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Huang W, Zhang Q, Wang R, Liu Z, Zhu Y, Yu F, Teo BK, Wang Z. Super-Excimer: Anomalous Bonding in a Metastable Excited-State Dimer of Superatomic Dimers. J Phys Chem Lett 2022; 13:8455-8461. [PMID: 36053267 DOI: 10.1021/acs.jpclett.2c02271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A new type of excimer formation was reported, which stems from an unexpected discovery of a short-lived excited-state dimer of superatomic dimers. In theoretical investigation of the dimer formation, it was found that the physical adsorption states maintain the closed-shell properties of the dimeric units via van der Waals interaction, while the chemical adsorption excited state is a broken-symmetry (BS) state, having a higher energy of about 0.5 eV. Potential energy surface calculations indicate that the short-lived metastable chemical bonding state can transform into energetically lower physical adsorption states by crossing a shallow energy barrier and eventually disintegrate into two ground-state dimers. Since the basic unit is a superatomic cluster, the chemical adsorption state discovered may be called "super-excimer", which opens up a new avenue for the discovery of tailorable excimer materials.
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Affiliation(s)
- Wanrong Huang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Qingyue Zhang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Rui Wang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Zhonghua Liu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Yu Zhu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Famin Yu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Boon K Teo
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Zhigang Wang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- College of Physics, Jilin University, Changchun 130012, China
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Shen W, Hu S, Lu X. Endohedral Metallofullerenes: New Structures and Unseen Phenomena. Chemistry 2020; 26:5748-5757. [PMID: 31886563 DOI: 10.1002/chem.201905306] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 12/27/2019] [Indexed: 02/06/2023]
Abstract
Endohedral metallofullerenes (EMFs), namely fullerenes with metallic species encapsulated inside, represent an ideal platform to investigate metal-metal or metal-carbon interactions at the sub-nanometer scale by means of single-crystal X-ray diffraction (XRD) crystallography. Herein, recent progress in the identification of new structures and unprecedented properties are discussed according to the categories of monometallofullerenes, dimetallofullerenes, carbide clusterfullerenes, and nitride clusterfullerenes. In particular, the dimerization and the cage-isomer dependent oxidation state of the inner metal atom are summarized in terms of pristine monometallofullerenes. Metal-metal bonds involving lanthanide-lanthanides or actinide-actinides are discussed based on both experimental and theoretical studies. The cluster-cage matching and/or mutual selections, as well as the rarely seen M=C double bonds, are discovered in M2 C2 @C2n , U2 C@C80 , M2 TiC@C80 , and Ti3 C3 @C80 . Subsequently, the geometries of different M3 N clusters in various cages are discussed, revealing size-matching between the internal M3 N cluster and the outer cage induced by the planarity of the cluster. Finally, an outlook regarding the future developments of the molecular structures and applications of EMFs is presented.
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Affiliation(s)
- Wangqiang Shen
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
| | - Shuaifeng Hu
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
| | - Xing Lu
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
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Singh MK, Shukla P, Khatua M, Rajaraman G. A Design Criteria to Achieve Giant Ising-Type Anisotropy in Co II -Encapsulated Metallofullerenes. Chemistry 2019; 26:464-477. [PMID: 31506987 DOI: 10.1002/chem.201903618] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/05/2019] [Indexed: 11/10/2022]
Abstract
Discovery of permanent magnetisation in molecules just like in hard magnets decades ago led to the proposal of utilising these molecules for information storage devices and also as Q-bits in quantum computing. A significant breakthrough with a blocking temperature as high as 80 K has been recently reported for lanthanocene complexes. While enhancing the blocking temperature further remains one of the primary challenges, obtaining molecules that are suitable for the fabrication of the devices sets the bar very high in this area. Encouraged by the fact that our earlier predictions of potential single-molecule magnets (SMMs) in lanthanide-containing endohedral fullerenes have been verified, here we set out to undertake a comprehensive study on CoII -ion-encapsulated fullerene as potential SMMs. To study this class of molecules, we have utilised an array of theoretical methods ranging from density functional to ab initio CASSCF/NEVPT2 methods for obtaining reliable estimate of zero-field splitting parameters D and E. Additionally, we have also employed, for the first time a combination of molecular dynamics based on DFT methods coupled with CASSCF/NEVPT2 methods to seek the role of conformational isomers in the relaxation of magnetisation. Particularly, we have studied, Co@C28 , Co@C38 and Co@C48 cages and their isomers as potential target molecules that could yield substantial magnetic anisotropy. Our calculations categorically reveal a very large Ising anisotropy in this class of molecules, with Co@C48 cages predicted to yield D values as high as -127 cm-1 . Our calculations on the smaller cages reveal the free movement of CoII ion inside the cage, leading to the likely scenario of faster relaxation of magnetisation. However, larger fullerene cages were found to solve this issue. Further models with incorporating units such as {CoOZn}, {CoScZnN} inside larger fullerenes yield axial zero-field splitting values as high as -200 cm-1 with negligible E/D values. As these units represent a strong axiality coupled with a viable way to obtain air-stable low-coordinate CoII complexes, this opens up a new paradigm in the search of SMMs in this class of molecules.
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Affiliation(s)
- Mukesh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Pratima Shukla
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Munmun Khatua
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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Konarev DV, Popov AA, Zorina LV, Khasanov SS, Lyubovskaya RN. Molecular Structure and Magnetic and Optical Properties of Endometallonitridofullerene Sc 3 N@I h -C 80 in Neutral, Radical Anion, and Dimeric Anionic Forms. Chemistry 2019; 25:14858-14869. [PMID: 31523861 DOI: 10.1002/chem.201902782] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/08/2019] [Indexed: 11/07/2022]
Abstract
A series of compounds with Sc3 N@Ih -C80 in the neutral, monomeric, and dimeric anion states have been prepared in the crystalline form and their molecular structures and optical and magnetic properties have been studied. The neutral Sc3 N@Ih -C80 ⋅3 C6 H4 Cl2 (1) and (Sc3 N@Ih -C80 )3 (TPC)2 ⋅5 C6 H4 Cl2 (2, TPC=triptycene) compounds both crystallized in a high-symmetry trigonal structure. The reduction of Sc3 N@Ih -C80 to the radical anion resulted in dimerization to form diamagnetic singly bonded (Sc3 N@Ih -C80 - )2 dimers. In contrast to {[2.2.2]cryptand(Na+ )}2 (Sc3 N@Ih -C80 - )2 ⋅2.5 C6 H4 Cl2 (3) with strongly disordered components, we synthesized new dimeric phases {[2.2.2]cryptand- (K+ )}2 (Sc3 N@Ih -C80 - )2 ⋅2 C6 H4 Cl2 (4) and {[2.2.2]cryptand- (Cs+ )}2 (Sc3 N@Ih -C80 - )2 ⋅2 C6 H4 Cl2 (5) in which only one major dimer orientation was found. The thermal stability of the (Sc3 N@Ih -C80 - )2 dimers was studied by EPR analysis of 3 to show their dissociation in the 400-460 K range producing monomeric Sc3 N@Ih -C80 .- radical anions. This species shows an EPR signal with a hyperfine splitting of 5.8 mT. The energy of the intercage C-C bond was estimated to be 234±7 kJ mol-1 , the highest value among negatively charged fullerene dimers. The EPR spectra of crystalline (Bu3 MeP+ )3 (Sc3 N@Ih -C80 .- )3 ⋅C6 H4 Cl2 (6) are presented for the first time. The salt shows an asymmetric EPR signal, which could be fitted by three lines. Two lines were attributed to Sc3 N@Ih -C80 .- . Hyperfine splitting is manifested above 180 K due to the hyperfine interaction of the electron spin with the three scandium atoms (a total of 22 lines with an average splitting of 5.32 mT are observed at 220 K). Furthermore, each of the 22 lines is additionally split into six lines with an average separation of 0.82 mT. The large splitting indicates intrinsic charge and spin density transfer from the fullerene cage to the Sc3 N cluster. Both the monomeric and dimeric Sc3 N@Ih -C80 - anions show an intrinsic shift of the IR bands attributed to the Sc3 N cluster and new bands corresponding to these species appear in the NIR range of their UV/Vis/NIR spectra, which allows these anions to be distinguished from neutral species.
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Affiliation(s)
- Dmitri V Konarev
- Department of Kinetics and Catalysis, Institute of Problems of Chemical Physics RAS, 142432, Moscow, Russian Federation
| | - Alexey A Popov
- Leibniz Institute for Solid State and Materials Research, Helmholtzstraße 20, 01069, Dresden, Germany
| | - Leokadiya V Zorina
- Institute of Solid State Physics RAS, 142432, Moscow, Russian Federation
| | - Salavat S Khasanov
- Institute of Solid State Physics RAS, 142432, Moscow, Russian Federation
| | - Rimma N Lyubovskaya
- Department of Kinetics and Catalysis, Institute of Problems of Chemical Physics RAS, 142432, Moscow, Russian Federation
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Jiang Y, Wang D, Xu D, Zhang J, Wang Z. Dimerization of Metallofullerenes to Obtain Materials with Enhanced Nonlinear Optical Properties. Chemphyschem 2018; 19:2995-3000. [DOI: 10.1002/cphc.201800797] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Yuhang Jiang
- Department of Chemistry; Renmin University of China; Beijing 100872 China
| | - Dongsheng Wang
- Department of Chemistry; Renmin University of China; Beijing 100872 China
| | - Dan Xu
- Department of Chemistry; Renmin University of China; Beijing 100872 China
| | - Jinying Zhang
- Center of Nanomaterials for Renewable Energy (CNRE); State Key Lab of Electrical Insulation and Power Equipment; School of Electrical Engineering; Xi'an Jiaotong University; Xi'an 710054 China
| | - Zhiyong Wang
- Department of Chemistry; Renmin University of China; Beijing 100872 China
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