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Ueta H, Fukutani K, Yamakawa K. Fast ortho-to-para conversion of molecular hydrogen in chemisorption and matrix-isolation systems. Front Chem 2023; 11:1258035. [PMID: 37711317 PMCID: PMC10497966 DOI: 10.3389/fchem.2023.1258035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 07/27/2023] [Indexed: 09/16/2023] Open
Abstract
Molecular hydrogen has two nuclear-spin modifications called ortho and para. Because of the symmetry restriction with respect to permutation of the two protons, the ortho and para isomers take only odd and even values of the rotational quantum number, respectively. The ortho-to-para conversion is promoted in condensed systems, to which the excess rotational energy and spin angular momentum are transferred. We review recent studies on fast ortho-to-para conversion of hydrogen in molecular chemisorption and matrix isolation systems, discussing the conversion mechanism as well as rotational-relaxation pathways.
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Affiliation(s)
- Hirokazu Ueta
- Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Katsuyuki Fukutani
- Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
| | - Koichiro Yamakawa
- Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
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H2O·HF@C70: Encapsulation Energetics and Thermodynamics. INORGANICS 2023. [DOI: 10.3390/inorganics11030123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023] Open
Abstract
This report deals with the quantum-chemical evaluation of the energetics and thermodynamics of the simultaneous encapsulation of HF and H2O by the IPR (isolated pentagon rule) C70 fullerene cage, yielding H2O·HF@C70 species which were synthesized and characterized recently, thus further expanding the family of fullerene endohedrals with non-metallic encapsulates. The structures were optimized at the DFT (density functional theory) M06-2X/6-31++G** level. The encapsulation energetics were further refined by the advanced B2PLYPD/6-31++G** and B2PLYPD/6-311++G** methods. After enhancement of the B2PLYPD/6-311++G** encapsulation energy for the BSSE and steric corrections, the encapsulation energy gain was obtained, as 26 kcal/mol. The equilibrium encapsulation thermodynamics were described using the M06-2X/6-31++G** partition functions. The results correspond to our previous evaluations for the water dimer encapsulation by C84 cages.
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Ilisca E, Houssais L, Ghiglieno F. Symmetry Breakings in the interactions of Molecular Hydrogen with Solids. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202226301013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The following conference report considers hydrogen gases with odd and even rotational quantum number as two separate gases, the ortho and para varieties which do not interconvert in absence of a catalyst. The physical catalysis of hydrogen is interpreted in terms of symmetry breakings introduced by the solid to pass round the peculiar selection rules of the molecular hydrogen assigned by the Pauli Principle. The catalytic effect presents the striking effect of reducing drastically the interconversion time, longer than the age of the universe for isolated molecules, to a few seconds or minutes when an hydrogen sample (gaseous or liquid) is brought into contact with an efficient catalyst. In the present report, the variety of new optical and electronic devices, measurements and interpretations that have been reported since the turning of the new century are reviewed. New experiments on non-magnetic catalysts measuring hydrogen conversion on the time scales of one-ten minutes turned upside down the previous theory, established in 1933, of the absolute necessity of a magnetic catalyst to break the Pauli Principle. The o-p catalyzed reaction is discussed for hydrogen molecules adsorbed on electric surfaces, or in confining porous structures or inside nanocages. New concepts and new electromagnetic conversion channels that interpret these experimental renewals are described in terms of how the hydrogen nuclei feel the solid-molecule electron cloud complex. The described channels differentiate one another owing to the catalyst and owing to the electronic path followed in the configuration space by the o-p reaction.
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Abstract
Hydrogen molecules exist in the form of two distinct isomers that can be interconverted by physical catalysis. These ortho and para forms have different thermodynamical properties. Over the last century, the catalysts developed to convert hydrogen from one form to another, in laboratories and industries, were magnetic and the interpretations relied on magnetic dipolar interactions. The variety concentration of a sample and the conversion rates induced by a catalytic action were mostly measured by thermal methods related to the diffusion of the o-p reaction heat. At the turning of the new century, the nature of the studied catalysts and the type of measures and motivations completely changed. Catalysts investigated now are non-magnetic and new spectroscopic measurements have been developed. After a fast survey of the past studies, the review details the spectroscopic methods, emphasizing their originalities, performances and refinements: how Infra-Red measurements characterize the catalytic sites and follow the conversion in real-time, Ultra-Violet irradiations explore the electronic nature of the reaction and hyper-frequencies driving the nuclear spins. The new catalysts, metallic or insulating, are detailed to display the operating electronic structure. New electromagnetic mechanisms, involving energy and momenta transfers, are discovered providing a classification frame for the newly observed reactions.
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Slanina Z, Uhlík F, Nagase S, Lu X, Akasaka T, Adamowicz L. Computed Relative Populations ofD2(22)-C84Endohedrals with Encapsulated Monomeric and Dimeric Water. Chemphyschem 2016; 17:1109-11. [DOI: 10.1002/cphc.201600076] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Zdeněk Slanina
- Life Science Center of Tsukuba Advanced Research Alliance; University of Tsukuba; Tsukuba 305-8577 Japan
| | - Filip Uhlík
- Department of Physical and Macromolecular Chemistry; Charles University in Prague; Faculty of Science; Albertov 6 128 43 Praha 2 Czech Republic
| | - Shigeru Nagase
- Fukui Institute for Fundamental Chemistry; Kyoto University; Kyoto 606-8103 Japan
| | - Xing Lu
- State Key Laboratory of Materials Processing and Die & Mould Technology; School of Material Science and Engineering; Huazhong University of Science & Technology; Wuhan 430074 China
| | - Takeshi Akasaka
- Life Science Center of Tsukuba Advanced Research Alliance; University of Tsukuba; Tsukuba 305-8577 Japan
| | - Ludwik Adamowicz
- Department of Chemistry and Biochemistry; University of Arizona; Tucson AZ 85721-0041 USA
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Shuttleworth PS, Baccile N, White RJ, Nectoux E, Budarin VL. Bulk and Surface Analysis of Carbonaceous Materials. POROUS CARBON MATERIALS FROM SUSTAINABLE PRECURSORS 2015. [DOI: 10.1039/9781782622277-00311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
It is difficult to fully characterise the surface chemistry and properties of the complex materials that are carbons. These can range from amorphous-based activated carbons to organised graphene, carbon nanotubes and other forms. However, a combination of techniques, such as, TG supplemented by TGIR, XPS and Boehm titration, bromination with various solid-state NMR methodologies can permit a comprehensive understanding of both their bulk and surface characteristics. The application of these techniques in the characterisation of both the bulk and surface features of carbon-based materials will be presented and discussed ADDIN EN.REFLIST .
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Affiliation(s)
- Peter S. Shuttleworth
- Departamento de Física de Polímeros, Elastómeros y Aplicaciones Energéticas, Instituto de Ciencia y Tecnología de Polímeros CSIC, c/ Juan de la Cierva, 3 28006 Madrid Spain
| | - Niki Baccile
- Laboratoire de Chimie de la Matière Condensée de Paris, Collège de France 11, Place M. Betrthelot 75005 Paris France
| | - Robin J. White
- Universität Freiburg, FMF - Freiburger Materialforschungszentrum, Stefan-Meier-Straße 21, 79104 Freiburg im Breisgau and Institut für Anorganische und Analytische Chemie Albertstrasse 21 79104 Freiburg Germany
| | - Eric Nectoux
- Green Chemistry Centre of Excellence, University of York Heslington, York Yorkshire YO10 5DD UK
| | - Vitaliy L. Budarin
- Green Chemistry Centre of Excellence, University of York Heslington, York Yorkshire YO10 5DD UK
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Krachmalnicoff A, Bounds R, Mamone S, Levitt MH, Carravetta M, Whitby RJ. Synthesis and characterisation of an open-cage fullerene encapsulating hydrogen fluoride. Chem Commun (Camb) 2015; 51:4993-6. [DOI: 10.1039/c5cc00499c] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the first encapsulation of HF in an open fullerene and its solution and solid-state NMR.
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Affiliation(s)
| | - Richard Bounds
- Chemistry
- University of Southampton
- Southampton SO17 1BJ
- UK
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Levitt MH. Spectroscopy of light-molecule endofullerenes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2013; 371:20120429. [PMID: 23918717 DOI: 10.1098/rsta.2012.0429] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Molecular endofullerenes are supramolecular systems consisting of fullerene cages encapsulating small molecules. Although most early examples consist of encapsulated metal clusters, recently developed synthetic routes have provided endofullerenes with non-metallic guest molecules in high purity and macroscopic quantities. The encapsulated light molecule behaves as a confined quantum rotor, displaying rotational quantization as well as translational quantization, and a rich coupling between the translational and rotational degrees of freedom. Furthermore, many encapsulated molecules display spin isomerism. Spectroscopies such as inelastic neutron scattering, nuclear magnetic resonance and infrared spectroscopy may be used to obtain information on the quantized energy level structure and spin isomerism of the guest molecules. It is also possible to study the influence of the guest molecules on the cages, and to explore the communication between the guest molecules and the molecular environment outside the cage.
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Affiliation(s)
- Malcolm H Levitt
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
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Affiliation(s)
- Michael L. McKee
- Department
of Chemistry and Biochemistry, Auburn University, 179 Chemistry Building, Alabama
36849, United States
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11
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Lu X, Trébosc J, Lafon O, Amoureux JP. Measurement of the shortest hetero-nuclear distances in multiple-spin systems using constant-time correlation NMR methods. CrystEngComm 2013. [DOI: 10.1039/c3ce40557e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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12
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Demers JP, Chevelkov V, Lange A. Progress in correlation spectroscopy at ultra-fast magic-angle spinning: basic building blocks and complex experiments for the study of protein structure and dynamics. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2011; 40:101-113. [PMID: 21880471 DOI: 10.1016/j.ssnmr.2011.07.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 07/21/2011] [Accepted: 07/22/2011] [Indexed: 05/31/2023]
Abstract
Recent progress in multi-dimensional solid-state NMR correlation spectroscopy at high static magnetic fields and ultra-fast magic-angle spinning is discussed. A focus of the review is on applications to protein resonance assignment and structure determination as well as on the characterization of protein dynamics in the solid state. First, the consequences of ultra-fast spinning on sensitivity and sample heating are considered. Recoupling and decoupling techniques at ultra-fast MAS are then presented, as well as more complex experiments assembled from these basic building blocks. Furthermore, we discuss new avenues in biomolecular solid-state NMR spectroscopy that become feasible in the ultra-fast spinning regime, such as sensitivity enhancement based on paramagnetic doping, and the prospect of direct proton detection.
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Affiliation(s)
- Jean-Philippe Demers
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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Vougioukalakis GC, Roubelakis MM, Orfanopoulos M. Open-cage fullerenes: towards the construction of nanosized molecular containers. Chem Soc Rev 2010; 39:817-44. [DOI: 10.1039/b913766a] [Citation(s) in RCA: 207] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ma F, Li ZR, Xu HL, Li ZJ, Wu D, Li ZS, Gu FL. Proton transfer in the complex H3N...HCl catalyzed by encapsulation into a C60 cage. Chemphyschem 2009; 10:1112-6. [PMID: 19347919 DOI: 10.1002/cphc.200800721] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We report proton transfer in the complex H(3)N...HCl to form the ion pair NH(4)(+)Cl(-), which is favored inside the C(60) cage according to quantum chemical calculations. The results show that the NH(4)(+)Cl(-)@C(60) is stable with an interaction energy of -2.78 kcal mol(-1). Compared with the complex H(3)N...HCl without proton transfer, it is found that the C(60) cage plays the role of a catalyst for proton transfer. In NH(4)(+)Cl(-)@C(60) a negative charge area in the C(60) cage is near the cation NH(4)(+) whereas a positive charge area is near the anion Cl(-). Also, a confinement effect of the C(60) cage is noticed, as the endohedral structure of NH(4)(+)Cl(-) is more compact than the structure of NH(4)(+)Cl(-) in the gas-phase complex. These findings indicate that the catalysis by the C(60) cage comes from two effects: 1) electrostatic inducement between the C(60) cage and endohedral molecules and 2) the confinement effect that compresses endohedral molecular structures inside the C(60) cage. In the infrared spectrum, it is found that the confinement effect of the cage can cause large blue shifts of the N-H stretching vibrations in NH(4)(+)Cl(-)@C(60) compared with those in the NH(4)(+)Cl(-)...H(2)O complex.
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Affiliation(s)
- Fang Ma
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
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Kabe Y, Hachiya H, Saito T, Shimizu D, Ishiwata M, Suzuki K, Yakushigawa Y, Ando W. Diastereoselective syntheses and oxygenation of silyl fulleroids. J Organomet Chem 2009. [DOI: 10.1016/j.jorganchem.2009.01.046] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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16
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Hu B, Wang Q, Lafon O, Trébosc J, Deng F, Amoureux JP. Robust and efficient spin-locked symmetry-based double-quantum homonuclear dipolar recoupling for probing (1)H-(1)H proximity in the solid-state. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 198:41-48. [PMID: 19185521 DOI: 10.1016/j.jmr.2009.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 12/19/2008] [Accepted: 01/08/2009] [Indexed: 05/27/2023]
Abstract
We report a novel symmetry-based method, using inversion elements bracketed by spin locks, for exciting double-quantum (DQ) coherences between spin-1/2 nuclei, such as protons. Compared to previous DQ-recoupling techniques, this new pulse sequence requires moderate rf field, even at ultra-fast MAS speeds. Furthermore, it is easy to implement and it displays higher robustness to both chemical shift anisotropy and to spreads in resonance frequencies. These advances greatly facilitate the observation of (1)H-(1)H proximities at high fields and high MAS frequencies.
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Affiliation(s)
- B Hu
- UCCS, CNRS-8181, Lille University, Fr-59652, Villeneuve d'Ascq Cedex, France
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Murata M, Maeda S, Morinaka Y, Murata Y, Komatsu K. Synthesis and Reaction of Fullerene C70 Encapsulating Two Molecules of H2. J Am Chem Soc 2008; 130:15800-1. [DOI: 10.1021/ja8076846] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michihisa Murata
- Institute for Chemical Research, Kyoto University, and PRESTO, Japan Science and Technology Agency (JST), Uji, Kyoto 611-0011, Japan
| | - Shuhei Maeda
- Institute for Chemical Research, Kyoto University, and PRESTO, Japan Science and Technology Agency (JST), Uji, Kyoto 611-0011, Japan
| | - Yuta Morinaka
- Institute for Chemical Research, Kyoto University, and PRESTO, Japan Science and Technology Agency (JST), Uji, Kyoto 611-0011, Japan
| | - Yasujiro Murata
- Institute for Chemical Research, Kyoto University, and PRESTO, Japan Science and Technology Agency (JST), Uji, Kyoto 611-0011, Japan
| | - Koichi Komatsu
- Institute for Chemical Research, Kyoto University, and PRESTO, Japan Science and Technology Agency (JST), Uji, Kyoto 611-0011, Japan
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Abstract
Recent attempts at the synthesis of endohedral fullerenes by organic reactions, so-called "molecular surgery" methods, are surveyed. The creation of an opening on the surface of fullerene cages allowed insertion of He, H(2), H(2)O, or CO within the cages. An effective route to "suture" an opening was established to realize a new endohedral fullerene, H(2)@C(60). Further development of this operation as well as the properties and reactions of H(2)@C(60) are summarized. Also the application of the encapsulated H(2) molecule as an NMR probe for the study of aromaticity of ionic fullerenes is described.
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Affiliation(s)
- Michihisa Murata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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Carravetta M, Johannessen OG, Levitt MH, Heinmaa I, Stern R, Samoson A, Horsewill AJ, Murata Y, Komatsu K. Cryogenic NMR spectroscopy of endohedral hydrogen-fullerene complexes. J Chem Phys 2007; 124:104507. [PMID: 16542088 DOI: 10.1063/1.2174012] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have observed 1H NMR spectra of hydrogen molecules trapped inside modified fullerene cages under cryogenic conditions. Experiments on static samples were performed at sample temperatures down to 4.3 K, while magic-angle-spinning (MAS) experiments were performed at temperatures down to 20 K at spinning frequencies of 15 kHz. Both types of NMR spectra show a large increase in the intramolecular 1H-1H dipolar coupling at temperatures below 50 K, revealing thermal selection of a small number of spatial rotational states. The static and MAS spectra were compared to estimate the degree of sample heating in high-speed cryogenic MAS-NMR experiments. The cryogenic MAS-NMR data show that the site resolution of magic-angle-spinning NMR may be combined with the high signal strength of cryogenic operation and that cryogenic phenomena may be studied with chemical site selectivity.
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Affiliation(s)
- M Carravetta
- School of Chemistry, Southampton University, Southampton SO17 1BJ, United Kingdom
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Zorin VE, Brown SP, Hodgkinson P. Origins of linewidth in 1H magic-angle spinning NMR. J Chem Phys 2007; 125:144508. [PMID: 17042610 DOI: 10.1063/1.2357602] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A detailed study of the factors determining the linewidth (and hence resolution) in 1H solid-state magic-angle spinning NMR is described. Although it has been known from the early days of magic-angle spinning (MAS) that resolution of spectra from abundant nuclear spins, such as 1H, increases approximately linearly with increasing sample rotation rate, the difficulty of describing the dynamics of extended networks of coupled spins has made it difficult to predict a priori the resolution expected for a given sample. Using recently developed, highly efficient methods of numerical simulation, together with experimental measurements on a variety of test systems, we propose a comprehensive picture of 1H resolution under MAS. The "homogeneous" component of the linewidth is shown to depend primarily on the ratio between an effective local coupling strength and the spin rate, modified by geometrical factors which loosely correspond to the "dimensionality" of the coupling network. The remaining "inhomogeneous" component of the natural linewidth is confirmed to have the same properties as in dilute-spin NMR. Variations in the NMR frequency due to chemical shift effects are shown to have minimal impact on 1H resolution. The implications of these results for solid-state NMR experiments involving 1H and other abundant-spin nuclei are discussed.
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Affiliation(s)
- Vadim E Zorin
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, United Kingdom
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Carravetta M, Danquigny A, Mamone S, Cuda F, Johannessen OG, Heinmaa I, Panesar K, Stern R, Grossel MC, Horsewill AJ, Samoson A, Murata M, Murata Y, Komatsu K, Levitt MH. Solid-state NMR of endohedral hydrogen–fullerene complexes. Phys Chem Chem Phys 2007; 9:4879-94. [PMID: 17912417 DOI: 10.1039/b707075f] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present an overview of solid-state NMR studies of endohedral H(2)-fullerene complexes, including (1)H and (13)C NMR spectra, (1)H and (13)C spin relaxation studies, and the results of (1)H dipole-dipole recoupling experiments. The available data involves three different endohedral H(2)-fullerene complexes, studied over a wide range of temperatures and applied magnetic fields. The symmetry of the cage influences strongly the motionally-averaged nuclear spin interactions of the endohedral H(2) species, as well as its spin relaxation behaviour. In addition, the non-bonding interactions between fullerene cages are influenced by the presence of endohedral hydrogen molecules. The review also presents several pieces of experimental data which are not yet understood, one example being the structured (1)H NMR lineshapes of endohedral H(2) molecules trapped in highly symmetric cages at cryogenic temperatures. This review demonstrates the richness of NMR phenomena displayed by H(2)-fullerene complexes, especially in the cryogenic regime.
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Affiliation(s)
- M Carravetta
- School of Chemistry, University of Southampton, Southampton, UK.
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Thilgen C, Diederich F. Structural Aspects of Fullerene ChemistryA Journey through Fullerene Chirality. Chem Rev 2006; 106:5049-135. [PMID: 17165683 DOI: 10.1021/cr0505371] [Citation(s) in RCA: 379] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carlo Thilgen
- Laboratory of Organic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland.
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Kawase T, Kurata H. Ball-, Bowl-, and Belt-Shaped Conjugated Systems and Their Complexing Abilities: Exploration of the Concave−Convex π−π Interaction. Chem Rev 2006; 106:5250-73. [PMID: 17165687 DOI: 10.1021/cr0509657] [Citation(s) in RCA: 465] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takeshi Kawase
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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Murata M, Murata Y, Komatsu K. Synthesis and Properties of Endohedral C60 Encapsulating Molecular Hydrogen. J Am Chem Soc 2006; 128:8024-33. [PMID: 16771518 DOI: 10.1021/ja061857k] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the details of our study to synthesize a new endohedral fullerene, H2@C60, in more than 100 mg quantities by closure of the 13-membered ring orifice of an open-cage fullerene using four-step organic reactions. The 13-membered ring orifice in a previously synthesized open-cage fullerene incorporating hydrogen in 100% yield was reduced to a 12-membered ring by extrusion of a sulfur atom at the rim of the orifice, and the ring was further reduced into an eight-membered ring by reductive coupling of two carbonyl groups also at the orifice. Final closure of the orifice was completed by a thermal reaction. Purification of H2@C60 was accomplished by recycle HPLC. A gradual downfield shift of the NMR signal for the encapsulated hydrogen observed upon reduction of the orifice size was interpreted based on the gauge-independent atomic orbital (GIAO) and the nucleus-independent chemical shift (NICS) calculations. The spectral as well as electrochemical examination of the properties of H2@C60 has shown that the electronic interaction between the encapsulated hydrogen and outer C60 pi-system is quite small but becomes appreciable when the outer pi-system acquires more than three extra electrons. Four kinds of exohedral derivatives of H2@C60 were synthesized. The tendency in the shift of the NMR signal of the inner hydrogen was found to be quite similar to that observed for the 3He NMR signal of the corresponding derivatives of 3He@C60.
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Affiliation(s)
- Michihisa Murata
- Institute for Chemical Research, Kyoto University, and PRESTO, Japan Science and Technology Agency (JST), Uji, Kyoto 611-0011, Japan
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Slanina Z, Pulay P, Nagase S. H2, Ne, and N2 Energies of Encapsulation into C60 Evaluated with the MPWB1K Functional. J Chem Theory Comput 2006; 2:782-5. [DOI: 10.1021/ct0503320] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zdeněk Slanina
- Department of Theoretical Molecular Science, Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Aichi, Japan, Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan−ROC, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701
| | - Peter Pulay
- Department of Theoretical Molecular Science, Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Aichi, Japan, Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan−ROC, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701
| | - Shigeru Nagase
- Department of Theoretical Molecular Science, Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Aichi, Japan, Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan−ROC, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701
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Zorin VE, Brown SP, Hodgkinson P. Quantification of homonuclear dipolar coupling networks from magic-angle spinning1H NMR. Mol Phys 2006. [DOI: 10.1080/00268970500351052] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Marin-Montesinos I, Brouwer DH, Antonioli G, Lai WC, Brinkmann A, Levitt MH. Heteronuclear decoupling interference during symmetry-based homonuclear recoupling in solid-state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2005; 177:307-17. [PMID: 16169757 DOI: 10.1016/j.jmr.2005.07.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 07/13/2005] [Accepted: 07/14/2005] [Indexed: 05/04/2023]
Abstract
We examine the influence of continuous-wave heteronuclear decoupling on symmetry-based double-quantum homonuclear dipolar recoupling, using experimental measurements, numerical simulations, and average Hamiltonian theory. There are two distinct regimes in which the heteronuclear interference effects are minimized. The first regime utilizes a moderate homonuclear recoupling field and a strong heteronuclear decoupling field; the second regime utilizes a strong homonuclear recoupling field and a weak or absent heteronuclear decoupling field. The second regime is experimentally accessible at moderate or high magic-angle-spinning frequencies and is particularly relevant for many realistic applications of solid-state NMR recoupling experiments to organic or biological materials.
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Hu YH, Ruckenstein E. Density functional theory calculations for endohedral complexes of non-πC60H60 cage with small guest molecules. J Chem Phys 2005; 123:144303. [PMID: 16238387 DOI: 10.1063/1.2055187] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hybrid density-functional theory (B3LYP) calculations were carried out to determine the structures and energies of endohedral complexes of non-pi C(60)H(60) with H(2), CO, and LiH. It was demonstrated that the endohedral complexes of C(60)H(60) with the above three guest molecules are more stable than the corresponding complexes with C(60). Furthermore, the interaction between C(60)H(60) and the inside H(2) or CO is negligible, but the formation of the LiH-C(60)H(60) complex is exothermic with a stabilization energy of -6.0 kcal/mol. While the bond lengths of H(2) and CO changed a little when placed inside the cages, that of the LiH molecule increased and decreased inside C(60)H(60) and C(60), respectively.
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Affiliation(s)
- Yun Hang Hu
- Department of Chemical and Biological Engineering, State University of New York at Buffalo, Amherst, New York 14260, USA.
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Slanina Z, Uhlík F, Adamowicz L, Nagase S. Computing fullerene encapsulation of non-metallic molecules: N2@C60and NH3@C60. MOLECULAR SIMULATION 2005. [DOI: 10.1080/08927020500283966] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Huang S, Xiao Z, Wang F, Zhou J, Yuan G, Zhang S, Chen Z, Thiel W, von Ragué Schleyer P, Zhang X, Hu X, Chen B, Gan L. Preparation of [5,6]- and [6,6]-Oxahomofullerene Derivatives and Their Interconversion by Lewis Acid Assisted Reactions of Fullerene Mixed Peroxides. Chemistry 2005; 11:5449-56. [PMID: 16001452 DOI: 10.1002/chem.200500393] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
[60]Fullerene mixed peroxides C60(O)(OOtBu)4 exhibit chemo- and regioselective reactions under mild conditions. The epoxy moiety is opened by ferric chloride to form vicinal hydroxy chloride C60Cl(OH)(OOtBu)4. BF3 is also effective in opening the epoxy moiety. The O-O bond of the fullerene mixed peroxide is cleaved by aluminum chloride to form both [5,6]- and [6,6]-fullerene hemiketals (oxohomo[60]fullerenes). A Hock-type rearrangement is proposed for the formation of the hemiketals, in which a fullerene C-C bond is cleaved. Lewis acids and/or visible light can initiate isomerization of the hemiketal isomers. Single-crystal X-ray analysis and theoretical calculations confirmed the results.
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Affiliation(s)
- Shaohua Huang
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education, Peking University, Beijing 100871, China
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Abstract
Fullerenes have unique chemistry owing to their cage structure, their richness in pi-electrons, and their large polarizabilities. They can trap atoms and small molecules to generate endohedral complexes as superconductors, drug carriers, molecular reactors, and ferroelectric materials. An important goal is to develop effective methods that can affect the behavior of the atoms and small molecules trapped inside the cage. In this paper, the quantum chemical density functional theory was employed to demonstrate that the stability and position of a guest molecule inside the C60 cage can be changed, and its orientation controlled, by modifying the C60 cage shell. The outside attachment of two hydrogen atoms to two adjacent carbon atoms located between two six-membered rings of the C60 cage affects the orientation of the LiF molecule inside and increases the stability of LiF inside the cage by 45%. In contrast, when 60 hydrogen atoms were attached to the outside surface of the C60 cage, thus transforming all C=C double bonds into single bonds, the stability of the LiF inside was reduced by 34%. If two adjacent carbon atoms were removed from C60, the stability of LiF inside this defect C60 was reduced by 41%.
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Affiliation(s)
- Yun Hang Hu
- Department of Chemical and Biological Engineering, State University of New York at Buffalo, Buffalo, NY14260, USA.
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35
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Komatsu K, Murata Y. A New Route to an Endohedral Fullerene by Way of σ-Framework Transformations. CHEM LETT 2005. [DOI: 10.1246/cl.2005.886] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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36
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Iwamatsu SI, Murata S, Andoh Y, Minoura M, Kobayashi K, Mizorogi N, Nagase S. Open-Cage Fullerene Derivatives Suitable for the Encapsulation of a Hydrogen Molecule. J Org Chem 2005; 70:4820-5. [PMID: 15932323 DOI: 10.1021/jo050251w] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The encapsulation of molecular hydrogen into an open-cage fullerene having a 16-membered ring orifice has been investigated. It is achieved by the pressurization of H2 at 0.6-13.5 MPa to afford endohedral hydrogen complexes of open-cage fullerenes in up to 83% yield. The efficiency of encapsulation is dominantly dependent on both H2 pressure and temperature. Hydrogen molecules inside the C60 cage are observed in the range of -7.3 to -7.5 ppm in 1H NMR spectra, and the formations of hydrogen complexes are further confirmed by mass spectrometry. The trapped hydrogen is released by heating. The activation energy barriers for this process are determined to be 22-24 kcal/mol. The DSC measurement of the endohedral H2 complex reveals that the escape of H2 from the C60 cage corresponds to an exothermic process, indicating that encapsulated H2 destabilizes the fullerene.
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Affiliation(s)
- Sho-ichi Iwamatsu
- Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan.
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Affiliation(s)
- Gregg S Kottas
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA
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Sawa H, Wakabayashi Y, Murata Y, Murata M, Komatsu K. Floating Single Hydrogen Molecule in an Open-Cage Fullerene. Angew Chem Int Ed Engl 2005; 44:1981-3. [PMID: 15726562 DOI: 10.1002/anie.200462850] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Hiroshi Sawa
- Institute of Materials Structure Science, High-Energy Accelerator Research Organization, Tsukuba 305-0801, Japan.
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Iwamatsu SI, Murata S. H2O@open-cage fullerene C60: control of the encapsulation property and the first mass spectroscopic identification. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.07.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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