1
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Inchausti A, Mollfulleda R, Swart M, Perles J, Herrero S, Baonza VG, Taravillo M, Lobato Á. Torsion Effects Beyond the δ Bond and the Role of π Metal-Ligand Interactions. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2401293. [PMID: 38569515 PMCID: PMC11220682 DOI: 10.1002/advs.202401293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/19/2024] [Indexed: 04/05/2024]
Abstract
Previous studies on bimetallic paddlewheel compounds have established a direct correlation between metal-metal distance and ligand torsion angles, leading to the rule that higher torsion results in longer metal-metal bond distances. Here, the new discovery based on diarylformamidinate Ru₂⁵⁺ paddlewheel compounds [Ru2Cl(DArF)4] that show an opposite behavior is reported: higher torsions lead to shorter metal-metal distances. This discovery challenges the assumption that internal rotation solely impacts the δ bond. By combining experimental and theoretical techniques, it is demostrated that this trend is associated with previously overlooked π metal-ligand interactions. These π metal-ligand interactions are a direct consequence of the paddlewheel structure and the conjugated nature of the bidentate ligands. This findings offer far-reaching insights into the influence of equatorial ligands and their π-conjugation characteristics on the electronic properties of paddlewheel complexes. That this effect is not exclusive of diruthenium compounds but also occurs in other bimetallic cores such as ditungsten or dirhodium is demonstrated, and with other ligands showing allyl type conjugation. These results provide a novel approach for fine-tuning the properties of these compounds with significant implications for materials design.
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Affiliation(s)
- Almudena Inchausti
- MALTA‐Consolider Team and Departamento de Química FísicaUniversidad Complutense de MadridPlz. Ciencias 2MadridE‐28040Spain
| | - Rosa Mollfulleda
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de QuímicaUniversitat de Girona, Campus de MontiliviParc UdGCataloniaGironaE–17003Spain
| | - Marcel Swart
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de QuímicaUniversitat de Girona, Campus de MontiliviParc UdGCataloniaGironaE–17003Spain
- ICREA Pg. Lluís Companys 23Barcelona08010Spain
| | - Josefina Perles
- Laboratorio de Difracción de Rayos X de MonocristalServicio Interdepartamental de Investigación, Universidad Autónoma de MadridMadridE‐28049Spain
| | - Santiago Herrero
- MatMoPol Research Group, Departamento de Química InorgánicaUniversidad Complutense de MadridPlz. Ciencias 2MadridE‐28040Spain
| | - Valentín G. Baonza
- MALTA‐Consolider Team and Departamento de Química FísicaUniversidad Complutense de MadridPlz. Ciencias 2MadridE‐28040Spain
| | - Mercedes Taravillo
- MALTA‐Consolider Team and Departamento de Química FísicaUniversidad Complutense de MadridPlz. Ciencias 2MadridE‐28040Spain
| | - Álvaro Lobato
- MALTA‐Consolider Team and Departamento de Química FísicaUniversidad Complutense de MadridPlz. Ciencias 2MadridE‐28040Spain
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2
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Dodd NA, Cao Y, Bacsa J, Towles EC, Gray TG, Sadighi JP. Three-Electron Nickel(I)/Nickel(0) Half-Bond. Inorg Chem 2022; 61:16317-16324. [PMID: 36179078 DOI: 10.1021/acs.inorgchem.2c02291] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An (N-heterocyclic carbene)nickel(I) cation precursor reacts with the corresponding nickel(0) complex to form a dinickel(I,0) monocation. The Ni···Ni distance in this cation is 0.93 Å shorter than in the analogous dinickel(0) complex. Although the solid-state structure shows equivalent Ni centers, density functional theory calculations indicate significant electronic localization. Reactions with CO and NO form mononuclear carbonyl and nitrosyl complexes. Oxidative addition of an aryl bromide results in C-arylation of the carbene ligands.
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Affiliation(s)
- Neil A Dodd
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Yu Cao
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - John Bacsa
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States.,X-ray Crystallography Center, Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Eric C Towles
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Thomas G Gray
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Joseph P Sadighi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
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3
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Roy MD, Trenerry MJ, Thakuri B, MacMillan SN, Liptak MD, Lancaster KM, Berry JF. Electronic Structure of Ru 26+ Complexes with Electron-Rich Anilinopyridinate Ligands. Inorg Chem 2022; 61:3443-3457. [PMID: 35175754 DOI: 10.1021/acs.inorgchem.1c03346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Diruthenium paddlewheel complexes supported by electron-rich anilinopyridinate (Xap) ligands were synthesized in the course of the first in-depth structural and spectroscopic interrogation of monocationic [Ru2(Xap)4Cl]+ species in the Ru26+ oxidation state. Despite paramagnetism of the compounds, 1H NMR spectroscopy proved highly informative for determining the isomerism of the Ru25+ and Ru26+ compounds. While most compounds are found to have the polar (4,0) geometry, with all four Xap ligands in the same orientation, some synthetic procedures resulted in a mixture of (4,0) and (3,1) isomers, most notably in the case of the parent compound Ru2(ap)4Cl. The isomerism of this compound has been overlooked in previous reports. Electrochemical studies demonstrate that oxidation potentials can be tuned by the installation of electron donating groups to the ligands, increasing accessibility of the Ru26+ oxidation state. The resulting Ru26+ monocations were found to have the expected (π*)2 ground state, and an in-depth study of the electronic transitions by Vis/NIR absorption and MCD spectroscopies with the aid of TD-DFT allowed for the assignment of the electronic spectra. The empty δ* orbital is the major acceptor orbital for the most prominent electronic transitions. Both Ru25+ and Ru26+ compounds were studied by Ru K-edge X-ray absorption spectroscopy; however, the rising edge energy is insensitive to redox changes in the compounds due to the broad line shape observed for 4d transition metal K-edges. DFT calculations indicate the presence of ligand orbitals at the frontier level, suggesting that further oxidation beyond Ru26+ will be ligand-centered rather than metal-centered.
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Affiliation(s)
- Michael D Roy
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Michael J Trenerry
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Biswash Thakuri
- Department of Chemistry, University of Vermont, Burlington, Vermont 05405, United States
| | - Samantha N MacMillan
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Matthew D Liptak
- Department of Chemistry, University of Vermont, Burlington, Vermont 05405, United States
| | - Kyle M Lancaster
- Department of Chemistry & Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - John F Berry
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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4
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Ehret F, Filippou V, Blickle S, Bubrin M, Záliš S, Kaim W. Structural and Oxidation State Alternatives in Platinum and Palladium Complexes of a Redox-Active Amidinato Ligand. Chemistry 2021; 27:3374-3381. [PMID: 32959415 PMCID: PMC7986709 DOI: 10.1002/chem.202003636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Indexed: 11/07/2022]
Abstract
Reaction of [Pt(DMSO)2 Cl2 ] or [Pd(MeCN)2 Cl2 ] with the electron-rich LH=N,N'-bis(4-dimethylaminophenyl)ethanimidamide yielded mononuclear [PtL2 ] (1) but dinuclear [Pd2 L4 ] (2), a paddle-wheel complex. The neutral compounds were characterized through experiments (crystal structures, electrochemistry, UV-vis-NIR spectroscopy, magnetic resonance) and TD-DFT calculations as metal(II) species with noninnocent ligands L- . The reversibly accessible cations [PtL2 ]+ and [Pd2 L4 ]+ were also studied, the latter as [Pd2 L4 ][B{3,5-(CF3 )2 C6 H3 }4 ] single crystals. Experimental and computational investigations were directed at the elucidation of the electronic structures, establishing the correct oxidation states within the alternatives [PtII (L- )2 ] or [Pt. (L )2 ], [PtII (L0.5- )2 ]+ or [PtIII (L- )2 ]+ , [(PdII )2 (μ-L- )4 ] or [(Pd1.5 )2 (μ-L0.75- )4 ], and [(Pd2.5 )2 (μ-L- )4 ]+ or [(PdII )2 (μ-L0.75- )4 ]+ . In each case, the first alternative was shown to be most appropriate. Remarkable results include the preference of platinum for mononuclear planar [PtL2 ] with an N-Pt-N bite angle of 62.8(2)° in contrast to [Pd2 L4 ], and the dimetal (Pd2 4+ →Pd2 5+ ) instead of ligand (L- →L ) oxidation of the dinuclear palladium compound.
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Affiliation(s)
- Fabian Ehret
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70550, Stuttgart, Germany
| | - Vasileios Filippou
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70550, Stuttgart, Germany
| | - Svenja Blickle
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70550, Stuttgart, Germany
| | - Martina Bubrin
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70550, Stuttgart, Germany
| | - Stanislav Záliš
- J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 18223, Prague, Czech Republic
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70550, Stuttgart, Germany
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5
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Kim RS, Wegener EC, Yang MC, O'Reilly ME, Oh S, Hendon CH, Miller JT, Surendranath Y. Rapid Electrochemical Methane Functionalization Involves Pd-Pd Bonded Intermediates. J Am Chem Soc 2020; 142:20631-20639. [PMID: 33231440 DOI: 10.1021/jacs.0c05894] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
High-valent Pd complexes are potent agents for the oxidative functionalization of inert C-H bonds, and it was previously shown that rapid electrocatalytic methane monofunctionalization could be achieved by electro-oxidation of PdII to a critical dinuclear PdIII intermediate in concentrated or fuming sulfuric acid. However, the structure of this highly reactive, unisolable intermediate, as well as the structural basis for its mechanism of electrochemical formation, remained elusive. Herein, we use X-ray absorption and Raman spectroscopies to assemble a structural model of the potent methane-activating intermediate as a PdIII dimer with a Pd-Pd bond and a 5-fold O atom coordination by HxSO4(x-2) ligands at each Pd center. We further use EPR spectroscopy to identify a mixed-valent M-M bonded Pd2II,III species as a key intermediate during the PdII-to-PdIII2 oxidation. Combining EPR and electrochemical data, we quantify the free energy of Pd dimerization as <-4.5 kcal/mol for Pd2II,III and <-9.1 kcal/mol for PdIII2. The structural and thermochemical data suggest that the aggregate effect of metal-metal and axial metal-ligand bond formation drives the critical Pd dimerization reaction in between electrochemical oxidation steps. This work establishes a structural basis for the facile electrochemical oxidation of PdII to a M-M bonded PdIII dimer and provides a foundation for understanding its rapid methane functionalization reactivity.
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Affiliation(s)
- R Soyoung Kim
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Evan C Wegener
- Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Min Chieh Yang
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
| | - Matthew E O'Reilly
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Seokjoon Oh
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Christopher H Hendon
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
| | - Jeffrey T Miller
- Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Yogesh Surendranath
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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6
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Uemura K, Ito D, Pirillo J, Hijikata Y, Saeki A. Modulation of Band Gaps toward Varying Conductivities in Heterometallic One-Dimensional Chains by Ligand Alteration and Third Metal Insertion. ACS OMEGA 2020; 5:30502-30518. [PMID: 33283099 PMCID: PMC7711699 DOI: 10.1021/acsomega.0c04317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/02/2020] [Indexed: 06/12/2023]
Abstract
A heterometallic one-dimensional (1-D) chain consisting of multiple kinds of metals, Rh, Pt, and Pd, with direct metal-metal bonds was successfully obtained by mixing a Rh dinuclear complex and Pt-Pd-Pt trinuclear complex. The Pt-Pd-Pt trinuclear complex can be reversibly one-electron-oxidized or -reduced, where the electron paramagnetic resonance spectrum of the one-electron-oxidized one shows an axially symmetric signal with hyperfine splitting by two Pt and Pd, indicating that an unpaired electron is delocalized to the d z 2 orbital of Pt-Pd-Pt. Utilized with the highest occupied molecular orbital and lowest unoccupied molecular orbital interaction at the d z 2 orbital, simple mixing of the Pt-Pd-Pt trinuclear complex and Rh dinuclear complex in adequate solvents afforded heterometallic 1-D chains, which are aligned as -Rh-Rh-Pt-Pd-Pt-. Several physical measurements revealed that the metal oxidation state is +2. Diffuse reflectance spectra and theoretical calculations show that heterometallic 1-D chains have σ-type conduction and valence bands where π*(Rh2) are lying between them, whose gaps become narrower than the prototype chains aligned as -Rh-Rh-Pt-Pt-Pt-Pt-. The narrower band gaps are induced by destabilization of the σ-type valence bands and accompanied by insertion of Pd ions because the d-orbital energy level of Pd is closer in value to Rh compared with Pt. Flash-photolysis time-resolved microwave conductivity measurements exhibited an increase in the product of charge carrier mobility and its generation efficiency (8.1 × 10-5 to 4.6 × 10-4 cm2 V-1 s-1) with narrowing the band gaps, suggesting that the better conductivity is attributed to shorter metal-metal distances in 1-D chains. These results imply the possibilities of controlling band gap with ligand modification and third metal insertion in heterometallic 1-D chains to show various conductivities.
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Affiliation(s)
- Kazuhiro Uemura
- Department
of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan
| | - Daiki Ito
- Department
of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan
| | - Jenny Pirillo
- Institute
for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
| | - Yuh Hijikata
- Institute
for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
| | - Akinori Saeki
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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7
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Abstract
The possibility of multiple bond formation between Periodic Table Group 13 – 15 elements is considered. The ways of triple bond formation between these elements are discussed; particular attention is paid to the B≡B triple bonds. New non-linear compounds with triple bonds and their molecular structures are considered. The causes are given for the formation of compounds with unusually short distances between chemically non-bonded atoms. The grounds of the theory of two-centre three-electron bonds are presented and conditions of existence of isolated square planar carbon clusters are analyzed.
The bibliography includes 181 references.
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8
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Vollmer MV, Xie J, Cammarota RC, Young VG, Bill E, Gagliardi L, Lu CC. Formal Nickelate(−I) Complexes Supported by Group 13 Ions. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201803356] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Matthew V. Vollmer
- Department of Chemistry and Supercomputing Institute University of Minnesota 207 Pleasant St. SE Minneapolis MN 55455 USA
| | - Jing Xie
- Department of Chemistry and Supercomputing Institute University of Minnesota 207 Pleasant St. SE Minneapolis MN 55455 USA
| | - Ryan C. Cammarota
- Department of Chemistry and Supercomputing Institute University of Minnesota 207 Pleasant St. SE Minneapolis MN 55455 USA
| | - Victor G. Young
- Department of Chemistry and Supercomputing Institute University of Minnesota 207 Pleasant St. SE Minneapolis MN 55455 USA
| | - Eckhard Bill
- Max-Planck-Institut für chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Laura Gagliardi
- Department of Chemistry and Supercomputing Institute University of Minnesota 207 Pleasant St. SE Minneapolis MN 55455 USA
| | - Connie C. Lu
- Department of Chemistry and Supercomputing Institute University of Minnesota 207 Pleasant St. SE Minneapolis MN 55455 USA
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9
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Vollmer MV, Xie J, Cammarota RC, Young VG, Bill E, Gagliardi L, Lu CC. Formal Nickelate(-I) Complexes Supported by Group 13 Ions. Angew Chem Int Ed Engl 2018; 57:7815-7819. [PMID: 29719097 DOI: 10.1002/anie.201803356] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Indexed: 11/08/2022]
Abstract
Formal nickelate(-I) complexes bearing Group 13 metalloligands (M=Al and Ga) were isolated. These 17 e- complexes were synthesized by one-electron reduction of the corresponding Ni0 →MIII precursors, and were investigated by single-crystal X-ray diffraction, EPR spectroscopy, and quantum chemical calculations. Collectively, the experimental and computational data support: 1) the strengthening of the Ni-M bond upon one-electron reduction, and 2) the delocalization of the unpaired spin across the Ni and M atoms. An intriguing electronic configuration is revealed where three valence electrons occupy two σ-type bonding interactions: Ni(3dz2 )2 →M and σ-(Ni-M)1 . The latter is an unusual Ni-M σ-bonding molecular orbital that comprises primarily the Ni 4pz and M npz /ns atomic orbitals.
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Affiliation(s)
- Matthew V Vollmer
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455, USA
| | - Jing Xie
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455, USA
| | - Ryan C Cammarota
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455, USA
| | - Victor G Young
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455, USA
| | - Eckhard Bill
- Max-Planck-Institut für chemische Energiekonversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Laura Gagliardi
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455, USA
| | - Connie C Lu
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455, USA
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10
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Zhang X, Wang H, Yuan J, Guo S. Palladacycles incorporating a carboxylate-functionalized phosphine ligand: syntheses, characterization and their catalytic applications toward Suzuki couplings in water. TRANSIT METAL CHEM 2017. [DOI: 10.1007/s11243-017-0181-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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11
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Diccianni JB, Hu C, Diao T. Binuclear, High‐Valent Nickel Complexes: Ni−Ni Bonds in Aryl–Halogen Bond Formation. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611572] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Justin B. Diccianni
- Chemistry Department New York University 100 Washington Square E. New York NY 10003 USA
| | - Chunhua Hu
- Chemistry Department New York University 100 Washington Square E. New York NY 10003 USA
| | - Tianning Diao
- Chemistry Department New York University 100 Washington Square E. New York NY 10003 USA
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12
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Diccianni JB, Hu C, Diao T. Binuclear, High‐Valent Nickel Complexes: Ni−Ni Bonds in Aryl–Halogen Bond Formation. Angew Chem Int Ed Engl 2017; 56:3635-3639. [DOI: 10.1002/anie.201611572] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 12/31/2016] [Indexed: 01/23/2023]
Affiliation(s)
- Justin B. Diccianni
- Chemistry Department New York University 100 Washington Square E. New York NY 10003 USA
| | - Chunhua Hu
- Chemistry Department New York University 100 Washington Square E. New York NY 10003 USA
| | - Tianning Diao
- Chemistry Department New York University 100 Washington Square E. New York NY 10003 USA
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13
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Kriegel BM, Naested LCE, Nocton G, Lakshmi KV, Lohrey TD, Bergman RG, Arnold J. Redox-Initiated Reactivity of Dinuclear β-Diketiminatoniobium Imido Complexes. Inorg Chem 2017; 56:1626-1637. [PMID: 28098983 DOI: 10.1021/acs.inorgchem.6b02735] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
High-valent dichloride and dimethylniobium complexes 1 and 2 bearing tert-butylimido and N,N'-bis(2,4,6-trimethylphenyl)-β-diketiminate (BDIAr) ligands were prepared. The dimethyl complex reacted with dihydrogen to release methane and generate the hydride-bridged diniobium(IV) complex 3 in high yield. One-electron oxidation of 3 with silver salts resulted in the release of dihydrogen and conversion to a mixed-valent NbIII-NbIV complex, 4, that displayed a frozen-solution X-band electron paramagnetic resonance signal consistent with a slight dissymmetry between the two Nb centers. Spectroscopic and computational analysis supported the presence of Nb-Nb σ-bonding interactions in both 3 and 4. Finally, one-electron reduction of 4 resulted in conversion to the highly dissymmetric NbV-NbV dimer 5 that formed from the reductive C-N bond cleavage of one of the BDIAr supporting ligands.
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Affiliation(s)
- Benjamin M Kriegel
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Lara C E Naested
- Department of Chemistry, University of California , Berkeley, California 94720, United States.,Ecole Polytechnique Fédérale de Lausanne, Institut des Sciences et Ingénierie Chimiques , CH-1015 Lausanne, Switzerland
| | - Grégory Nocton
- LCM, CNRS, Ecole Polytechnique, Université Paris-Saclay , Route de Saclay, 91128 Palaiseau Cedex, France
| | - K V Lakshmi
- Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Trevor D Lohrey
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Robert G Bergman
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - John Arnold
- Department of Chemistry, University of California , Berkeley, California 94720, United States
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14
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Dudkina YB, Kholin KV, Gryaznova TV, Islamov DR, Kataeva ON, Rizvanov IK, Levitskaya AI, Fominykh OD, Balakina MY, Sinyashin OG, Budnikova YH. Redox trends in cyclometalated palladium(ii) complexes. Dalton Trans 2017; 46:165-177. [DOI: 10.1039/c6dt03786k] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrochemical and DFT studies on palladacycles revealed an increase in the metal–metal distance in the complexes leads to higher oxidation potentials.
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15
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Sunderland TL, Berry JF. Metal-Metal Single Bonds with the Magnetic Anisotropy of Quadruple Bonds: A Systematic Series of Heterobimetallic Bismuth(II)-Rhodium(II) Formamidinate Complexes. Chemistry 2016; 22:18564-18571. [DOI: 10.1002/chem.201604007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Travis L. Sunderland
- Department of Chemistry; University of Wisconsin-Madison; 1101 University Ave. Madison WI 53706 USA
| | - John F. Berry
- Department of Chemistry; University of Wisconsin-Madison; 1101 University Ave. Madison WI 53706 USA
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16
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Petrone DA, Ye J, Lautens M. Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation. Chem Rev 2016; 116:8003-104. [DOI: 10.1021/acs.chemrev.6b00089] [Citation(s) in RCA: 394] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- David A. Petrone
- Department of Chemistry, University of Toronto Davenport Research Laboratories, 80 St. George St. Toronto, Ontario M5S 3H6, Canada
| | - Juntao Ye
- Department of Chemistry, University of Toronto Davenport Research Laboratories, 80 St. George St. Toronto, Ontario M5S 3H6, Canada
| | - Mark Lautens
- Department of Chemistry, University of Toronto Davenport Research Laboratories, 80 St. George St. Toronto, Ontario M5S 3H6, Canada
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17
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Berry JF. Two-Center/Three-Electron Sigma Half-Bonds in Main Group and Transition Metal Chemistry. Acc Chem Res 2016; 49:27-34. [PMID: 26741459 DOI: 10.1021/acs.accounts.5b00517] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
First proposed in a classic Linus Pauling paper, the two-center/three-electron (2c/3e) σ half-bond challenges the extremes of what may or may not be considered a chemical bond. Two electrons occupying a σ bonding orbital and one electron occupying the antibonding σ* orbital results in bond orders of ∼0.5 that are characteristic of metastable and exotic species, epitomized in the fleetingly stable He2(+) ion. In this Account, I describe the use of coordination chemistry to stabilize such fugacious three-electron bonded species at disparate ends of the periodic table. A recent emphasis in the chemistry of metal-metal bonds has been to prepare compounds with extremely short metal-metal distances and high metal-metal bond orders. But similar chemistry can be used to explore metal-metal bond orders less than one, including 2c/3e half-bonds. Bimetallic compounds in the Ni2(II,III) and Pd2(II,III) oxidation states were originally examined in the 1980s, but the evidence collected at that time suggested that they did not contain 2c/3e σ bonds. Both classes of compounds have been re-examined using EPR spectroscopy and modern computational methods that show the unpaired electron of each compound to occupy a M-M σ* orbital, consistent with 2c/3e Ni-Ni and Pd-Pd σ half-bonds. Elsewhere on the periodic table, a seemingly unrelated compound containing a trigonal bipyramidal Cu3S2 core caused a stir, leaving prominent theorists at odds with one another as to whether the compound contains a S-S bond. Due to my previous experience with 2c/3e metal-metal bonds, I suggested that the Cu3S2 compound could contain a 2c/3e S-S σ half-bond in the previously unknown oxidation state of S2(3-). By use of the Cambridge Database, a number of other known compounds were identified as potentially containing S2(3-) ligands, including a noteworthy set of cyclopentadienyl-supported compounds possessing diamond-shaped Ni2E2 units with E = S, Se, and Te. These compounds were subjected to extensive studies using X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, density functional theory, and wave function-based computational methods, as well as chemical oxidation and reduction. The compounds contain E-E 2c/3e σ half-bonds and unprecedented E2(3-) "subchalcogenide" ligands, ushering in a new oxidation state paradigm for transition metal-chalcogen chemistry.
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Affiliation(s)
- John F. Berry
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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Haines BE, Berry JF, Yu JQ, Musaev DG. Factors Controlling Stability and Reactivity of Dimeric Pd(II) Complexes in C–H Functionalization Catalysis. ACS Catal 2016. [DOI: 10.1021/acscatal.5b02447] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brandon E. Haines
- Cherry
L. Emerson Center for Scientific Computation, Emory University, 1515
Dickey Drive, Atlanta, Georgia 30322, United States
| | - John F. Berry
- Department
of Chemistry, University of Wisconsin − Madison, 1101 University
Avenue, Madison, Wisconsin 53706, United States
| | - Jin-Quan Yu
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Djamaladdin G. Musaev
- Cherry
L. Emerson Center for Scientific Computation, Emory University, 1515
Dickey Drive, Atlanta, Georgia 30322, United States
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Falvello LR, Foxman BM, Murillo CA. Fitting the Pieces of the Puzzle: The δ Bond. Inorg Chem 2014; 53:9441-56. [DOI: 10.1021/ic500119h] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Larry R. Falvello
- Departamento de Química Inorgánica, ICMA, Universidad de Zaragoza, CSIC, Pedro Cerbuna 12, E-50009 Zaragoza, Spain
| | - Bruce M. Foxman
- Department of Chemistry, MS 015, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Carlos A. Murillo
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, United States
- Department
of Chemistry, University of Texas at El Paso, El Paso, Texas 79968, United States
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Kornecki KP, Berry JF, Powers DC, Ritter T. MetalMetal Bond-Containing Complexes as Catalysts for CH Functionalization. PROGRESS IN INORGANIC CHEMISTRY 2014. [DOI: 10.1002/9781118792797.ch04] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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21
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Dalal NS, Murillo CA. The usefulness of EPR spectroscopy in the study of compounds with metal–metal multiple bonds. Dalton Trans 2014; 43:8565-76. [DOI: 10.1039/c4dt00506f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A discussion of how EPR spectroscopy has contributed to the understanding of the electronic structure of paddlewheel compounds with multiple bonds between metal atoms is presented while commemorating the 50th anniversary of the paper describing the quadruple bond and the identification of the delta bond in the Re2Cl82− anion.
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Affiliation(s)
- Naresh S. Dalal
- Department of Chemistry and Biochemistry
- and National High Magnetic Field
- Florida State University
- Tallahassee, USA
| | - Carlos A. Murillo
- Department of Chemistry
- College Station, USA
- University of Texas at El Paso
- El Paso, USA
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22
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Campbell MG, Zheng SL, Ritter T. One-Dimensional Palladium Wires: Influence of Molecular Changes on Supramolecular Structure. Inorg Chem 2013; 52:13295-7. [DOI: 10.1021/ic4019635] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Michael G. Campbell
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Shao-Liang Zheng
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Tobias Ritter
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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Chiarella GM, Cotton FA, Ibragimov SA, Murillo CA, Wilkinson CC, Young MD. Syntheses of very soluble alkylated bicyclic guanidinate ligands and structural characterization of a dipalladium paddlewheel. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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24
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Durrell AC, Jackson MN, Hazari N, Gray HB. Making Carbon–Chlorine Bonds by Dipalladium Electrocatalysis. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201201498] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Alec C. Durrell
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125, USA, http://www.bilrc.caltech.edu
| | - Megan N. Jackson
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125, USA, http://www.bilrc.caltech.edu
| | - Nilay Hazari
- Department of Chemistry, Yale University, P. O. Box 208107, New Haven, Connecticut 06520, USA
| | - Harry B. Gray
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125, USA, http://www.bilrc.caltech.edu
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Chiarella GM, Cotton FA, Dalal NS, Murillo CA, Wang Z, Young MD. Direct evidence from electron paramagnetic resonance for additional configurations in uncommon paddlewheel Re2(7+) units surrounded by an unsymmetrical bicyclic guanidinate. Inorg Chem 2012; 51:5257-63. [PMID: 22506487 DOI: 10.1021/ic300169f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Three rare compounds have been synthesized and structurally characterized; these species have paddlewheel structures and Re(2)(7+) cores surrounded by four bicyclic guanidinates and two axial ligands along the Re-Re axis. Each possesses a formal bond order of 3.5 and a σ(2)π(4)δ(1) electronic configuration that entails the presence of one unpaired electron for each compound. The guanidinate ligands characterized by having CH(2) entities and a central C(N)(3) unit that joins two cyclic units--one having two fused 6-membered rings (hpp) and the other having a 5- and a 6-membered ring fused together (tbn)--allowed the isolation of [Re(2)(tbn)(4)Cl(2)]PF(6), 1, [Re(2)(tbn)(4)Cl(2)]Cl, 2, and [Re(2)(hpp)(4)(O(3)SCF(3))(2)](O(3)SCF(3)), 3. Because of the larger bite angle of the tbn relative to the hpp ligand, the Re-Re bond distances in 1 and 2 (2.2691(14) and 2.2589(14) Å, respectively) are much longer than that in 3 (2.1804(8) Å). Importantly, electron paramagnetic resonance (EPR) studies at both X-band (~9.4 GHz) and W-band (112 GHz) in the solid and in frozen solution show unusually low g-values (~1.75) and the absence of zero-field splitting, providing direct evidence for the presence of one metal-based unpaired electron for both 1 and 3. These spectroscopic data suggest that the unsymmetrical 5-/6-membered ligand leads to the formation of isomers, as shown by significantly broader EPR signals for 1 than for 3, even though both compounds possess what appears to be similar ideal crystallographic axial symmetry on the X-ray time scale.
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Affiliation(s)
- Gina M Chiarella
- Department of Chemistry, Texas A&M University, P.O. Box 3012, College Station, Texas 77842-3012, USA
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Eitel SH, Bauer M, Schweinfurth D, Deibel N, Sarkar B, Kelm H, Krüger HJ, Frey W, Peters R. Paramagnetic Palladacycles with PdIII Centers Are Highly Active Catalysts for Asymmetric Aza-Claisen Rearrangements. J Am Chem Soc 2012; 134:4683-93. [DOI: 10.1021/ja2098222] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Simon H. Eitel
- Institut für
Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Matthias Bauer
- Fachbereich Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger Straße Gebäude 54/684, 67663
Kaiserslautern, Germany
| | - David Schweinfurth
- Institut für
Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Naina Deibel
- Institut für
Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Biprajit Sarkar
- Institut für
Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Harald Kelm
- Fachbereich Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger Straße Gebäude 54/655, 67663
Kaiserslautern, Germany
| | - Hans-Jörg Krüger
- Fachbereich Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger Straße Gebäude 54/655, 67663
Kaiserslautern, Germany
| | - Wolfgang Frey
- Institut für
Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - René Peters
- Institut für
Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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Li Manni G, Dzubak AL, Mulla A, Brogden DW, Berry JF, Gagliardi L. Assessing metal-metal multiple bonds in Cr-Cr, Mo-Mo, and W-W compounds and a hypothetical U-U compound: a quantum chemical study comparing DFT and multireference methods. Chemistry 2012; 18:1737-49. [PMID: 22237933 DOI: 10.1002/chem.201103096] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Indexed: 11/07/2022]
Abstract
To gain insights into the trends in metal-metal multiple bonding among the Group 6 elements, density functional theory has been employed in combination with multiconfigurational methods (CASSCF and CASPT2) to investigate a selection of bimetallic, multiply bonded compounds. For the compound [Ar-MM-Ar] (Ar=2,6-(C(6)H(5))(2)-C(6)H(3), M=Cr, Mo, W) the effect of the Ar ligand on the M(2) core has been compared with the analogous [Ph-MM-Ph] (Ph=phenyl, M=Cr, Mo, W) compounds. A set of [M(2)(dpa)(4)] (dpa=2,2'-dipyridylamide, M=Cr, Mo, W, U) compounds has also been investigated. All of the compounds studied here show important multiconfigurational behavior. For the Mo(2) and W(2) compounds, the σ(2)π(4)δ(2) configuration dominates the ground-state wavefunction, contributing at least 75%. The Cr(2) compounds show a more nuanced electronic structure, with many configurations contributing to the ground state. For the Cr, Mo, and W compounds the electronic absorption spectra have been studied, combining density functional theory and multireference methods to make absorption feature assignments. In all cases, the main features observed in the visible spectra may be assigned as charge-transfer bands. For all compounds investigated the Mayer bond order (MBO) and the effective bond order (EBO) were calculated by density functional theory and CASSCF methods, respectively. The MBO and EBO values share a similar trend toward higher values at shorter normalized metal-metal bond lengths.
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Affiliation(s)
- Giovanni Li Manni
- Department of Physical Chemistry, University of Geneva, 30, q. E. Ansermet, 1211 Genève, Switzerland
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Campbell MG, Powers DC, Raynaud J, Graham MJ, Xie P, Lee E, Ritter T. Synthesis and structure of solution-stable one-dimensional palladium wires. Nat Chem 2011; 3:949-53. [PMID: 22109275 DOI: 10.1038/nchem.1197] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 10/10/2011] [Indexed: 12/28/2022]
Abstract
One-dimensional metal wires are valuable materials because of their optical and electronic anisotropy, and they have potential utility in devices such as photovoltaic cells and molecular sensors. However, despite more than a century of research, only a few examples exist of well-defined one-dimensional (1D) metal wires that allow for the rational variation of conductivity. Herein we describe the first examples of 1D molecular wires supported by Pd-Pd bonds, the thin-film conductive properties of which can be altered by controlled molecular changes. Wires based on Pd(III) give semiconducting films with a modifiable bandgap, whereas wires based on Pd(2.5) give films that display metallic conductivity above 200 K: a metallic state has not been reported previously for any polymer composed of 1D metal wires. The wires are infinite in the solid state and maintain 1D structures in solution with lengths of up to 750 nm. Solution stability enables thin film coating, a requisite for device fabrication using molecular wires.
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Affiliation(s)
- Michael G Campbell
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA
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Kozitsyna NY, Nefedov SE, Klyagina AP, Markov AA, Dobrokhotova ZV, Velikodny YA, Kochubey DI, Zyubina TS, Gekhman AE, Vargaftik MN, Moiseev II. Novel heterometallic palladium–silver complex. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.02.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Powers DC, Benitez D, Tkatchouk E, Goddard WA, Ritter T. Bimetallic reductive elimination from dinuclear Pd(III) complexes. J Am Chem Soc 2011; 132:14092-103. [PMID: 20858006 DOI: 10.1021/ja1036644] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In 2009, we reported C-halogen reductive elimination reactions from dinuclear Pd(III) complexes and implicated dinuclear intermediates in Pd(OAc)(2)-catalyzed C-H oxidation chemistry. Herein, we report results of a thorough experimental and theoretical investigation of the mechanism of reductive elimination from such dinuclear Pd(III) complexes, which establish the role of each metal during reductive elimination. Our results implicate reductive elimination from a complex in which the dinuclear core is intact and suggest that redox synergy between the two metals is responsible for the facile reductive elimination reactions observed.
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Affiliation(s)
- David C Powers
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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Abstract
While the organometallic chemistry of Pd in its (0), (+II), and (+IV) oxidation states is well-established, organometallic Pd(III) chemistry remains widely unexplored. Few characterized Pd(III) complexes are known, which has inhibited detailed study of the organometallic chemistry of Pd(III). In this review, the potential roles of both mono- and dinuclear Pd(III) complexes in organometallic chemistry will be discussed. While not widely recognized, Pd in the (+III) oxidation state may play a significant role in a variety of known Pd-catalyzed reactions.
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Chen TR, Lee HP, Chen JD, Chen KHC. An 18+δ iridium dimer releasing metalloradicals spontaneously. Dalton Trans 2010; 39:9458-61. [DOI: 10.1039/c0dt00605j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Pap JS, Snyder JL, Piccoli PMB, Berry JF. Chloro and azido diruthenium complexes bearing electron-rich N,N',N''-triphenylguanidinate ligands. Inorg Chem 2009; 48:9846-52. [PMID: 19780542 DOI: 10.1021/ic901419w] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of Ru(2)(OAc)(4)Cl with N,N',N''-triphenylguanidine (HTPG) produces one of two different compounds depending on the reaction conditions. In acetone in the presence of triethyl amine, the reaction produces tri-substituted Ru(2)(TPG)(3)(OAc)Cl, and in refluxing xylene, the tetra-substituted Ru(2)(TPG)(4)Cl is produced. Both of these new complexes can be cleanly converted into their corresponding azido analogues by reaction with sodium azide in methanol. The X-ray crystal structures of Ru(2)(TPG)(3)(OAc)Cl, Ru(2)(TPG)(3)(OAc)N(3), and Ru(2)(TPG)(4)Cl are presented, along with magnetic, electrochemical, and spectral measurements for each compound. Studies in solution show that, in contrast to Ru(2)(TPG)(3)(OAc)Cl, Ru(2)(TPG)(4)Cl is sterically hindered at the axial positions, and readily dissociates a chloride ion at high ionic strength. Equilibrium constants for chloride association and dissociation have been estimated. Mass spectrometric data suggest that the two azido complexes are precursors to new diruthenium nitrido species.
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Affiliation(s)
- József S Pap
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, USA
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Pang K, Figueroa JS, Tonks IA, Sattler W, Parkin G. 2-Mercapto-1-t-butylimidazolyl as a Bridging Ligand: Synthesis and Structural Characterization of Nickel and Palladium Paddlewheel Complexes. Inorganica Chim Acta 2009; 362:4609-4615. [PMID: 20161357 PMCID: PMC2777662 DOI: 10.1016/j.ica.2009.05.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nickel and palladium paddlewheel complexes that feature 2-mercapto-1-t-butylimidazolyl (mim(Bu(t) )) bridging ligands, namely Ni(2)[mim (Bu(t) )](4) and Pd(2)[mim (Bu(t) )](4), have been synthesized and structurally characterized by X-ray diffraction. Since the mim (Bu(t) ) ligand bridges in an asymmetric manner via a sulfur and nitrogen donor, paddlewheel compounds of the type M(2)[mim (Bu(t) )](4) may exist as isomers that are distinguished by the relative orientations of the ligands. In this regard, the (4,0)-Ni(2)[mim (Bu(t) )](4) and trans-(2,2)-Ni(2)[mim (Bu(t) )](4) isomers have been isolated for the nickel system, while the (4,0)-Pd(2)[mim (Bu(t) )](4) and (3,1)-Pd(2)[mim (Bu(t) )](4) isomers have been isolated for the palladium system.
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Affiliation(s)
- Keliang Pang
- Department of Chemistry, Columbia University, New York, New York 10027, USA
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Markov AA, Klyagina AP, Dolin SP, Akhmadullina NS, Kozitsyna NY, Cherkashina NV, Nefedov SE, Vargaftik MN, Moiseev II. On the nature of the chemical bond in heterobimetallic palladium(II) complexes with divalent 3d metals. RUSS J INORG CHEM+ 2009. [DOI: 10.1134/s0036023609060114] [Citation(s) in RCA: 12] [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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Bimetallic Pd(III) complexes in palladium-catalysed carbon–heteroatom bond formation. Nat Chem 2009; 1:302-9. [DOI: 10.1038/nchem.246] [Citation(s) in RCA: 494] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Nippe M, Timmer GH, Berry JF. Remarkable regioselectivity in the preparation of the first heterotrimetallic Mo[quadruple bond]W...Cr chain. Chem Commun (Camb) 2009:4357-9. [PMID: 19597591 DOI: 10.1039/b907402c] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Addition of CrCl(2) to the dinuclear synthon MoW(dpa)(4) yields a regioselectively formed heterotrimetallic Mo[quadruple bond]W...Cr chain; computational studies suggest that the polarization of the Mo[quadruple bond]W quadruple bond partially accounts for this unexpected selectivity.
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Affiliation(s)
- Michael Nippe
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
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41
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Cotton FA, Murillo CA, Wang Q, Young MD. Unusual Magnetism of an Unsymmetrical Trinickel Chain. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800808] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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The efficacy and selectivity of tumor cell killing by Akt inhibitors are substantially increased by chloroquine. Bioorg Med Chem 2008; 16:7888-93. [PMID: 18691894 DOI: 10.1016/j.bmc.2008.07.076] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 07/23/2008] [Accepted: 07/25/2008] [Indexed: 11/22/2022]
Abstract
This study was to evaluate the enhancement value of chloroquine (CQ) in cancer cell killing when used in combination with Akt inhibitors. The results showed that the combination of CQ and Akt inhibitors is much more effective than either one alone. Importantly, the CQ-mediated chemosensitization of cell killing effects by Akt inhibitors is cancer specific. In particular, when combined with 10 microM CQ, 1,3-dihydro-1-(1-((4-(6-phenyl-1H-imidazo[4,5-g]quinoxalin-7-yl)phenyl)methyl)-4-piperidinyl)-2H-benzimidazol-2-one (an Akt1 and 2 inhibitor; compound 8) killed cancer cells 10-120 times more effectively than normal cells. Thus, CQ is a very effective and cancer-specific chemosensitizer when used in combination with Akt inhibitors.
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Arai S, Ochiai M, Ishihara K, Matsumoto K. Mixed-Valent Linear Chain Pt2PdPt2 Complexes. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200601247] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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