1
|
Wingering PMR, Krämer F, Dilanas MEA, Ruiz-Martínez C, Fernández I, Breher F. Structure and Solution Behavior of Rare-Earth-Metal Complexes with Tripodal N-Donor Ligands. Chemistry 2024; 30:e202400781. [PMID: 38668679 DOI: 10.1002/chem.202400781] [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: 02/26/2024] [Indexed: 06/27/2024]
Abstract
Rare-earth-metal complexes (Ln=Y, La, Ce, Sm and Lu) of tripodal N-donor ligands respecting the CHON principle have been synthetized and characterized. The selectivity of the ligands through the lanthanide cations was investigated and related to their donor strength.
Collapse
Affiliation(s)
- Perrine M R Wingering
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Felix Krämer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Melina E A Dilanas
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Cristina Ruiz-Martínez
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Ctra. Sacramento s/n, 04120, Almería, Spain
| | - Ignacio Fernández
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Ctra. Sacramento s/n, 04120, Almería, Spain
| | - Frank Breher
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| |
Collapse
|
2
|
Jiang W, Rajeshkumar T, Guo M, Lin Y, Maron L, Zhang L. Rare-earth metal ethylene and ethyne complexes. Chem Sci 2024; 15:3495-3501. [PMID: 38455028 PMCID: PMC10915835 DOI: 10.1039/d3sc06599e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/26/2024] [Indexed: 03/09/2024] Open
Abstract
Guanidinate homometallic rare-earth ethyl complexes [LLn(μ2-η1:η2-Et)(Et)]2 (Ln = Y(1-Y), Lu(1-Lu)) and heterobimetallic rare-earth ethyl complexes LLn(Et)(μ2-η1:η2-Et)(μ2-η1-Et)(AlEt2) (Ln = Y(2-Y), Lu(2-Lu)) have been synthesized by the treatment of LLn(CH2C6H4NMe2-o)2 (L = (PhCH2)2NC(NC6H3iPr2-2,6)2) with different equivalents of AlEt3 in toluene at ambient temperature. Interestingly, the unprecedented rare-earth ethyne complex [LY(μ2-η1-Et)2(AlEt)]2(μ4-η1:η1:η2:η2-C2H2) (3-Y) containing a [C2H2]4- unit was afforded from 2-Y. The formation mechanism study on 3-Y was carried out by DFT calculations. Furthermore, the nature of the bonding of 3-Y was also revealed by NBO analysis. The reactions of LLn(CH2 C6H4NMe2-o)2 (Ln = Y, Lu) with AlEt3 (4 equiv.) in toluene at 50 °C produced firstly the non-Cp rare-earth ethylene complex LY(μ3-η1:η1:η2-C2H4)[(μ2-η1-Et)(AlEt2)(μ2-η1-Et)2(AlEt)] (4-Y), and the Y/Al ethyl complex LY[(μ2-η1-Et)2(AlEt2)]2 (5-Y) as an intermediate of 4-Y was isolated from the reaction of LY(CH2C6H4NMe2-o)2 with AlEt3 (4 equiv.) in toluene at -10 °C.
Collapse
Affiliation(s)
- Wen Jiang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University 2005 Songhu Road, Jiangwan Campus Shanghai 200438 P. R. China
| | | | - Mengyue Guo
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University 2005 Songhu Road, Jiangwan Campus Shanghai 200438 P. R. China
| | - Yuejian Lin
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University 2005 Songhu Road, Jiangwan Campus Shanghai 200438 P. R. China
| | | | - Lixin Zhang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University 2005 Songhu Road, Jiangwan Campus Shanghai 200438 P. R. China
| |
Collapse
|
3
|
Hansen C, Docherty SR, Cao W, Yakimov AV, Copéret C. 109Ag NMR chemical shift as a descriptor for Brønsted acidity from molecules to materials. Chem Sci 2024; 15:3028-3032. [PMID: 38404381 PMCID: PMC10882518 DOI: 10.1039/d3sc04067d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 01/16/2024] [Indexed: 02/27/2024] Open
Abstract
Molecular-level understanding of the acid/base properties of heterogeneous catalysts requires the development of selective spectroscopic probes to establish structure-activity relationships. In this work we show that substituting the surface protons in oxide supports by isolobal N-heterocyclic carbene (NHC) Ag cations and measuring their 109Ag nuclear magnetic resonance (NMR) signatures enables to probe the speciation and to evaluate the corresponding Brønsted acidity of the substituted OH surface sites. Specifically, a series of silver N-heterocyclic carbene (NHC) Ag(i) complexes of general formula [(NHC)AgX] are synthesized and characterized, showing that the 109Ag NMR chemical shift of the series correlates with the Brønsted acidity of the conjugate acid of X- (i.e., HX), thus establishing an acidity scale based on 109Ag NMR chemical shift. The methodology is then used to evaluate the Brønsted acidity of the OH sites of representative oxide materials using Dynamic Nuclear Polarization (DNP-)enhanced solid-state NMR spectroscopy.
Collapse
Affiliation(s)
- Colin Hansen
- ETH Zurich, Department of Chemistry and Applied Biosciences Vladimir Prelog Weg 1-5 CH-8093 Zurich Switzerland
| | - Scott R Docherty
- ETH Zurich, Department of Chemistry and Applied Biosciences Vladimir Prelog Weg 1-5 CH-8093 Zurich Switzerland
| | - Weicheng Cao
- ETH Zurich, Department of Chemistry and Applied Biosciences Vladimir Prelog Weg 1-5 CH-8093 Zurich Switzerland
| | - Alexander V Yakimov
- ETH Zurich, Department of Chemistry and Applied Biosciences Vladimir Prelog Weg 1-5 CH-8093 Zurich Switzerland
| | - Christophe Copéret
- ETH Zurich, Department of Chemistry and Applied Biosciences Vladimir Prelog Weg 1-5 CH-8093 Zurich Switzerland
| |
Collapse
|
4
|
Hermosilla-Palacios MA, Martinez M, Doud EA, Hertel T, Spokoyny AM, Cambré S, Wenseleers W, Kim YH, Ferguson AJ, Blackburn JL. Carrier density and delocalization signatures in doped carbon nanotubes from quantitative magnetic resonance. NANOSCALE HORIZONS 2024; 9:278-284. [PMID: 38044846 DOI: 10.1039/d3nh00480e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
High-performance semiconductor materials and devices are needed to supply the growing energy and computing demand. Organic semiconductors (OSCs) are attractive options for opto-electronic devices, due to their low cost, extensive tunability, easy fabrication, and flexibility. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have been extensively studied due to their high carrier mobility, stability and opto-electronic tunability. Although molecular charge transfer doping affords widely tunable carrier density and conductivity in s-SWCNTs (and OSCs in general), a pervasive challenge for such systems is reliable measurement of charge carrier density and mobility. In this work we demonstrate a direct quantification of charge carrier density, and by extension carrier mobility, in chemically doped s-SWCNTs by a nuclear magnetic resonance approach. The experimental results are verified by a phase-space filling doping model, and we suggest this approach should be broadly applicable for OSCs. Our results show that hole mobility in doped s-SWCNT networks increases with increasing charge carrier density, a finding that is contrary to that expected for mobility limited by ionized impurity scattering. We discuss the implications of this important finding for additional tunability and applicability of s-SWCNT and OSC devices.
Collapse
Affiliation(s)
| | - Marissa Martinez
- National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
| | - Evan A Doud
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
| | - Tobias Hertel
- Institute of Physical and Theoretical Chemistry, Julius-Maximilian, University Würzburg, 97074, Würzburg, Germany
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
| | - Sofie Cambré
- Department of Physics, University of Antwerp, Antwerp 2610, Belgium
| | - Wim Wenseleers
- Department of Physics, University of Antwerp, Antwerp 2610, Belgium
| | - Yong-Hyun Kim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | | | | |
Collapse
|
5
|
Wingering PMR, Hohnstein S, Krämer F, Dilanas MEA, Ruiz-Martínez C, Fernández I, Breher F. Synthesis, Crystal Structures, and Ion Pairing of κ 6 N Complexes with Rare-Earth Elements in the Solid State and in Solution. Chemistry 2023; 29:e202301529. [PMID: 37294063 DOI: 10.1002/chem.202301529] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/09/2023] [Accepted: 06/09/2023] [Indexed: 06/10/2023]
Abstract
The rare earth element complexes (Ln=Y, La, Sm, Lu, Ce) of several podant κ6 N-coordinating ligands have been synthetized and thoroughly characterized. The structural properties of the complexes have been investigated by X-ray diffraction in the solid state and by advanced NMR methods in solution. To estimate the donor capabilities of the presented ligands, an experimental comparison study has been conducted by cyclic voltammetry as well as absorption experiments using the cerium complexes and by analyzing 89 Y NMR chemical shifts of the different yttrium complexes. In order to obtain a complete and detailed picture, all experiments were corroborated by state-of-the-art quantum chemical calculations. Finally, coordination competition studies have been carried out by means of 1 H and 31 P NMR spectroscopy to investigate the correlation with donor properties and selectivity.
Collapse
Affiliation(s)
- Perrine M R Wingering
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Silvia Hohnstein
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Felix Krämer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Melina E A Dilanas
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Cristina Ruiz-Martínez
- Laboratory of Organic Chemistry, University of Almería Carretera de Sacramento s/n, 04120, Almería, Spain
| | - Ignacio Fernández
- Laboratory of Organic Chemistry, University of Almería Carretera de Sacramento s/n, 04120, Almería, Spain
| | - Frank Breher
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| |
Collapse
|
6
|
Smith ME. Recent progress in solid-state NMR of spin-½ low-γ nuclei applied to inorganic materials. Phys Chem Chem Phys 2022; 25:26-47. [PMID: 36421944 DOI: 10.1039/d2cp03663k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Significant technological and methodological advances in solid-state NMR techniques in recent years have increased the accessibility of nuclei with small magnetic moments (hereafter termed low-γ) underpinning an increased range of applications of such nuclei. These methodological advances are briefly summarised, including improvements in hardware and pulse sequences, as well as important developments in associated computational methods (e.g. first principles calculations, spectral simulation). Here spin-½ nuclei are the focus, with this Perspective complementing a very recent review that looked at half-integer spin low-γ quadrupolar nuclei. Reference is made to some of the original reports of such spin-½ nuclei, but recent progress in the relevant methodology and applications to inorganic materials (most within the last 10 years) of these nuclei are the focus. An overview of the current state-of-the-art of studying these nuclei is thereby provided for both NMR spectroscopists and materials researchers.
Collapse
Affiliation(s)
- Mark E Smith
- Vice-Chancellor and President's Office and Department of Chemistry, University of Southampton, Southampton, SO17 1BJ, UK. .,Department of Chemistry, Lancaster University, Bailrigg, Lancaster, LA1 4YB, UK.,Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| |
Collapse
|
7
|
Nater DF, Kaul CJ, Lätsch L, Tsurugi H, Mashima K, Copéret C. Olefin Metathesis Catalysts Generated In Situ from Molybdenum(VI)-Oxo Complexes by Tuning Pendant Ligands. Chemistry 2022; 28:e202200559. [PMID: 35234311 PMCID: PMC9313794 DOI: 10.1002/chem.202200559] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Indexed: 12/01/2022]
Abstract
Tailored molybdenum(VI)‐oxo complexes of the form MoOCl2(OR)2(OEt2) catalyse olefin metathesis upon reaction with an organosilicon reducing agent at 70 °C, in the presence of olefins. While this reactivity parallels what has recently been observed for the corresponding classical heterogeneous catalysts based on supported metal oxide under similar conditions, the well‐defined nature of our starting molecular systems allows us to understand the influence of structural, spectroscopic and electronic characteristics of the catalytic precursor on the initiation and catalytic proficiency of the final species. The catalytic performances of the pre‐catalysts are determined by the highly electron withdrawing (σ‐donation) character of alkoxide ligands, OtBuF9 being the best. This activity correlates with both the 95Mo chemical shift and the reduction potential that follows the same trend: OtBuF9>OtBuF6>OtBuF3.
Collapse
Affiliation(s)
- Darryl F Nater
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093, Zürich, Switzerland
| | - Christoph J Kaul
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093, Zürich, Switzerland
| | - Lukas Lätsch
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093, Zürich, Switzerland
| | - Hayato Tsurugi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, 1-3, Machikaneyama-cho, Toyonaka, Osaka, 560-8531, Japan
| | - Kazushi Mashima
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, 1-3, Machikaneyama-cho, Toyonaka, Osaka, 560-8531, Japan
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093, Zürich, Switzerland
| |
Collapse
|
8
|
Mortis A, Maichle-Mössmer C, Anwander R. Yttrium tris(trimethylsilylmethyl) complexes grafted onto MCM-48 mesoporous silica nanoparticles. Dalton Trans 2021; 51:1070-1085. [PMID: 34939637 DOI: 10.1039/d1dt03876a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of tris(trimethylsilylmethyl) yttrium donor adduct complexes was synthesized and fully characterized by X-ray diffraction, 1H/13C/29Si/31P/89Y heteronuclear NMR and FTIR spectroscopies as well as elemental analyses. Treatment of Y(CH2SiMe3)3(thf)x with various donors Do led to complete (Do = TMEDA, DMAP) and partial displacement of THF (Do = NHCiPr, DMPE). Exceptionally large 89Y NMR shifts to low field were observed for the new complexes. Complexes Y(CH2SiMe3)3(tmeda) and Y(CH2SiMe3)3(dmpe)(thf) were chosen to perform surface organometallic chemistry, due to a comparatively higher thermal stability and the availability of the 31P nucleus as a spectroscopic probe, respectively. Mesoporous nanoparticles of the MCM-48-type were synthesized and used as a 3rd generation silica support. The parent and hybrid materials were characterized using X-ray powder diffraction, solid-state-NMR spectroscopy, DRIFTS, elemental analyses, N2-physisorption, and scanning electron microscopy (SEM). The presence of surface-bound yttrium alkyl moieties was further proven by the reaction with carbon dioxide. Quantification of the surface silanol population by means of HN(SiHMe2)2-promoted surface silylation is shown to be superior to titration with lithium alkyl LiCH2SiMe3.
Collapse
Affiliation(s)
- Alexandros Mortis
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany.
| | - Cäcilia Maichle-Mössmer
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany.
| | - Reiner Anwander
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany.
| |
Collapse
|
9
|
Liu Z, Liang L, Xiao D, Ji Y, Zhao Z, Xu J, Hou G. 89Y chemical shift anisotropy: a sensitive structural probe of layered yttrium hydroxides revealed by solid-state NMR spectroscopy and DFT calculations. Phys Chem Chem Phys 2021; 23:27244-27252. [PMID: 34859801 DOI: 10.1039/d1cp04247e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Anion-exchangeable Y2(OH)5X·nH2O (LYH-X, X = monovalent anions, n ≈ 1.5) materials are an ideal platform for incorporating the unique properties of layered metal hydroxides and rare-earth (RE) ions, and thus have exhibited promising prospects for various applications. To further improve the performance of LYH-X and related functional materials, their structure-property relationships must be explored. However, due to the intrinsic felxibility, extracting the local structural details of these materials is particularly challenging. In this work, we utilized a combined approach of 89Y solid-state NMR (ssNMR) spectroscopy and density functional theory (DFT) calculations to reveal the response of 89Y chemical shift anisotropy (CSA) in LYH-X to the structural changes including a small displacement of cationic yttrium hydroxide layers and intercalated anions. Such subtle structural changes are often associated with dehydration/rehydration, anion-exchange, exfoliation, and the self-assembly process of LYH-X and related functional materials, which are exceedingly difficult to detect using other techniques. The principal components of 89Y CSA show a larger variation range than isotropic chemical shifts, making CSA a more sensitive probe. In addition, it is found that the response of 89Y CSA to structural changes is distinct for Y sites with different local coordination environments, opening great opportunities to analyze each Y site within these materials. All these observations suggest that the strategy involving both experimental (89Y ssNMR) and theoretical (DFT) approaches can be utilized to extract previously unavailable ultrafine structural information of LYH-X and related materials, and provide fruitful insights into their thorough structure-property relationships.
Collapse
Affiliation(s)
- Zhengmao Liu
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lixin Liang
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong Xiao
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - Yi Ji
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenchao Zhao
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - Jun Xu
- Center for Rare Earth and Inorganic Functional Materials, Tianjin Key Lab for Rare Earth Materials and Applications, School of Materials Science and Engineering & National Institute for Advanced Materials, Nankai University, Tianjin 300350, China.
| | - Guangjin Hou
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| |
Collapse
|
10
|
Gordon CP, Lätsch L, Copéret C. Nuclear Magnetic Resonance: A Spectroscopic Probe to Understand the Electronic Structure and Reactivity of Molecules and Materials. J Phys Chem Lett 2021; 12:2072-2085. [PMID: 33617260 DOI: 10.1021/acs.jpclett.0c03520] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This Perspective focuses on the ability of chemical shift to identify and characterize the electronic structure and associated reactivity of molecules and materials. After a general introduction on NMR parameters, we will show selected examples where the chemical shift of various NMR active nuclei has been used to investigate and understand electronic properties, with a particular focus on organometallic compounds and inorganic materials with relevance to catalysis. We will demonstrate how the NMR parameter of probe molecules and ligands can be used to elucidate the nature of active sites and how they can help to understand and predict their reactivity. Lastly, we will give an overview over recent advances in deciphering metal NMR parameters. Overall, we show how chemical shift is a reactivity descriptor that can be analyzed and understood on a molecular level.
Collapse
Affiliation(s)
- Christopher P Gordon
- ETH Zurich, Department of Chemistry and Applied Biosciences, Vladimir-Prelog-Weg 2, Zurich, Switzerland
| | - Lukas Lätsch
- ETH Zurich, Department of Chemistry and Applied Biosciences, Vladimir-Prelog-Weg 2, Zurich, Switzerland
| | - Christophe Copéret
- ETH Zurich, Department of Chemistry and Applied Biosciences, Vladimir-Prelog-Weg 2, Zurich, Switzerland
| |
Collapse
|
11
|
Dawoud Bani-Yaseen A, Sarayrah R, Nabilla F. The effects of substituents on the reductive elimination of difluoromethylated hydrazones from small bite-angle PdII molecular catalyst: A DFT study. COMPUT THEOR CHEM 2021. [DOI: 10.1016/j.comptc.2021.113162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
12
|
Raynaud C, Norbert-Agaisse E, James BR, Eisenstein O. 31P Chemical Shifts in Ru(II) Phosphine Complexes. A Computational Study of the Influence of the Coordination Sphere. Inorg Chem 2020; 59:17038-17048. [PMID: 33156986 DOI: 10.1021/acs.inorgchem.0c02256] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The NMR chemical shift has been the most versatile marker of chemical structures, by reflecting global and local electronic structures, and is very sensitive to any change within the chemical species. In this work, Ru(II) complexes with the same five ligands and a variable sixth ligand L (none, H2O, H2S, CH3SH, H2, N2, N2O, NO+, C═CHPh, and CO) are studied by using as the NMR reporter the phosphorus PA of a coordinated bidentate PA-N ligand (PA-N = o-diphenylphosphino-N,N'-dimethylaniline). The chemical shift of PA in RuCl2(PA-N)(PR3)(L) (R = phenyl, p-tolyl, or p-FC6H4) was shown to increase as the Ru-PA bond distance decreases, an observation that was not rationalized. This work, using density functional theory (DFT) calculations, reproduces reasonably well the observed 31P chemical shifts for these complexes and the correlation between the shifts and the Ru-PA bond distance as L varies. An interpretation of this correlation is proposed by using a natural chemical shift (NCS) analysis based on the natural bonding orbital (NBO) method. This analysis of the principal components of the chemical shift tensors shows how the σ-donating properties of L have a particularly high influence on the phosphine chemical shifts.
Collapse
Affiliation(s)
| | | | - Brian R James
- Department of Chemistry, University of Vancouver, Vancouver, BC V6T 1Z1, Canada
| | - Odile Eisenstein
- ICGM, Université de Montpellier, CNRS, ENSCM, Montpellier 34095, France.,Department of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, Oslo 0315, Norway
| |
Collapse
|
13
|
Hillenbrand J, Leutzsch M, Gordon CP, Copéret C, Fürstner A. 183 W NMR Spectroscopy Guides the Search for Tungsten Alkylidyne Catalysts for Alkyne Metathesis. Angew Chem Int Ed Engl 2020; 59:21758-21768. [PMID: 32820864 PMCID: PMC7756321 DOI: 10.1002/anie.202009975] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/21/2020] [Indexed: 12/12/2022]
Abstract
Triarylsilanolates are privileged ancillary ligands for molybdenum alkylidyne catalysts for alkyne metathesis but lead to disappointing results and poor stability in the tungsten series. 1 H,183 W heteronuclear multiple bond correlation spectroscopy, exploiting a favorable 5 J-coupling between the 183 W center and the peripheral protons on the alkylidyne cap, revealed that these ligands upregulate the Lewis acidity to an extent that the tungstenacyclobutadiene formed in the initial [2+2] cycloaddition step is over-stabilized and the catalytic turnover brought to a halt. Guided by the 183 W NMR shifts as a proxy for the Lewis acidity of the central atom and by an accompanying chemical shift tensor analysis of the alkylidyne unit, the ligand design was revisited and a more strongly π-donating all-alkoxide ligand prepared. The new expanded chelate complex has a tempered Lewis acidity and outperforms the classical Schrock catalyst, carrying monodentate tert-butoxy ligands, in terms of rate and functional-group compatibility.
Collapse
Affiliation(s)
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Christopher P. Gordon
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 1–58093ZürichSwitzerland
| | - Christophe Copéret
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 1–58093ZürichSwitzerland
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| |
Collapse
|
14
|
Hillenbrand J, Leutzsch M, Gordon CP, Copéret C, Fürstner A. 183
W NMR Spectroscopy Guides the Search for Tungsten Alkylidyne Catalysts for Alkyne Metathesis. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202009975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Christopher P. Gordon
- Department of Chemistry and Applied Biosciences ETH Zürich Vladimir-Prelog-Weg 1–5 8093 Zürich Switzerland
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences ETH Zürich Vladimir-Prelog-Weg 1–5 8093 Zürich Switzerland
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| |
Collapse
|