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Naina VR, Singh AK, Shubham, Krätschmer F, Lebedkin S, Kappes MM, Roesky PW. Heteroleptic copper(I) complexes with coumarin-substituted aminodiphosphine and diimine ligands: synthesis and photophysical studies. Dalton Trans 2023; 52:12618-12622. [PMID: 37642577 DOI: 10.1039/d3dt02317f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The synthesis of heteroleptic Cu(I) complexes with coumarin-functionalized aminodiphosphine and diimine ligands is described. The complexes show yellow to deep-red phosphorescence in the solid state at ambient temperature with quantum yields up to 21%. The emission color of the complexes can be tuned by systematic modifications in the ligand system.
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Affiliation(s)
- Vanitha R Naina
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe, Germany.
| | - Akhil K Singh
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe, Germany.
| | - Shubham
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe, Germany.
| | - Frederic Krätschmer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe, Germany.
| | - Sergei Lebedkin
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| | - Manfred M Kappes
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131, Karlsruhe, Germany
| | - Peter W Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe, Germany.
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Cáceres-Vásquez J, Jara DH, Costamagna J, Martínez-Gómez F, Silva CP, Lemus L, Freire E, Baggio R, Vera C, Guerrero J. Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes. RSC Adv 2023; 13:825-838. [PMID: 36686905 PMCID: PMC9810106 DOI: 10.1039/d2ra05341a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 12/06/2022] [Indexed: 01/05/2023] Open
Abstract
A series of six new Cu(i) complexes with ([Cu(N-{4-R}pyridine-2-yl-methanimine)(PPh3)Br]) formulation, where R corresponds to a donor or acceptor p-substituent, have been synthesized and were used to study self-association effects on their structural and electrochemical properties. X-ray diffraction results showed that in all complexes the packing is organized from a dimer generated by supramolecular π stacking and hydrogen bonding. 1H-NMR experiments at several concentrations showed that all complexes undergo a fast-self-association monomer-dimer equilibrium in solution, while changes in resonance frequency towards the high or low field in specific protons of the imine ligand allow establishing that dimers have similar structures to those found in the crystal. The thermodynamic parameters for this self-association process were calculated from dimerization constants determined by VT-1H-NMR experiments for several concentrations at different temperatures. The values for K D (4.0 to 70.0 M-1 range), ΔH (-1.4 to -2.6 kcal mol-1 range), ΔS (-0.2 to 2.1 cal mol-1 K-1 range), and ΔG 298 (-0.8 to -2.0 kcal mol-1 range) are of the same order and indicate that the self-dimerization process is enthalpically driven for all complexes. The electrochemical profile of the complexes shows two redox Cu(ii)/Cu(i) processes whose relative intensities are sensitive to concentration changes, indicating that both species are in chemical equilibrium, with the monomer and the dimer having different electrochemical characteristics. We associate this behaviour with the structural lability of the Cu(i) centre that allows the monomeric molecules to reorder conformationally to achieve a more adequate assembly in the non-covalent dimer. As expected, structural properties in the solid and in solution, as well as their electrochemical properties, are not correlated with the electronic parameters usually used to evaluate R substituent effects. This confirms that the properties of the Cu(i) complexes are usually more influenced by steric effects than by the inductive effects of substituents of the ligands. In fact, the results obtained showed the importance of non-covalent intermolecular interactions in the structuring of the coordination geometry around the Cu centre and in the coordinative stability to avoid dissociative equilibria.
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Affiliation(s)
- Joaquín Cáceres-Vásquez
- Laboratorio de Compuestos de Coordinación y Química Supramolecular, Facultad de Química y Biología, Universidad de Santiago de ChileAv. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile
| | - Danilo H. Jara
- Facultad de Ingenieria y Ciencias, Universidad Adolfo IbáñezAv. Padre Hurtado 750Viña del MarChile
| | - Juan Costamagna
- Laboratorio de Compuestos de Coordinación y Química Supramolecular, Facultad de Química y Biología, Universidad de Santiago de ChileAv. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile,Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile
| | - Fabián Martínez-Gómez
- Laboratorio de Compuestos de Coordinación y Química Supramolecular, Facultad de Química y Biología, Universidad de Santiago de ChileAv. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile,Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile
| | - Carlos P. Silva
- Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile
| | - Luis Lemus
- Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile
| | - Eleonora Freire
- Gerencia de Investigación y Aplicaciones, Centro Atómico Constituyentes, Comisión Nacional de Energía AtómicaAvenida Gral. Paz 1499, 1650, San MartínBuenos AiresArgentina,Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, Argentina and Gerencia de Investigación y Aplicaciones, Centro Atómico Constituyentes, Comisión Nacional de Energía AtómicaBuenos AiresArgentina,Member of CONICETArgentina
| | - Ricardo Baggio
- Gerencia de Investigación y Aplicaciones, Centro Atómico Constituyentes, Comisión Nacional de Energía AtómicaAvenida Gral. Paz 1499, 1650, San MartínBuenos AiresArgentina
| | - Cristian Vera
- Laboratorio de Compuestos de Coordinación y Química Supramolecular, Facultad de Química y Biología, Universidad de Santiago de ChileAv. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile
| | - Juan Guerrero
- Laboratorio de Compuestos de Coordinación y Química Supramolecular, Facultad de Química y Biología, Universidad de Santiago de ChileAv. Libertador Bernardo O'Higgins 3363, Estación Central, Casilla 40, Correo 33SantiagoChile
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Zeng P, Zhang WD. A strategy for integrating transition metal-complex cocatalyst onto g-C3N4 to enable efficient photocatalytic hydrogen evolution. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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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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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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Díaz DE, Llanos L, Arce P, Lorca R, Guerrero J, Costamagna J, Aravena D, Ferraudi G, Oliver A, Lappin AG, Lemus L. Steric and Electronic Factors Affecting the Conformation of Bimetallic CuI
Complexes: Effect of the Aliphatic Spacer of Tetracoordinating Schiff-Base Ligands. Chemistry 2018; 24:13839-13849. [DOI: 10.1002/chem.201802290] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Daniel E. Díaz
- Facultad de Química y Biología, Departamento de Química de los, Materiales; Universidad de Santiago de Chile; Av. Libertador Bernardo O'Higgins 3363, Estación Central Santiago Chile
| | - Leonel Llanos
- Facultad de Química y Biología, Departamento de Química de los, Materiales; Universidad de Santiago de Chile; Av. Libertador Bernardo O'Higgins 3363, Estación Central Santiago Chile
| | - Pablo Arce
- Facultad de Química y Biología, Departamento de Química de los, Materiales; Universidad de Santiago de Chile; Av. Libertador Bernardo O'Higgins 3363, Estación Central Santiago Chile
| | - Romina Lorca
- Facultad de Química y Biología, Departamento de Química de los, Materiales; Universidad de Santiago de Chile; Av. Libertador Bernardo O'Higgins 3363, Estación Central Santiago Chile
| | - Juan Guerrero
- Facultad de Química y Biología, Departamento de Química de los, Materiales; Universidad de Santiago de Chile; Av. Libertador Bernardo O'Higgins 3363, Estación Central Santiago Chile
| | - Juan Costamagna
- Facultad de Química y Biología, Departamento de Química de los, Materiales; Universidad de Santiago de Chile; Av. Libertador Bernardo O'Higgins 3363, Estación Central Santiago Chile
| | - Daniel Aravena
- Facultad de Química y Biología, Departamento de Química de los, Materiales; Universidad de Santiago de Chile; Av. Libertador Bernardo O'Higgins 3363, Estación Central Santiago Chile
| | - Guillermo Ferraudi
- Department of Chemistry and Biochemistry; University of Notre Dame; 46556-5670 Notre Dame IN USA
| | - Allen Oliver
- Department of Chemistry and Biochemistry; University of Notre Dame; 46556-5670 Notre Dame IN USA
| | - A. Graham Lappin
- Department of Chemistry and Biochemistry; University of Notre Dame; 46556-5670 Notre Dame IN USA
| | - Luis Lemus
- Facultad de Química y Biología, Departamento de Química de los, Materiales; Universidad de Santiago de Chile; Av. Libertador Bernardo O'Higgins 3363, Estación Central Santiago Chile
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7
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Arce P, Vera C, Escudero D, Guerrero J, Lappin A, Oliver A, Jara DH, Ferraudi G, Lemus L. Structural diversity in Cu(i) complexes of the PNP ligand: from pincer to binuclear coordination modes and their effects upon the electrochemical and photophysical properties. Dalton Trans 2017; 46:13432-13445. [PMID: 28948992 DOI: 10.1039/c7dt02244a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A set of new copper(i) complexes is synthesized and characterized using a labile PNP pincer ligand (PNP = N,N'-bis(diphenylphosphine)-2,6-diaminopyridine). A homoleptic Cu(i) complex [Cu(PNP-κP1:κN1)2]+, (1), was prepared, and taking advantage of the uncoordinated phosphorus atoms in (1), reaction with a second Cu(i) atom bearing secondary ligands (PPh3, phen or dmp) allows the formation of new complexes: a bimetallic helicate [Cu(PNP)2(phen)]2+, (2), a mononuclear pincer complex [CuI(PNP)(PPh3)]+, (3), and a heteroleptic complex [CuI(PNP)(dmp)]+, (4). All complexes were characterized by X-ray crystallography, NMR (VT-NMR for (1) and (4)), cyclic-voltammetry, and steady-state and time-resolved luminescence spectroscopy. The fluxional behavior in (1) was studied by 31P VT-NMR, where an Ea value of 47.42 kJ mol-1 was calculated for the intramolecular alternating coordination of -PPh2 moieties in PNP to the metal atom. This set of compounds reveals the versatility of the PNP ligand when added to the coordinating properties of Cu(i). The four complexes exhibit emission in solution and complexes (2)-(4) display intense luminescence in the solid state. The oscillographic traces showing the decay of the luminescence were fitted to biexponential functions with time constants: 8.0 μs > τem,1 > 0.37 μs and 50 μs >τem, 2 > 2.2 μs for complexes (2), (3) and (4), respectively. Radiative relaxation is associated with electronic transitions in both the ligand PNP and metal-to-ligand charge transfer (MLCT).
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Affiliation(s)
- Pablo Arce
- Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Libertador Bernardo O'Higgins 3363, Estación Central, Santiago, Chile.
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Wolińska E, Karczmarzyk Z, Wysocki W. Structural characterization of copper complexes with chiral 1,2,4-triazine-oxazoline ligands. HETEROCYCL COMMUN 2016. [DOI: 10.1515/hc-2016-0103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AbstractThe crystal structure determination of oxazoline-1,2,4-triazine ligand
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9
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Latouche C, Akdas-Kilig H, Malval JP, Fillaut JL, Boucekkine A, Barone V. Theoretical evidence of metal-induced structural distortions in a series of bipyrimidine-based ligands. Dalton Trans 2015; 44:506-10. [PMID: 25434809 DOI: 10.1039/c4dt03291h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we report theoretical evidence of the geometric changes occurring upon complexation, for a series of octupolar bipyrimidine-based ligands incorporating the NPh2 terminal donor group. It is shown that ligands 1 and 2 (4,4',6,6'-tetrakis(N,N-diphenylaminostyryl)-[2,2']bipyrimidine and 4,4',6,6'-tetrakis((N,N-diphenyl)-9,9'-dioctyl-9H-fluorene-2-amine)-2,2'-bipyrimidine) exhibit a non-planar geometry with a torsion angle between both pyrimidine moieties of ∼25° and 50° respectively. 1a (complex of 1) becomes planar upon addition of ZnCl2 to the bipyrimidine moiety whereas 2a remains distorted. Furthermore, an assignment of the absorption bands for all compounds is presented.
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Affiliation(s)
- Camille Latouche
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.
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Mohankumar M, Monti F, Holler M, Niess F, Delavaux-Nicot B, Armaroli N, Sauvage JP, Nierengarten JF. Combining topological and steric constraints for the preparation of heteroleptic copper(I) complexes. Chemistry 2014; 20:12083-90. [PMID: 25056825 DOI: 10.1002/chem.201402429] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Indexed: 11/09/2022]
Abstract
Heteroleptic copper(I) complexes have been prepared from a macrocyclic ligand incorporating a 2,9-diphenyl-1,10-phenanthroline subunit (M30) and two bis-phosphines, namely bis[(2-diphenylphosphino)phenyl] ether (POP) and 1,3-bis(diphenylphosphino)propane (dppp). In both cases, the diphenylphosphino moieties of the PP ligand are too bulky to pass through the 30-membered ring of M30 during the coordination process, hence the formation of C2v-symmetrical pseudo-rotaxanes is prevented. When POP is used, X-ray crystal structure analysis shows the formation of a highly distorted [Cu(M30)(POP)](+) complex in which the POP ligand is only partially threaded through the M30 unit. This compound is poorly stable as the Cu(I) cation is not in a favorable coordination environment due to steric constraints. By contrast, in the case of dppp, the bis-phosphine ligand undergoes both steric and topological constraints and adopts a nonchelating coordination mode to generate [Cu2(M30)2(μ-dppp)](BF4)2. This compound exhibits metal-to-ligand charge transfer (MLCT) emission characterized by a very large Stokes' shift (≈200 nm) that is not attributed to a dramatic structural distortion between the ground and the emitting states but to very weak MLCT absorption transitions at longer wavelengths. Accordingly, [Cu2(M30)2(μ-dppp)](BF4)2 shows unusually high luminescence quantum yields for Cu(I) complexes, both in solution and in the solid state (0.5 and 7 %, respectively).
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Affiliation(s)
- Meera Mohankumar
- Laboratoire de Chimie des Matériaux Moléculaires, Université de Strasbourg et CNRS (UMR 7509), Ecole Européenne de Chimie, Polymères et Matériaux, 25 rue Becquerel, 67087 Strasbourg Cedex 2 (France)
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11
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Tran AT, Liu P, Houk KN, Nicholas KM. Regioselectivity in the Cu(I)-Catalyzed [4 + 2]-Cycloaddition of 2-Nitrosopyridine with Unsymmetrical Dienes. J Org Chem 2014; 79:5617-26. [DOI: 10.1021/jo5005907] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anh T. Tran
- Departments
of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Peng Liu
- University of California at Los Angeles, Los
Angeles, California 90095, United States
| | - K. N. Houk
- University of California at Los Angeles, Los
Angeles, California 90095, United States
| | - Kenneth M. Nicholas
- Departments
of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
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Kaeser A, Mohankumar M, Mohanraj J, Monti F, Holler M, Cid JJ, Moudam O, Nierengarten I, Karmazin-Brelot L, Duhayon C, Delavaux-Nicot B, Armaroli N, Nierengarten JF. Heteroleptic copper(I) complexes prepared from phenanthroline and bis-phosphine ligands. Inorg Chem 2013; 52:12140-51. [PMID: 24083360 DOI: 10.1021/ic4020042] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Preparation of [Cu(NN)(PP)](+) derivatives has been systematically investigated starting from two libraries of phenanthroline (NN) derivatives and bis-phosphine (PP) ligands, namely, (A) 1,10-phenanthroline (phen), neocuproine (2,9-dimethyl-1,10-phenanthroline, dmp), bathophenanthroline (4,7-diphenyl-1,10-phenanthroline, Bphen), 2,9-diphenethyl-1,10-phenanthroline (dpep), and 2,9-diphenyl-1,10-phenanthroline (dpp); (B) bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,2-bis(diphenylphosphino)benzene (dppb), 1,1'-bis(diphenylphosphino)ferrocene (dppFc), and bis[(2-diphenylphosphino)phenyl] ether (POP). Whatever the bis-phosphine ligand, stable heteroleptic [Cu(NN)(PP)](+) complexes are obtained from the 2,9-unsubstituted-1,10-phenanthroline ligands (phen and Bphen). By contrast, heteroleptic complexes obtained from dmp and dpep are stable in the solid state, but a dynamic ligand exchange reaction is systematically observed in solution, and the homoleptic/heteroleptic ratio is highly dependent on the bis-phosphine ligand. Detailed analysis revealed that the dynamic equilibrium resulting from ligand exchange reactions is mainly influenced by the relative thermodynamic stability of the different possible complexes. Finally, in the case of dpp, only homoleptic complexes were obtained whatever the bis-phosphine ligand. Obviously, steric effects resulting from the presence of the bulky phenyl rings on the dpp ligand destabilize the heteroleptic [Cu(NN)(PP)](+) complexes. In addition to the remarkable thermodynamic stability of [Cu(dpp)2]BF4, this negative steric effect drives the dynamic complexation scenario toward almost exclusive formation of homoleptic [Cu(NN)2](+) and [Cu(PP)2](+) complexes. This work provides the definitive rationalization of the stability of [Cu(NN)(PP)](+) complexes, marking the way for future developments in this field.
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Affiliation(s)
- Adrien Kaeser
- Laboratoire de Chimie des Matériaux Moléculaires, Université de Strasbourg et CNRS (UMR 7509) , 25 rue Becquerel, 67087 Strasbourg Cedex 2, France
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13
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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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16
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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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17
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Furusho Y, Goto H, Itomi K, Katagiri H, Miyagawa T, Yashima E. Synthesis and optical resolution of a Cu(I) double-stranded helicate with ketimine-bridged tris(bipyridine) ligands. Chem Commun (Camb) 2011; 47:9795-7. [PMID: 21818481 DOI: 10.1039/c1cc13333k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A tetranuclear Cu(I) double-stranded helicate was synthesized from ketimine-bridged tris(bipyridine) ligands and Cu(I) ions, and the racemate was successfully resolved by diastereomeric salt formation using an optically pure phosphate anion followed by anion exchange with NaPF(6) without racemization.
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Affiliation(s)
- Yoshio Furusho
- Yashima Super-Structured Helix Project, ERATO, Japan Science and Technology Agency (JST), Japan.
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18
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Wang L, Bian X, Liu H, Sun Q, Wang C. One-Pot Synthesis of 4,6-Diarylpyrimidin-2(1H)-Ones via Multicomponent Reaction Promoted by Chlorotrimethylsilane. JOURNAL OF CHEMICAL RESEARCH 2010. [DOI: 10.3184/030823410x12857507693355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
4,6-Diarylpyrimidin-2(1 H)-ones were effectively synthesised by utilising chlorotrimethylsilane (TMSCI) as an efficient promoter in the cyclisation condensation of arylketones, substituted benzaldehydes and urea by a one-pot, three-component reaction under air in DMF/CH3CN. The clean, mild reaction conditions, operational simplicity and high yields were attractive features of the reaction which enables a facile preparative procedure for building the pyrimidine ring.
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Affiliation(s)
- Lizhong Wang
- Department of Environmental and Chemical Engineering, Taizhou Polytechnic College, Taizhou 225300, P. R. China
| | - Xiaoqin Bian
- Department of Environmental and Chemical Engineering, Taizhou Polytechnic College, Taizhou 225300, P. R. China
| | - Hui Liu
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, P. R. China
| | - Qian Sun
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, P. R. China
| | - Cunde Wang
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, P. R. China
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19
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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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20
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De S, Mahata K, Schmittel M. Metal-coordination-driven dynamic heteroleptic architectures. Chem Soc Rev 2010; 39:1555-75. [PMID: 20419210 DOI: 10.1039/b922293f] [Citation(s) in RCA: 341] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic heteroleptic coordination at metal centres is quite common in Nature and often related to a specific biological function, such as in zinc finger proteins and in hemoglobin for oxygen transport. To achieve the required high heteroleptic fidelity, representative biological systems avail themselves of "intramolecular" multidentate coordination using the protein backbone as a "superligand". In contrast, dynamic heteroleptic coordination at a single metal centre in solution requires to bind different freely exchanging ligands under thermodynamic control. In this tutorial review we present the emerging principles of how to assemble dissimilar ligands at dynamically exchanging metal centres, with a particular emphasis on using the precepts for the fabrication of heteroleptic supramolecular assemblies in solution.
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Affiliation(s)
- Soumen De
- Center of Micro and Nanochemistry and Engineering, Organische Chemie I, Universität Siegen, Adolf-Reichwein-Str., 2, D-57068 Siegen, Germany
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21
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Akdas-Kilig H, Roisnel T, Ledoux I, Le Bozec H. A new class of bipyrimidine-based octupolar chromophores: synthesis, fluorescent and quadratic nonlinear optical properties. NEW J CHEM 2009. [DOI: 10.1039/b907323j] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Jakob A, Ecorchard P, Köhler K, Lang H. 2,2′-Bipyrimidine transition metal complexes: Synthesis, reaction chemistry and solid state structures. J Organomet Chem 2008. [DOI: 10.1016/j.jorganchem.2008.08.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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23
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Inagaki A, Yatsuda S, Edure S, Suzuki A, Takahashi T, Akita M. Synthesis of Pd complexes combined with photosensitizing of a ruthenium(II) polypyridyl moiety through a series of substituted bipyrimidine bridges. Substituent effect of the bridging ligand on the photocatalytic dimerization of alpha-methylstyrene. Inorg Chem 2007; 46:2432-45. [PMID: 17328538 DOI: 10.1021/ic0612909] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mononuclear ruthenium complexes and dinuclear Ru...Pd complexes having a series of 2,2'-bipyrimidine ligands, [(bpy)2Ru(Ln)]2+ [Ln = 2,2'-bipyrimidine (L1), 5,5'-dimethyl-2,2'-bipyrimidine (L2), 5,5'-dibromo-2,2'-bipyrimidine (L3), 4,4'-dimethyl-2,2'-bipyrimidine (L4), and 4,4',6,6'-tetramethyl- 2,2'-bipyrimidine (L5)] and [(bpy)2Ru(Ln)PdL]m+ [Ln = L1-L3; PdL = PdMeCl (m = 2) and PdMe(solvent) (m = 3)], are prepared, and the obtained complexes are characterized by means of spectroscopic and crystallographic methods. Introduction of the substituents on the bipyrimidine ligands led to the substantial differences in their electrochemical and photophysical properties. Density functional theory calculations have been performed to understand the substituent effect on the ground-state molecular orbital energy level. Reactivity studies on the catalytic dimerization of alpha-methylstyrene revealed that the Pd complex having a Br-substituted bipyrimidine ligand were much more active than those of the corresponding Pd complexes having methyl-substituted or nonsubstituted bipyrimidine ligands.
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Affiliation(s)
- Akiko Inagaki
- Chemical Resources Laboratory, Tokyo Institute of Technology, R1-27, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
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24
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Company A, Güell M, Popa D, Benet-Buchholz J, Parella T, Fontrodona X, Llobet A, Solà M, Ribas X, Luis JM, Costas M. Redox-Controlled Molecular Flipper Based on a Chiral Cu Complex. Inorg Chem 2006; 45:9643-5. [PMID: 17112258 DOI: 10.1021/ic0618549] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A molecular bipaddled flipper based on a tetradentate chiral Cu complex has been designed. The paddling motion of this unprecedented molecular-scale machine can be controlled by reversible oxidation of the metal center. Kinetic and computational (density functional theory) analyses provide a detailed picture of the flipper motion at the molecular scale, rationalize the switching role of the metal-ion oxidation state, and pose the basis for the fine-tuning of the dynamic motion of this new class of molecular-scale devices.
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Affiliation(s)
- Anna Company
- Departament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain
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25
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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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26
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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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27
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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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28
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Owiny D, Kingston JV, Maynor M, Parkin S, Kampf JW, Ladipo FT. Reductive Coupling of [(RO)2Ti(L2)2] Complexes Containing a Chelating Bis(aryloxide) Ligand with Ketones (L2 = bpy, dmbpy, or phen). Organometallics 2005. [DOI: 10.1021/om050231k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David Owiny
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Jesudoss V. Kingston
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Marc Maynor
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Sean Parkin
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Jeff W. Kampf
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Folami T. Ladipo
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
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29
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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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