1
|
Tomat E, Curtis CJ, Astashkin AV, Conradie J, Ghosh A. Multicenter interactions and ligand field effects in platinum(II) tripyrrindione radicals. Dalton Trans 2023; 52:6559-6568. [PMID: 37185585 DOI: 10.1039/d3dt00894k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The tripyrrin-1,14-dione biopyrrin, which shares the scaffold of several naturally occurring heme metabolites, is a redox-active platform for metal coordination. We report the synthesis of square planar platinum(II) tripyrrindiones, in which the biopyrrin binds as a tridentate radical and the fourth coordination position is occupied by either aqua or tert-butyl isocyanide ligands. These complexes are stable through chromatographic purification and exposure to air. Electron paramagnetic resonance (EPR) data and density functional theory (DFT) analysis confirm that the spin density is located predominantly on the tripyrrindione ligand. Pancake bonding in solution between the Pt(II) tripyrrindione radicals leads to the formation of diamagnetic π dimers at low temperatures. The identity of the monodentate ligand (i.e., aqua vs. isocyanide) affects both the thermodynamic parameters of dimerization and the tripyrrindione-based redox processes in these complexes. Isolation and structural characterization of the oxidized complexes revealed stacking of the diamagnetic tripyrrindiones in the solid state as well as a metallophilic Pt(II)-Pt(II) contact in the case of the aqua complex. Overall, the properties of Pt(II) tripyrrindiones, including redox potentials and intermolecular interactions in solution and in the solid state, are modulated through easily accessible changes in the redox state of the biopyrrin ligand or the nature of the monodentate ligand.
Collapse
Affiliation(s)
- Elisa Tomat
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721-0041, USA.
| | - Clayton J Curtis
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721-0041, USA.
| | - Andrei V Astashkin
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721-0041, USA.
| | - Jeanet Conradie
- Department of Chemistry, University of the Free State, Bloemfontein 9300, Republic of South Africa
- Department of Chemistry, UiT - The Arctic University of Norway, N-9037 Tromsø, Norway.
| | - Abhik Ghosh
- Department of Chemistry, UiT - The Arctic University of Norway, N-9037 Tromsø, Norway.
| |
Collapse
|
2
|
Avan İ, Kani İ, Çalıkuşu L. Bis(dipyrrinato)zinc(II) Complexes: Synthesis and catalytic activity towards alcohol oxidation. INORG CHEM COMMUN 2023. [DOI: 10.1016/j.inoche.2023.110518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
|
3
|
Synthetic Exploration of Bis(phenolate) Aza-BODIPYs and Heavier Group 13 Chelates. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238256. [PMID: 36500349 PMCID: PMC9737893 DOI: 10.3390/molecules27238256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022]
Abstract
A series of boron, aluminum, gallium, and indium chelates containing the underexplored bis(phenolate) aza-dipyrromethene (aza-DIPY) core were prepared. These compounds were found to possess near-infrared absorption and emission profiles in the 710 to 770 nm domain and exhibit quantum yield values up to 14%. X-ray diffraction analysis revealed that heavier group 13 bis(phenolate) aza-DIPY chelates possessed octahedral geometries with either THF or pyridine groups occupying the axial positions as opposed to the tetrahedral geometry of the boron chelate.
Collapse
|
4
|
Wu T, Wang S, Lv Y, Fu T, Jiang J, Lu X, Yu ZP, zhang J, Wang L, Zhou HP. A New Bis(thioether)-Dipyrrin N2S2 Ligand and Its Coordination Behaviors to Nickel, Copper and Zinc. Dalton Trans 2022; 51:9699-9707. [DOI: 10.1039/d2dt01282k] [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
Tetradentate N2S2 coordination platforms are widespread in biological system and have endowed the metalloenzymes and metalloproteins with abundant reactivities and functions. However, there have only three types of N2S2 scaffolds...
Collapse
|
5
|
Feng S, Li L, Li P, Dong W. Construction of novel hexanuclear Co(II) and dinuclear Ni(II) bis(salamo)‐type complexes. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6501] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Shan‐Shan Feng
- School of Chemistry and Chemical Engineering Lanzhou Jiaotong University Lanzhou Gansu China
| | - Li‐Li Li
- School of Chemistry and Chemical Engineering Lanzhou Jiaotong University Lanzhou Gansu China
| | - Peng Li
- School of Chemistry and Chemical Engineering Lanzhou Jiaotong University Lanzhou Gansu China
| | - Wen‐Kui Dong
- School of Chemistry and Chemical Engineering Lanzhou Jiaotong University Lanzhou Gansu China
| |
Collapse
|
6
|
Fang Y, Osterloh WR, Desbois N, Pacquelet S, Fleurat-Lessard P, Gros CP, Kadish KM. Solvent and Anion Effects on the Electrochemistry of Manganese Dipyrrin-Bisphenols. Inorg Chem 2020; 59:15913-15927. [PMID: 33064946 DOI: 10.1021/acs.inorgchem.0c02416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of "N2O2-type" manganese dipyrrin-bisphenols (DPP), formulated as (Ar)DPPMn, where Ar = pentafluorophenyl (F5Ph), phenyl (Ph), or mesityl (Mes), were electrochemically and spectroscopically characterized in nonaqueous media with and without added anions in the form of tetrabutylammonium salts (TBAX where X = ClO4-, PF6-, BF4-, F-, Cl-, OH-, or CN-). Two major one-electron reductions are observed under most solution conditions, the first of which is assigned as a MnIII/II process and the second as electron addition to the π-ring system as confirmed by spectroelectrochemistry. Each MnIII complex also exhibits one or two one-electron oxidations, the exact number depending upon the positive potential limit of the electrochemical solvent. The two oxidations are separated by 580-590 mV in CH3CN containing 0.1 M TBAPF6 and are assigned as π-ring-centered electron transfers to stepwise form a (Ar)DPPMnIII π-cation radical and dication under these solution conditions. Comparisons are made between redox properties of (Ar)DPPMn and manganese(III) porphyrins, corroles, and corrolazines each of which contains an innocent trianionic complexing ligand. The redox behavior and spectroscopic properties of [(Ar)DPPMn]n where n = 0, -1, or +1 are also compared to that of other structurally related [(Ar)DPPM]n complexes under similar solution conditions where M = CoII, CuII, BIII, or AuIII.
Collapse
Affiliation(s)
- Yuanyuan Fang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China.,Department of Chemistry, University of Houston, Houston, Texas 77204-5003 United States
| | - W Ryan Osterloh
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003 United States
| | - Nicolas Desbois
- ICMUB, UMR CNRS 6302, Université Bourgogne Franche-Comté, 21000 Dijon, France
| | - Sandrine Pacquelet
- ICMUB, UMR CNRS 6302, Université Bourgogne Franche-Comté, 21000 Dijon, France
| | | | - Claude P Gros
- ICMUB, UMR CNRS 6302, Université Bourgogne Franche-Comté, 21000 Dijon, France
| | - Karl M Kadish
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003 United States
| |
Collapse
|
7
|
Nabeshima T, Chiba Y, Nakamura T, Matsuoka R. Synthesis and Functions of Oligomeric and Multidentate Dipyrrin Derivatives and their Complexes. Synlett 2020. [DOI: 10.1055/s-0040-1707155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The dipyrrin–metal complexes and especially the boron complex 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) have recently attracted considerable attention because of their interesting properties and possible applications. We have developed two unique and useful ways to extend versatility and usefulness of the dipyrrin complexes. The first one is the linear and macrocyclic oligomerization of the BODIPY units. These arrangements of the B–F moieties of the oligomerized BODIPY units provide sophisticated functions, such as unique recognition ability toward cationic guest, associated with changes in the photophysical properties by utilizing unprecedented interactions between the B–F and a cationic species. The second one is introduction of additional ligating moieties into the dipyrrin skeleton. The multidentate N2Ox dipyrrin ligands thus obtained form a variety of complexes with 13 and 14 group elements, which are difficult to synthesize using the original N2 dipyrrin derivatives. Interestingly, these unique complexes exhibit novel structures, properties, and functions such as guest recognition, stimuli-responsive structural conversion, switching of the optical properties, excellent stability of the neutral radicals, etc. We believe that these multifunctional dipyrrin complexes will advance the basic chemistry of the dipyrrin complexes and develop their applications in the materials and medicinal chemistry fields.1 Introduction2 Linear Oligomers of Boron–Dipyrrin Complexes3 Cyclic Oligomers of Boron–Dipyrrin Complexes4 A Cyclic Oligomer of Zinc–Dipyrrin Complexes5 Group 13 Element Complexes of N2Ox Dipyrrins6 Chiral N2 and N2Ox Dipyrrin Complexes7 Group 14 Element Complexes of N2O2 Dipyrrins8 Other N2O2 Dipyrrin Complexes with Unique Properties and Functions9 Conclusion
Collapse
|
8
|
van
Leest NP, Stroek W, Siegler MA, van der Vlugt JI, Bruin BD. Ligand-Mediated Spin-State Changes in a Cobalt-Dipyrrin-Bisphenol Complex. Inorg Chem 2020; 59:12903-12912. [PMID: 32815718 PMCID: PMC7482399 DOI: 10.1021/acs.inorgchem.0c01979] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Indexed: 12/20/2022]
Abstract
The influence of a redox-active ligand on spin-changing events induced by the coordination of exogenous donors is investigated within the cobalt complex [CoII(DPP·2-)], bearing a redox-active DPP2- ligand (DPP = dipyrrin-bis(o,p-di-tert-butylphenolato) with a pentafluorophenyl moiety on the meso-position. This square-planar complex was subjected to the coordination of tetrahydrofuran (THF), pyridine, tBuNH2, and AdNH2 (Ad = 1-adamantyl), and the resulting complexes were analyzed with a variety of experimental (X-ray diffraction, NMR, UV-visible, high-resolution mass spectrometry, superconducting quantum interference device, Evans' method) and computational (density functional theory, NEVPT2-CASSCF) techniques to elucidate the respective structures, spin states, and orbital compositions of the corresponding octahedral bis-donor adducts, relative to [CoII(DPP·2-)]. This starting species is best described as an open-shell singlet complex containing a DPP·2- ligand radical that is antiferromagnetically coupled to a low-spin (S = 1/2) cobalt(II) center. The redox-active DPPn- ligand plays a crucial role in stabilizing this complex and in its facile conversion to the triplet THF adduct [CoII(DPP·2-)(THF)2] and closed-shell singlet pyridine and amine adducts [CoIII(DPP3-)(L)2] (L = py, tBuNH2, or AdNH2). Coordination of the weak donor THF to [CoII(DPP·2-)] changes the orbital overlap between the DPP·2- ligand radical π-orbitals and the cobalt(II) metalloradical d-orbitals, which results in a spin-flip to the triplet ground state without changing the oxidation states of the metal or DPP·2- ligand. In contrast, coordination of the stronger donors pyridine, tBuNH2, or AdNH2 induces metal-to-ligand single-electron transfer, resulting in the formation of low-spin (S = 0) cobalt(III) complexes [CoIII(DPP3-)(L)2] containing a fully reduced DPP3- ligand, thus explaining their closed-shell singlet electronic ground states.
Collapse
Affiliation(s)
- Nicolaas P. van
Leest
- Homogeneous, Supramolecular
and Bio-Inspired Catalysis Group, van’t Hoff Institute for
Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| | - Wowa Stroek
- Homogeneous, Supramolecular
and Bio-Inspired Catalysis Group, van’t Hoff Institute for
Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| | - Maxime A. Siegler
- Department of Chemistry, John Hopkins University, Baltimore 21218, Maryland, United States
| | - Jarl Ivar van der Vlugt
- Homogeneous, Supramolecular
and Bio-Inspired Catalysis Group, van’t Hoff Institute for
Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| | - Bas de Bruin
- Homogeneous, Supramolecular
and Bio-Inspired Catalysis Group, van’t Hoff Institute for
Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| |
Collapse
|
9
|
|
10
|
Abstract
Sometimes named half-porphyrins, bis-pyrrolic dipyrrin ligands endow their metal complexes with unique properties such as the potential to functionalize the heterocyclic backbone or the meso position and the ability to catalyze interesting chemical transformations. Thus, strategies towards the derivatization of or at the meso group and the use of dipyrrin metal complexes for the formation of a broad range of polypyrrolic derivatives such as 2,2'-bis-dipyrrins, nor-/hetero-corroles and porphynoids have been elaborated. Furthermore, the chelating ability of dipyrrins and the possibility of modifying their steric and electronic characteristics by functionalization can be exploited for the development of numerous complexes featuring appealing properties. Hence, C-H activation/amination, polymerization or oxidation reactions can be catalyzed by dipyrrin metal complexes and classical reagents such as Grignard species, Rh-based or Suzuki-Miyaura catalysts have been revisited by incorporation of dipyrrins in the coordination sphere of the metal cations. This contribution aims to review and illustrate all these aspects, highlighting the potential of these complexes for the design and synthesis of valuable organic compounds and metallo-organic architectures.
Collapse
Affiliation(s)
- Stéphane A Baudron
- Université de Strasbourg, CNRS, CMC UMR 7140, 4 rue Blaise Pascal, F-67000, Strasbourg, France.
| |
Collapse
|
11
|
Thomas KE, Desbois N, Conradie J, Teat SJ, Gros CP, Ghosh A. Gold dipyrrin-bisphenolates: a combined experimental and DFT study of metal–ligand interactions. RSC Adv 2020; 10:533-540. [PMID: 35492572 PMCID: PMC9047278 DOI: 10.1039/c9ra09228e] [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] [Received: 11/07/2019] [Accepted: 12/18/2019] [Indexed: 11/21/2022] Open
Abstract
Given that noninnocent and metalloradical-type electronic structures are ubiquitous among dipyrrin-bisphenolate (DPP) complexes, we synthesized the gold(iii) derivatives as potentially innocent paradigms against which the properties of other metallo-DPP derivatives can be evaluated. Electronic absorption spectra, electrochemical studies, a single-crystal X-ray structure, and DFT calculations all suggest that the ground states of the new complexes indeed correspond to an innocent AuIII–DPP3−, paralleling a similar description noted for Au corroles. Interestingly, while DFT calculations indicate purely ligand-centered oxidations, reduction of AuDPP is predicted to occur across both the metal and the ligand. The first gold dipyrrin-bisphenolates have been synthesized. Like their corrole analogues, they exhibit AuIII–L3− ground states, providing rare innocent paradigms for a class of complexes that commonly occur as metalloradicals.![]()
Collapse
Affiliation(s)
- Kolle E. Thomas
- Department of Chemistry
- UiT – The Arctic University of Norway
- Tromsø N-9037
- Norway
| | - Nicolas Desbois
- Institut de Chimie Moléculaire de l’Université de Bourgogne (ICMUB)
- UMR CNRS 6302
- Université Bourgogne-Franche Comté
- 21078 Dijon Cedex
- France
| | - Jeanet Conradie
- Department of Chemistry
- UiT – The Arctic University of Norway
- Tromsø N-9037
- Norway
- Department of Chemistry
| | - Simon J. Teat
- Advanced Light Source
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
| | - Claude P. Gros
- Institut de Chimie Moléculaire de l’Université de Bourgogne (ICMUB)
- UMR CNRS 6302
- Université Bourgogne-Franche Comté
- 21078 Dijon Cedex
- France
| | - Abhik Ghosh
- Department of Chemistry
- UiT – The Arctic University of Norway
- Tromsø N-9037
- Norway
| |
Collapse
|
12
|
Shan W, Desbois N, Pacquelet S, Stéphane Brandès, Rousselin Y, Conradie J, Ghosh A, Gros CP, Kadish KM. Ligand Noninnocence in Cobalt Dipyrrin-Bisphenols: Spectroscopic, Electrochemical, and Theoretical Insights Indicating an Emerging Analogy with Corroles. Inorg Chem 2019; 58:7677-7689. [PMID: 30653313 DOI: 10.1021/acs.inorgchem.8b03006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Three cobalt dipyrrin-bisphenol (DPPCo) complexes with different meso-aryl groups (pentafluorophenyl, phenyl, and mesityl) were synthesized and characterized based on their electrochemistry and spectroscopic properties in nonaqueous media. Each DPPCo undergoes multiple oxidations and reductions with the potentials, reversibility, and number of processes depending on the specific solution conditions, the specific macrocyclic substituents, and the type and number of axially coordinated ligands on the central cobalt ion. Theoretical calculations of the compounds with different coordination numbers are given in the current study in order to elucidate the cobalt-ion oxidation state and the innocence or noninnocence of the macrocyclic ligand as a function of the changes in the solvent properties and degree of axial coordination. Electron paramagnetic resonance spectra of the compounds are obtained to experimentally assess the electron spin state. An X-ray structure of the six-coordinate complex is also presented. The investigated chemical properties of DPPCo compounds under different solution conditions are compared to those of cobalt corroles, where the macrocycle and metal ion also possess formal 3- and 3+ oxidation states in their air-stable forms.
Collapse
Affiliation(s)
- Wenqian Shan
- Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States
| | - Nicolas Desbois
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) , UMR CNRS 6302, Université de Bourgogne-Franche-Comté , 9 avenue Alain Savary , B.P. 47870, 21078 Dijon, Cedex , France
| | - Sandrine Pacquelet
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) , UMR CNRS 6302, Université de Bourgogne-Franche-Comté , 9 avenue Alain Savary , B.P. 47870, 21078 Dijon, Cedex , France
| | - Stéphane Brandès
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) , UMR CNRS 6302, Université de Bourgogne-Franche-Comté , 9 avenue Alain Savary , B.P. 47870, 21078 Dijon, Cedex , France
| | - Yoann Rousselin
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) , UMR CNRS 6302, Université de Bourgogne-Franche-Comté , 9 avenue Alain Savary , B.P. 47870, 21078 Dijon, Cedex , France
| | - Jeanet Conradie
- Department of Chemistry , University of the Free State , Bloemfontein 9300 , Republic of South Africa
| | - Abhik Ghosh
- Department of Chemistry , UiT-The Arctic University of Norway , Tromsø N-9037 , Norway
| | - Claude P Gros
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) , UMR CNRS 6302, Université de Bourgogne-Franche-Comté , 9 avenue Alain Savary , B.P. 47870, 21078 Dijon, Cedex , France
| | - Karl M Kadish
- Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States
| |
Collapse
|
13
|
Sumiyoshi A, Chiba Y, Matsuoka R, Noda T, Nabeshima T. Efficient luminescent properties and cation recognition ability of heavy group 13 element complexes of N2O2- and N2O4-type dipyrrins. Dalton Trans 2019; 48:13169-13175. [DOI: 10.1039/c9dt02403d] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Heavy group 13 element complexes of N2O2- and N2O4-type dipyrrins exhibited efficient luminescent properties and cation recognition ability.
Collapse
Affiliation(s)
- Akinobu Sumiyoshi
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Yusuke Chiba
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Ryota Matsuoka
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Takumu Noda
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Tatsuya Nabeshima
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS)
- University of Tsukuba
- Tsukuba
- Japan
| |
Collapse
|
14
|
Curcio M, Henschel D, Hüttenschmidt M, Sproules S, Love JB. Radical Relatives: Facile Oxidation of Hetero-Diarylmethene Anions to Neutral Radicals. Inorg Chem 2018; 57:9592-9600. [PMID: 29969020 DOI: 10.1021/acs.inorgchem.8b00554] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Furan and thiophene diarylmethenes are potential redox-active ligands for metal centers that could be exploited in the development of nontraditional, stoichiometric, and catalytic redox reactions. As such, we describe here the selective meso-deprotonations of dithiophene, difuran, and diimine-difuran diarylmethanes to form the π-conjugated anions, for which only the diimino-difuryl anion is truly isolable and studied by X-ray crystallography. In all cases, facile one-electron oxidation of these anions occurs, which allows the isolation of the neutral dithienyl and diimino-difuryl radicals. UV-Visible and time-dependent density functional theory studies reveal that the oxidation of the dithienyl anion to its radical is associated with an increase in the highest (singly) occupied molecular orbital-lowest unoccupied molecular orbital gap, evident through a hypsochromic shift of the main absorption band in the electronic spectrum, whereas oxidation of the diimino-difuryl anion causes only minor spectroscopic changes. Electrochemical studies support the stability of the radicals with respect to the anion, showing strongly negative oxidation potentials. The control of the redox activity of these diarylmethene carbanions through variation of the nature of the substituents, donor-atom, and the conjugated π-system and their potential as ligands for redox-inert metal centers makes them intriguing candidates as noninnocent partners for redox reactions.
Collapse
Affiliation(s)
- Massimiliano Curcio
- EaStCHEM School of Chemistry , University of Edinburgh , The King's Buildings, David Brewster Road , Edinburgh EH9 3FJ , U.K
| | - Daniel Henschel
- EaStCHEM School of Chemistry , University of Edinburgh , The King's Buildings, David Brewster Road , Edinburgh EH9 3FJ , U.K.,Fakultät für Chemie , Technische Universität München , Lichtenbergstraße 4 , 85748 Garching , Germany
| | - Mareike Hüttenschmidt
- EaStCHEM School of Chemistry , University of Edinburgh , The King's Buildings, David Brewster Road , Edinburgh EH9 3FJ , U.K.,Institut für Chemie , Universität Rostock , Albert-Einstein-Straße 3a , 18059 Rostock , Germany
| | - Stephen Sproules
- WestCHEM School of Chemistry , University of Glasgow, University Avenue , Glasgow G12 8QQ , U.K
| | - Jason B Love
- EaStCHEM School of Chemistry , University of Edinburgh , The King's Buildings, David Brewster Road , Edinburgh EH9 3FJ , U.K
| |
Collapse
|
15
|
Lecarme L, Kochem A, Chiang L, Moutet J, Berthiol F, Philouze C, Leconte N, Storr T, Thomas F. Electronic Structure and Reactivity of One-Electron-Oxidized Copper(II) Bis(phenolate)–Dipyrrin Complexes. Inorg Chem 2018; 57:9708-9719. [DOI: 10.1021/acs.inorgchem.8b00044] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Lauréline Lecarme
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, B.P. 53, 38041 Grenoble Cedex 9, France
| | - Amélie Kochem
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, B.P. 53, 38041 Grenoble Cedex 9, France
| | - Linus Chiang
- Department of Chemistry, University of the Fraser Valley, Abbotsford, British Columbia V2S 7M8, Canada
| | - Jules Moutet
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, B.P. 53, 38041 Grenoble Cedex 9, France
| | - Florian Berthiol
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, B.P. 53, 38041 Grenoble Cedex 9, France
| | - Christian Philouze
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, B.P. 53, 38041 Grenoble Cedex 9, France
| | - Nicolas Leconte
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, B.P. 53, 38041 Grenoble Cedex 9, France
| | - Tim Storr
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Fabrice Thomas
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, B.P. 53, 38041 Grenoble Cedex 9, France
| |
Collapse
|
16
|
Moutet J, Philouze C, du Moulinet d'Hardemare A, Leconte N, Thomas F. Ni(II) Complexes of the Redox-Active Bis(2-aminophenyl)dipyrrin: Structural, Spectroscopic, and Theoretical Characterization of Three Members of an Electron Transfer Series. Inorg Chem 2017; 56:6380-6392. [PMID: 28513171 DOI: 10.1021/acs.inorgchem.7b00433] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The sterically hindered bis(2-aminophenyl)dipyrrin ligand H3NL was prepared. X-ray diffraction discloses a bifurcated hydrogen bonding network involving the dipyrrin and one aniline ring. The reaction of H3NL with one equivalent of nickel(II) in the air produces a paramagnetic neutral complex, which absorbs intensively in the Vis-NIR region. Its electron paramagnetic resonance spectrum displays resonances at g1 = 2.033, g2 = 2.008, and g3 = 1.962 that are reminiscent of an (S = 1/2) system having a predominant organic radical character. Both the structural investigation (X-ray diffraction) and density functional theory calculations on [NiII(NL•)] points to an unprecedented mixed "pyrrolyl-anilinyl" radical character. The neutral complex [NiII(NL•)] exhibits both a reversible oxidation wave at -0.28 V vs Fc+/Fc and a reversible reduction wave at -0.91 V. The anion was found to be highly air-sensitive, but could be prepared by reduction with cobaltocene and structurally characterized. It comprises a Ni(II) ion coordinated to a closed-shell trianionic ligand and hence can be formulated as [NiII(NL)]-. The cation was generated by reacting [NiII(NL•)] with one equivalent of silver hexafluoroantimonate. By X-ray diffraction we established that it contains an oxidized, closed-shell ligand coordinated to a nickel(II) ion. We found that a reliable hallmark for both the oxidation state of the ligand and the extent of delocalization within the series is the bond connecting the dipyrrin and the aniline, which ranges between 1.391 Å (cation) and 1.449 Å (anion). The cation and anion exhibit a rich Vis-NIR spectrum, despite their nonradical nature. The low energy bands correspond to ligand-based electronic excitations. Hence, the HOMO-LUMO gap is small, and the redox processes in the electron transfer series are exclusively ligand-centered.
Collapse
Affiliation(s)
- Jules Moutet
- 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
| | - Amaury du Moulinet d'Hardemare
- 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
| | - Fabrice Thomas
- Département de Chimie Moléculaire - Chimie Inorganique Redox (CIRE) - UMR CNRS 5250, Université Grenoble Alpes , B. P. 53, 38041 Grenoble cedex 9, France
| |
Collapse
|
17
|
Suzuki S, Kira S, Kozaki M, Yamamura M, Hasegawa T, Nabeshima T, Okada K. An efficient synthetic method for organometallic radicals: structures and properties of gold(i)-(nitronyl nitroxide)-2-ide complexes. Dalton Trans 2017; 46:2653-2659. [DOI: 10.1039/c6dt04685a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
One-pot synthesis of (nitronyl nitroxide)-gold(i)-phosphine (NN-Au-P) complexes has been developed using chloro(tetrahydrothiophene)gold(i), phosphine ligands, nitronyl nitroxide radicals, and sodium hydroxide.
Collapse
Affiliation(s)
- Shuichi Suzuki
- Graduate School of Science
- Osaka City University
- Osaka
- Japan
- Graduate School of Engineering Science
| | - Sayaka Kira
- Graduate School of Science
- Osaka City University
- Osaka
- Japan
| | | | - Masaki Yamamura
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Toru Hasegawa
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Tatsuya Nabeshima
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Keiji Okada
- Graduate School of Science
- Osaka City University
- Osaka
- Japan
| |
Collapse
|
18
|
Pankhurst JR, Bell NL, Zegke M, Platts LN, Lamfsus CA, Maron L, Natrajan LS, Sproules S, Arnold PL, Love JB. Inner-sphere vs. outer-sphere reduction of uranyl supported by a redox-active, donor-expanded dipyrrin. Chem Sci 2016; 8:108-116. [PMID: 28451154 PMCID: PMC5304617 DOI: 10.1039/c6sc02912d] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 10/11/2016] [Indexed: 11/21/2022] Open
Abstract
The uranyl(vi) complex UO2Cl(L) of the redox-active, acyclic diimino-dipyrrin anion, L- is reported and its reaction with inner- and outer-sphere reductants studied. Voltammetric, EPR-spectroscopic and X-ray crystallographic studies show that chemical reduction by the outer-sphere reagent CoCp2 initially reduces the ligand to a dipyrrin radical, and imply that a second equivalent of CoCp2 reduces the U(vi) centre to form U(v). Cyclic voltammetry indicates that further outer-sphere reduction to form the putative U(iv) trianion only occurs at strongly cathodic potentials. The initial reduction of the dipyrrin ligand is supported by emission spectra, X-ray crystallography, and DFT; the latter also shows that these outer-sphere reactions are exergonic and proceed through sequential, one-electron steps. Reduction by the inner-sphere reductant [TiCp2Cl]2 is also likely to result in ligand reduction in the first instance but, in contrast to the outer-sphere case, reduction of the uranium centre becomes much more favoured, allowing the formation of a crystallographically characterised, doubly-titanated U(iv) complex. In the case of inner-sphere reduction only, ligand-to-metal electron-transfer is thermodynamically driven by coordination of Lewis-acidic Ti(iv) to the uranyl oxo, and is energetically preferable over the disproportionation of U(v). Overall, the involvement of the redox-active dipyrrin ligand in the reduction chemistry of UO2Cl(L) is inherent to both inner- and outer-sphere reduction mechanisms, providing a new route to accessing a variety of U(vi), U(v), and U(iv) complexes.
Collapse
Affiliation(s)
- James R Pankhurst
- EaStCHEM School of Chemistry , The University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK . ;
| | - Nicola L Bell
- EaStCHEM School of Chemistry , The University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK . ;
| | - Markus Zegke
- EaStCHEM School of Chemistry , The University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK . ;
| | - Lucy N Platts
- EaStCHEM School of Chemistry , The University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK . ;
| | - Carlos Alvarez Lamfsus
- LPCNO , INSA , Université de Toulouse , 135, avenue de Rangueil , 31077 Toulouse cedex 4 , France
| | - Laurent Maron
- LPCNO , INSA , Université de Toulouse , 135, avenue de Rangueil , 31077 Toulouse cedex 4 , France
| | - Louise S Natrajan
- Centre for Radiochemisty Research , School of Chemistry , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK
| | - Stephen Sproules
- WestCHEM School of Chemistry , University of Glasgow , Glasgow , G12 8QQ , UK
| | - Polly L Arnold
- EaStCHEM School of Chemistry , The University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK . ;
| | - Jason B Love
- EaStCHEM School of Chemistry , The University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK . ;
| |
Collapse
|