1
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Reversible Diels–Alder Addition to Fullerenes: A Study of Dimethylanthracene with H2@C60. NANOMATERIALS 2022; 12:nano12101667. [PMID: 35630891 PMCID: PMC9144212 DOI: 10.3390/nano12101667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/25/2022] [Accepted: 04/29/2022] [Indexed: 01/27/2023]
Abstract
The study of isolated atoms or molecules inside a fullerene cavity provides a unique environment. It is likely to control the outer carbon cage and study the isolated species when molecules or atoms are trapped inside a fullerene. We report the Diels–Alder addition reaction of 9,10-dimethyl anthracene (DMA) to H2@C60 while 1H NMR spectroscopy is utilized to characterize the Diels–Alder reaction of the DMA with the fullerene. Through 1H NMR spectroscopy, a series of isomeric adducts are identified. The obtained peaks are sharp, precise, and straightforward. Moreover, in this paper, H2@C60 and its isomers are described for the first time.
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2
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Buchachenko AL. Compressed Molecules and Enzymes. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2022. [DOI: 10.1134/s1990793122010031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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3
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Hoffman G, Walkey MC, Gräsvik J, Bacanu GR, Alom S, Bloodworth S, Light ME, Levitt MH, Whitby RJ. A Solid-State Intramolecular Wittig Reaction Enables Efficient Synthesis of Endofullerenes Including Ne@C 60 , 3 He@C 60 , and HD@C 60. Angew Chem Int Ed Engl 2021; 60:8960-8966. [PMID: 33554419 PMCID: PMC8048630 DOI: 10.1002/anie.202100817] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Indexed: 11/24/2022]
Abstract
An open-cage fullerene incorporating phosphorous ylid and carbonyl group moieties on the rim of the orifice can be filled with gases (H2 , He, Ne) in the solid state, and the cage opening then contracted in situ by raising the temperature to complete an intramolecular Wittig reaction, trapping the atom or molecule inside. Known transformations complete conversion of the product fullerene to C60 containing the endohedral species. As well as providing an improved synthesis of large quantities of 4 He@C60 , H2 @C60 , and D2 @C60 , the method allows the efficient incorporation of expensive gases such as HD and 3 He, to prepare HD@C60 and 3 He@C60 . The method also enables the first synthesis of Ne@C60 by molecular surgery, and its characterization by crystallography and 13 C NMR spectroscopy.
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Affiliation(s)
- Gabriela Hoffman
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Mark C. Walkey
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - John Gräsvik
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
- Current address: Iggesund Paperboard ABIggesunds BrukLSKA82580IggesundSweden
| | - George R. Bacanu
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Shamim Alom
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Sally Bloodworth
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Mark E. Light
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Malcolm H. Levitt
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Richard J. Whitby
- Chemistry, Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
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4
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Hoffman G, Walkey MC, Gräsvik J, Bacanu GR, Alom S, Bloodworth S, Light ME, Levitt MH, Whitby RJ. A Solid‐State Intramolecular Wittig Reaction Enables Efficient Synthesis of Endofullerenes Including Ne@C
60
,
3
He@C
60
, and HD@C
60. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Gabriela Hoffman
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
| | - Mark C. Walkey
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
| | - John Gräsvik
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
- Current address: Iggesund Paperboard AB Iggesunds Bruk LSKA 82580 Iggesund Sweden
| | - George R. Bacanu
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
| | - Shamim Alom
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
| | - Sally Bloodworth
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
| | - Mark E. Light
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
| | - Malcolm H. Levitt
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
| | - Richard J. Whitby
- Chemistry, Faculty of Engineering and Physical Sciences University of Southampton Southampton SO17 1BJ UK
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5
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Fu X, Han H, Zhang D, Yu H, He Q, Zhao D. A polycyclic aromatic hydrocarbon diradical with pH-responsive magnetic properties. Chem Sci 2020; 11:5565-5571. [PMID: 32874500 PMCID: PMC7441688 DOI: 10.1039/d0sc00770f] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 05/11/2020] [Indexed: 12/17/2022] Open
Abstract
By integrating azulene with a quinoid moiety, a novel non-alternant polycyclic aromatic hydrocarbon molecule BCHF1 exhibiting manifold zwitterionic, quinoidal and diradical behaviors is designed and synthesized. Its zwitterionic feature is evidenced by the changes shown by the 1H-NMR and absorption spectra when the molecule undergoes reversible protonation and deprotonation reactions at varied pH. The diradical facet, manifesting a small singlet-triplet energy gap (ΔE S-T), is characterized with a paramagnetic resonance signal detected by the EPR spectroscopy at room temperature. As the diradical properties are not observed in the protonated form, BCHF1+H+ , a pH-controlled reversible magnetic switching behavior is illustrated by monitoring the on and off cycles of EPR signals upon successively adding bases and acids to a solution or exposing a thin film of BCHF1+H+ to base vapor followed by acid vapor.
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Affiliation(s)
- Xiangyu Fu
- Beijing National Laboratory for Molecular Sciences , Centre for the Soft Matter Science and Engineering , Key Lab of Polymer Chemistry & Physics of the Ministry of Education , College of Chemistry , Peking University , Beijing , 100871 , China .
| | - Han Han
- Beijing National Laboratory for Molecular Sciences , Centre for the Soft Matter Science and Engineering , Key Lab of Polymer Chemistry & Physics of the Ministry of Education , College of Chemistry , Peking University , Beijing , 100871 , China .
| | - Di Zhang
- Beijing National Laboratory for Molecular Sciences , Centre for the Soft Matter Science and Engineering , Key Lab of Polymer Chemistry & Physics of the Ministry of Education , College of Chemistry , Peking University , Beijing , 100871 , China .
| | - Han Yu
- Beijing National Laboratory for Molecular Sciences , Centre for the Soft Matter Science and Engineering , Key Lab of Polymer Chemistry & Physics of the Ministry of Education , College of Chemistry , Peking University , Beijing , 100871 , China .
| | - Qilin He
- Beijing National Laboratory for Molecular Sciences , Centre for the Soft Matter Science and Engineering , Key Lab of Polymer Chemistry & Physics of the Ministry of Education , College of Chemistry , Peking University , Beijing , 100871 , China .
| | - Dahui Zhao
- Beijing National Laboratory for Molecular Sciences , Centre for the Soft Matter Science and Engineering , Key Lab of Polymer Chemistry & Physics of the Ministry of Education , College of Chemistry , Peking University , Beijing , 100871 , China .
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6
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Beejapur HA, Zhang Q, Hu K, Zhu L, Wang J, Ye Z. TEMPO in Chemical Transformations: From Homogeneous to Heterogeneous. ACS Catal 2019. [DOI: 10.1021/acscatal.8b05001] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hazi Ahmad Beejapur
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Qi Zhang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Kecheng Hu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Li Zhu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Jianli Wang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Zhibin Ye
- Department of Chemical and Materials Engineering, Concordia University, Montreal, Quebec H3G 1M8, Canada
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7
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Nguyen HVT, Chen Q, Paletta JT, Harvey P, Jiang Y, Zhang H, Boska MD, Ottaviani MF, Jasanoff A, Rajca A, Johnson JA. Nitroxide-Based Macromolecular Contrast Agents with Unprecedented Transverse Relaxivity and Stability for Magnetic Resonance Imaging of Tumors. ACS CENTRAL SCIENCE 2017; 3:800-811. [PMID: 28776023 PMCID: PMC5532724 DOI: 10.1021/acscentsci.7b00253] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Indexed: 05/18/2023]
Abstract
Metal-free magnetic resonance imaging (MRI) agents could overcome the established toxicity associated with metal-based agents in some patient populations and enable new modes of functional MRI in vivo. Herein, we report nitroxide-functionalized brush-arm star polymer organic radical contrast agents (BASP-ORCAs) that overcome the low contrast and poor in vivo stability associated with nitroxide-based MRI contrast agents. As a consequence of their unique nanoarchitectures, BASP-ORCAs possess per-nitroxide transverse relaxivities up to ∼44-fold greater than common nitroxides, exceptional stability in highly reducing environments, and low toxicity. These features combine to provide for accumulation of a sufficient concentration of BASP-ORCA in murine subcutaneous tumors up to 20 h following systemic administration such that MRI contrast on par with metal-based agents is observed. BASP-ORCAs are, to our knowledge, the first nitroxide MRI contrast agents capable of tumor imaging over long time periods using clinical high-field 1H MRI techniques.
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Affiliation(s)
- Hung V.-T. Nguyen
- Department
of Chemistry, Department of Biological Engineering, Department of Brain
and Cognitive Sciences, and Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Qixian Chen
- Department
of Chemistry, Department of Biological Engineering, Department of Brain
and Cognitive Sciences, and Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Joseph T. Paletta
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Peter Harvey
- Department
of Chemistry, Department of Biological Engineering, Department of Brain
and Cognitive Sciences, and Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Yivan Jiang
- Department
of Chemistry, Department of Biological Engineering, Department of Brain
and Cognitive Sciences, and Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Hui Zhang
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Michael D. Boska
- Department
of Radiology, University of Nebraska Medical
Center, Omaha, Nebraska 68198, United
States
| | | | - Alan Jasanoff
- Department
of Chemistry, Department of Biological Engineering, Department of Brain
and Cognitive Sciences, and Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Andrzej Rajca
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Jeremiah A. Johnson
- Department
of Chemistry, Department of Biological Engineering, Department of Brain
and Cognitive Sciences, and Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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8
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Vallejo J, Pardo E, Viciano-Chumillas M, Castro I, Amorós P, Déniz M, Ruiz-Pérez C, Yuste-Vivas C, Krzystek J, Julve M, Lloret F, Cano J. Reversible solvatomagnetic switching in a single-ion magnet from an entatic state. Chem Sci 2017; 8:3694-3702. [PMID: 28580105 PMCID: PMC5437488 DOI: 10.1039/c6sc05188j] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 02/13/2017] [Indexed: 12/23/2022] Open
Abstract
A vast impact on molecular nanoscience can be achieved using simple transition metal complexes as dynamic chemical systems to perform specific and selective tasks under the control of an external stimulus that switches "ON" and "OFF" their electronic properties. While the interest in single-ion magnets (SIMs) lies in their potential applications in information storage and quantum computing, the switching of their slow magnetic relaxation associated with host-guest processes is insufficiently explored. Herein, we report a unique example of a mononuclear cobalt(ii) complex in which geometrical constraints are the cause of easy and reversible water coordination and its release. As a result, a reversible and selective colour and SIM behaviour switch occurs between a "slow-relaxing" deep red anhydrous material (compound 1) and its "fast-relaxing" orange hydrated form (compound 2). The combination of this optical and magnetic switching in this new class of vapochromic and thermochromic SIMs offers fascinating possibilities for designing multifunctional molecular materials.
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Affiliation(s)
- J Vallejo
- Institut de Ciència Molecular (ICMOL) , Universitat de València , 46980 Paterna , València , Spain . ;
| | - E Pardo
- Institut de Ciència Molecular (ICMOL) , Universitat de València , 46980 Paterna , València , Spain . ;
| | - M Viciano-Chumillas
- Institut de Ciència Molecular (ICMOL) , Universitat de València , 46980 Paterna , València , Spain . ;
| | - I Castro
- Institut de Ciència Molecular (ICMOL) , Universitat de València , 46980 Paterna , València , Spain . ;
| | - P Amorós
- Institut de Ciència del Materials (ICMUV) , Universitat de València , 46980 Paterna , València , Spain
| | - M Déniz
- Laboratorio de Rayos X y Materiales Moleculares , Departamento de Física , Facultad de Ciencias (Sección Física) , Universidad de La Laguna , 38201 Tenerife , Spain
| | - C Ruiz-Pérez
- Laboratorio de Rayos X y Materiales Moleculares , Departamento de Física , Facultad de Ciencias (Sección Física) , Universidad de La Laguna , 38201 Tenerife , Spain
| | - C Yuste-Vivas
- Institut de Ciència Molecular (ICMOL) , Universitat de València , 46980 Paterna , València , Spain . ;
| | - J Krzystek
- National High Magnetic Field Laboratory (NHMFL) , Florida State University , Tallahassee , Florida 32310 , USA
| | - M Julve
- Institut de Ciència Molecular (ICMOL) , Universitat de València , 46980 Paterna , València , Spain . ;
| | - F Lloret
- Institut de Ciència Molecular (ICMOL) , Universitat de València , 46980 Paterna , València , Spain . ;
| | - J Cano
- Institut de Ciència Molecular (ICMOL) , Universitat de València , 46980 Paterna , València , Spain . ;
- Fundació General de la Universitat de València (FGUV) , Spain
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9
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Mamone S, Johnson MR, Ollivier J, Rols S, Levitt MH, Horsewill AJ. Symmetry-breaking in the H2@C60 endofullerene revealed by inelastic neutron scattering at low temperature. Phys Chem Chem Phys 2016; 18:1998-2005. [DOI: 10.1039/c5cp07146a] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fine structure of the rotational ground state of molecular ortho-hydrogen confined inside the fullerene cage C60 is investigated by inelastic neutron scattering (INS).
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Affiliation(s)
- Salvatore Mamone
- School of Physics and Astronomy
- University of Nottingham
- NG7 2RD Nottingham
- UK
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10
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Wu B, Wang T, Feng Y, Zhang Z, Jiang L, Wang C. Molecular magnetic switch for a metallofullerene. Nat Commun 2015; 6:6468. [PMID: 25732144 PMCID: PMC4366484 DOI: 10.1038/ncomms7468] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/30/2015] [Indexed: 12/28/2022] Open
Abstract
The endohedral fullerenes lead to well-protected internal species by the fullerene cages, and even highly reactive radicals can be stabilized. However, the manipulation of the magnetic properties of these radicals from outside remains challenging. Here we report a system of a paramagnetic metallofullerene Sc3C2@C80 connected to a nitroxide radical, to achieve the remote control of the magnetic properties of the metallofullerene. The remote nitroxide group serves as a magnetic switch for the electronic spin resonance (ESR) signals of Sc3C2@C80 via spin–spin interactions. Briefly, the nitroxide radical group can ‘switch off’ the ESR signals of the Sc3C2@C80 moiety. Moreover, the strength of spin–spin interactions between Sc3C2@C80 and the nitroxide group can be manipulated by changing the distance between these two spin centres. In addition, the ESR signals of the Sc3C2@C80 moiety can be switched on at low temperatures through weakened spin–lattice interactions. Endohedral fullerenes are known to stabilize reactive radicals; however, the external magnetic manipulation of these species’ remains challenging. Here, the authors link a nitroxide radical to a paramagnetic fullerene system and are able to alter the spin behaviour of the fullerene via spin–spin interactions.
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Affiliation(s)
- Bo Wu
- Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Taishan Wang
- Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yongqiang Feng
- Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhuxia Zhang
- Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Li Jiang
- Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Chunru Wang
- Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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11
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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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12
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Beejapur HA, Campisciano V, Giacalone F, Gruttadauria M. Catalytic Synergism in a C60IL10TEMPO2Hybrid in the Efficient Oxidation of Alcohols. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201400641] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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13
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Beejapur HA, Campisciano V, Franchi P, Lucarini M, Giacalone F, Gruttadauria M. Fullerene as a Platform for Recyclable TEMPO Organocatalysts for the Oxidation of Alcohols. ChemCatChem 2014. [DOI: 10.1002/cctc.201402262] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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14
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Krachmalnicoff A, Levitt MH, Whitby RJ. An optimised scalable synthesis of H2O@C60 and a new synthesis of H2@C60. Chem Commun (Camb) 2014; 50:13037-40. [DOI: 10.1039/c4cc06198e] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New efficient and practical routes to H2O@C60, D2O@C60 and H2@C60 are described.
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15
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Mamone S, Concistrè M, Heinmaa I, Carravetta M, Kuprov I, Wall G, Denning M, Lei X, Chen JYC, Li Y, Murata Y, Turro NJ, Levitt MH. Nuclear magnetic resonance of hydrogen molecules trapped inside C70 fullerene cages. Chemphyschem 2013; 14:3121-30. [PMID: 23788291 PMCID: PMC4068279 DOI: 10.1002/cphc.201300269] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Indexed: 11/29/2022]
Abstract
We present a solid-state NMR study of H2 molecules confined inside the cavity of C70 fullerene cages over a wide range of temperatures (300 K to 4 K). The proton NMR spectra are consistent with a model in which the dipole-dipole coupling between the ortho-H2 protons is averaged over the rotational/translational states of the confined quantum rotor, with an additional chemical shift anisotropy δ(H)(CSA)=10.1 ppm induced by the carbon cage. The magnitude of the chemical shift anisotropy is consistent with DFT estimates of the chemical shielding tensor field within the cage. The experimental NMR data indicate that the ground state of endohedral ortho-H2 in C70 is doubly degenerate and polarized transverse to the principal axis of the cage. The NMR spectra indicate significant magnetic alignment of the C70 long axes along the magnetic field, at temperatures below ~10 K.
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Affiliation(s)
- Salvatore Mamone
- School of Chemistry, Southampton University, Southampton SO17 1BJ (United Kingdom).
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16
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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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17
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Chen JYC, Li Y, Frunzi M, Lei X, Murata Y, Lawler RG, Turro NJ. Nuclear spin isomers of guest molecules in H₂@C₆₀, H₂O@C₆₀ and other endofullerenes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2013; 371:20110628. [PMID: 23918710 DOI: 10.1098/rsta.2011.0628] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Spectroscopic studies of recently synthesized endofullerenes, in which H₂, H₂O and other atoms and small molecules are trapped in cages of carbon atoms, have shown that although the trapped molecules interact relatively weakly with the internal environment they are nevertheless susceptible to appropriately applied external perturbations. These properties have been exploited to isolate and study samples of H₂ in C₆₀ and other fullerenes that are highly enriched in the para spin isomer. Several strategies for spin-isomer enrichment, potential extensions to other endofullerenes and possible applications of these materials are discussed.
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Affiliation(s)
- Judy Y-C Chen
- Department of Chemistry, Columbia University, New York, NY 10027, USA
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18
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Cai J, Xing Y, Yang M, Zhao X. Preparation of modified γ-alumina as stationary phase in gas–solid chromatography and its separation performance for hydrogen isotopes. ADSORPTION 2013. [DOI: 10.1007/s10450-013-9499-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Li Y, Chen JYC, Lei X, Lawler RG, Murata Y, Komatsu K, Turro NJ. Comparison of Nuclear Spin Relaxation of H2O@C60 and H2@C60 and Their Nitroxide Derivatives. J Phys Chem Lett 2012; 3:1165-1168. [PMID: 26288052 DOI: 10.1021/jz3002794] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The successful synthesis of H2O@C60 makes possible the study of magnetic interactions of an isolated water molecule in a geometrically well-defined hydrophobic environment. Comparisons are made between the T1 values of H2O@C60 and the previously studied H2@C60 and their nitroxide derivatives. The value of T1 is approximately six times longer for H2O@C60 than for H2@C60 at room temperature, is independent of solvent viscosity or polarity, and increases monotonically with decreasing temperature, implying that T1 is dominated by the spin-rotation interaction. Paramagnetic nitroxides, either attached covalently to the C60 cage or added to the medium, produce strikingly similar T1 enhancements for H2O@C60 and H2@C60 that are consistent with through-space interaction between the internal nuclear spins and the external electron spin. This indicates that it should be possible to apply to the endo-H2O molecule the same methodologies for manipulating the ortho and para spin isomers that have proven successful for H2@C60.
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Affiliation(s)
- Yongjun Li
- †Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Judy Y-C Chen
- †Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Xuegong Lei
- †Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Ronald G Lawler
- ‡Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Yasujiro Murata
- §Institute for Chemical Research, Kyoto University, Kyoto 611-0011, Japan
| | - Koichi Komatsu
- ∥Department of Environmental and Biological Chemistry, Fukui University of Technology, Gakuen, Fukui 910-8505, Japan
| | - Nicholas J Turro
- †Department of Chemistry, Columbia University, New York, New York 10027, United States
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Li Y, Chen JYC, Lei X, Lawler RG, Murata Y, Komatsu K, Turro NJ. Comparison of Nuclear Spin Relaxation of H2O@C60 and H2@C60 and Their Nitroxide Derivatives. J Phys Chem Lett 2012. [PMID: 26288052 DOI: 10.1021/jz100645w] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The successful synthesis of H2O@C60 makes possible the study of magnetic interactions of an isolated water molecule in a geometrically well-defined hydrophobic environment. Comparisons are made between the T1 values of H2O@C60 and the previously studied H2@C60 and their nitroxide derivatives. The value of T1 is approximately six times longer for H2O@C60 than for H2@C60 at room temperature, is independent of solvent viscosity or polarity, and increases monotonically with decreasing temperature, implying that T1 is dominated by the spin-rotation interaction. Paramagnetic nitroxides, either attached covalently to the C60 cage or added to the medium, produce strikingly similar T1 enhancements for H2O@C60 and H2@C60 that are consistent with through-space interaction between the internal nuclear spins and the external electron spin. This indicates that it should be possible to apply to the endo-H2O molecule the same methodologies for manipulating the ortho and para spin isomers that have proven successful for H2@C60.
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Affiliation(s)
- Yongjun Li
- †Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Judy Y-C Chen
- †Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Xuegong Lei
- †Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Ronald G Lawler
- ‡Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Yasujiro Murata
- §Institute for Chemical Research, Kyoto University, Kyoto 611-0011, Japan
| | - Koichi Komatsu
- ∥Department of Environmental and Biological Chemistry, Fukui University of Technology, Gakuen, Fukui 910-8505, Japan
| | - Nicholas J Turro
- †Department of Chemistry, Columbia University, New York, New York 10027, United States
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Turro NJ. Fun with photons, reactive intermediates, and friends. Skating on the edge of the paradigms of physical organic chemistry, organic supramolecular photochemistry, and spin chemistry. J Org Chem 2011; 76:9863-90. [PMID: 22074596 DOI: 10.1021/jo201786a] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This Perspective presents a review and survey of the science and philosophy of my research career over the past five decades at Columbia as a physical organic chemist and photochemist. I explore the role of paradigms, structure, and geometric thinking in my own cognitive and intellectual development. The Perspective describes my investigations of high energy content molecules in electronically excited states and the development of electronic spin and supramolecular photochemistry chemistry. Current research dealing with the nuclear spin chemistry of H(2) incarcerated in buckyballs is illustrated. In the second part of this Perspective, I recount a personal role of the philosophy and history of science and the scientific communities' use of paradigms in their every day research and intellectual activities. Examples are given of the crucial role of geometry and structure in the rapid development of organic chemistry and physical organic chemistry over the past century.
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Affiliation(s)
- Nicholas J Turro
- Chemistry Department, Columbia University, New York, New York 10027, USA.
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Frunzi M, Jockusch S, Chen JYC, Krick Calderon RM, Lei X, Murata Y, Komatsu K, Guldi DM, Lawler RG, Turro NJ. A photochemical on-off switch for tuning the equilibrium mixture of H2 nuclear spin isomers as a function of temperature. J Am Chem Soc 2011; 133:14232-5. [PMID: 21842909 DOI: 10.1021/ja206383n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The photochemical interconversion of the two allotropes of the hydrogen molecule [para-H(2) (pH(2)) and ortho-H(2) (oH(2))] incarcerated inside the fullerene C(70) (pH(2)@C(70) and oH(2)@C(70), respectively) is reported. Photoexcitation of H(2)@C(70) generates a fullerene triplet state that serves as a spin catalyst for pH(2)/oH(2) conversion. This method provides a means of changing the pH(2)/oH(2) ratio inside C(70) by simply irradiating H(2)@C(70) at different temperatures, since the equilibrium ratio is temperature-dependent and the electronic triplet state of the fullerene produced by absorption of the photon serves as an "on-off" spin catalyst. However, under comparable conditions, no photolytic pH(2)/oH(2) interconversion was observed for H(2)@C(60), which was rationalized by the significantly shorter triplet lifetime of H(2)@C(60) relative to H(2)@C(70).
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Affiliation(s)
- Michael Frunzi
- Department of Chemistry, Columbia University, New York, New York 10027, USA
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Caregnato P, Jarocha LE, Esinhart HS, Lebedeva NV, Tarasov VF, Forbes MDE. Electrostatic control of spin exchange between mobile spin-correlated radical pairs created in micellar solutions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:5304-5309. [PMID: 21476533 DOI: 10.1021/la2005997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A series of photoinduced H-atom abstraction reactions between anthraquinone-2,6,-disulfonate, disodium salt (AQDS) and differently charged micellar substrates is presented. After a 248 nm excimer laser flash, the first excited triplet state of AQDS is rapidly formed and then quenched by abstraction of a hydrogen atom from the alkyl chain of the micelle surfactant, leading to a spin-correlated radical pair (SCRP). The SCRP is detected 500 ns after the laser flash using time-resolved (direct detection) electron paramagnetic resonance (TREPR) spectroscopy at X-band (9.5 GHz). By changing the charge on the surfactant headgroup from negative (sodium dodecyl sulfate, SDS) to positive (dodecyltrimethylammonium chloride, DTAC), TREPR spectra with different degrees of antiphase structure (APS) in their line shape were observed. The first derivative-like APS line shape is the signature of an SCRP experiencing an electron spin exchange interaction between the radical centers, which was clearly observable in DTAC micelles and absent in SDS micellar solutions. Solutions with surfactant concentrations well below the critical micelle concentration (cmc) or solutions where micellar formation had been disrupted (1:1 v/v CH(3)CN/H(2)O) also showed no APS line shapes in their TREPR spectra. These results support the conclusion that electrostatic forces between the sensitizer (AQDS) charge and the substrate (surfactant) headgroup charge are responsible for the observed effects. The results represent a new example of electrostatic control of a spin exchange interaction in mobile radical pairs.
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Affiliation(s)
- Paula Caregnato
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, C.C. 16, suc. 4, (1900) La Plata, Argentina
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Jiménez-Osés G, García JI, Corzana F, Elguero J. Accurate Calculation of Chemical Shifts in Highly Dynamic H2@C60 through an Integrated Quantum Mechanics/Molecular Dynamics Scheme. Org Lett 2011; 13:2528-31. [DOI: 10.1021/ol2004116] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Gonzalo Jiménez-Osés
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - José I. García
- Departamento de Química Orgánica, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
| | - Francisco Corzana
- Departamento de Química Universidad de La Rioja, 26006 Logroño, Spain
| | - José Elguero
- Instituto de Química Médica (CSIC), Serrano 117, 28006 Madrid, Spain
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Mamone S, Chen JYC, Bhattacharyya R, Levitt MH, Lawler RG, Horsewill AJ, Rõõm T, Bačić Z, Turro NJ. Theory and spectroscopy of an incarcerated quantum rotor: The infrared spectroscopy, inelastic neutron scattering and nuclear magnetic resonance of H2@C60 at cryogenic temperature. Coord Chem Rev 2011. [DOI: 10.1016/j.ccr.2010.12.029] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Li Y, Lei X, Lawler RG, Murata Y, Komatsu K, Turro NJ. Synthesis and characterization of bispyrrolidine derivatives of H2@C60: differentiation of isomers using 1H NMR spectroscopy of endohedral H2. Chem Commun (Camb) 2011; 47:2282-4. [DOI: 10.1039/c0cc04862c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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