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Zaripov R, Avdoshenko S, Khairuzhdinov I, Salikhov K, Voronkova V, Weheabby S, Rüffer T, Popov A, Büchner B, Kataev V. Effect of the Diamagnetic Single-Crystalline Host on the Angular-Resolved Electron Nuclear Double Resonance Experiments: Case of Paramagnetic [ nBu 4N] 2[Cu(opba)] Embedded in Diamagnetic [ nBu 4N] 2[Ni(opba)]. J Phys Chem Lett 2019; 10:6565-6571. [PMID: 31593633 DOI: 10.1021/acs.jpclett.9b02523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The electron spin resonance (ESR) and electron nuclear double resonance (ENDOR) spectroscopies are frequently used to determine hyperfine (A) and quadrupole (Q) tensors for the paramagnetic transition-metal complexes, which knowledge enables estimation of the spin density distribution in the complex and the assessment of magnetic exchange pathways in polynuclear molecular networks. The most accurate results can be obtained if paramagnetic complexes are isolated in a single-crystalline diamagnetic host. In this work we were able to detect angle-resolved ESR/ENDOR spectra of the paramagnetic [nBu4N]2[Cu(opba)] (opba = o-phenylenebis(oxamato) complex hosted by the single crystal of diamagnetic [nBu4N]2[Ni(opba)], which allow recovery of A, Q, and g-tensors, all at once. Remarkably, with the aid of theoretical modeling, our data have unveiled the effect of multipositional hosting of the paramagnetic complex in the diamagnetic matrix. This effect can have a profound influence on the data handling and must be carefully considered while interpreting similar experiments.
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Affiliation(s)
- Ruslan Zaripov
- Zavoisky Physical-Technical Institute , FRC Kazan Scientific Center of RAS , 420029 Kazan , Russia
| | - Stanislav Avdoshenko
- Leibniz Institute for Solid State and Materials Research IFW Dresden , D-01171 Dresden , Germany
| | - Iskander Khairuzhdinov
- Zavoisky Physical-Technical Institute , FRC Kazan Scientific Center of RAS , 420029 Kazan , Russia
| | - Kev Salikhov
- Zavoisky Physical-Technical Institute , FRC Kazan Scientific Center of RAS , 420029 Kazan , Russia
| | - Violeta Voronkova
- Zavoisky Physical-Technical Institute , FRC Kazan Scientific Center of RAS , 420029 Kazan , Russia
| | - Saddam Weheabby
- Technische Universität Chemnitz , Fakultät für Naturwissenschaften, Institut für Chemie , Straße der Nationen 62 , D-09111 Chemnitz , Germany
| | - Tobias Rüffer
- Technische Universität Chemnitz , Fakultät für Naturwissenschaften, Institut für Chemie , Straße der Nationen 62 , D-09111 Chemnitz , Germany
| | - Alexey Popov
- Leibniz Institute for Solid State and Materials Research IFW Dresden , D-01171 Dresden , Germany
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research IFW Dresden , D-01171 Dresden , Germany
- Institut für Festkörper- und Materialphysik , Technische Universität Dresden , D-01062 Dresden , Germany
| | - Vladislav Kataev
- Institut für Festkörper- und Materialphysik , Technische Universität Dresden , D-01062 Dresden , Germany
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2
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Hsu CY, Tseng HC, Vandavasi JK, Lu WY, Wang LF, Chiang MY, Lai YC, Chen HY, Chen HY. Investigation of the dinuclear effect of aluminum complexes in the ring-opening polymerization of ε-caprolactone. RSC Adv 2017. [DOI: 10.1039/c7ra02136d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Al complexes bearing hydrazine-bridging Schiff base ligands showed the best catalytic activity, approximately 3- to 11-fold higher than that of dinuclear Al complexes bearing Salen ligands and mononuclear Al complexes bearing Schiff base ligands.
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Affiliation(s)
- Chiao-Yin Hsu
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Republic of China
| | - Hsi-Ching Tseng
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Republic of China
| | | | - Wei-Yi Lu
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Republic of China
| | - Li-Fang Wang
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Republic of China
| | - Michael Y. Chiang
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Republic of China
- Department of Chemistry
| | - Yi-Chun Lai
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Republic of China
| | - Hsing-Yin Chen
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Republic of China
| | - Hsuan-Ying Chen
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Republic of China
- Department of Medical Research
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3
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Mangion I, Liu Y, Reibarkh M, Williamson RT, Welch CJ. Using Electron Paramagnetic Resonance Spectroscopy To Facilitate Problem Solving in Pharmaceutical Research and Development. J Org Chem 2016; 81:6937-44. [DOI: 10.1021/acs.joc.6b00937] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ian Mangion
- Department of Process & Analytical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
| | - Yizhou Liu
- Department of Process & Analytical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
| | - Mikhail Reibarkh
- Department of Process & Analytical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
| | - R. Thomas Williamson
- Department of Process & Analytical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
| | - Christopher J. Welch
- Department of Process & Analytical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
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Damon PL, Liss CJ, Lewis RA, Morochnik S, Szpunar DE, Telser J, Hayton TW. Quantifying the Electron Donor and Acceptor Abilities of the Ketimide Ligands in M(N═C(t)Bu2)4 (M = V, Nb, Ta). Inorg Chem 2015; 54:10081-95. [PMID: 26419513 PMCID: PMC4659433 DOI: 10.1021/acs.inorgchem.5b02017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Addition of 4 equiv of Li(N═C(t)Bu2) to VCl3 in THF, followed by addition of 0.5 equiv of I2, generates the homoleptic V(IV) ketimide complex, V(N═C(t)Bu2)4 (1), in 42% yield. Similarly, reaction of 4 equiv of Li(N═C(t)Bu2) with NbCl4(THF)2 in THF affords the homoleptic Nb(IV) ketimide complex, Nb(N═C(t)Bu2)4 (2), in 55% yield. Seeking to extend the series to the tantalum congener, a new Ta(IV) starting material, TaCl4(TMEDA) (3), was prepared via reduction of TaCl5 with Et3SiH, followed by addition of TMEDA. Reaction of 3 with 4 equiv of Li(N═C(t)Bu2) in THF results in the isolation of a Ta(V) ketimide complex, Ta(Cl)(N═C(t)Bu2)4 (5), which can be isolated in 32% yield. Reaction of 5 with Tl(OTf) yields Ta(OTf)(N═C(t)Bu2)4 (6) in 44% yield. Subsequent reduction of 6 with Cp*2Co in toluene generates the homoleptic Ta(IV) congener Ta(N═C(t)Bu2)4 (7), although the yields are poor. All three homoleptic group 5 ketimide complexes exhibit squashed tetrahedral geometries in the solid state, as determined by X-ray crystallography. This geometry leads to a d(x(2)-y(2))(1) ((2)B1 in D(2d)) ground state, as supported by DFT calculations. EPR spectroscopic analysis of 1 and 2, performed at X- and Q-band frequencies (∼9 and 35 GHz, respectively), further supports the (2)B1 ground-state assignment, whereas comparison of 1, 2, and 7 with related group 5 tetra(aryl), tetra(amido), and tetra(alkoxo) complexes shows a higher M-L covalency in the ketimide-metal interaction. In addition, a ligand field analysis of 1 and 2 demonstrates that the ketimide ligand is both a strong π-donor and strong π-acceptor, an unusual combination found in very few organometallic ligands.
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Affiliation(s)
- Peter L. Damon
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Cameron J. Liss
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 S. Michigan Ave. Chicago, Illinois 60605-1394 United States
| | - Richard A. Lewis
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Simona Morochnik
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - David E. Szpunar
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 S. Michigan Ave. Chicago, Illinois 60605-1394 United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 S. Michigan Ave. Chicago, Illinois 60605-1394 United States
| | - Trevor W. Hayton
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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5
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Schweinfurth D, Zalibera M, Kathan M, Shen C, Mazzolini M, Trapp N, Crassous J, Gescheidt G, Diederich F. Helicene Quinones: Redox-Triggered Chiroptical Switching and Chiral Recognition of the Semiquinone Radical Anion Lithium Salt by Electron Nuclear Double Resonance Spectroscopy. J Am Chem Soc 2014; 136:13045-52. [DOI: 10.1021/ja5069323] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- David Schweinfurth
- Laboratory
of Organic Chemistry, ETH Zurich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Michal Zalibera
- Institute
of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - Michael Kathan
- Laboratory
of Organic Chemistry, ETH Zurich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Chengshuo Shen
- Institut des Sciences
Chimiques de Rennes, UMR 6226, CNRS—Université de Rennes
1, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Marcella Mazzolini
- Laboratory
of Organic Chemistry, ETH Zurich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Nils Trapp
- Laboratory
of Organic Chemistry, ETH Zurich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Jeanne Crassous
- Institut des Sciences
Chimiques de Rennes, UMR 6226, CNRS—Université de Rennes
1, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Georg Gescheidt
- Institute
of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - François Diederich
- Laboratory
of Organic Chemistry, ETH Zurich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
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6
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Tanaka K, Iwashita T, Sasaki C, Takahashi H. Ring-expanded chiral rhombamine macrocycles for efficient NMR enantiodiscrimination of carboxylic acid derivatives. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.tetasy.2014.03.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Hong X, Mellah M, Schulz E. Heterobimetallic dual-catalyst systems for the hydrolytic kinetic resolution of terminal epoxides. Catal Sci Technol 2014. [DOI: 10.1039/c4cy00235k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Yang J, Hong K, Bonnesen PV. Synthesis ofN1-tritylethane-1,1,2,2-d4-1,2-diamine: a novel mono-protected C-deuterated ethylenediamine synthon. J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.2977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jun Yang
- Center for Nanophase Materials Sciences; Oak Ridge National Laboratory; Oak Ridge; TN; 37831-6494; USA
| | - Kunlun Hong
- Center for Nanophase Materials Sciences; Oak Ridge National Laboratory; Oak Ridge; TN; 37831-6494; USA
| | - Peter V. Bonnesen
- Center for Nanophase Materials Sciences; Oak Ridge National Laboratory; Oak Ridge; TN; 37831-6494; USA
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9
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Zamani S, Carter E, Murphy DM, Van Doorslaer S. Probing differences in binding of methylbenzylamine enantiomers to chiral cobalt(ii) salen complexes. Dalton Trans 2012; 41:6861-70. [DOI: 10.1039/c2dt30207a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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11
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Murphy DM, Caretti I, Carter E, Fallis IA, Göbel MC, Landon J, Doorslaer SV, Willock DJ. Visualizing Diastereomeric Interactions of Chiral Amine–Chiral Copper Salen Adducts by EPR Spectroscopy and DFT. Inorg Chem 2011; 50:6944-55. [DOI: 10.1021/ic200113u] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Extraction separation of Am(III) and Eu(III) using divalent quadridentate Schiff bases-bis-salicylaldehyde ethylenediamine. J Radioanal Nucl Chem 2011. [DOI: 10.1007/s10967-011-1052-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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14
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Carter E, Fallis IA, Kariuki BM, Morgan IR, Murphy DM, Tatchell T, Van Doorslaer S, Vinck E. Structure and pulsed EPR characterization of N,N′-bis(5-tert-butylsalicylidene)-1,2-cyclohexanediamino-vanadium(iv) oxide and its adducts with propylene oxide. Dalton Trans 2011; 40:7454-62. [DOI: 10.1039/c1dt10378d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Clegg W, Harrington RW, North M, Pasquale R. Cyclic carbonate synthesis catalysed by bimetallic aluminium-salen complexes. Chemistry 2010; 16:6828-43. [PMID: 20437423 DOI: 10.1002/chem.201000030] [Citation(s) in RCA: 266] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The development of bimetallic aluminium-salen complexes [{Al(salen)}(2)O] as catalysts for the synthesis of cyclic carbonates (including the commercially important ethylene and propylene carbonates) from a wide range of terminal epoxides in the presence of tetrabutylammonium bromide as a cocatalyst is reported. The bimetallic structure of one complex was confirmed by X-ray crystallography. The bimetallic complexes displayed exceptionally high catalytic activity and in the presence of tetrabutylammonium bromide could catalyse cyclic carbonate synthesis at atmospheric pressure and room temperature. Catalyst-reuse experiments demonstrated that one bimetallic complex was stable for over 60 reactions, though the tetrabutylammonium bromide decomposed in situ by a retro-Menschutkin reaction to form tributylamine and had to be regularly replaced. The mild reaction conditions allowed a full analysis of the reaction kinetics to be carried out and this showed that the reaction was first order in aluminium complex concentration, first order in epoxide concentration, first order in carbon dioxide concentration (except when used in excess) and unexpectedly second order in tetrabutylammonium bromide concentration. Further kinetic experiments demonstrated that the tributylamine formed in situ was involved in the catalysis and that addition of butyl bromide to reconvert the tributylamine into tetrabutylammonium bromide resulted in inhibition of the reaction. The reaction kinetics also indicated that no kinetic resolution of racemic epoxides was possible with this class of catalysts, even when the catalyst was derived from a chiral salen ligand. However, it was shown that if enantiomerically pure styrene oxide was used as substrate, then enantiomerically pure styrene carbonate was formed. On the basis of the kinetic and other experimental data, a catalytic cycle that explains why the bimetallic complexes display such high catalytic activity has been developed.
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Affiliation(s)
- William Clegg
- School of Chemistry and University Research Centre in Catalysis and Intensified Processing, Newcastle University, Bedson Building, Newcastle upon Tyne, NE1 7RU, UK
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16
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Probing the role of weak outer sphere interactions (H-bonds) in VO(3,5-tBu2-salophen) – Epoxide adducts by EPR, ENDOR and HYSCORE. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2009.12.066] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Kurahashi T, Hada M, Fujii H. Critical role of external axial ligands in chirality amplification of trans-cyclohexane-1,2-diamine in salen complexes. J Am Chem Soc 2009; 131:12394-405. [PMID: 19705918 DOI: 10.1021/ja904635n] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of Mn(IV)(salen)(L)(2) complexes bearing different external axial ligands (L = Cl, NO(3), N(3), and OCH(2)CF(3)) from chiral salen ligands with trans-cyclohexane-1,2-diamine as a chiral scaffold are synthesized, to gain insight into conformational properties of metal salen complexes. X-ray crystal structures show that Mn(IV)(salen)(OCH(2)CF(3))(2) and Mn(IV)(salen)(N(3))(2) adopt a stepped conformation with one of two salicylidene rings pointing upward and the other pointing downward due to the bias from the trans-cyclohexane-1,2-diamine moiety, which is in clear contrast to a relatively planar solid-state conformation for Mn(IV)(salen)(Cl)(2). The CH(2)Cl(2) solution of Mn(IV)(salen)(L)(2) shows circular dichroism of increasing intensity in the order L = Cl < NO(3) << N(3) < OCH(2)CF(3), which indicates Mn(IV)(salen)(L)(2) adopts a solution conformation of an increasing chiral distortion in this order. Quantum-chemical calculations with a symmetry adapted cluster-configuration interaction method indicate that a stepped conformation exhibits more intense circular dichroism than a planar conformation. The present study clarifies an unexpected new finding that the external axial ligands (L) play a critical role in amplifying the chirality in trans-cyclohexane-1,2-diamine in Mn(IV)(salen)(L)(2) to facilitate the formation of a chirally distorted conformation, possibly a stepped conformation.
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Affiliation(s)
- Takuya Kurahashi
- Institute for Molecular Science, National Institutes of Natural Sciences, Myodaiji, Okazaki, Aichi 444-8787, Japan
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18
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Van Doorslaer S, Caretti I, Fallis I, Murphy D. The power of electron paramagnetic resonance to study asymmetric homogeneous catalysts based on transition-metal complexes. Coord Chem Rev 2009. [DOI: 10.1016/j.ccr.2008.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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19
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Kemper S, Hrobárik P, Kaupp M, Schlörer NE. Jacobsen's catalyst for hydrolytic kinetic resolution: structure elucidation of paramagnetic Co(III) salen complexes in solution via combined NMR and quantum chemical studies. J Am Chem Soc 2009; 131:4172-3. [PMID: 19275230 DOI: 10.1021/ja806151g] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
NMR investigation of chiral Co(III) salen catalysts, important for enantioselective hydrolytic kinetic resolution (HKR), revealed the presence of a paramagnetic high-spin Co(III) species, which is in solvent- and temperature-dependent equilibrium with the known diamagnetic low-spin Co(III) complex. Combined with quantum chemical DFT calculations, the para- and diamagnetic chemical shifts were used to study the salen ligand conformation of the para- and diamagnetic complexes, resulting in a mechanistic proposal for the enantioselective step in catalysis.
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Affiliation(s)
- Sebastian Kemper
- Department für Chemie, Universität zu Köln, Greinstrasse 4, 50939 Köln, Germany
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20
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Murphy DM, Fallis IA, Carter E, Willock DJ, Landon J, Van Doorslaer S, Vinck E. Enantioselective binding of structural epoxide isomers by a chiral vanadyl salen complex: a pulsed EPR, cw-ENDOR and DFT investigation. Phys Chem Chem Phys 2009; 11:6757-69. [DOI: 10.1039/b907807j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Vinck E, Doorslaer SV, Murphy DM, Fallis IA. The electronic structure of N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexane-diamino cobalt(II). Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.08.103] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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22
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Kylmälä T, Kuuloja N, Xu Y, Rissanen K, Franzén R. Synthesis of Chlorinated Biphenyls by Suzuki Cross-Coupling Using Diamine or Diimine-Palladium Complexes. European J Org Chem 2008. [DOI: 10.1002/ejoc.200800119] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Murphy D, Fallis I, Willock D, Landon J, Carter E, Vinck E. Discrimination of Geometrical Epoxide Isomers by ENDOR Spectroscopy and DFT Calculations: The Role of Hydrogen Bonds. Angew Chem Int Ed Engl 2008; 47:1414-6. [DOI: 10.1002/anie.200703537] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Murphy D, Fallis I, Willock D, Landon J, Carter E, Vinck E. Discrimination of Geometrical Epoxide Isomers by ENDOR Spectroscopy and DFT Calculations: The Role of Hydrogen Bonds. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200703537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Walz I, Bertogg A, Togni A. Cationic Vanadium(IV) Complexes as Efficient Catalysts for Nazarov Cyclizations. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700156] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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26
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Murphy DM, Farley RD. Principles and applications of ENDOR spectroscopy for structure determination in solution and disordered matrices. Chem Soc Rev 2006; 35:249-68. [PMID: 16505919 DOI: 10.1039/b500509b] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Both electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) spectroscopies are extremely powerful and versatile methods for the characterisation of paramagnetic systems in biology, chemistry, and physics. However, by comparison to EPR, ENDOR remains a less widely used technique. In this tutorial review the basic principles of continuous wave ENDOR are described. The theory of orientation selective ENDOR, for structure determination in frozen solutions and powders, is then described. A range of examples, illustrating the type of information obtained from the ENDOR spectrum, is finally presented.
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Affiliation(s)
- Damien M Murphy
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, UKCF10 3AT
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