer films similarly to the corresponding nickel complex. There are no details of electrochemistry, doping mechanism and charge transfer pathways in the polymers of pristine Salen-type ligands. We studied a previously uncharacterized electrochemically active polymer of a Salen-type ligand H2(3-MeOSalen) by a combination of cyclic voltammetry, in situ ultraviolet-visible (UV-VIS) spectroelectrochemistry, in situ electrochemical quartz crystal microbalance and Fourier Transform infrared spectroscopy (FTIR) spectroscopy. By directly comparing it with the polymer of a Salen-type nickel complex poly-Ni(3-MeOSalen) we elucidate the effect of the central metal atom on the structure and charge transport properties of the electrochemically doped polymer films. We have shown that the mechanism of charge transfer in the polymeric ligand poly-H2(3-MeOSalen) are markedly different from the corresponding polymeric nickel complex. Due to deviation from planarity of N2O2 sphere for the ligand H2(3-MeOSalen), the main pathway of electron transfer in the polymer film poly-H2(3-MeOSalen) is between π-stacked structures (the π-electronic systems of phenyl rings are packed face-to-face) and C-C bonded phenyl rings. The main way of electron transfer in the polymer film poly-Ni(3-MeOSalen) is along the polymer chain, while redox processes are ligand-based.
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13
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Bag J, Barman S, Maiti BK, Pal K. M(II) (M = Cu, Ni) Assisted C‐S Bond Cleavage and Oxidative Dehydrogenation of Amine On Non‐Innocent Salen Type Ligands Platform Varying Nitrogen vs. Sulfur Coordination Atoms. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202101107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Jayanta Bag
- University of Calcutta Rashbehari Siksha Prangan: University of Calcutta - Rajabazar Science College Campus CHEMISTRY INDIA
| | - Souvik Barman
- University of Calcutta Rashbehari Siksha Prangan: University of Calcutta - Rajabazar Science College Campus CHEMISTRY INDIA
| | - Biplab K Maiti
- NIT Sikkim: National Institute of Technology Sikkim CHEMISTRY INDIA
| | - Kuntal Pal
- University of Calcutta Rashbehari Siksha Prangan: University of Calcutta - Rajabazar Science College Campus Department of Chemistry 92 apc road, Rajabazar Science college 700009 kolkata INDIA
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14
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Maleeva AV, Ershova IV, Trofimova OY, Arsenyeva KV, Yakushev IA, Piskunov AV. Near-IR absorbing donor–acceptor charge-transfer gallium complex, an example from non-transition metal chemistry. MENDELEEV COMMUNICATIONS 2022. [DOI: 10.1016/j.mencom.2022.01.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Herasymchuk K, Allain M, MacNeil GA, Carré V, Aubriet F, Leznoff DB, Sallé M, Goeb S, Storr T. Exciton Coupling in Redox-Active Salen based Self-Assembled Metallacycles. Chemistry 2021; 27:16161-16172. [PMID: 34595790 DOI: 10.1002/chem.202102745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Indexed: 11/09/2022]
Abstract
The incorporation of a redox-active nickel salen complex into supramolecular structures was explored via coordination-driven self-assembly with homobimetallic ruthenium complexes (bridged by oxalato or 5,8-dihydroxy-1,4-naphthoquinato ligands). The self-assembly resulted in the formation of a discrete rectangle using the oxalato complex and either a rectangle or a catenane employing the larger naphthoquinonato complex. The formation of the interlocked self-assembly was determined to be solvent and concentration dependent. The electronic structure and stability of the oxidized metallacycles was probed using electrochemical experiments, UV-Vis-NIR absorption, EPR spectroscopy and DFT calculations, confirming ligand radical formation. Exciton coupling of the intense near-infrared (NIR) ligand radical intervalence charge transfer (IVCT) bands provided further confirmation of the geometric and electronic structures in solution.
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Affiliation(s)
| | - Magali Allain
- Univ Angers, CNRS, MOLTECH-ANJOU, 2 bd Lavoisier, 49000, Angers, France) E-mails: E-mails
| | - Gregory A MacNeil
- Department of Chemistry, Simon Fraser University, Burnaby, V5A 1S6, Canada
| | - Vincent Carré
- LCP-A2MC, FR 3624, Université de Lorraine, ICPM, 1 Bd Arago, 57078, Metz Cedex 03, France
| | - Frédéric Aubriet
- LCP-A2MC, FR 3624, Université de Lorraine, ICPM, 1 Bd Arago, 57078, Metz Cedex 03, France
| | - Daniel B Leznoff
- Department of Chemistry, Simon Fraser University, Burnaby, V5A 1S6, Canada
| | - Marc Sallé
- Univ Angers, CNRS, MOLTECH-ANJOU, 2 bd Lavoisier, 49000, Angers, France) E-mails: E-mails
| | - Sébastien Goeb
- Univ Angers, CNRS, MOLTECH-ANJOU, 2 bd Lavoisier, 49000, Angers, France) E-mails: E-mails
| | - Tim Storr
- Department of Chemistry, Simon Fraser University, Burnaby, V5A 1S6, Canada
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16
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Devonport J, Sully L, Boudalis AK, Hassell-Hart S, Leech MC, Lam K, Abdul-Sada A, Tizzard GJ, Coles SJ, Spencer J, Vargas A, Kostakis GE. Room-Temperature Cu(II) Radical-Triggered Alkyne C-H Activation. JACS AU 2021; 1:1937-1948. [PMID: 34841411 PMCID: PMC8611675 DOI: 10.1021/jacsau.1c00310] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Indexed: 06/13/2023]
Abstract
A dimeric Cu(II) complex [Cu(II)2L2(μ2-Cl)Cl] (1) built from an asymmetric tridentate ligand (2-(((2-aminocyclohexyl)imino)methyl)-4,6-di-tert-butylphenol) and weakly coordinating anions has been synthesized and structurally characterized. In dichloromethane solution, 1 exists in a monomeric [Cu(II)LCl] (1') (85%)-dimeric (1) (15%) equilibrium, and cyclic voltammetry (CV) and electron paramagnetic resonance (EPR) studies indicate structural stability and redox retention. Addition of phenylacetylene to the CH2Cl2 solution populates 1' and leads to the formation of a transient radical species. Theoretical studies support this notion and show that the radical initiates an alkyne C-H bond activation process via a four-membered ring (Cu(II)-O···H-Calkyne) intermediate. This unusual C-H activation method is applicable for the efficient synthesis of propargylamines, without additives, within 16 h, at low loadings and in noncoordinating solvents including late-stage functionalization of important bioactive molecules. Single-crystal X-ray diffraction studies, postcatalysis, confirmed the framework's stability and showed that the metal center preserves its oxidation state. The scope and limitations of this unconventional protocol are discussed.
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Affiliation(s)
- Jack Devonport
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - Lauren Sully
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - Athanassios K. Boudalis
- Institut
de Chimie de Strasbourg (UMR 7177, CNRS-Unistra), Université
de Strasbourg, 4 rue Blaise Pascal, CS 90032, F-67081 Strasbourg, France
- Université
de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux
de Strasbourg (IPCMS), UMR 7504, F-67000 Strasbourg, France
| | - Storm Hassell-Hart
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - Matthew C. Leech
- School
of Science, Department of Pharmaceutical Chemical and Environmental
Sciences, University of Greenwich, Central Avenue, Chatham Maritime ME4 4TB, U.K.
| | - Kevin Lam
- School
of Science, Department of Pharmaceutical Chemical and Environmental
Sciences, University of Greenwich, Central Avenue, Chatham Maritime ME4 4TB, U.K.
| | - Alaa Abdul-Sada
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - Graham J. Tizzard
- UK
National Crystallography Service, Chemistry, University of Southampton, Southampton SO1 71BJ, U.K.
| | - Simon J. Coles
- UK
National Crystallography Service, Chemistry, University of Southampton, Southampton SO1 71BJ, U.K.
| | - John Spencer
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - Alfredo Vargas
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - George E. Kostakis
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
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17
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Hein NM, MacNeil GA, Storr T. Elaboration on the Electronics of Salen Manganese Nitrides: Investigations into Alkoxy-Substituted Ligand Scaffolds. Inorg Chem 2021; 60:16895-16905. [PMID: 34719930 DOI: 10.1021/acs.inorgchem.1c02668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ligand electronics of salen manganese nitride complexes directly influence the locus of oxidation and, thus, the reactivity of the resulting oxidized species. This work investigates the influence of tert-butoxy, isopropoxy, and methoxy substituents on the electronics of salen manganese nitride species and includes the first documentation of the para Hammett value for the tert-butoxy substituent (σpara = -0.13 ± 0.03). Each alkoxy-substituted complex undergoes metal-based oxidation to form manganese(VI), and the kinetics of bimolecular homocoupling to form N2 were assessed by cyclic voltammetry. Bis-oxidation of the manganese complexes was investigated at low temperature using cyclic voltammery and UV-vis-near-IR spectroscopy, and in combination with theoretical calculations, plausible electronic structures of the dications are provided.
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Affiliation(s)
- Nicholas M Hein
- Department of Chemistry, Simon Fraser University (SFU), 8888 University Drive, Burnaby, British Columbia V5A 1S4, Canada
| | - Gregory A MacNeil
- Department of Chemistry, Simon Fraser University (SFU), 8888 University Drive, Burnaby, British Columbia V5A 1S4, Canada
| | - Tim Storr
- Department of Chemistry, Simon Fraser University (SFU), 8888 University Drive, Burnaby, British Columbia V5A 1S4, Canada
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18
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Redox-active ligands: Recent advances towards their incorporation into coordination polymers and metal-organic frameworks. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213891] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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19
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20
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Svirskiy GI, Generalov AV, Vinogradov NA, Brykalova XO, Vereshchagin AV, Levin OV, Lyalin AG, Preobrajenski AB, Vinogradov AS. Electronic structure of the [Ni(Salen)] complex studied by core-level spectroscopies. Phys Chem Chem Phys 2021; 23:11015-11027. [PMID: 33942044 DOI: 10.1039/d1cp00511a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The nature and structure of occupied and empty valence electronic states (molecular orbitals, MOs) of the [Ni(Salen)] molecular complex (NiO2N2C16H14) have been studied by X-ray photoemission and absorption spectroscopy combined with density functional theory (DFT) calculations. As a result, the composition of the high-lying occupied and low-lying unoccupied electronic states has been identified. In particular, the highest occupied molecular orbital (HOMO) of the complex is found to be predominantly located on the phenyl rings of the salen ligand, while the states associated with the occupied Ni 3d-derived molecular orbitals (MOs) are at higher binding energies. The lowest unoccupied molecular orbital (LUMO) is also located on the salen ligand and is formed by the 2pπ orbitals of carbon atoms in phenyl groups of the salen macrocycle. The unoccupied MOs above the LUMO reflect σ- and π-bonding between Ni and its nearest neighbours. All valence states have highly mixed character. The specific nature of the unoccupied Ni 3d-derived σ-MO is a consequence of donor-acceptor chemical bonding in [Ni(Salen)].
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Affiliation(s)
- Gleb I Svirskiy
- V.A. Fock Institute of Physics, St. Petersburg State University, 198504 St. Petersburg, Russia.
| | - Alexander V Generalov
- V.A. Fock Institute of Physics, St. Petersburg State University, 198504 St. Petersburg, Russia. and MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
| | - Nikolay A Vinogradov
- V.A. Fock Institute of Physics, St. Petersburg State University, 198504 St. Petersburg, Russia. and MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
| | - Xenia O Brykalova
- V.A. Fock Institute of Physics, St. Petersburg State University, 198504 St. Petersburg, Russia.
| | | | - Oleg V Levin
- Institute of Chemistry, St. Petersburg State University, 198504 St. Petersburg, Russia
| | - Andrey G Lyalin
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan and Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Alexei B Preobrajenski
- V.A. Fock Institute of Physics, St. Petersburg State University, 198504 St. Petersburg, Russia. and MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
| | - Alexander S Vinogradov
- V.A. Fock Institute of Physics, St. Petersburg State University, 198504 St. Petersburg, Russia.
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21
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Arnold A, Sherbow TJ, Bohanon AM, Sayler RI, Britt RD, Smith AM, Fettinger JC, Berben LA. Delocalization tunable by ligand substitution in [L 2Al] n− complexes highlights a mechanism for strong electronic coupling. Chem Sci 2021; 12:675-682. [PMID: 34163799 PMCID: PMC8179017 DOI: 10.1039/d0sc02812f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Organo-aluminum mixed-valent complexes combine properties of both organic and transition element mixed-valent compounds. This supports delocalized electronic structures that are structurally and electronically tunable.
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Affiliation(s)
- Amela Arnold
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA, 95616, USA
| | - Tobias J. Sherbow
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA, 95616, USA
| | - Amanda M. Bohanon
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA, 95616, USA
| | - Richard I. Sayler
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA, 95616, USA
| | - R. David Britt
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA, 95616, USA
| | - Allison M. Smith
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA, 95616, USA
| | - James C. Fettinger
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA, 95616, USA
| | - Louise A. Berben
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA, 95616, USA
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22
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Plaza‐Lozano D, Morales‐Martínez D, González FJ, Olguín J. Homoleptic Mononuclear Tris‐Chelate Complexes of Fe
II
, Co
II
, Ni
II
, and Zn
II
Based on a Redox‐Active Imidazolyl‐2‐thione Ligand: Structural and Electrochemical Correlation. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000120] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Diego Plaza‐Lozano
- Departamento de Química Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav) Avenida IPN 2508, Col. San Pedro Zacatenco 07360 Ciudad de México México
| | - Daniel Morales‐Martínez
- Departamento de Química Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav) Avenida IPN 2508, Col. San Pedro Zacatenco 07360 Ciudad de México México
| | - Felipe J. González
- Departamento de Química Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav) Avenida IPN 2508, Col. San Pedro Zacatenco 07360 Ciudad de México México
| | - Juan Olguín
- Departamento de Química Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav) Avenida IPN 2508, Col. San Pedro Zacatenco 07360 Ciudad de México México
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23
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Kanso H, Clarke RM, Kochem A, Arora H, Philouze C, Jarjayes O, Storr T, Thomas F. Effect of Distortions on the Geometric and Electronic Structures of One-Electron Oxidized Vanadium(IV), Copper(II), and Cobalt(II)/(III) Salen Complexes. Inorg Chem 2020; 59:5133-5148. [DOI: 10.1021/acs.inorgchem.0c00381] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hussein Kanso
- Univ. Grenoble Alpes, CNRS, DCM, F-38000 Grenoble, France
| | - Ryan M. Clarke
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Amélie Kochem
- Univ. Grenoble Alpes, CNRS, DCM, F-38000 Grenoble, France
| | - Himanshu Arora
- Univ. Grenoble Alpes, CNRS, DCM, F-38000 Grenoble, France
| | | | | | - Tim Storr
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Fabrice Thomas
- Univ. Grenoble Alpes, CNRS, DCM, F-38000 Grenoble, France
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24
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Benabid W, Ouari K, Bendia S, Bourzami R, Ait Ali M. Crystal structure, spectroscopic studies, DFT calculations, cyclic voltammetry and biological activity of a copper (II) Schiff base complex. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127313] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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25
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Mekhail MA, Pota K, Schwartz TM, Green KN. Functionalized pyridine in pyclen-based iron( iii) complexes: evaluation of fundamental properties. RSC Adv 2020; 10:31165-31170. [PMID: 34094507 PMCID: PMC8174454 DOI: 10.1039/d0ra05756h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Six iron(iii) pyridinophane complexes were evaluated to determine whether functionalizing the pyridine ring could introduce a handle by which electrochemical properties and thermodynamic stability can be tuned.
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Affiliation(s)
- Magy A. Mekhail
- Department of Chemistry and Biochemistry
- Texas Christian University
- Fort Worth
- USA
| | - Kristof Pota
- Department of Chemistry and Biochemistry
- Texas Christian University
- Fort Worth
- USA
| | - Timothy M. Schwartz
- Department of Chemistry and Biochemistry
- Texas Christian University
- Fort Worth
- USA
| | - Kayla N. Green
- Department of Chemistry and Biochemistry
- Texas Christian University
- Fort Worth
- USA
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26
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Dmitrieva EA, Chepurnaya IA, Karushev MP, Timonov AM. The Nature of Charge Carriers in Polymeric Complexes of Nickel with Schiff Bases Containing Electron-Withdrawing Substituents. RUSS J ELECTROCHEM+ 2019. [DOI: 10.1134/s1023193519110041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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27
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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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28
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Jangir R, Ansari M, Kaleeswaran D, Rajaraman G, Palaniandavar M, Murugavel R. Unprecedented Copper(II) Complex with a Topoquinone-like Moiety as a Structural and Functional Mimic for Copper Amine Oxidase: Role of Copper(II) in the Genesis and Amine Oxidase Activity. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02326] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Ritambhara Jangir
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Mursaleem Ansari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | | | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Mallayan Palaniandavar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Ramaswamy Murugavel
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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29
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Gutiérrez KJ, Pedreira WM, Piñero Cruz DM. Synthesis, structural, electrochemical and spectroscopic characterization, and theoretical calculations of two new Cu(II) and Ni(II) complexes from 2-(1-((pyridine-2-ylmethyl)imino)ethyl)naphtalen-1-ol. J COORD CHEM 2019. [DOI: 10.1080/00958972.2019.1670348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Keily J. Gutiérrez
- Department of Chemistry and the Molecular Sciences Research Center, University of Puerto Rico at Río Piedras, San Juan, Puerto Rico
| | - Wilfredo M. Pedreira
- Department of Chemistry and the Molecular Sciences Research Center, University of Puerto Rico at Río Piedras, San Juan, Puerto Rico
| | - Dalice M. Piñero Cruz
- Department of Chemistry and the Molecular Sciences Research Center, University of Puerto Rico at Río Piedras, San Juan, Puerto Rico
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30
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Spielvogel KD, Coughlin EJ, Petras H, Luna JA, Benson A, Donahue CM, Kibasa A, Lee K, Salacinski R, Bart SC, Shaw SK, Shepherd JJ, Daly SR. The Influence of Redox-Innocent Donor Groups in Tetradentate Ligands Derived from o-Phenylenediamine: Electronic Structure Investigations with Nickel. Inorg Chem 2019; 58:12756-12774. [DOI: 10.1021/acs.inorgchem.9b01675] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Kyle D. Spielvogel
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Ezra J. Coughlin
- H.C. Brown Laboratory, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Hayley Petras
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Javier A. Luna
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Austin Benson
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Courtney M. Donahue
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Amani Kibasa
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Kyounghoon Lee
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Ryan Salacinski
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Suzanne C. Bart
- H.C. Brown Laboratory, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Scott K. Shaw
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - James J. Shepherd
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
| | - Scott R. Daly
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242-1294, United States
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31
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Katari M, Carmichael D, Jacquemin D, Frison G. Structure of Electronically Reduced N-Donor Bidentate Ligands and Their Heteroleptic Four-Coordinate Zinc Complexes: A Survey of Density Functional Theory Results. Inorg Chem 2019; 58:7169-7179. [PMID: 31117621 DOI: 10.1021/acs.inorgchem.8b03549] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of Hartree-Fock exchange in describing the structural changes occurring upon reduction of bipyridine-based ligands and their complexes is investigated within the framework of density functional theory (DFT) calculations. A set of four free ligands in their neutral and radical anionic forms, and two of their zinc complexes in their dicationic and monocationic radical forms, is used to compare a large panel of pure, conventional, and long-range corrected hybrid DFT functionals; coupled cluster single and double calculations are used alongside experimental results as benchmarks. Particular attention has been devoted to the magnitude of the change, upon reduction, of the Δ-parameter, which measures the difference between the Cpy-Cpy and the C-N bond lengths in bipyridine ligand and is known to experimentally correlate with the charge of the ligands. Our results indicate that the structural changes significantly depend on the amount of exact exchange included in the functional. A progressive evolution is observed for the free ligands, whereas two distinct sets of results are obtained for the complexes. Functionals with a small degree of HF exchange, e.g., B3LYP, do not adequately describe geometric changes for the considered species, and, quite surprisingly, the same holds for the CC2 method. The best agreement to experimental and CCSD values is obtained with functionals that include a significant but not excessive part of exact exchange, e.g., CAM-B3LYP, M06-2X, and ωB97X-D. The calculated localization of the added electron after reduction, which depends on the self-interaction error, is used to rationalize these outcomes. Static correlation is also shown to play a role in the accurate description of the electronic structure.
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Affiliation(s)
| | - Duncan Carmichael
- LCM, CNRS, Ecole Polytechnique , IP Paris , F-91128 Palaiseau , France
| | - Denis Jacquemin
- University of Nantes , CNRS, CEISAM (UMR 6230), 2 chemin de la Houssinière , 44322 Nantes , Cedex 03 , France
| | - Gilles Frison
- LCM, CNRS, Ecole Polytechnique , IP Paris , F-91128 Palaiseau , France
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32
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Herasymchuk K, Miller JJ, MacNeil GA, Sergeenko AS, McKearney D, Goeb S, Sallé M, Leznoff DB, Storr T. Coordination-driven assembly of a supramolecular square and oxidation to a tetra-ligand radical species. Chem Commun (Camb) 2019; 55:6082-6085. [PMID: 31066383 DOI: 10.1039/c9cc02320h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The design and synthesis of a supramolecular square was achieved by coordination-driven assembly of redox-active nickel(ii) salen linkers and (ethylenediamine)palladium(ii) nodes. The tetrameric geometry of the supramolecular structure was confirmed via MS, NMR, and electrochemical experiments. While oxidation of the monomeric metalloligand Schiff-base affords a Ni(iii) species, oxidation of the coordination-driven assembly results in ligand radical formation.
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Affiliation(s)
| | - Jessica J Miller
- Department of Chemistry, Simon Fraser University, Burnaby, Canada.
| | | | - Ania S Sergeenko
- Department of Chemistry, Simon Fraser University, Burnaby, Canada.
| | - Declan McKearney
- Department of Chemistry, Simon Fraser University, Burnaby, Canada.
| | - Sébastien Goeb
- Laboratoire MOLTECH-Anjou, UMR CNRS 6200, UNIV Angers, SFR MATRIX, 2 Bd Lavoisier, 49045 Angers Cedex, France
| | - Marc Sallé
- Laboratoire MOLTECH-Anjou, UMR CNRS 6200, UNIV Angers, SFR MATRIX, 2 Bd Lavoisier, 49045 Angers Cedex, France
| | - Daniel B Leznoff
- Department of Chemistry, Simon Fraser University, Burnaby, Canada.
| | - Tim Storr
- Department of Chemistry, Simon Fraser University, Burnaby, Canada.
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33
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Pratihar JL, Mandal P, Lai CK, Chattopadhyay S. Tetradentate amido azo Schiff base Cu(II), Ni(II) and Pd(II) complexes: Synthesis, characterization, spectral properties, and applications to catalysis in C–C coupling and oxidation reaction. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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34
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Rajput A, Saha A, Barman SK, Lloret F, Mukherjee R. [Cu II{(L ISQ)˙ -} 2] (H 2L: thioether-appended o-aminophenol ligand) monocation triggers change in donor site from N 2O 2 to N 2O (2)S and valence-tautomerism. Dalton Trans 2019; 48:1795-1813. [PMID: 30644480 DOI: 10.1039/c8dt03778g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Using a potentially tridentate o-aminophenol-based redox-active ligand H2L1 (2-[2-(benzylthio)phenylamino]-4,6-di-tert-butylphenol) in its deprotonated form, [Cu(L1)2] has been synthesized and crystallized as [CuII(L1)2]·CH2Cl2 (1·CH2Cl2). A cyclic voltammetry experiment (in CH2Cl2; V vs. SCE (saturated calomel electrode)) on 1·CH2Cl2 exhibits two oxidative (E = 0.20 V (peak-to-peak separation, ΔEp = 100 mV) and E = 0.90 V (ΔEp = 140 mV)) and two reductive (E = -0.52 V (ΔEp = 110 mV) and E = -0.92 V (ΔEp = 120 mV)) responses. Upon oxidation using a stoichiometric amount of [FeIII(η5-C5H5)2](PF6), 1·CH2Cl2 yielded [Cu(L1)2](PF6) (2). Structural analysis (100 K) reveals that 1·CH2Cl2 is a four-coordinate bis(iminosemiquinonato)copper(ii) complex (CuN2O2 coordination), and that the thioethers remain uncoordinated. The twisted geometry of 1 (distorted tetrahedral) results in considerable changes in the electronic structure, compared to well-known square-planar analogues. Crystallographic analysis of 2 both at 100 K and at 293 K reveals that it is effectively a four-coordinate complex with a CuN2OS coordination; however, a substantial interaction with the other phenolate O is observed. The metal-ligand bond distances and metric parameters associated with the o-aminophenolate rings indicate a valence-tautomeric (VT) equilibrium involving monocationic (iminosemiquinonato)(iminoquinone)copper(ii) and bis(iminoquinone)copper(i). Complex 1·CH2Cl2 is a three-spin system and a magnetic study (4-300 K) established that it has a S = 1/2 ground-state, owing to the strong antiferromagnetic coupling between the unpaired spin of the copper(ii) and the iminosemiquinonate(1-) π-radical anion. Electron paramagnetic resonance (EPR) spectral studies corroborate this result. Complex 2 is diamagnetic and the existence of VT in 2 was probed using variable-temperature (248-328 K) 1H NMR and EPR (100-298 K) spectral measurements and X-ray photoelectron spectroscopic studies at 298 K. Remarkably, modification of the well-studied 2-anilino-4,6-di-tert-butylphenol by incorporation of a benzylthioether arm leads to the occurrence of VT in 2. The electronic structure of 1·CH2Cl2 and 2 has been assigned using density functional theory (DFT) calculations at the B3LYP-D3 level of theory. Time-dependent (TD)-DFT calculations have been performed to elucidate the origin of the observed UV-VIS-NIR absorptions.
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Affiliation(s)
- Amit Rajput
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India. and Department of Basic and Applied Sciences, School of Engineering, G. D. Goenka University, Sohna Road, Gurugram 122 103, Haryana, India
| | - Anannya Saha
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India
| | - Suman K Barman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India.
| | - Francesc Lloret
- Departament de Quımíca, Inorgànica/Instituto de Ciencia Molecular (ICMOL), Universitat de Valeńcia, Polígono de la Coma, s/n, 46980-Paterna, València, Spain
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Maity S, Ghosh S, Ghosh A. Elucidating the secondary effect in the Lewis acid mediated anodic shift of electrochemical oxidation of a Cu(ii) complex with a N2O2 donor unsymmetrical ligand. Dalton Trans 2019; 48:14898-14913. [DOI: 10.1039/c9dt03323h] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The causes behind the fluctuations from a linear dependence of the electrochemical signal of a guest bound metalloligand [CuL] with the Lewis acidity of redox-inactive cations were established by using UV-vis spectroscopy and cyclic voltammetry.
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Affiliation(s)
- Souvik Maity
- Department of Chemistry
- University College of Science
- University of Calcutta
- Kolkata 700009
- India
| | - Soumavo Ghosh
- Department of Chemistry
- University College of Science
- University of Calcutta
- Kolkata 700009
- India
| | - Ashutosh Ghosh
- Department of Chemistry
- University College of Science
- University of Calcutta
- Kolkata 700009
- India
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Rajput A, Sharma AK, Barman SK, Lloret F, Mukherjee R. Six-coordinate [Co III(L) 2] z (z = 1-, 0, 1+) complexes of an azo-appended o-aminophenolate in amidate(2-) and iminosemiquinonate π-radical (1-) redox-levels: the existence of valence-tautomerism. Dalton Trans 2018; 47:17086-17101. [PMID: 30465680 DOI: 10.1039/c8dt03257b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Aerobic reaction of the ligand H2L1, 2-(2-phenylazo)-anilino-4,6-di-tert-butylphenol, CoCl2·6H2O and Et3N in MeOH under refluxing conditions produces, after work-up and recrystallization, black crystals of [Co(L1)2] (1). When examined by cyclic voltammetry, 1 displays in CH2Cl2 three one-electron redox responses: two oxidative, E11/2 = 0.30 V (peak-to-peak separation, ΔEp = 100 mV) and E21/2 = 1.04 V (ΔEp = 120 mV), and one reductive E1/2 = -0.27 V (ΔEp = 120 mV) vs. SCE. Consequently, 1 is chemically oxidized by 1 equiv. of [FeIII(η5-C5H5)2][PF6], affording the isolation of deep purple crystals of [Co(L1)2][PF6]·2CH2Cl2 (2), and one-electron reduction with [CoII(η5-C5H5)2] yielded bluish-black crystals of [CoIII(η5-C5H5)2][Co(L1)2]·MeCN (3). A solid sample of 1 exhibits temperature-independent (50-300 K) magnetism, revealing the presence of a free radical (S = 1/2), which exhibits an isotropic EPR signal (g = 2.003) at 298 K and at 77 K an eight-line feature characteristic of hyperfine-interaction of the radical with the Co (I = 7/2) nucleus. Based on X-ray structural parameters of 1-3 at 100 K, magnetic and EPR spectral behaviour of 1, and variable-temperature (233-313 K) 1H NMR spectral features of 1-3 and 13C NMR spectra at 298 K of 2 and 3 in CDCl3 point to the electronic structure of the complexes as either [CoIII{(LAP)2-}{(LISQ)}˙-] or [CoIII{(L1)2}˙3-] (delocalized nature favours the latter description) (1), [CoIII{(LISQ)˙-}2][PF6]·2CH2Cl2 (2) and [CoIII(η5-C5H5)2][CoIII{(LAP)2-}2]·MeCN (3) [(LAP)2- and (LISQ)˙- represent the redox-level of coordinated ligands o-amidophenolate(2-) ion and o-iminobenzosemiquinonate(1-) π-radical ion, respectively]. Notably, all the observed redox processes are ligand-centred. To the best of our knowledge, this is the first time that six-coordinate complexes of a common tridentate o-aminophenolate-based ligand have been structurally characterized for the parent 1, its monocation 2 and the monoanion 3 counterparts. Temperature-dependent 1H NMR spectra reveal the existence of valence-tautomeric equilibria in 1-3. Density Functional Theory (DFT) calculations at the B3LYP-level of theory corroborate the electronic structural assignment of 1-3 from experimental data. The origins of the observed UV-VIS-NIR absorptions for 1-3 have been assigned, based on time-dependent (TD)-DFT calculations.
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Affiliation(s)
- Amit Rajput
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India.
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Coordination chemistry of a redox non-innocent NHC bis(phenolate) pincer ligand with nickel(II). Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2018.06.046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Chiang L, Wasinger EC, Shimazaki Y, Young V, Storr T, Stack TDP. Electronic Structure and Reactivity Studies of a Nonsymmetric One-Electron Oxidized Cu II Bis-phenoxide Complex. Inorganica Chim Acta 2018; 481:151-158. [PMID: 30581226 PMCID: PMC6301013 DOI: 10.1016/j.ica.2017.09.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The tetradentate mixed imino/amino phenoxide ligand (N-(3,5-di-tert-butylsalicylidene)-N'-(2-hydroxyl-3,5-di-tert-butylbenzyl))-trans-1,2-cyclohexanediamine (salalen) was complexed with CuII, and the resulting Cu complex (2) was characterized by a number of experimental techniques and theoretical calculations. Two quasi-reversible redox processes for 2, as observed by cyclic voltammetry, demonstrated the potential stability of oxidized forms, and also the increased electron-donating ability of the salalen ligand in comparison to the salen analogue. The electronic structure of the one-electron oxidized [2]+ was then studied in detail, and Cu K-edge X-ray Absorption Spectroscopy (XAS) measurements confirmed a CuII-phenoxyl radical complex in solution. Subsequent resonance Raman (rR) and variable temperature 1H NMR studies, coupled with theoretical calculations, showed that [2• ]+ is a triplet (S = 1) CuII-phenoxyl radical species, with localization of the radical on the more electron-rich aminophenoxide. Attempted isolation of X-ray quality crystals of [2• ]+ afforded [2H]+, with a protonated phenol bonded to CuII, and an additional H-bonding interaction with the SbF6 - counterion. Stoichiometric reaction of dilute solutions of [2• ]+ with benzyl alcohol showed that the complex reacted in a similar manner as the oxidized CuII-salen analogue, and does not exhibit a substrate-binding pre-equilibrium as observed for the oxidized bisaminophenoxide CuII-salan derivative.
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Affiliation(s)
- Linus Chiang
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Erik C Wasinger
- Department of Chemistry and Biochemistry, California State University, Chico, CA 95928, USA
| | - Yuichi Shimazaki
- College of Science, Ibaraki University. Bunkyo, Mito, 310-8512, Japan
| | - Victor Young
- Department of Chemistry, The University of Minnesota, Minneapolis, MN 55455, USA
| | - Tim Storr
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - T Daniel P Stack
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
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Pratihar JL, Mandal P, Brandão P, Mal D, Felix V. Synthesis, characterization, spectral and catalytic activity of tetradentate (NNNO) azo-imine Schiff base copper(II) complexes. Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2018.04.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Kwak SW, Kwon H, Lee JH, Hwang H, Kim M, Chung Y, Kim Y, Lee KM, Park MH. Salen-indium/triarylborane triads: synthesis and ratiometric emission-colour changes by fluoride ion binding. Dalton Trans 2018; 47:5310-5317. [PMID: 29582029 DOI: 10.1039/c8dt00153g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Salen-based indium triads, [{(3-tBu)2-(5-Mes2B)2-salen}In-Me] (1) and [{(3-tBu)2-(5-Mes2Bphenyl)2-salen}In-Me] (2), bearing triarylborane (TAB) units were prepared and fully characterised by NMR spectroscopy and elemental analysis. The major absorption bands of 1 and 2 appeared in the region centred at 347 nm and 374 nm, respectively, and the intense emission spectra were observed in the sky blue (λem = 491 nm for 1) and bluish-green (λem = 498 nm for 2) regions, respectively. The solvatochromism effects in various organic solvents and computational calculation results strongly suggested that these absorption and emission features are mainly attributed to intramolecular charge transfer (ICT) transitions between the salen ligand moieties and the TAB units. Furthermore, UV-vis and photoluminescence (PL) titration experiments by the addition of fluoride anions demonstrated ratiometric quenching patterns in both the absorption and emission spectra, indicating that binding of the fluoride anion to the boron centres interrupts these ICT transitions in each compound. Interestingly, both triads exhibited a gradual red-shifted response in each emission spectrum upon the addition of the fluoride anions, resulting in a dramatic colour-change to yellow. The computational calculation results of the S1 states revealed that these emission-colour change properties arise from the elevation of HOMO levels, which are mainly localised on the TAB moieties, resulting from the fluoride anion binding to the borane centres.
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Affiliation(s)
- Sang Woo Kwak
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea.
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41
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Tomczyk D, Bukowski W, Bester K. Redox processes in the solution of Ni(II) complex with salen type ligand and in the polymer films. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.02.051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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42
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Shao L, Chen Q, Qi C. Air Oxidation of Benzoin Catalyzed by Metal-Salen Complexes. KINETICS AND CATALYSIS 2018. [DOI: 10.1134/s002315841801010x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Accurate Ionization Energies for Mononuclear Copper Complexes Remain a Challenge for Density Functional Theory. Chemphyschem 2018; 19:959-966. [DOI: 10.1002/cphc.201701334] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Indexed: 12/21/2022]
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Zhang C, Sutherland M, Herasymchuk K, Clarke RM, Thompson JR, Chiang L, Walsby CJ, Storr T. Octahedral Co(III) salen complexes: the role of peripheral ligand electronics on axial ligand release upon reduction. CAN J CHEM 2018. [DOI: 10.1139/cjc-2017-0277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A series of octahedral CoIII salen complexes (where salen represents a N2O2 bis-Schiff-base bis-phenolate framework) were prepared with axial imidazole ligating groups. When using 1-methylimidazole (1-MeIm) axial ligands, the CoIII/CoII reduction potential could be altered by 220 mV via variation of the electron-donating ability of the para-ring substituents (R = H (1), OMe (2), tBu (3), Br (4), NO2 (5), and CF3 (6)). In addition, the irreversibility of the reduction process suggested substantial geometrical changes and axial ligand exchange upon reduction to the more labile CoII oxidation state. Installing an imidazole-coumarin conjugate as the axial ligands resulted in fluorescence quenching when bound to the CoIII centre (R = H (7), OMe (8), and CF3 (9)). The redox properties and fluorescence increase upon ligand release for 7–9 were studied under reducing conditions and in the presence of excess competing ligand (1-MeIm). It was determined that the Lewis acidity of the CoIII centre was the dominant factor in controlling axial ligand exchange for this series of complexes.
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Affiliation(s)
- Chen Zhang
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Mathew Sutherland
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Khrystyna Herasymchuk
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Ryan M. Clarke
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - John R. Thompson
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Linus Chiang
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Charles J. Walsby
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Tim Storr
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
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Brandenburg H, Krahmer J, Fischer K, Schwager B, Flöser B, Näther C, Tuczek F. Coordination-Induced Spin-State Switching with Nickel(II) salpn Complexes: Electronic versus Steric Effects and Influence of Intermolecular Interactions. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201701281] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hannah Brandenburg
- Institut für Anorganische Chemie; Christian-Albrechts-Universität Kiel; Max-Eyth-Str. 2 24118 Kiel Germany
| | - Jan Krahmer
- Institut für Anorganische Chemie; Christian-Albrechts-Universität Kiel; Max-Eyth-Str. 2 24118 Kiel Germany
| | - Kim Fischer
- Institut für Anorganische Chemie; Christian-Albrechts-Universität Kiel; Max-Eyth-Str. 2 24118 Kiel Germany
| | - Bettina Schwager
- Institut für Anorganische Chemie; Christian-Albrechts-Universität Kiel; Max-Eyth-Str. 2 24118 Kiel Germany
| | - Benedikt Flöser
- Institut für Anorganische Chemie; Christian-Albrechts-Universität Kiel; Max-Eyth-Str. 2 24118 Kiel Germany
| | - Christian Näther
- Institut für Anorganische Chemie; Christian-Albrechts-Universität Kiel; Max-Eyth-Str. 2 24118 Kiel Germany
| | - Felix Tuczek
- Institut für Anorganische Chemie; Christian-Albrechts-Universität Kiel; Max-Eyth-Str. 2 24118 Kiel Germany
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46
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Marín IM, Auffrant A. Phosphasalen vs. Salen Ligands: What Does the Phosphorus Change? Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201701210] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Irene Mustieles Marín
- LCM, CNRS-Ecole polytechnique; Université Paris-Saclay; F-91128 Palaiseau Cedex France
| | - Audrey Auffrant
- LCM, CNRS-Ecole polytechnique; Université Paris-Saclay; F-91128 Palaiseau Cedex France
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Lecarme L, Chiang L, Moutet J, Leconte N, Philouze C, Jarjayes O, Storr T, Thomas F. The structure of a one-electron oxidized Mn(iii)-bis(phenolate)dipyrrin radical complex and oxidation catalysis control via ligand-centered redox activity. Dalton Trans 2018; 45:16325-16334. [PMID: 27711805 DOI: 10.1039/c6dt02163h] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The tetradentate ligand dppH3, which features a half-porphyrin and two electron-rich phenol moieties, was prepared and chelated to manganese. The mononuclear Mn(iii)-dipyrrophenolate complex 1 was structurally characterized. The metal ion lies in a square pyramidal environment, the apical position being occupied by a methanol molecule. Complex 1 displays two reversible oxidation waves at 0.00 V and 0.47 V vs. Fc+/Fc, which are assigned to ligand-centered processes. The one-electron oxidized species 1+ SbF6- was crystallized, showing an octahedral Mn(iii) center with two water molecules coordinated at both apical positions. The bond distance analysis and DFT calculations disclose that the radical is delocalized over the whole aromatic framework. Complex 1+ SbF6- exhibits an Stot = 3/2 spin state due to the antiferromagnetic coupling between Mn(iii) and the ligand radical. The zero field splitting parameters are D = 1.6 cm-1, E/D = 0.18(1), g⊥ = 1.99 and g∥ = 1.98. The dication 12+ is an integer spin system, which is assigned to a doubly oxidized ligand coordinated to a Mn(iii) metal center. Both 1 and 1+ SbF6- catalyze styrene oxidation in the presence of PhIO, but the nature of the main reaction product is different. Styrene oxide is the main reaction product when using 1, but phenylacetaldehyde is formed predominantly when using 1+ SbF6-. We examined the ability of complex 1+ SbF6- to catalyze the isomerization of styrene oxide and found that it is an efficient catalyst for the anti-Markovnikov opening of styrene oxide. The formation of phenylacetaldehyde from styrene therefore proceeds in a tandem E-I (epoxidation-isomerization) mechanism in the case of 1+ SbF6-. This is the first evidence of control of the reactivity for styrene oxidation by changing the oxidation state of a catalyst based on a redox-active ligand.
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Affiliation(s)
- Laureline Lecarme
- Département de Chimie Moléculaire - Chimie Inorganique Redox (CIRE) - UMR CNRS 5250, Université Grenoble Alpes, B. P. 53, 38041 Grenoble cedex 9, France.
| | - Linus Chiang
- Simon Fraser University, Department of Chemistry, 8888 University Drive, Burnaby, British Columbia V5A-1S4, Canada
| | - Jules Moutet
- Département de Chimie Moléculaire - Chimie Inorganique Redox (CIRE) - UMR CNRS 5250, Université Grenoble Alpes, B. P. 53, 38041 Grenoble cedex 9, France.
| | - Nicolas Leconte
- Département de Chimie Moléculaire - Chimie Inorganique Redox (CIRE) - UMR CNRS 5250, Université Grenoble Alpes, B. P. 53, 38041 Grenoble cedex 9, France.
| | - Christian Philouze
- Département de Chimie Moléculaire - Chimie Inorganique Redox (CIRE) - UMR CNRS 5250, Université Grenoble Alpes, B. P. 53, 38041 Grenoble cedex 9, France.
| | - Olivier Jarjayes
- Département de Chimie Moléculaire - Chimie Inorganique Redox (CIRE) - UMR CNRS 5250, Université Grenoble Alpes, B. P. 53, 38041 Grenoble cedex 9, France.
| | - Tim Storr
- Simon Fraser University, Department of Chemistry, 8888 University Drive, Burnaby, British Columbia V5A-1S4, Canada
| | - Fabrice Thomas
- Département de Chimie Moléculaire - Chimie Inorganique Redox (CIRE) - UMR CNRS 5250, Université Grenoble Alpes, B. P. 53, 38041 Grenoble cedex 9, France.
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Viqueira J, Durán ML, García-Vázquez JA, Castro J, Platas-Iglesias C, Esteban-Gómez D, Alzuet-Piña G, Moldes A, Nascimento OR. Modulating the DNA cleavage ability of copper(ii) Schiff bases through ternary complex formation. NEW J CHEM 2018. [DOI: 10.1039/c8nj03292k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Copper(ii) Schiff-bases were electrochemically synthesized and characterized. The presence of co-ligands such as 2,2′-bpy or phen in the metal coordination environment increases the DNA cleavage efficiency.
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Affiliation(s)
- Joaquín Viqueira
- Departamento de Química Inorgánica
- Campus Vida
- Universidad de Santiago de Compostela
- 15782 Santiago de Compostela
- Spain
| | - María L. Durán
- Departamento de Química Inorgánica
- Campus Vida
- Universidad de Santiago de Compostela
- 15782 Santiago de Compostela
- Spain
| | - José A. García-Vázquez
- Departamento de Química Inorgánica
- Campus Vida
- Universidad de Santiago de Compostela
- 15782 Santiago de Compostela
- Spain
| | - Jesús Castro
- Departamento de Química Inorgánica
- Facultade de Química
- Edificio de Ciencias Experimentais
- Universidade de Vigo
- 36310 Vigo
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química
- Universidade da Coruña
- Campus da Zapateira
- 15008 A Coruña
- Spain
| | - David Esteban-Gómez
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química
- Universidade da Coruña
- Campus da Zapateira
- 15008 A Coruña
- Spain
| | - Gloria Alzuet-Piña
- Departament de Química Inorgànica
- Facultat de Farmàcia
- Universitat de València
- 46100 Burjassot
- Spain
| | - Angeles Moldes
- Departament de Química Inorgànica
- Facultat de Farmàcia
- Universitat de València
- 46100 Burjassot
- Spain
| | - Otaciro R. Nascimento
- Instituto de Física de Sao Carlos
- Universidade de Sao Paulo
- 13560-250 Sao Carlos
- Brazil
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Clarke RM, Jeen T, Rigo S, Thompson JR, Kaake LG, Thomas F, Storr T. Exploiting exciton coupling of ligand radical intervalence charge transfer transitions to tune NIR absorption. Chem Sci 2017; 9:1610-1620. [PMID: 29675206 PMCID: PMC5887452 DOI: 10.1039/c7sc04537a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 12/18/2017] [Indexed: 12/03/2022] Open
Abstract
We detail the rational design of a series of bimetallic bis-ligand radical Ni salen complexes in which the relative orientation of the ligand radical chromophores provides a mechanism to tune the energy of intense intervalence charge transfer (IVCT) bands in the near infrared (NIR) region.
We detail the rational design of a series of bimetallic bis-ligand radical Ni salen complexes in which the relative orientation of the ligand radical chromophores provides a mechanism to tune the energy of intense intervalence charge transfer (IVCT) bands in the near infrared (NIR) region. Through a suite of experimental (electrochemistry, electron paramagnetic resonance spectroscopy, UV-vis-NIR spectroscopy) and theoretical (density functional theory) techniques, we demonstrate that bimetallic Ni salen complexes form bis-ligand radicals upon two-electron oxidation, whose NIR absorption energies depend on the geometry imposed in the bis-ligand radical complex. Relative to the oxidized monomer [1˙]+ (E = 4500 cm–1, ε = 27 700 M–1 cm–1), oxidation of the cofacially constrained analogue 2 to [2˙˙]2+ results in a blue-shifted NIR band (E = 4830 cm–1, ε = 42 900 M–1 cm–1), while oxidation of 5 to [5˙˙]2+, with parallel arrangement of chromophores, results in a red-shifted NIR band (E = 4150 cm–1, ε = 46 600 M–1 cm–1); the NIR bands exhibit double the intensity in comparison to the monomer. Oxidation of the intermediate orientations results in band splitting for [3˙˙]2+ (E = 4890 and 4200 cm–1; ε = 26 500 and 21 100 M–1 cm–1), and a red-shift for [4˙˙]2+ using ortho- and meta-phenylene linkers, respectively. This study demonstrates for the first time, the applicability of exciton coupling to ligand radical systems absorbing in the NIR region and shows that by simple geometry changes, it is possible to tune the energy of intense low energy absorption by nearly 400 nm.
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Affiliation(s)
- Ryan M Clarke
- Department of Chemistry , Simon Fraser University , V5A1S6 , Burnaby , BC , Canada .
| | - Tiffany Jeen
- Department of Chemistry , Simon Fraser University , V5A1S6 , Burnaby , BC , Canada .
| | - Serena Rigo
- Department of Chemistry , Simon Fraser University , V5A1S6 , Burnaby , BC , Canada .
| | - John R Thompson
- Department of Chemistry , Simon Fraser University , V5A1S6 , Burnaby , BC , Canada .
| | - Loren G Kaake
- Department of Chemistry , Simon Fraser University , V5A1S6 , Burnaby , BC , Canada .
| | - Fabrice Thomas
- Départment de Chimie Moléculaire - Chimie Inorganique Redox (CIRE) - UMR CNRS 5250 , Université Grenoble-Alpes , B.P. 53 , 38041 Grenoble Cedex 9 , France
| | - Tim Storr
- Department of Chemistry , Simon Fraser University , V5A1S6 , Burnaby , BC , Canada .
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