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Nagata K, Hino A, Ube H, Sato H, Shionoya M. Synthesis and molecular structural studies of racemic chiral-at-vanadium(V) complexes using an unsymmetric achiral phenolic bidentate ligand. Dalton Trans 2023; 52:3295-3299. [PMID: 36648316 DOI: 10.1039/d2dt03436k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Mononuclear oxovanadium(V) complexes [V(O)XL (1: X = Ot-Bu, 2: X = Cl)] [H2L: 2,2'-methylene bis(4,6-di-tert-butylphenol)(4'-tert-butyl-6'-(1-adamantyl)phenol)] directed towards asymmetric catalysis have been synthesised as racemic compounds using an unsymmetric and achiral phenolic bidentate ligand (H2L), and NMR and UV-vis absorption spectroscopies, single-crystal X-ray diffraction, and IR spectroscopy revealed their racemic chiral-at-vanadium structures in solution and in the crystal. In addition, theoretical calculations revealed that the HOMO-LUMO energy gap is smaller for unsymmetric ligands, which promotes d-orbital splitting of the metal centre.
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Affiliation(s)
- Koichi Nagata
- Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Ayako Hino
- Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Hitoshi Ube
- Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Hiroyasu Sato
- Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima, Tokyo 196-8666, Japan
| | - Mitsuhiko Shionoya
- Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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2
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Endo K, Liu Y, Ube H, Nagata K, Shionoya M. Precise Design of Chiral-at-Metal Complexes: Synthesis and Catalytic Functions of a Tetrahedral Chiral Zinc Complex. J SYN ORG CHEM JPN 2022. [DOI: 10.5059/yukigoseikyokaishi.80.498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | | | | | | | - Mitsuhiko Shionoya
- Department of Chemistry, Graduate School of Science, The University of Tokyo
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Asymmetric construction of tetrahedral chiral zinc with high configurational stability and catalytic activity. Nat Commun 2020; 11:6263. [PMID: 33298960 PMCID: PMC7726038 DOI: 10.1038/s41467-020-20074-7] [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: 07/21/2020] [Accepted: 11/12/2020] [Indexed: 12/13/2022] Open
Abstract
Chiral metal complexes show promise as asymmetric catalysts and optical materials. Chiral-at-metal complexes composed of achiral ligands have expanded the versatility and applicability of chiral metal complexes, especially for octahedral and half-sandwich complexes. However, Werner-type tetrahedral complexes with a stereogenic metal centre are rarely used as chiral-at-metal complexes because they are too labile to ensure the absolute configuration of the metal centre. Here we report the asymmetric construction of a tetrahedral chiral-at-zinc complex with high configurational stability, using an unsymmetric tridentate ligand. Coordination/substitution of a chiral auxiliary ligand on zinc followed by crystallisation yields an enantiopure chiral-only-at-zinc complex (> 99% ee). The enantiomer excess remains very high at 99% ee even after heating at 70 °C in benzene for one week. With this configurationally stable zinc complex of the tridentate ligand, the remaining one labile site on the zinc can be used for a highly selective asymmetric oxa-Diels-Alder reaction (98% yield, 87% ee) without substantial racemisation.
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Stroscio GD, Ribson RD, Hadt RG. Quantifying Entatic States in Photophysical Processes: Applications to Copper Photosensitizers. Inorg Chem 2019; 58:16800-16817. [DOI: 10.1021/acs.inorgchem.9b02976] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gautam D. Stroscio
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Ryan D. Ribson
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Ryan G. Hadt
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
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Dridi S, Mechria A, Msaddek M. Crystal Structure of Cationic η3-Methallylpalladium Complexes Bearing Aliphatic Iminopyridine Ligands. J STRUCT CHEM+ 2019. [DOI: 10.1134/s0022476619070126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Saha S, Biswas PK, Schmittel M. Reversible Interconversion of a Static Metallosupramolecular Cage Assembly into a High-Speed Rotor: Stepless Adjustment of Rotational Exchange by Nucleophile Addition. Inorg Chem 2019; 58:3466-3472. [PMID: 30789716 DOI: 10.1021/acs.inorgchem.8b03567] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The self-assembled cage ROT-1 was prepared from the pyridine-terminated rotator 1, the phenanthroline-appended stator 2, DABCO, and copper(I) ions in a ratio of 1:1:1:4. This four-component assembly is held together by two pyridine→[Cu(phenAr2)]+ as well as two DABCO→zinc porphyrin interactions (phenAr2 = 2,9-diarylphenanthroline) and does not show any motion on the NMR time scale ( k < 0.1 s-1, 298 K). However, it is converted to the fast nanorotor ROT-1 xCD3CN by addition of CD3CN [ x = (v/v)% of acetonitrile in dichloromethane] due to acceleration of both pyridine→copper(I) dissociation steps. Now the rotator is able to visit all four copper(I)-loaded phenanthroline stations of the stator. Depending on the amount of CD3CN, the exchange frequency of the nanorotor varies from 0.7 s-1 (CD3CN:CD2Cl2 = 1:29) to 8000 s-1 (CD3CN:CD2Cl2 = 1:5) at 25 °C. When iodide (I-) is added to the static assembly ROT-1, the rotational speed increases even more drastically ( k = 20 000 s-1), again due to accelerating the rate-determining pyridine→copper(I) dissociation step. In both cases, a sigmoidal relationship is established between exchange frequency and the concentration of added nucleophile (CD3CN or iodide) that suggests the presence of a cooperative effect. Reversible switching between the static assembly and fast rotor was performed several times without any decomposition of the system. In contrast, addition of the common nucleophile PPh3 to ROT-1 does not increase the rotational speed, a finding that is explained on thermodynamic grounds.
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Affiliation(s)
- Suchismita Saha
- Center of Micro- and Nanochemistry and Engineering , Organische Chemie I , Adolf-Reichwein-Str. 2 , D-57068 Siegen , Germany
| | - Pronay Kumar Biswas
- Center of Micro- and Nanochemistry and Engineering , Organische Chemie I , Adolf-Reichwein-Str. 2 , D-57068 Siegen , Germany
| | - Michael Schmittel
- Center of Micro- and Nanochemistry and Engineering , Organische Chemie I , Adolf-Reichwein-Str. 2 , D-57068 Siegen , Germany
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Saito Y, Nishikawa M, Tsubomura T. Water-soluble copper( i) complexes bearing 2,2′-bicinchoninic acid dipotassium salt with red-light absorption and repeatable colour change upon freezing operation. NEW J CHEM 2019. [DOI: 10.1039/c8nj05147j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The repeatable colour change upon freezing–melting operation of a water solution of a Cu(i) complex is found. Efficient red light absorption is also one of the advantages of this complex.
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Affiliation(s)
- Yuma Saito
- Department of Materials and Life Science
- Seikei University
- Tokyo
- Japan
| | | | - Taro Tsubomura
- Department of Materials and Life Science
- Seikei University
- Tokyo
- Japan
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Heteroleptic copper phenanthroline complexes in motion: From stand-alone devices to multi-component machinery. Coord Chem Rev 2018; 376:478-505. [PMID: 32287354 PMCID: PMC7126816 DOI: 10.1016/j.ccr.2018.08.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/07/2018] [Accepted: 08/13/2018] [Indexed: 12/27/2022]
Abstract
Two and a half decades of copper phenanthroline-based switches, devices and machines have illustrated the rich dynamic nature of these metal complexes. With an emphasis on the metal-ligand dissociation as the rate-determining step the present review summarizes not only spectacular examples of machinery, but also highlights rate data collected during a variety of investigations. Copper-ligand exchange reactions are mostly triggered by redox processes, addition of metal ions or addition of ligands. While the rate data spread over >8 orders of magnitude, individual effects of solvent, steric bulk, flexibility, σ-basicity and the trajectory (intra- vs. intermolecular dissociation) have large impact. Unfortunately, in many cases the exact mechanism in the rate-determining step (nucleophile-induced vs. monomolecular metal-ligand dissociation) has not been determined, suggesting to invest further efforts in the physical (in)organic chemistry of such coordination-driven systems.
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Nishikawa M, Takara Y, Hattori Y, Nomoto K, Kusamoto T, Kume S, Nishihara H. Structural modification on copper(I)-pyridylpyrimidine complexes for modulation of rotational dynamics, redox properties, and phototriggered isomerization. Inorg Chem 2013; 52:8962-70. [PMID: 23883176 DOI: 10.1021/ic4011295] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The redox properties of copper pyridylpyrimidine complexes, which undergo linkage isomerism based on pyrimidine ring rotation, were compared under different coordination environments. A newly synthesized compound, [Cu(Mepypm)(L(Mes))]BF4 (1·BF4, Mepypm = 4-methyl-2-(2'-pyridyl)pyrimidine, L(Mes) = 2,9-dimesityl-1,10-phenanthroline) was compared with previously reported complexes of [Cu(MepmMepy)(L(Mes))]BF4 (2·BF4, MepmMepy = 4-methyl-2-(6'-methyl-2'-pyridyl)pyrimidine), Cu(Mepypm)(DPEphos)]BF4 (3·BF4, DPEphos = bis[2-(diphenylphosphino)phenyl]ether), [Cu(Mepypm)(L(Anth))]BF4 (4·BF4, L(Anth) = 2,9-bis(9-anthryl)-1,10-phenanthroline), and [Cu(Mepypm)(L(Macro))]BF4 (5·BF4). Isomer ratios, isomerization dynamics, redox properties, and photoelectron conversion functions varied with the coordination structure. Methyl substituents on the 6-position of the pyridine moiety increased steric repulsion and contributed to quicker rotation, enhanced photoluminescence, and increased photodriven rotational isomerization.
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Affiliation(s)
- Michihiro Nishikawa
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Jung J, Jo J, Laskar M, Lee D. Stereodynamics of Metal-Ligand Assembly: What Lies Beneath the “Simple” Spectral Signatures ofC2-Symmetric Chiral Chelates. Chemistry 2013; 19:5156-68. [DOI: 10.1002/chem.201204216] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Indexed: 11/09/2022]
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Nishikawa M, Kume S, Nishihara H. Stimuli-responsive pyrimidine ring rotation in copper complexes for switching their physical properties. Phys Chem Chem Phys 2013; 15:10549-65. [DOI: 10.1039/c3cp44710c] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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12
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Nishikawa M, Nomoto K, Kume S, Nishihara H. Solvated-Ion-Pairing-Sensitive Molecular Bistability Based on Copper(I)-Coordinated Pyrimidine Ring Rotation. Inorg Chem 2012; 52:369-80. [DOI: 10.1021/ic302141z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michihiro Nishikawa
- Department of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kuniharu Nomoto
- Department of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shoko Kume
- Department of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroshi Nishihara
- Department of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Nishikawa M, Nomoto K, Kume S, Nishihara H. Reversible Copper(II)/(I) Electrochemical Potential Switching Driven by Visible Light-Induced Coordinated Ring Rotation. J Am Chem Soc 2012; 134:10543-53. [DOI: 10.1021/ja3028873] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michihiro Nishikawa
- Department of Chemistry,
School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
| | - Kuniharu Nomoto
- Department of Chemistry,
School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
| | - Shoko Kume
- Department of Chemistry,
School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
| | - Hiroshi Nishihara
- Department of Chemistry,
School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
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Goto H, Hayakawa T, Furutachi K, Sugimoto H, Inoue S. Planar-chiral metal complexes comprised of square-planar metal and achiral tetradentate ligands: design, optical resolution, and thermodynamics. Inorg Chem 2012; 51:4134-42. [PMID: 22435891 DOI: 10.1021/ic2024742] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Planar-chiral palladium complexes {[[N,N'-[1,4-butanediylbis(oxy-7,1-naphthalenediyl)]bis(2-pyridinecarboxamidato)](2-)-κN(1),κN(1)',κN(2),κN(2)']palladium (PdL(4)) and [[2,2'-[1,4-butanediylbis[[(oxy-7,1-naphthalenediyl)imino]methyl]]dipyrrolato](2-)-κN(1),κN(1)',κN(2),κN(2)']palladium (PdL(5))} were synthesized from achiral tetradentate ligands N,N'-[1,4-butanediylbis(oxy-7,1-naphthalenediyl)]bis(2-pyridinecarboxamide) (H(2)L(4)) and N,N'-bis[(1H-pyrrol-2-yl)methylidene]-7,7'-(1,4-butanediyldioxy)bis(1-naphthalenamine) (H(2)L(5)) bearing two dissymmetric bidentate units at both ends and a Pd(II) ion, respectively. The palladium complexes were crystallized in the monoclinic space group P2(1)/n with the unit cell parameters a = 16.5464(6) Å, b = 11.3534(4) Å, c = 17.6697(7) Å, β = 115.5300(10)°, and Z = 4 for PdL(4) and a = 17.2271(8) Å, b = 10.1016(5) Å, c = 17.9361(9) Å, β = 105.6310(10)°, and Z = 4 for PdL(5). The planar-chiral structures of PdL(4) and PdL(5) were confirmed by single-crystal X-ray analyses, resulting in the fact that the crystals were racemic mixtures. The racemic mixtures were successfully resolved by using chiral high-performance liquid-chromatography techniques. Racemizations of the complexes were found to be drastically dependent on the arrangement of the charged or uncharged metal-binding N atoms of the ligands.
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Affiliation(s)
- Hidetoshi Goto
- Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 12-1 Ichigaya-funagawara, Shinjuku, Tokyo 162-0826, Japan
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Wenzel TJ, Chisholm CD. Using NMR spectroscopic methods to determine enantiomeric purity and assign absolute stereochemistry. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2011; 59:1-63. [PMID: 21600355 DOI: 10.1016/j.pnmrs.2010.07.003] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 07/28/2010] [Indexed: 05/30/2023]
Affiliation(s)
- Thomas J Wenzel
- Department of Chemistry, Bates College, Lewiston, Maine 04240, USA.
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Lacour J. Chiral hexacoordinated phosphates: From pioneering studies to modern uses in stereochemistry. CR CHIM 2010. [DOI: 10.1016/j.crci.2010.02.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Share AI, Parimal K, Flood AH. Bilability is defined when one electron is used to switch between concerted and stepwise pathways in Cu(I)-based bistable [2/3]pseudorotaxanes. J Am Chem Soc 2010; 132:1665-75. [PMID: 20070081 DOI: 10.1021/ja908877d] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Supramolecular switches operate as simple machines by using a stimulus to turn stations off and on, generating thermodynamic differences that define bistability and enable motion. What has not been previously investigated, yet is required to gain further control over molecular movements for complex operations, is an understanding of how the same stimulus can also switch pathways off and on, thus, defining the kinetic property of bilability. To address this challenge, the mechanisms of the forward and return reactions of redox-switchable Cu(I)-based [2/3]pseudorotaxanes have been quantitatively characterized utilizing mechanistic cyclic voltammetry and employing a series of isosteric bis-bidentate ligands. First, the bistability of the switch is retained across the series of ligands: Reduction of the ligand drives the reaction forward where a [2]pseudorotaxane switches into a reduced [3]pseudorotaxane and reoxidation drives the switching cycle back to the beginning. Second, the switch is bilabile with the forward reaction following an association-activated interchange pathway (concerted), whereas the reverse reaction follows a different dissociation-based dethreading pathway (stepwise). The forward reaction is more sensitive to denticity (bidentate tetrazinyl ligand, k(2) = 12,000 M(-1) s(-1), versus the monodentate pyrazinyl ligand, k(2) = 1500 M(-1) s(-1)) than to electronics (k(2) = 12,000 M(-1) s(-1) for methyl and trifluoromethyl substituents). The rate of return with the pyrazinyl ligand is k(1) = 50 s(-1). Consequently, both the mechanism and the thermodynamics of switching are stimuli dependent; they change with the oxidation state of the ligand. These findings have implications for the future design of molecular motors, which can be built from systems displaying allosterically coupled bistability and bilability.
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Affiliation(s)
- Andrew I Share
- Department of Chemistry, University of Indiana, Bloomington, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, USA
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Massa W, Dehghanpour S, Jahani K. Structure-dependent spectroscopic and redox properties of copper(I) complexes with bidentate iminopyridine ligands. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.01.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Dehghanpour S, Rominger F. Synthesis and characterization of the [Cu(Cin2bda)2]ClO4 and [Cu(Ncin2bda)2]ClO4 complexes: Crystal structure of [Cu(Ncin2bda)2]ClO4. RUSS J COORD CHEM+ 2009. [DOI: 10.1134/s1070328409040058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Chow HS, Constable EC, Frantz R, Housecroft CE, Lacour J, Neuburger M, Rappoport D, Schaffner S. Conformationally-locked metallomacrocycles—prototypes for a novel type of axial chirality. NEW J CHEM 2009. [DOI: 10.1039/b819588a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Gschwind RM. Organocuprates and Diamagnetic Copper Complexes: Structures and NMR Spectroscopic Structure Elucidation in Solution. Chem Rev 2008; 108:3029-53. [DOI: 10.1021/cr800286r] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ruth M. Gschwind
- Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, D-93040 Regensburg, Germany
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22
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Pérollier C, Bernardinelli G, Lacour J. Sugar derived hexacoordinated phosphates: Chiral anionic auxiliaries with general asymmetric efficiency. Chirality 2008; 20:313-24. [PMID: 17614326 DOI: 10.1002/chir.20441] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Mannose-derived hexacoordinated phosphate anions, prepared in as few as two steps from methyl-alpha-D-mannopyranoside and tris(dimethylamino)phosphine, are chiral anionic auxiliaries with broad asymmetric efficiency. These chemically robust anions are effective NMR chiral solvating agents and efficient asymmetry-inducers, able to control the configuration of conformationally labile C2-symmetric monomethinium cations (organic, helical, charge 1+, P or M enantiomers) and D3-symmetric iron(II) trisdiimine complexes (metallo-organic, octahedral, charge 2+, Delta or Lambda enantiomers). Diastereomeric control with often unmatched selective levels was achieved with the help of mannopyranoside backbone of the anions and the substituents on the [1,3]dioxane ring that play a key role in the recognition process, something not obvious at first sight.
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Affiliation(s)
- Céline Pérollier
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Geneva 4, Switzerland
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Gonçalves-Farbos MH, Vial L, Lacour J. Enantioselective [1,2]-Stevens rearrangement of quaternary ammonium salts. A mechanistic evaluation. Chem Commun (Camb) 2008:829-31. [DOI: 10.1039/b716488b] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Winkelmann O, Linder D, Lacour J, Näther C, Lüning U. Chiral Concave Imidazolinium Salts as Precursors to Chiral ConcaveN-Heterocyclic Carbenes. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700206] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Dehghanpour S, Mahmoudi A. Synthesis, structure, and redox properties of copper(I) complexes with phenylpyridin-2-ylmethyleneamine derivatives. MAIN GROUP CHEMISTRY 2007. [DOI: 10.1080/10241220801889025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Dehghanpour S, Bouslimani N, Welter R, Mojahed F. Synthesis, spectral characterization, properties and structures of copper(I) complexes containing novel bidentate iminopyridine ligands. Polyhedron 2007. [DOI: 10.1016/j.poly.2006.08.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Amirnasr M, Kickelbick G, Dehghanpour S. Synthesis, Characterization, and X-Ray Crystal Structures of Bis[N-(3,3-diphenylallylidene)quinolin-8-amine-κN,κN8]copper(1+) Tetraphenylborate(1−) ([Cu(dpa-qa)2]BPh4) and Bis[N,N′-bis(3,3-diphenylallylidene)-[1,1′-biphenyl]-2,2′-diamine-κN,κN′]copper(1+) Perchlorate ([Cu(bdpa-bda)2]ClO4 ⋅ 3 H2O). Helv Chim Acta 2006. [DOI: 10.1002/hlca.200690031] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Habermehl NC, Angus PM, Kilah NL, Norén L, Rae AD, Willis AC, Wild SB. Asymmetric Transformation of a Double-Stranded, Dicopper(I) Helicate Containing Achiral Bis(bidentate) Schiff Bases. Inorg Chem 2006; 45:1445-62. [PMID: 16471956 DOI: 10.1021/ic051478c] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions of the bis(bidentate) Schiff-bases N,N'-bis(6-alkyl-2-pyridylmethylene)ethane-1,2-diamine (where alkyl = H, Me, iPr) (L) with tetrakis(acetonitrile)copper(I) hexafluorophosphate and silver(I) hexafluorophosphate afforded, respectively, the double-stranded, dinuclear metal helicates [T-4-(R,R)]-(+/-)-[M2L2](PF6)2 (M = Cu, Ag). The helicates were characterized by 1H and 13C NMR spectroscopy, conductivity, microanalysis, and single-crystal X-ray structure determinations on selected compounds. Intermolecular ligand exchange and intramolecular inversion rates for the complexes were investigated by 1H NMR spectroscopy. Reversible intermolecular ligand exchange between two differently substituted helicates followed first-order kinetics. The rate constants (k) and corresponding half-lives (t(1/2)) for ligand exchange for the dicopper(I) helicates were k = (1.6-1.8) x 10(-6) s(-1) (t(1/2) = 110-120 h) in acetone-d6, k = 4.9 x 10(-6) s(-1) (t(1/2) = 40 h) in dichloromethane-d2, and k > 2 x 10(-3) s(-1) (t(1/2) < 5 min) in acetonitrile-d3. Ligand exchange for the disilver(I) helicates occurred with k > 2 x 10(-3) s(-1) (t(1/2) < 5 min). Racemization of the dicopper(I) helicate by an intramolecular mechanism was investigated by determination of the coalescence temperature for the diastereotopic isopropyl-Me groups in the appropriate complex, and DeltaG() >> 76 kJ mol(-1) was calculated for the process in acetone-d6, nitromethane-d3, and dichloromethane-d2 with DeltaG() = 75 kJ mol(-1) in acetonitrile-d3. Complete anion exchange of the hexafluorophosphate salt of a dicopper(I) helicate with the enantiomerically pure Delta-(-)-tris(catecholato)arsenate(V) ([As(cat)3]-) in the presence of Dabco gave the two diastereomers (R,R)-[Cu2L2][Delta-(-)-[As(cat)3]]2 and (S,S)-[Cu2L2][Delta-(-)-[As(cat)3]]2 in up to 54% diastereomeric excess, as determined by (1)H NMR spectroscopy. The diastereomerically and enantiomerically pure salt (R,R)-[Cu(2)L2][Delta-(-)-[As(cat)3]]2 crystallized from the solution in a typical second-order asymmetric transformation. The asymmetric transformation of the dicopper(I) helicate is the first synthesis of a diastereomerically and enantiomerically pure dicopper(I) helicate containing achiral ligands.
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Affiliation(s)
- Nicolle C Habermehl
- Research School of Chemistry, Institute of Advanced Studies, Australian National University, Canberra, ACT
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Hebbe-Viton V, Desvergnes V, Jodry JJ, Dietrich-Buchecker C, Sauvage JP, Lacour J. Chiral spiro Cu(i) complexes. Supramolecular stereocontrol and isomerisation dynamics by the use of TRISPHAT anions. Dalton Trans 2006:2058-65. [PMID: 16625249 DOI: 10.1039/b515540a] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Association of enantiopure TRISPHAT anion (1) with chiral spiro [Cu(LL')2] complexes (LL' = 2-R-phen, 2, 6-R-bpy, 3, and 2-iminopyridine, 4) leads to an efficient NMR enantiodifferentiation. Variable temperature 1H NMR spectroscopy has been used to determine the isomerisation kinetics of these pseudo-tetrahedral complexes and to evaluate their configurational stability; the latter depending on the structure of the diimine ligands. In the case of the 2-anthracenyl-phen derivative, a decent level of supramolecular stereocontrol was noted (d.e. up to 45%); the configuration of the complex being determined by electronic circular dichroism (ECD).
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Affiliation(s)
- Virginie Hebbe-Viton
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, CH-1211, Geneva 4, Switzerland
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Hutin M, Nitschke J. Solvent-tunable inversion of chirality transfer from carbon to copper. Chem Commun (Camb) 2006:1724-6. [PMID: 16609784 DOI: 10.1039/b601012a] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A change of solvent causes an inversion of the stereochemistry at copper of the chiral Cu(I) complex described herein.
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Affiliation(s)
- Marie Hutin
- Department of Organic Chemistry, University of Geneva, 30 Quai Ernest Ansermet, 1211 Genève 4, Switzerland
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31
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Chen CL, Tan HY, Yao JH, Wan YQ, Su CY. Disilver(I) Rectangular-Shaped Metallacycles: X-ray Crystal Structure and Dynamic Behavior in Solution. Inorg Chem 2005; 44:8510-20. [PMID: 16270991 DOI: 10.1021/ic050673o] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reaction of the ditopic semirigid ligand 1,2-bis(imidazolylmethyl)benzene (1,2-bImb) or the flexible ligand 1,4-bis(2-benzimidazolyl)butane (C4BIm) with AgX (X = ClO4-, BF4-, CF3CO2-) afforded five new complexes, namely, [Ag2(1,2-bImb)2](ClO4)2 (1), [Ag2(1,2-bImb)2](BF4)2 (2), [Ag2(1,2-bImb)2](CF3CO2)2.2CH3OH (3.2CH3OH), [Ag2(C4BIm)2](ClO4)2.2DMF (4.2DMF), and [Ag2(C4BIm)2](CF3CO2)2.2H2O (5.2H2O), all of which contain a centrosymmetric, rectangular-shaped cationic disilver(I) metallacycle [Ag2(L)2]2+. In 1-3, a pair of 1,2-bImb ligands takes on the syn conformation to connect two Ag(I) ions to give a compressed rectangle with a transannular Ag...Ag separation of 3.27-3.36 angstroms, whereas in 4 and 5, the pair of planar C4BIm ligands acts in the cis conformation to connect two Ag(I) ions to yield a normal rectangle with a transannular Ag...Ag separation of 7.67-7.91 angstroms. The anions form Ag...O or Ag...F weak interactions in 1-3 and O-H...O or N-H...O hydrogen bonds in 4 and 5 in crystal packing but exhibit no significant influence on the formation of the disilver(I) macrocycles. The solution structure and dynamic behavior of the complexes studied by electrospray ionization mass spectrometry, 1H NMR, and variable-temperature NMR indicated that the dynamic equilibrium between the [Ag2(L)2]2+ cation and the open-ring oligomers or other potential species occurs via solvent-assisted dissociative exchange. The metal-ligand exchange barrier was estimated to be 54.5 kJ mol(-1).
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Affiliation(s)
- Chun-Long Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering and Instrumentation Analysis & Research Center, Sun Yat-Sen University, Guangzhou 510275, China
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Llewellyn DB, Arndtsen BA. Synthesis of a library of chiral α-amino acid-based borate counteranions and their application to copper catalyzed olefin cyclopropanation. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.tetasy.2005.04.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Bas D, Bürgi T, Lacour J, Vachon J, Weber J. Vibrational and electronic circular dichroism of Δ-TRISPHAT [tris(tetrachlorobenzenediolato)phosphate(V)] anion. Chirality 2005; 17 Suppl:S143-8. [PMID: 15806572 DOI: 10.1002/chir.20131] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Herein is reported an experimental and theoretical study of the circular dichroism properties of TRISPHAT (1) anion. ECD analysis of the [tetramethylammonium][delta-1] salt confirms the absolute configuration assignment obtained through X-ray crystallographic analysis of the parent cinchonidium salt. The structure, infrared, and vibrational circular dichroism (VCD) spectra derived from density functional theory (DFT) calculations are compared with experimental data.
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Affiliation(s)
- Delphine Bas
- Département de Chimie Organique, Université de Genève, Genève, Switzerland
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Favarger F, Goujon-Ginglinger C, Monchaud D, Lacour J. Large-Scale Synthesis and Resolution of TRISPHAT [Tris(tetrachlorobenzenediolato) Phosphate(V)] Anion. J Org Chem 2004; 69:8521-4. [PMID: 15549835 DOI: 10.1021/jo048641q] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Both enantiomers of TRISPHAT anion can be obtained on a multigram scale through a novel resolution procedure. The Lambda enantiomer is isolated as the tri-n-butylammonium salt, [(n)()Bu(3)NH][Lambda-1], which is soluble in pure CHCl(3) and CH(2)Cl(2). The Delta enantiomer is prepared as the cinchonidinium derivative, which is only soluble in polar solvent mixtures (>7.5% DMSO in CHCl(3)).
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Affiliation(s)
- France Favarger
- Département de Chimie Organique, Université de Genève, quai Ernest-Ansermet 30, CH-1211 Genève 4, Switzerland
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Oakley SH, Coles MP, Hitchcock PB. Structural Consequences of the Prohibition of Hydrogen Bonding in Copper−Guanidine Systems. Inorg Chem 2004; 43:5168-72. [PMID: 15285694 DOI: 10.1021/ic0495970] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and structure of copper(I) complexes supported by N-substituted bicyclic guanidines is described. The N-methyl-substituted bicyclic guanidine 1,3,4,6,7,8-hexahydro-1-methyl-2H-pyrimido[1,2-a]pyrimidine (hppMe) reacted with copper(I) chloride to afford the ion-pair [Cu(hppMe)(2)][CuCl(2)] (1), a rare example of a compound containing an unsupported Cu...Cu interaction. The analogous reaction with CuI, however, afforded the molecular mu,mu-dihalo-bridged dimer [CuI(hppMe)](2) (2). Inclusion of a trimethylsilyl substituent at nitrogen provided a sufficiently sterically encumbered environment to support a two coordinate copper center in CuCl(hppSiMe(3)) (3). Compounds 1-3 have been fully characterized, including single-crystal X-ray diffraction studies.
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Affiliation(s)
- Sarah H Oakley
- Department of Chemistry, University of Sussex, Falmer, Brighton BN1 9QJ, U.K
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Pianet I, Vincent JM. Isomerization Dynamics in Homo- and Heterochiral Atropoisomer Copper(I) Diimine Complexes: A 2D EXSY NMR Study. Inorg Chem 2004; 43:2947-53. [PMID: 15106983 DOI: 10.1021/ic0353108] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two-dimensional exchange NMR spectroscopy has been employed to study the isomerization process of copper(I) complexes formed upon complexation of Cu+ with a racemic mixture of the atropoisomer diimine benzimidazole-pyridine ligands 1-3 and evaluate the configurational stability of the pseudotetrahedral complexes [Cu(1-3)2]PF6. Racemization of the heterochiral isomers RSLambda/RSDelta proceeds through an intramolecular ligand rearrangement on a time scale of about 1.9 s(-1) for 1, 4.4 s(-1) for 2, and 0.3 s(-1) for 3 in CD2Cl2 at room temperature. The intramolecular Lambda/Delta isomerizations in the homochiral diastereoisomers RRDelta/SSLambda and RRLambda/SSDelta of [Cu(1)2]PF6 proceed at room temperature on a time scale of about 0.6 s(-1) for the conversion of RRDelta/SSLambda into RRLambda/SSDelta and 13 s(-1) for the conversion of RRLambda/SSDelta into RRDelta/SSLambda. The kinetics of these intramolecular exchange processes were found to be sensitive to the stabilizing interligand pi-stacking interactions that develop within the [Cu(1-3)2]+ structure and to the bulkiness of the benzimidazole aryl substituents. The kinetics of racemization in the heterochiral RSLambda/RSDelta isomers of [Cu(3)2]PF6 with the bulky cumyl-derived ligand were 1 order of magnitude lower than in [Cu(2)2]PF6 with the tolyl-based ligand. Slower intermolecular ligand exchanges between all the isomers have also been shown to occur at ambient temperature in CD2Cl2 through complete ligand dissociation. Free energies at 298 K varying between 66.7 and 74.4 kJ.mol(-1) and entropies varying between -26.4 and 28.3 J.K(-1).mol(-1) were determined for the intramolecular Lambda/Delta isomerizations. For the intermolecular ligand exchanges free energies at 298 K varying between 55.6 and 62.5 kJ.mol(-1) and entropies varying between -97.9 and -74.5 J.K(-1).mol(-1) were measured.
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Affiliation(s)
- Isabelle Pianet
- Laboratoire de Chimie Organique et Organométallique (UMR-CNRS 5802), Université Bordeaux 1, 351 cours de la Libération, 33405 Talence, France.
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Oakley SH, Coles MP, Hitchcock PB. Structural and catalytic properties of bis(guanidine)copper(I) halides. Inorg Chem 2003; 42:3154-6. [PMID: 12739952 DOI: 10.1021/ic034213b] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The neutral, bicyclic guanidine 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH) coordinates to Cu(I) halides via the imine nitrogen, and the complexes are stabilized by intramolecular NH...X interactions (X = Cl, Br) or are partially dissociated (X = I) in the solid state; in all cases, fluxional behavior is observed in solution. Selected complexes have been tested as catalysts for the polymerization of methyl methacrylate.
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Affiliation(s)
- Sarah H Oakley
- Department of Chemistry, University of Sussex, Falmer, Brighton BN1-9QJ, U.K
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