1
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Kumar P, Rautiainen JM, Novotný J, Ward JS, Marek R, Rissanen K, Puttreddy R. The Impact of ortho-substituents on Bonding in Silver(I) and Halogen(I) Complexes of 2-Mono- and 2,6-Disubstituted Pyridines: An In-Depth Experimental and Theoretical Study. Chemistry 2023:e202303643. [PMID: 38055221 DOI: 10.1002/chem.202303643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
The coordination nature of 2-mono- and 2,6-disubstituted pyridines with electron-withdrawing halogen and electron-donating methyl groups for [N-X-N]+ (X=I, Br) complexations have been studied using 15 N NMR, X-ray crystallography, and Density Functional Theory (DFT) calculations. The 15 N NMR chemical shifts reveal iodine(I) and bromine(I) prefer to form complexes with 2-substituted pyridines and only 2,6-dimethylpyridine. The crystalline halogen(I) complexes of 2-substituted pyridines were characterized by using X-ray diffraction analysis, but 2,6-dihalopyridines were unable to form stable crystalline halogen(I) complexes due to the lower nucleophilicity of the pyridinic nitrogen. In contrast, the halogen(I) complexes of 2,6-dimethylpyridine, which has a more basic nitrogen, are characterized by X-crystallography, which complements the 15 N NMR studies. DFT calculations reveal that the bond energies for iodine(I) complexes vary between -291 and -351 kJ mol-1 and for bromine between -370 and -427 kJ mol-1 . The bond energies of halogen(I) complexes of 2-halopyridines with more nucleophilic nitrogen are 66-76 kJ mol-1 larger than those of analogous 2,6-dihalopyridines with less nucleophilic nitrogen. The experimental and DFT results show that the electronic influence of ortho-halogen substituents on pyridinic nitrogen leads to a completely different preference for the coordination bonding of halogen(I) ions, providing new insights into bonding in halogen(I) chemistry.
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Affiliation(s)
- Parveen Kumar
- Department of chemistry, University of Jyvaskyla, Jyvaskyla, P.O. BOX 35, FI-40014, Finland
| | - J Mikko Rautiainen
- Department of chemistry, University of Jyvaskyla, Jyvaskyla, P.O. BOX 35, FI-40014, Finland
| | - Jan Novotný
- Department of Chemistry, Faculty of Science, Masaryk university, Kamenice 5, 62500, Brno, Czechia
| | - Jas S Ward
- Department of chemistry, University of Jyvaskyla, Jyvaskyla, P.O. BOX 35, FI-40014, Finland
| | - Radek Marek
- Department of Chemistry, Faculty of Science, Masaryk university, Kamenice 5, 62500, Brno, Czechia
| | - Kari Rissanen
- Department of chemistry, University of Jyvaskyla, Jyvaskyla, P.O. BOX 35, FI-40014, Finland
| | - Rakesh Puttreddy
- Department of chemistry, University of Jyvaskyla, Jyvaskyla, P.O. BOX 35, FI-40014, Finland
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2
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Biskup D, Schnakenburg G, Boeré RT, Espinosa Ferao A, Streubel RK. Challenging an old paradigm by demonstrating transition metal-like chemistry at a neutral nonmetal center. Nat Commun 2023; 14:6456. [PMID: 37833259 PMCID: PMC10575908 DOI: 10.1038/s41467-023-42127-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
We describe nonmetal adducts of the phosphorus center of terminal phosphinidene complexes using classical C- and N-ligands from metal coordination chemistry. The nature of the L-P bond has been analyzed by various theoretical methods including a refined method on the variation of the Laplacian of electron density ∇2ρ along the L-P bond path. Studies on thermal stability reveal stark differences between N-ligands such as N-methyl imidazole and C-ligands such as tert-butyl isocyanide, including ligand exchange reactions and a surprising formation of white phosphorus. A milestone is the transformation of a nonmetal-bound isocyanide into phosphaguanidine or an acyclic bisaminocarbene bound to phosphorus; the latter is analogous to the chemistry of transition metal-bound isocyanides, and the former reveals the differences. This example has been studied via cutting-edge DFT calculations leading to two pathways differently favored depending on variations in steric demand. This study reveals the emergence of organometallic from coordination chemistry of a neutral nonmetal center.
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Affiliation(s)
- David Biskup
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany
| | - Gregor Schnakenburg
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany
| | - René T Boeré
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB, T1K3M4, Canada
| | - Arturo Espinosa Ferao
- Departamento de Química Orgánica, Facultad de Química, Campus de Espinardo, Universidad de Murcia, 30100, Murcia, Spain.
| | - Rainer K Streubel
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany.
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3
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Krivdin LB. Computational 1 H and 13 C NMR in structural and stereochemical studies. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2022; 60:733-828. [PMID: 35182410 DOI: 10.1002/mrc.5260] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
Present review outlines the advances and perspectives of computational 1 H and 13 C NMR applied to the stereochemical studies of inorganic, organic, and bioorganic compounds, involving in particular natural products, carbohydrates, and carbonium ions. The first part of the review briefly outlines theoretical background of the modern computational methods applied to the calculation of chemical shifts and spin-spin coupling constants at the DFT and the non-empirical levels. The second part of the review deals with the achievements of the computational 1 H and 13 C NMR in the stereochemical investigation of a variety of inorganic, organic, and bioorganic compounds, providing in an abridged form the material partly discussed by the author in a series of parent reviews. Major attention is focused herewith on the publications of the recent years, which were not reviewed elsewhere.
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Affiliation(s)
- Leonid B Krivdin
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
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4
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Jónsson HF, Sethio D, Wolf J, Huber SM, Fiksdahl A, Erdelyi M. Halogen Bond Activation in Gold Catalysis. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Helgi Freyr Jónsson
- Department of Chemistry, Norwegian University of Science and Technology, Høgskoleringen 5, Trondheim 7491, Norway
| | - Daniel Sethio
- Department of Chemistry─BMC, Uppsala University, Uppsala SE-751 23, Sweden
| | - Julian Wolf
- Faculty of Chemistry and Biochemistry, Organic Chemistry I, Ruhr-Universität Bochum, Universitätsstraße 150, Bochum 44801, Germany
| | - Stefan M. Huber
- Faculty of Chemistry and Biochemistry, Organic Chemistry I, Ruhr-Universität Bochum, Universitätsstraße 150, Bochum 44801, Germany
| | - Anne Fiksdahl
- Department of Chemistry, Norwegian University of Science and Technology, Høgskoleringen 5, Trondheim 7491, Norway
| | - Mate Erdelyi
- Department of Chemistry─BMC, Uppsala University, Uppsala SE-751 23, Sweden
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5
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Hylland KT, Schmidtke IL, Wragg DS, Nova A, Tilset M. Synthesis of substituted (N,C) and (N,C,C) Au(III) complexes: the influence of sterics and electronics on cyclometalation reactions. Dalton Trans 2022; 51:5082-5097. [PMID: 35262546 DOI: 10.1039/d2dt00371f] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cyclometalated Au(III) complexes are of interest due to their catalytic, medicinal, and photophysical properties. Herein, we describe the synthesis of derivatives of the type (N,C)Au(OAcF)2 (OAcF = trifluoroacetate) and (N,C,C)AuOAcF by a cyclometalation route, where (N,C) and (N,C,C) are chelating 2-arylpyridine ligands. The scope of the synthesis is explored by substituting the 2-arylpyridine core with electron donor or acceptor substituents at one or both rings. Notably, a variety of functionalized Au(III) complexes can be obtained in one step from the corresponding ligand and Au(OAc)3, eliminating the need for organomercury intermediates, which is commonly reported for similar syntheses. The influence of substituents in the ligand backbone on the resulting complexes was assessed using DFT calculations, 15N NMR spectroscopy and single-crystal X-ray diffraction analysis. A correlation between the electronic properties of the (N,C) ligands and their ability to undergo cyclometalation was found from experimental studies combined with natural charge analysis, suggesting the cyclometalation at Au(III) to take place via an electrophilic aromatic substitution-type mechanism. The formation of Au(III) pincer complexes from tridentate (N,C,C) ligands was investigated by synthesis and DFT calculations, in order to assess the feasibility of C(sp3)-H bond activation as a synthetic pathway to (N,C,C) cyclometalated Au(III) complexes. It was found that C(sp3)-H bond activation is feasible for ligands containing different alkyl groups (isopropyl and ethyl), although the C-H activation is less energetically favored compared to a ligand containing tert-butyl groups.
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Affiliation(s)
- Knut T Hylland
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway
| | - Inga L Schmidtke
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway
| | - David S Wragg
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway
| | - Ainara Nova
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway.,Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, N-0315 Oslo, Norway.,UiT-The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Mats Tilset
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway.,Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, N-0315 Oslo, Norway
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6
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Hylland KT, Gerz I, Wragg DS, Øien‐Ødegaard S, Tilset M. The Reactivity of Multidentate Schiff Base Ligands Derived from Bi‐ and Terphenyl Polyamines towards M(II) (M=Ni, Cu, Zn, Cd) and M(III) (M=Co, Y, Lu). Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Knut Tormodssønn Hylland
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - Isabelle Gerz
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - David S. Wragg
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - Sigurd Øien‐Ødegaard
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - Mats Tilset
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
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7
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Sethio D, Raggi G, Lindh R, Erdélyi M. Halogen Bond of Halonium Ions: Benchmarking DFT Methods for the Description of NMR Chemical Shifts. J Chem Theory Comput 2020; 16:7690-7701. [PMID: 33136388 PMCID: PMC7726912 DOI: 10.1021/acs.jctc.0c00860] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Indexed: 12/20/2022]
Abstract
Because of their anisotropic electron distribution and electron deficiency, halonium ions are unusually strong halogen-bond donors that form strong and directional three-center, four-electron halogen bonds. These halogen bonds have received considerable attention owing to their applicability in supramolecular and synthetic chemistry and have been intensely studied using spectroscopic and crystallographic techniques over the past decade. Their computational treatment faces different challenges to those of conventional weak and neutral halogen bonds. Literature studies have used a variety of wave functions and DFT functionals for prediction of their geometries and NMR chemical shifts, however, without any systematic evaluation of the accuracy of these methods being available. In order to provide guidance for future studies, we present the assessment of the accuracy of 12 common DFT functionals along with the Hartree-Fock (HF) and the second-order Møller-Plesset perturbation theory (MP2) methods, selected from an initial set of 36 prescreened functionals, for the prediction of 1H, 13C, and 15N NMR chemical shifts of [N-X-N]+ halogen-bond complexes, where X = F, Cl, Br, and I. Using a benchmark set of 14 complexes, providing 170 high-quality experimental chemical shifts, we show that the choice of the DFT functional is more important than that of the basis set. The M06 functional in combination with the aug-cc-pVTZ basis set is demonstrated to provide the overall most accurate NMR chemical shifts, whereas LC-ωPBE, ωB97X-D, LC-TPSS, CAM-B3LYP, and B3LYP to show acceptable performance. Our results are expected to provide a guideline to facilitate future developments and applications of the [N-X-N]+ halogen bond.
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Affiliation(s)
- Daniel Sethio
- Department of Chemistry—BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Gerardo Raggi
- Department of Chemistry—BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Roland Lindh
- Department of Chemistry—BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Máté Erdélyi
- Department of Chemistry—BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
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8
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Sheehy KJ, Bateman LM, Flosbach NT, Breugst M, Byrne PA. Competition between N and O: use of diazine N-oxides as a test case for the Marcus theory rationale for ambident reactivity. Chem Sci 2020; 11:9630-9647. [PMID: 34094230 PMCID: PMC8162281 DOI: 10.1039/d0sc02834g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/23/2020] [Indexed: 11/21/2022] Open
Abstract
The preferred site of alkylation of diazine N-oxides by representative hard and soft alkylating agents was established conclusively using the 1H-15N HMBC NMR technique in combination with other NMR spectroscopic methods. Alkylation of pyrazine N-oxides (1 and 2) occurs preferentially on nitrogen regardless of the alkylating agent employed, while O-methylation of pyrimidine N-oxide (3) is favoured in its reaction with MeOTf. As these outcomes cannot be explained in the context of the hard/soft acid/base (HSAB) principle, we have instead turned to Marcus theory to rationalise these results. Marcus intrinsic barriers (ΔG ‡ 0) and Δr G° values were calculated at the DLPNO-CCSD(T)/def2-TZVPPD/SMD//M06-2X-D3/6-311+G(d,p)/SMD level of theory for methylation reactions of 1 and 3 by MeI and MeOTf, and used to derive Gibbs energies of activation (ΔG ‡) for the processes of N- and O-methylation, respectively. These values, as well as those derived directly from the DFT calculations, closely reproduce the observed experimental N- vs. O-alkylation selectivities for methylation reactions of 1 and 3, indicating that Marcus theory can be used in a semi-quantitative manner to understand how the activation barriers for these reactions are constructed. It was found that N-alkylation of 1 is favoured due to the dominant contribution of Δr G° to the activation barrier in this case, while O-alkylation of 3 is favoured due to the dominant contribution of the intrinsic barrier (ΔG ‡ 0) for this process. These results are of profound significance in understanding the outcomes of reactions of ambident reactants in general.
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Affiliation(s)
- Kevin J Sheehy
- School of Chemistry, Analytical and Biological Chemistry Research Facility, University College Cork College Road Cork Ireland
| | - Lorraine M Bateman
- School of Chemistry, Analytical and Biological Chemistry Research Facility, University College Cork College Road Cork Ireland
- School of Pharmacy, University College Cork College Road Ireland
- SSPC (Synthesis and Solid State Pharmaceutical Centre) Cork Ireland
| | - Niko T Flosbach
- Department für Chemie, Universität zu Köln Greinstraße 4 50939 Köln Germany
| | - Martin Breugst
- Department für Chemie, Universität zu Köln Greinstraße 4 50939 Köln Germany
| | - Peter A Byrne
- School of Chemistry, Analytical and Biological Chemistry Research Facility, University College Cork College Road Cork Ireland
- SSPC (Synthesis and Solid State Pharmaceutical Centre) Cork Ireland
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9
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Sheehy KJ, Bateman LM, Flosbach NT, Breugst M, Byrne PA. Identification of N‐ or O‐Alkylation of Aromatic Nitrogen Heterocycles and
N
‐Oxides Using
1
H–
15
N HMBC NMR Spectroscopy. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Kevin J. Sheehy
- School of Chemistry Analytical and Biological Chemistry Research Facility University College Cork Kane Building T12 K8AF Cork Ireland
| | - Lorraine M. Bateman
- School of Chemistry Analytical and Biological Chemistry Research Facility University College Cork Kane Building T12 K8AF Cork Ireland
- School of Pharmacy University College Cork Cork Ireland
- SSPC (Synthesis and Solid State Pharmaceutical Centre) Cork Ireland
| | - Niko T. Flosbach
- Department für Chemie Universität zu Köln Greinstraße 4 50939 Köln Germany
| | - Martin Breugst
- Department für Chemie Universität zu Köln Greinstraße 4 50939 Köln Germany
| | - Peter A. Byrne
- School of Chemistry Analytical and Biological Chemistry Research Facility University College Cork Kane Building T12 K8AF Cork Ireland
- SSPC (Synthesis and Solid State Pharmaceutical Centre) Cork Ireland
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10
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Krivdin LB. Computational 1 H NMR: Part 2. Chemical applications. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2020; 58:5-14. [PMID: 31125992 DOI: 10.1002/mrc.4896] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 05/12/2019] [Accepted: 05/18/2019] [Indexed: 06/09/2023]
Abstract
This is the second one of three closely interrelated reviews dealing with computation of 1 H NMR chemical shifts and 1 H-1 H spin-spin coupling constants prepared for Magnetic Resonance in Chemistry. Presented in this review are some basic notes and illustrative examples of how modern computational 1 H NMR could be used for structural elucidation and stereoelectronic studies of the medium-sized organic molecules involving saturated, unsaturated, aromatic, and heteroaromatic compounds together with their functional derivatives and coordination complexes to get deeper insight into their stereochemical structure and stereodynamic behavior.
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Affiliation(s)
- Leonid B Krivdin
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033, Irkutsk, Russia
- Chair of Chemistry, Angarsk State Technical University, Tchaikovsky St. 60, 665835, Angarsk, Russia
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11
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Krivdin LB. Computational protocols for calculating 13C NMR chemical shifts. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2019; 112-113:103-156. [PMID: 31481156 DOI: 10.1016/j.pnmrs.2019.05.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 05/19/2019] [Accepted: 05/20/2019] [Indexed: 06/10/2023]
Abstract
The most recent results dealing with the computation of 13C NMR chemical shifts in chemistry (small molecules, saturated, unsaturated and aromatic compounds, heterocycles, functional derivatives, coordination complexes, carbocations, and natural products) are reviewed, paying special attention to theoretical background and accuracy, the latter involving solvent effects, vibrational corrections, and relativistic effects.
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Affiliation(s)
- Leonid B Krivdin
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033 Irkutsk, Russia.
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12
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Ruiz-Muelle AB, García-García A, García-Valdivia AA, Oyarzabal I, Cepeda J, Seco JM, Colacio E, Rodríguez-Diéguez A, Fernández I. Design and synthesis of a family of 1D-lanthanide-coordination polymers showing luminescence and slow relaxation of the magnetization. Dalton Trans 2018; 47:12783-12794. [PMID: 30152820 DOI: 10.1039/c8dt02592d] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have designed and synthesized eight isostructural 1D coordination polymers (CPs) with the general formula {[Ln(aapc)3(DMF)]}n [where Ln(iii) = Y (2), La (3), Nd (4), Eu (5), Gd (6), Tb (7), Dy (8), Er (9); and aapc = 3-((anthraquinone-1-yl)amino)propanoate]. These CPs consist of Ln-carboxylate infinite rods in which the bulky anthraquinone scaffolds arise from it in such a way that the resulting supramolecular packing exhibits isolated 1D chains. Solution structures have been corroborated through NMR methods including PGSE and EXSY NMR studies and, due to the presence of lanthanide ions, magnetic and luminescence properties have been studied. Alternating current magnetic measurements of compound 8 show slow relaxation of the magnetization, a characteristic of single molecule magnets (SMMs). The evaluation of solid-state photophysical properties reveals that the aapc scaffold sensitizes lanthanide(iii) based emission of compounds 4-9 both in the visible and near-infrared (NIR) regions at 10 K.
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Affiliation(s)
- Ana Belén Ruiz-Muelle
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Ctra. Sacramento s/n, 04120 Almería, Spain.
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13
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Richards JE, Hooper AJJ, Bayfield OW, Cockett MCR, Dear GJ, Holmes AJ, John RO, Mewis RE, Pridmore N, Roberts AD, Whitwood AC, Duckett SB. Using hyperpolarised NMR and DFT to rationalise the unexpected hydrogenation of quinazoline to 3,4-dihydroquinazoline. Chem Commun (Camb) 2018; 54:10375-10378. [PMID: 30152480 PMCID: PMC6136267 DOI: 10.1039/c8cc04826f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 07/17/2018] [Indexed: 11/21/2022]
Abstract
PHIP and SABRE hyperpolarized NMR methods are used to follow the unexpected metal-catalysed hydrogenation of quinazoline (Qu) to 3,4-dihydroquinazoline as the sole product. A solution of [IrCl(IMes)(COD)] in dichloromethane reacts with H2 and Qu to form [IrCl(H)2(IMes)(Qu)2] (2). The addition of methanol then results in its conversion to [Ir(H)2(IMes)(Qu)3]Cl (3) which catalyses the hydrogenation reaction. Density functional theory calculations are used to rationalise a proposed outer sphere mechanism in which (3) converts to [IrCl(H)2(H2)(IMes)(Qu)2]Cl (4) and neutral [Ir(H)3(IMes)(Qu)2] (6), both of which are involved in the formation of 3,4-dihydroquinazoline via the stepwise transfer of H+ and H-, with H2 identified as the reductant. Successive ligand exchange in 3 results in the production of thermodynamically stable [Ir(H)2(IMes)(3,4-dihydroquinazoline)3]Cl (5).
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Affiliation(s)
- Josh E. Richards
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Alexander J. J. Hooper
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Oliver W. Bayfield
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Martin C. R. Cockett
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Gordon J. Dear
- GlaxoSmithKline Research and Development Ltd
, Park Road
,
Ware
, Hertfordshire
SG12 0DP
, UK
| | - A. Jonathon Holmes
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Richard O. John
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Ryan E. Mewis
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Natalie Pridmore
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Andy D. Roberts
- GlaxoSmithKline Research and Development Ltd
, Park Road
,
Ware
, Hertfordshire
SG12 0DP
, UK
| | - Adrian C. Whitwood
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
| | - Simon B. Duckett
- Centre for Hyperpolarisation in Magnetic Resonance
, University of York
,
Heslington
, York
YO10 5NY
, UK
.
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14
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15
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Abstract
Kinetic information that cannot be acquired with other techniques can be obtained by carefully planned and dynamic NMR experiments.
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Affiliation(s)
- István Bányai
- Department of Physical Chemistry
- University of Debrecen
- 4032 Debrecen
- Hungary
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16
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Krivdin LB. Calculation of 15N NMR chemical shifts: Recent advances and perspectives. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 102-103:98-119. [PMID: 29157495 DOI: 10.1016/j.pnmrs.2017.08.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 08/21/2017] [Accepted: 08/21/2017] [Indexed: 06/07/2023]
Abstract
Recent advances in computation of 15N NMR chemical shifts are reviewed, concentrating mainly on practical aspects of computational protocols and accuracy factors. The review includes the discussion of the level of theory, the choice of density functionals and basis sets together with taking into account solvent effects, rovibrational corrections and relativistic effects. Computational aspects of 15N NMR are illustrated for the series of neutral and protonated open-chain nitrogen-containing compounds and nitrogen heterocycles, coordination and intermolecular complexes.
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Affiliation(s)
- Leonid B Krivdin
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033 Irkutsk, Russia.
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17
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Reiß F, Reiß M, Spannenberg A, Jiao H, Hollmann D, Arndt P, Rosenthal U, Beweries T. Titanocene Silylpropyne Complexes: Promising Intermediates en route to a Four-Membered 1-Metallacyclobuta-2,3-diene? Chemistry 2017; 23:14158-14162. [PMID: 28846172 DOI: 10.1002/chem.201703444] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Indexed: 11/10/2022]
Abstract
Coordination of the alkyl-substituted alkynes Me3 SiC2 CH2 R (1: R=SiMe3 ; 2: R=N(SiMe3 )2 ) to titanocene centres [Cp'2 Ti] (Cp'=Cp, Cp*) yields stable alkyne complexes of the type Cp'2 Ti(η2 -Me3 SiC2 CH2 R) (3: Cp'=Cp, R=SiMe3 ; 5: Cp'=Cp, R=N(SiMe3 )2 ; 6: Cp'=Cp*, R=SiMe3 ) that are not prone to alkyne/allene isomerisation. When reacting alkyne 2 with Cp*2 TiCl2 and Mg formation of the complex Cp*2 Ti(III)(η3 -Me3 SiC2 CH2 ) (7) which displays a propargylic unit coordinated to the TiIII centre takes place. All complexes were fully characterised, the molecular structures for 5, 6, and 7 are discussed.
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Affiliation(s)
- Fabian Reiß
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Melanie Reiß
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Haijun Jiao
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Dirk Hollmann
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Perdita Arndt
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Uwe Rosenthal
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Torsten Beweries
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
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18
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Lin W, Zhou X, Cai J, Chen K, He X, Kong X, Li H, Wang C. Anion-Functionalized Pillararenes for Efficient Sulfur Dioxide Capture: Significant Effect of the Anion and the Cavity. Chemistry 2017; 23:14143-14148. [DOI: 10.1002/chem.201703007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Wenjun Lin
- Department of Chemistry; ZJU-NHU United R&D Center; Zhejiang University; Hangzhou 310027 P.R. China
| | - Xiuyuan Zhou
- Department of Chemistry; ZJU-NHU United R&D Center; Zhejiang University; Hangzhou 310027 P.R. China
| | - Jingsong Cai
- Department of Chemistry; ZJU-NHU United R&D Center; Zhejiang University; Hangzhou 310027 P.R. China
| | - Kaihong Chen
- Department of Chemistry; ZJU-NHU United R&D Center; Zhejiang University; Hangzhou 310027 P.R. China
| | - Xi He
- Department of Chemistry; ZJU-NHU United R&D Center; Zhejiang University; Hangzhou 310027 P.R. China
| | - Xueqian Kong
- Department of Chemistry; ZJU-NHU United R&D Center; Zhejiang University; Hangzhou 310027 P.R. China
| | - Haoran Li
- Department of Chemistry; ZJU-NHU United R&D Center; Zhejiang University; Hangzhou 310027 P.R. China
| | - Congmin Wang
- Department of Chemistry; ZJU-NHU United R&D Center; Zhejiang University; Hangzhou 310027 P.R. China
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19
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Raya-Barón Á, Oyarzabal I, Arrabal-Campos FM, Seco JM, Rodríguez-Diéguez A, Fernández I. Dinuclear Coordination Compounds Based on a 5-Nitropicolinic Carboxylate Ligand with Single-Molecule Magnet Behavior. Inorg Chem 2017; 56:8768-8775. [DOI: 10.1021/acs.inorgchem.7b00388] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Álvaro Raya-Barón
- Department of Chemistry
and Physics, University of Almería, Ctra. Sacramento s/n, 04120 Almería, Spain
| | - Itziar Oyarzabal
- Department of Applied Chemistry, University of The Basque Country (UPV/EHU), 20018 San Sebastián, Spain
| | | | - José Manuel Seco
- Department of Applied Chemistry, University of The Basque Country (UPV/EHU), 20018 San Sebastián, Spain
| | | | - Ignacio Fernández
- Department of Chemistry
and Physics, University of Almería, Ctra. Sacramento s/n, 04120 Almería, Spain
- BITAL, Research Centre for Agricultural and Food Biotechnology, Ctra. Sacramento, s/n, E-04120, Almería, Spain
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20
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Bhadra M, Sasmal HS, Basu A, Midya SP, Kandambeth S, Pachfule P, Balaraman E, Banerjee R. Predesigned Metal-Anchored Building Block for In Situ Generation of Pd Nanoparticles in Porous Covalent Organic Framework: Application in Heterogeneous Tandem Catalysis. ACS APPLIED MATERIALS & INTERFACES 2017; 9:13785-13792. [PMID: 28368103 DOI: 10.1021/acsami.7b02355] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The development of nanoparticle-polymer-hybrid-based heterogeneous catalysts with high reactivity and good recyclability is highly desired for their applications in the chemical and pharmaceutical industries. Herein, we have developed a novel synthetic strategy by choosing a predesigned metal-anchored building block for in situ generation of metal (Pd) nanoparticles in the stable, porous, and crystalline covalent organic framework (COF), without using conventional reducing agents. In situ generation of Pd nanoparticles in the COF skeleton is explicitly confirmed from PXRD, XPS, TEM images, and 15N NMR spectral analysis. This hybrid material is found to be an excellent reusable heterogeneous catalyst for the synthesis of biologically and pharmaceutically important 2-substituted benzofurans from 2-bromophenols and terminal alkynes via a tandem process with the turnover number up to 1101. The heterogeneity of the catalytic process is unambiguously verified by a mercury poisoning experiment and leaching test. This hybrid material shows superior catalytic performance compared to commercially available homogeneous as well as heterogeneous Pd catalysts.
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Affiliation(s)
- Mohitosh Bhadra
- Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India
- Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India
| | - Himadri Sekhar Sasmal
- Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India
- Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India
| | - Arghya Basu
- Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India
| | - Siba P Midya
- Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India
- CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India
| | - Sharath Kandambeth
- Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India
- Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India
| | - Pradip Pachfule
- Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India
| | - Ekambaram Balaraman
- Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India
- CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India
| | - Rahul Banerjee
- Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India
- Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India
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21
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Olaru AM, Burns MJ, Green GGR, Duckett SB. SABRE hyperpolarisation of vitamin B3 as a function of pH. Chem Sci 2016; 8:2257-2266. [PMID: 28507682 PMCID: PMC5409243 DOI: 10.1039/c6sc04043h] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/07/2016] [Indexed: 12/21/2022] Open
Abstract
NMR sensitivity enhanced through SABRE hyperpolarisation and pH manipulation enables the use of vitamin B3 as a pH probe.
In this work we describe how the signal enhancements obtained through the SABRE process in methanol-d4 solution are significantly affected by pH. Nicotinic acid (vitamin B3, NA) is used as the agent, and changing pH is shown to modify the level of polarisation transfer by over an order of magnitude, with significant improvements being seen in terms of the signal amplitude and relaxation rate at high pH values. These observations reveal that manipulating pH to improve SABRE enhancements levels may improve the potential of this method to quantify low concentrations of analytes in mixtures. 1H NMR spectroscopy results link this change to the form of the SABRE catalyst, which changes with pH, resulting in dramatic changes in the magnitude of the ligand exchange rates. The presented data also uses the fact that the chemical shifts of the nicotinic acids NMR resonances are affected by pH to establish that hyperpolarised 1H-based pH mapping with SABRE is possible. Moreover, the strong polarisation transfer field dependence shown in the amplitudes of the associated higher order longitudinal terms offers significant opportunities for the rapid detection of hyperpolarised NA in H2O itself without solvent suppression. 1H and 13C MRI images of hyperpolarised vitamin B3 in a series of test phantoms are presented that show pH dependent intensity and contrast. This study therefore establishes that when the pH sensitivity of NA is combined with the increase in signal gain provided for by SABRE hyperpolarisation, a versatile pH probe results.
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Affiliation(s)
- A M Olaru
- Centre for Hyperpolarisation in Magnetic Resonance , Department of Chemistry , University of York , YO10 5NY , York , UK .
| | - M J Burns
- Centre for Hyperpolarisation in Magnetic Resonance , Department of Chemistry , University of York , YO10 5NY , York , UK .
| | - G G R Green
- York Neuroimaging Centre , University of York , YO10 5NY , York , UK
| | - S B Duckett
- Centre for Hyperpolarisation in Magnetic Resonance , Department of Chemistry , University of York , YO10 5NY , York , UK .
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22
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Ruddlesden AJ, Mewis RE, Green GGR, Whitwood AC, Duckett SB. Catalytic Transfer of Magnetism using a Neutral Iridium Phenoxide Complex. Organometallics 2015; 34:2997-3006. [PMID: 28239225 PMCID: PMC5321507 DOI: 10.1021/acs.organomet.5b00311] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A novel neutral iridium carbene complex Ir(κC,O-L1)(COD) (1) [where COD = cyclooctadiene and L1 = 3-(2-methylene-4-nitrophenolate)-1-(2,4,6-trimethylphenyl) imidazolylidene] with a pendant alkoxide ligand has been prepared and characterized. It contains a strong Ir-O bond and X-ray analysis reveals a distorted square planar structure. NMR spectroscopy reveals dynamic solution state behavior commensurate with rapid seven-membered ring flipping. In CD2Cl2 solution, under hydrogen at low temperature, this complex dominates although it exists in equilibrium with a reactive iridium dihydride cyclooctadiene complex. 1 reacts with pyridine and H2 to form neutral Ir(H)2(κC,O-L1)(py)2 which also exists in two conformers that differ according to the orientation of the seven-membered metallocycle and whilst its Ir-O bond remains intact, the complex undergoes both pyridine and H2 exchange. As a consequence, when placed under parahydrogen, efficient polarization transfer catalysis (PTC) is observed via the Signal Amplification By Reversible Exchange (SABRE) approach. Due to the neutral character of this catalyst, good hyperpolarization activity is shown in a wide range of solvents for a number of substrates. These observations reflect a dramatic improvement in solvent tolerance of SABRE over that reported for the best PTC precursor IrCl(IMes)(COD). For THF, the associated 1H NMR signal enhancement for the ortho proton signal of pyridine shows an increase of 600-fold at 298 K. The level of signal enhancement can be increased further through warming or varying the magnetic field experienced by the sample at the point of catalytic magnetization transfer.
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Affiliation(s)
- Amy J. Ruddlesden
- Department of Chemistry, University of York, Heslington, YO10 5DD; Tel: 01904 322564
| | - Ryan E. Mewis
- Department of Chemistry, University of York, Heslington, YO10 5DD; Tel: 01904 322564
| | - Gary G. R. Green
- York Neuroimaging Centre, The BiocentreYork, Science Park, Heslington, York, YO10 5NY
| | - Adrian C. Whitwood
- Department of Chemistry, University of York, Heslington, YO10 5DD; Tel: 01904 322564
| | - Simon B. Duckett
- Department of Chemistry, University of York, Heslington, YO10 5DD; Tel: 01904 322564
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23
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Niedzielska D, Pawlak T, Wojtczak A, Pazderski L, Szlyk E. Structural and 1H, 13C, 15N NMR spectroscopic studies of Pd(II) chloride organometallics with 2-phenylpyridine and ammonia, pyridine or its methyl derivatives. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.02.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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24
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Appleby KM, Mewis RE, Olaru AM, Green GGR, Fairlamb IJS, Duckett SB. Investigating pyridazine and phthalazine exchange in a series of iridium complexes in order to define their role in the catalytic transfer of magnetisation from para-hydrogen. Chem Sci 2015; 6:3981-3993. [PMID: 29218168 PMCID: PMC5707471 DOI: 10.1039/c5sc00756a] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/27/2015] [Indexed: 11/22/2022] Open
Abstract
Reaction of [Ir(IMes)(COD)Cl] with pyridazine (pdz) or phthalazine (phth) and H2 results in the formation of the para-hydrogen magnetisation transfer catalysts [Ir(H)2(IMes)(pdz)3]Cl and [Ir(H)2(IMes)(phth)3]Cl.
The reaction of [Ir(IMes)(COD)Cl], [IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, COD = 1,5-cyclooctadiene] with pyridazine (pdz) and phthalazine (phth) results in the formation of [Ir(COD)(IMes)(pdz)]Cl and [Ir(COD)(IMes)(phth)]Cl. These two complexes are shown by nuclear magnetic resonance (NMR) studies to undergo a haptotropic shift which interchanges pairs of protons within the bound ligands. When these complexes are exposed to hydrogen, they react to form [Ir(H)2(COD)(IMes)(pdz)]Cl and [Ir(H)2(COD)(IMes)(phth)]Cl, respectively, which ultimately convert to [Ir(H)2(IMes)(pdz)3]Cl and [Ir(H)2(IMes)(phth)3]Cl, as the COD is hydrogenated to form cyclooctane. These two dihydride complexes are shown, by NMR, to undergo both full N-heterocycle dissociation and a haptotropic shift, the rates of which are affected by both steric interactions and free ligand pKa values. The use of these complexes as catalysts in the transfer of polarisation from para-hydrogen to pyridazine and phthalazine via signal amplification by reversible exchange (SABRE) is explored. The possible future use of drugs which contain pyridazine and phthalazine motifs as in vivo or clinical magnetic resonance imaging probes is demonstrated; a range of NMR and phantom-based MRI measurements are reported.
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Affiliation(s)
- Kate M Appleby
- Centre for Hyperpolarization in Magnetic Resonance , University of York , York Science Park , York , YO10 5NY , UK . .,Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK
| | - Ryan E Mewis
- Centre for Hyperpolarization in Magnetic Resonance , University of York , York Science Park , York , YO10 5NY , UK . .,Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK
| | - Alexandra M Olaru
- Centre for Hyperpolarization in Magnetic Resonance , University of York , York Science Park , York , YO10 5NY , UK . .,Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK
| | - Gary G R Green
- Centre for Hyperpolarization in Magnetic Resonance , University of York , York Science Park , York , YO10 5NY , UK . .,Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK
| | - Ian J S Fairlamb
- Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK
| | - Simon B Duckett
- Centre for Hyperpolarization in Magnetic Resonance , University of York , York Science Park , York , YO10 5NY , UK . .,Department of Chemistry , University of York , Heslington , York , YO10 5DD , UK
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25
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García-Simón C, Gramage-Doria R, Raoufmoghaddam S, Parella T, Costas M, Ribas X, Reek JNH. Enantioselective hydroformylation by a Rh-catalyst entrapped in a supramolecular metallocage. J Am Chem Soc 2015; 137:2680-7. [PMID: 25632976 DOI: 10.1021/ja512637k] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Regio- and enantioselective hydroformylation of styrenes is attained upon embedding a chiral Rh complex in a nonchiral supramolecular cage formed from coordination-driven self-assembly of macrocyclic dipalladium complexes and tetracarboxylate zinc porphyrins. The resulting supramolecular catalyst converts styrene derivatives into aldehyde products with much higher chiral induction in comparison to the nonencapsulated Rh catalyst. Spectroscopic analysis shows that encapsulation does not change the electronic properties of the catalyst nor its first coordination sphere. Instead, enhanced enantioselectivity is rationalized by the modification of the second coordination sphere occurring upon catalyst inclusion inside the cage, being one of the few examples in achieving an enantioselective outcome via indirect through-space control of the chirality around the catalyst center. This effect resembles those taking place in enzymatic sites, where structural constraints imposed by the enzyme cavity can impart stereoselectivities that cannot be attained in bulk. These results are a showcase for the future development of asymmetric catalysis by using size-tunable supramolecular capsules.
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Affiliation(s)
- Cristina García-Simón
- Grup de Química Bioinorgànica i Supramolecular, Institut de Química Computacional i Catàlisi, and Departament de Química, Universitat de Girona. Campus Montilivi , Girona E17071 Catalonia, Spain
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26
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Requet A, Colin O, Bourdreux F, Salim SM, Marque S, Thomassigny C, Greck C, Farjon J, Prim D. Pyridylalkylamine ligands and their palladium complexes: structure and reactivity revisited by NMR. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2014; 52:273-278. [PMID: 24652706 DOI: 10.1002/mrc.4058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/28/2014] [Accepted: 02/17/2014] [Indexed: 06/03/2023]
Abstract
Pyridylmethylamines or pma are versatile platforms for different catalytic transformations. Five pma-ligands and their respective Pd complexes have been studied by liquid state NMR. By comparing (1)H, (13)C and (15)N chemical shifts for each pma/pma-Pd couple, a general trend for the metallacycle atoms concerns variations of the electronic distribution at the pendant arm, especially at the nitrogen atom of the ligand. Moreover, the increase of the chemical shift of the pendant arm nitrogen atom from primary to tertiary amine is also related to the increase of crowding within the complex. This statement is in good agreement with X-ray data collected for several complexes. Catalytic results for the Suzuki-Miyaura reaction involving the pma-Pd complexes showed within this series that a sterically crowded and electron-rich ligand in the metallacycle was essential to reach the coupling product with a good selectivity. In this context, NMR study of chemical shifts of all active nuclei especially in the metallacycle could give a trend of reactivity in the studied family of pma-Pd complexes.
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Affiliation(s)
- Alexandre Requet
- Université de Versailles Saint-Quentin-en-Yvelines, Institut Lavoisier de Versailles, UMR CNRS 8180, 45, avenue des Etats-Unis, 78035, Versailles, France
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27
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Pawlak T, Niedzielska D, Vícha J, Marek R, Pazderski L. Dimeric Pd(II) and Pt(II) chloride organometallics with 2-phenylpyridine and their solvolysis in dimethylsulfoxide. J Organomet Chem 2014. [DOI: 10.1016/j.jorganchem.2014.02.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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Cmoch P, Głaszczka R, Jaźwiński J, Kamieński B, Senkara E. Adducts of nitrogenous ligands with rhodium(II) tetracarboxylates and tetraformamidinate: NMR spectroscopy and density functional theory calculations. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2014; 52:61-68. [PMID: 24327228 DOI: 10.1002/mrc.4035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 09/29/2013] [Accepted: 11/04/2013] [Indexed: 06/03/2023]
Abstract
Complexation of tetrakis(μ2-N,N'-diphenylformamidinato-N,N')-di-rhodium(II) with ligands containing nitrile, isonitrile, amine, hydroxyl, sulfhydryl, isocyanate, and isothiocyanate functional groups has been studied in liquid and solid phases using (1)H, (13)C and (15)N NMR, (13)C and (15)N cross polarisation-magic angle spinning NMR, and absorption spectroscopy in the visible range. The complexation was monitored using various NMR physicochemical parameters, such as chemical shifts, longitudinal relaxation times T1 , and NOE enhancements. Rhodium(II) tetraformamidinate selectively bonded only unbranched amine (propan-1-amine), pentanenitrile, and (1-isocyanoethyl)benzene. No complexation occurred in the case of ligands having hydroxyl, sulfhydryl, isocyanate, and isothiocyanate functional groups, and more expanded amine molecules such as butan-2-amine and 1-azabicyclo[2.2.2]octane. Such features were opposite to those observed in rhodium(II) tetracarboxylates, forming adducts with all kind of ligands. Special attention was focused on the analysis of Δδ parameters, defined as a chemical shift difference between signal in adduct and corresponding signal in free ligand. In the case of (1)H NMR, Δδ values were either negative in adducts of rhodium(II) tetraformamidinate or positive in adducts of rhodium(II) tetracarboxylates. Experimental findings were supported by density functional theory molecular modelling and gauge independent atomic orbitals chemical shift calculations. The calculation of chemical shifts combined with scaling procedure allowed to reproduce qualitatively Δδ parameters.
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Affiliation(s)
- Piotr Cmoch
- Institute of Organic Chemistry PAS, ul. Kasprzaka 44/52, 01-224, Warsaw, Poland
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29
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Lloyd LS, Asghar A, Burns MJ, Charlton A, Coombes S, Cowley MJ, Dear GJ, Duckett SB, Genov GR, Green GGR, Highton LAR, Hooper AJJ, Khan M, Khazal IG, Lewis RJ, Mewis RE, Roberts AD, Ruddlesden AJ. Hyperpolarisation through reversible interactions with parahydrogen. Catal Sci Technol 2014. [DOI: 10.1039/c4cy00464g] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ir(COD)(NHC)Cl complexes provide significant insight into the catalytic processes underpinning SABRE hyperpolarization.
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Affiliation(s)
- Lyrelle S. Lloyd
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | - Aziz Asghar
- Hull York Medical School
- University of Hull
- Hull, UK
| | - Michael J. Burns
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | | | - Steven Coombes
- AstraZeneca R&D Pharmaceutical Development
- Macclesfield, UK
| | - Michael J. Cowley
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | | | - Simon B. Duckett
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | - Georgi R. Genov
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | - Gary G. R. Green
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | | | | | - Majid Khan
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | - Iman G. Khazal
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | - Richard. J. Lewis
- AstraZeneca R&D Mölndal
- Respiratory & Inflammation Innovative Medicines
- , Sweden
| | - Ryan E. Mewis
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
| | | | - Amy J. Ruddlesden
- Centre for Hyperpolarization in Magnetic Resonance
- University of York
- York, UK
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30
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NMR characterisation and dynamic behaviour of [Pt(bipy)(R-Thiourea)2]Cl2 and [Pt(phen)(R-Thiourea)2]Cl2 complexes. Inorganica Chim Acta 2014. [DOI: 10.1016/j.ica.2013.10.014] [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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31
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Carlsson ACC, Uhrbom M, Karim A, Brath U, Gräfenstein J, Erdélyi M. Solvent effects on halogen bond symmetry. CrystEngComm 2013. [DOI: 10.1039/c2ce26745d] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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32
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Structural and spectroscopic studies of Au(III) and Pd(II) chloride complexes and organometallics with 2-benzylpyridine. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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Mixed-ligand complexes of zinc(II), cobalt(II) and cadmium(II) with sulfur, nitrogen and oxygen ligands. Analysis of the solid state structure and solution behavior. Implications for metal ion substitution in alcohol dehydrogenase. Polyhedron 2011. [DOI: 10.1016/j.poly.2011.01.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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34
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Ho HA, Gray TS, Baird B, Ellern A, Sadow AD. Allylic C–H bond activation and functionalization mediated by tris(oxazolinyl)borato rhodium(i) and iridium(i) compounds. Dalton Trans 2011; 40:6500-14. [DOI: 10.1039/c1dt10249d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Pazderski L, Pawlak T, Sitkowski J, Kozerski L, Szłyk E. (1)H NMR assignment corrections and (1)H, (13)C, (15)N NMR coordination shifts structural correlations in Fe(II), Ru(II) and Os(II) cationic complexes with 2,2'-bipyridine and 1,10-phenanthroline. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2010; 48:450-457. [PMID: 20474023 DOI: 10.1002/mrc.2600] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
(1)H, (13)C and (15)N NMR studies of iron(II), ruthenium(II) and osmium(II) tris-chelated cationic complexes with 2,2'-bipyridine and 1,10-phenanthroline of the general formula [M(LL)(3)](2+) (M = Fe, Ru, Os; LL = bpy, phen) were performed. Inconsistent literature (1)H signal assignments were corrected. Significant shielding of nitrogen-adjacent protons [H(6) in bpy, H(2) in phen] and metal-bonded nitrogens was observed, being enhanced in the series Ru(II) --> Os(II) --> Fe(II) for (1)H, Fe(II) --> Ru(II) --> Os(II) for (15)N and bpy --> phen for both nuclei. The carbons are deshielded, the effect increasing in the order Ru(II) --> Os(II) --> Fe(II).
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Affiliation(s)
- Leszek Pazderski
- Faculty of Chemistry, Nicholas Copernicus University, Gagarina 7, PL-87100 Toruń, Poland.
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36
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Holló-Sitkei E, Szalontai G, Lois I, Gömöry A, Pollreisz F, Párkányi L, Jude H, Besenyei G. Sterically-directed consecutive and size-selective self-assembly of palladium diphosphane complexes with an Ar-BIAN ligand: unexpected formation of pentameric and hexameric aggregates. Chemistry 2009; 15:10620-33. [PMID: 19746472 DOI: 10.1002/chem.200901126] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The coordination properties of N,N'-bis[4-(4-pyridyl)phenyl]acenaphthenequinonediimine (L(1)) and N,N'-bis[4-(2-pyridyl)phenyl]acenaphthenequinonediimine (L(2)) were investigated in self-assembly with palladium diphosphane complexes [Pd(P;P)(H(2)O)(2)](OTf)(2) (OTf = triflate) by using various analytical techniques, including multinuclear ((1)H, (15)N, and (31)P) NMR spectroscopy and mass spectrometry (P;P = dppp, dppf, dppe; dppp = bis(diphenylphosphanyl)propane, dppf = bis(diphenylphosphanyl)ferrocene, and dppe = bis(diphenylphosphanyl)ethane). Beside the expected trimeric and tetrameric species, the interaction of an equimolar mixture of [Pd(dppp)](2+) ions and L(1) also generates pentameric aggregates. Due to the E/Z isomerism of L(1), a dimeric product was also observed. In all of these species, which correspond to the general formula [Pd(dppp)L(1)](n)(OTf)(2n) (n = 2-5), the L(1) ligand is coordinated to the Pd center only through the terminal pyridyl groups. Introduction of a second equivalent of the [Pd(dppp)](2+) tecton results in coordination to the internal, sterically more encumbered chelating site and induces enhancement of the higher nuclearity components. The presence of higher-order aggregates (n = 5, 6), which were unexpected for the interaction of cis-protected palladium corners with linear ditopic bridging ligands, has been demonstrated both by mass-spectrometric and DOSY NMR spectroscopic analysis. The sequential coordination of the [Pd(dppp)](2+) ion is attributed to the dissimilar steric properties of the two coordination sites. In the self-assembled species formed in a 1:1:1 mixture of [Pd(dppp)](2+)/[Pd(dppe)](2+)/L(1), the sterically more demanding [Pd(dppp)](2+) tectons are attached selectively to the pyridyl groups, whereas the more hindered imino nitrogen atoms coordinate the less bulky dppe complexes, thus resulting in a sterically directed, size-selective sorting of the metal tectons. The propensity of the new ligands to incorporate hydrogen-bonded solvent molecules at the chelating site was confirmed by X-ray diffraction studies.
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Affiliation(s)
- Eszter Holló-Sitkei
- Chemical Research Center, Hungarian Academy of Sciences, 1525 Budapest, POB 17, Hungary
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37
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Pazderski L, Pawlak T, Sitkowski J, Kozerski L, Szłyk E. 1H, 13C, 15N and 195Pt NMR studies of Au(III) and Pt(II) chloride organometallics with 2-phenylpyridine. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2009; 47:932-941. [PMID: 19691018 DOI: 10.1002/mrc.2491] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
(1)H, (13)C, (15)N and (195)Pt NMR studies of gold(III) and platinum(II) chloride organometallics with N(1),C(2')-chelated, deprotonated 2-phenylpyridine (2ppy*) of the formulae [Au(2ppy*)Cl(2)], trans(N,N)-[Pt(2ppy*)(2ppy)Cl] and trans(S,N)-[Pt(2ppy*)(DMSO-d(6))Cl] (formed in situ upon dissolving [Pt(2ppy*)(micro-Cl)](2) in DMSO-d(6)) were performed. All signals were unambiguously assigned by HMBC/HSQC methods and the respective (1)H, (13)C and (15)N coordination shifts (i.e. differences between chemical shifts of the same atom in the complex and ligand molecules: Delta(1H)(coord) = delta(1H)(complex) - delta(1H)(ligand), Delta(13C)(coord) = delta(13C)(complex) - delta(13C)(ligand), Delta(15N)(coord) = delta(15N)(complex) - delta(15N)(ligand)), as well as (195)Pt chemical shifts and (1)H-(195)Pt coupling constants discussed in relation to the known molecular structures. Characteristic deshielding of nitrogen-adjacent H(6) protons and metallated C(2') atoms as well as significant shielding of coordinated N(1) nitrogens is discussed in respect to a large set of literature NMR data available for related cyclometallated compounds.
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Affiliation(s)
- Leszek Pazderski
- Faculty of Chemistry, Nicholas Copernicus University, Gagarina 7, PL-87100, Toruń, Poland.
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38
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Pazderski L, Tousek J, Sitkowski J, Kozerski L, Szłyk E. 1H, 13C and 15N nuclear magnetic resonance coordination shifts in Au(III), Pd(II) and Pt(II) chloride complexes with phenylpyridines. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2009; 47:658-665. [PMID: 19472306 DOI: 10.1002/mrc.2445] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
1H, 13C and 15N nuclear magnetic resonance studies of gold(III), palladium(II) and platinum(II) chloride complexes with phenylpyridines (PPY: 4-phenylpyridine, 4ppy; 3-phenylpyridine, 3ppy; and 2-phenylpyridine, 2ppy) having the general formulae [Au(PPY)Cl3], trans-/cis-[Pd(PPY)2Cl2] and trans-/cis-[Pt(PPY)2Cl2] were performed and the respective chemical shifts (delta1H, delta13C and delta15N) reported. 1H, 13C and 15N coordination shifts (i.e. differences between chemical shifts of the same atom in the complex and ligand molecules: Delta(coord)(1H) = delta(complex)(1H)-delta(ligand)(1H), Delta(coord)(13C) = delta(complex)(13C)-delta(ligand)(13C), Delta(coord)(15N) = delta(complex)(15N)-delta(ligand)(15N)) were discussed in relation to the type of the central atom (Au(III), Pd(II) and Pt(II)), geometry (trans-/cis-) and the position of a phenyl group in the pyridine ring system.
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Affiliation(s)
- Leszek Pazderski
- Faculty of Chemistry, Nicholas Copernicus University, Gagarina 7, PL-87100, Toruń, Poland.
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39
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Oña-Burgos P, Fernández I, Roces L, Torre Fernández L, García-Granda S, López Ortiz F. An Unprecedented Phosphinamidic Gold(III) Metallocycle: Synthesis via Tin(IV) Precursors, Structure, and Multicomponent Catalysis. Organometallics 2009. [DOI: 10.1021/om801137y] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pascual Oña-Burgos
- Área de Química Orgánica, Universidad de Almería, Crta. Sacramento s/n, 04230, Almería, Spain, and Departamento de Química Física y Analítica, Universidad de Oviedo, C/ Julián Clavería 8, 33006 Oviedo, Spain
| | - Ignacio Fernández
- Área de Química Orgánica, Universidad de Almería, Crta. Sacramento s/n, 04230, Almería, Spain, and Departamento de Química Física y Analítica, Universidad de Oviedo, C/ Julián Clavería 8, 33006 Oviedo, Spain
| | - Laura Roces
- Área de Química Orgánica, Universidad de Almería, Crta. Sacramento s/n, 04230, Almería, Spain, and Departamento de Química Física y Analítica, Universidad de Oviedo, C/ Julián Clavería 8, 33006 Oviedo, Spain
| | - Laura Torre Fernández
- Área de Química Orgánica, Universidad de Almería, Crta. Sacramento s/n, 04230, Almería, Spain, and Departamento de Química Física y Analítica, Universidad de Oviedo, C/ Julián Clavería 8, 33006 Oviedo, Spain
| | - Santiago García-Granda
- Área de Química Orgánica, Universidad de Almería, Crta. Sacramento s/n, 04230, Almería, Spain, and Departamento de Química Física y Analítica, Universidad de Oviedo, C/ Julián Clavería 8, 33006 Oviedo, Spain
| | - Fernando López Ortiz
- Área de Química Orgánica, Universidad de Almería, Crta. Sacramento s/n, 04230, Almería, Spain, and Departamento de Química Física y Analítica, Universidad de Oviedo, C/ Julián Clavería 8, 33006 Oviedo, Spain
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40
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Krummenacher I, Fernández I, Rüegger H, Weigend F, Breher F. Neutral and cationic main group element cages of germanium(ii) with pyrazolyl ligands: solid state structures, DFT calculations and advanced solution NMR investigations. Dalton Trans 2009:5335-47. [DOI: 10.1039/b901711a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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