101
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Franco C, Burrezo PM, Lloveras V, Caballero R, Alcón I, Bromley ST, Mas-Torrent M, Langa F, López Navarrete JT, Rovira C, Casado J, Veciana J. Operative Mechanism of Hole-Assisted Negative Charge Motion in Ground States of Radical-Anion Molecular Wires. J Am Chem Soc 2017; 139:686-692. [DOI: 10.1021/jacs.6b08649] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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102
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Zafra JL, Qiu L, Yanai N, Mori T, Nakano M, Alvarez MP, Navarrete JTL, Gómez-García CJ, Kertesz M, Takimiya K, Casado J. Reversible Dimerization and Polymerization of a Janus Diradical To Produce Labile C−C Bonds and Large Chromic Effects. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201605997] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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103
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Zafra JL, Qiu L, Yanai N, Mori T, Nakano M, Alvarez MP, Navarrete JTL, Gómez‐García CJ, Kertesz M, Takimiya K, Casado J. Reversible Dimerization and Polymerization of a Janus Diradical To Produce Labile C−C Bonds and Large Chromic Effects. Angew Chem Int Ed Engl 2016; 55:14563-14568. [DOI: 10.1002/anie.201605997] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Indexed: 11/09/2022]
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104
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Rudebusch GE, Espejo GL, Zafra JL, Peña-Alvarez M, Spisak SN, Fukuda K, Wei Z, Nakano M, Petrukhina MA, Casado J, Haley MM. A Biradical Balancing Act: Redox Amphoterism in a Diindenoanthracene Derivative Results from Quinoidal Acceptor and Aromatic Donor Motifs. J Am Chem Soc 2016; 138:12648-54. [DOI: 10.1021/jacs.6b07882] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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105
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Streifel BC, Zafra JL, Espejo GL, Gómez‐García CJ, Casado J, Tovar JD. Corrigendum: An Unusually Small Singlet–Triplet Gap in a Quinoidal 1,6‐Methano[10]annulene Resulting from Baird's 4
n
π‐Electron Triplet Stabilization. Angew Chem Int Ed Engl 2016; 55:9122. [DOI: 10.1002/anie.201605796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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106
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Rodríguez-Cabo T, Casado J, Rodríguez I, Ramil M, Cela R. Selective extraction and determination of neonicotinoid insecticides in wine by liquid chromatography–tandem mass spectrometry. J Chromatogr A 2016; 1460:9-15. [DOI: 10.1016/j.chroma.2016.07.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/01/2016] [Accepted: 07/04/2016] [Indexed: 01/09/2023]
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107
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Streifel BC, Zafra JL, Espejo GL, Gómez‐García CJ, Casado J, Tovar JD. Berichtigung: An Unusually Small Singlet–Triplet Gap in a Quinoidal 1,6‐Methano[10]annulene Resulting from Baird's 4
n
π‐Electron Triplet Stabilization. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201605796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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108
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Das S, Herng TS, Zafra JL, Burrezo PM, Kitano M, Ishida M, Gopalakrishna TY, Hu P, Osuka A, Casado J, Ding J, Casanova D, Wu J. Fully Fused Quinoidal/Aromatic Carbazole Macrocycles with Poly-radical Characters. J Am Chem Soc 2016; 138:7782-90. [DOI: 10.1021/jacs.6b04539] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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109
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Shen C, Loas G, Srebro‐Hooper M, Vanthuyne N, Toupet L, Cador O, Paul F, López Navarrete JT, Ramírez FJ, Nieto‐Ortega B, Casado J, Autschbach J, Vallet M, Crassous J. Iron Alkynyl Helicenes: Redox‐Triggered Chiroptical Tuning in the IR and Near‐IR Spectral Regions and Suitable for Telecommunications Applications. Angew Chem Int Ed Engl 2016; 55:8062-6. [DOI: 10.1002/anie.201601633] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Indexed: 02/05/2023]
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110
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Shen C, Loas G, Srebro‐Hooper M, Vanthuyne N, Toupet L, Cador O, Paul F, López Navarrete JT, Ramírez FJ, Nieto‐Ortega B, Casado J, Autschbach J, Vallet M, Crassous J. Iron Alkynyl Helicenes: Redox‐Triggered Chiroptical Tuning in the IR and Near‐IR Spectral Regions and Suitable for Telecommunications Applications. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601633] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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111
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Shi X, Quintero E, Lee S, Jing L, Herng TS, Zheng B, Huang KW, López Navarrete JT, Ding J, Kim D, Casado J, Chi C. Benzo-thia-fused [ n]thienoacenequinodimethanes with small to moderate diradical characters: the role of pro-aromaticity versus anti-aromaticity. Chem Sci 2016; 7:3036-3046. [PMID: 29997794 PMCID: PMC6005137 DOI: 10.1039/c5sc04706d] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 01/17/2016] [Indexed: 02/05/2023] Open
Abstract
Open-shell singlet diradicaloids have recently received much attention due to their unique optical, electronic and magnetic properties and promising applications in materials science. Among various diradicaloids, quinoidal π-conjugated molecules have become the prevailing design. However, the need for a fundamental understanding on how the fusion mode and pro-aromaticity/anti-aromaticity affect their diradical character and physical properties remains unaddressed. In this work, a series of pro-aromatic benzo-thia-fused [n]thienoacenequinodimethanes (Thn-TIPS (n = 1-3) and BDTh-TIPS) were synthesized and compared with the previously reported anti-aromatic bisindeno-[n]thienoacenes (Sn-TIPS, n = 1-4). The ground-state geometric and electronic structures of these new quinoidal molecules were systematically investigated by X-ray crystallographic analysis, variable temperature NMR, ESR, SQUID, Raman, and electronic absorption spectroscopy, assisted by DFT calculations. It was found that the diradical character index (y0) increased from nearly zero for Th1-TIPS to 2.4% for Th2-TIPS, 18.2% for Th3-TIPS, and 38.2% for BDTh-TIPS, due to the enhanced aromatic stabilization. Consequently, with the extension of molecular size, the one-photon absorption spectra are gradually red-shifted, the two-photon absorption (TPA) cross section values increase, and the singlet excited state lifetimes decrease. By comparison with the corresponding anti-aromatic analogues Sn-TIPS (n = 1-3), the pro-aromatic Thn-TIPS (n = 1-3) exhibit larger diradical character, longer singlet excited state lifetime and larger TPA cross section value. At the same time, they display distinctively different electronic absorption spectra and improved electrochemical amphotericity. Spectroelectrochemical studies revealed a good linear relationship between the optical energy gaps and the molecular length in the neutral, radical cationic and dicationic forms. Our research work discloses a significant difference between the pro-aromatic and anti-aromatic quinoidal compounds and provides guidance for the design of new diradicaloids with desirable properties.
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112
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Alvarez MP, Ruiz Delgado MC, Taravillo M, Baonza VG, López Navarrete JT, Evans P, Jasti R, Yamago S, Kertesz M, Casado J. The Raman fingerprint of cyclic conjugation: the case of the stabilization of cations and dications in cycloparaphenylenes. Chem Sci 2016; 7:3494-3499. [PMID: 29997841 PMCID: PMC6007183 DOI: 10.1039/c6sc00765a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/06/2016] [Indexed: 11/21/2022] Open
Abstract
Cyclic conjugation and Biradical formation in charged cycloparaphenylenes are described by Raman spectroscopy and DFT.
Radical cations and dications of [n]CPP from n = 5 to n = 12 have been studied by Raman spectroscopy and density functional theory. Small [n]CPP dications owe their stability to the closed-shell electronic structure imposed by cyclic conjugation surpassing the destabilizing effect of ring strain and of the electron deficiency of the charged states. Large [n]CPP dications mitigate cyclic strain by forming diradicals. The Raman spectra reflect the balance among cyclic conjugation, cyclic strain and biradicaloid stabilization by finding an unexpected turning point in the frequency behavior of the G vibrational modes as a function of size. These Raman data represent the vibrational fingerprint of this rare form of conjugation which is central to stabilize both cations and dications of [n]CPP macrocycles.
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113
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Riaño A, Arrechea‐Marcos I, Mancheño MJ, Mayorga Burrezo P, de la Peña A, Loser S, Timalsina A, Facchetti A, Marks TJ, Casado J, López Navarrete JT, Ponce Ortiz R, Segura JL. Benzotrithiophene versus Benzo/Naphthodithiophene Building Blocks: The Effect of Star‐Shaped versus Linear Conjugation on Their Electronic Structures. Chemistry 2016; 22:6374-81. [DOI: 10.1002/chem.201504526] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Indexed: 11/08/2022]
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114
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Peña-Alvarez M, Qiu L, Taravillo M, Baonza VG, Delgado MCR, Yamago S, Jasti R, Navarrete JTL, Casado J, Kertesz M. From linear to cyclic oligoparaphenylenes: electronic and molecular changes traced in the vibrational Raman spectra and reformulation of the bond length alternation pattern. Phys Chem Chem Phys 2016; 18:11683-92. [DOI: 10.1039/c5cp05500h] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Linear versus cyclic π-electron conjugation is discussed in oligoparaphenylenes.
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115
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Moreno-Yruela C, Garín J, Orduna J, Franco S, Quintero E, López Navarrete JT, Diosdado BE, Villacampa B, Casado J, Andreu R. D−π–A Compounds with Tunable Intramolecular Charge Transfer Achieved by Incorporation of Butenolide Nitriles as Acceptor Moieties. J Org Chem 2015; 80:12115-28. [DOI: 10.1021/acs.joc.5b02051] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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116
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Liu F, Espejo GL, Qiu S, Oliva MM, Pina J, Seixas de Melo JS, Casado J, Zhu X. Multifaceted Regioregular Oligo(thieno[3,4-b]thiophene)s Enabled by Tunable Quinoidization and Reduced Energy Band Gap. J Am Chem Soc 2015; 137:10357-66. [DOI: 10.1021/jacs.5b05940] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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117
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Casado J, Hernández V, López Navarrete JT. Vibrational Raman Shifts and Aromaticity: The Case of Oligothiophenes. CHEM REC 2015. [DOI: 10.1002/tcr.201500025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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118
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Zeng Z, Lee S, Son M, Fukuda K, Burrezo PM, Zhu X, Qi Q, Li RW, Navarrete JTL, Ding J, Casado J, Nakano M, Kim D, Wu J. Push–Pull Type Oligo(N-annulated perylene)quinodimethanes: Chain Length and Solvent-Dependent Ground States and Physical Properties. J Am Chem Soc 2015; 137:8572-83. [DOI: 10.1021/jacs.5b04156] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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119
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Nieto-Ortega B, Casado J, López Navarrete JT, Ramírez FJ, Tommasini M, Longhi G, Mazzeo G, Abbate S. Understanding the origin of the VCD signals on the basis of a nonredundant coordinate definition. J Chem Theory Comput 2015; 11:2633-41. [PMID: 26575560 DOI: 10.1021/acs.jctc.5b00106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The relationships between the chiroptical activity and the vibrational normal modes of epichlorohydrin have been investigated on the basis of a nonredundant internal coordinate definition not reported until now. These coordinates were verified by comparing, for the lower energy conformers, the diagonal quadratic force constants and were found to display similar values among conformers and to be consistent with the molecular structure of epichlorohydrin and its vibrational circular dichroism (VCD) spectrum. Boltzmann population factors were used to calculate the weighted sum of the individual VCD and IR spectra of the three lower energy conformers, which accurately fitted the experimental spectra of (R)-epichlorohydrin. The electric and magnetic transition dipole moments of the 24 vibrational normal modes were calculated for the most stable conformers. The combined analysis of these vectors and the normal mode description, given in terms of the potential energy distribution, allowed us to investigate the role of the functional groups (methylene, chlorine) and the type of internal coordinates (stretching, bending, etc.) in the chiroptical activity of the vibrations.
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Streifel BC, Zafra JL, Espejo GL, Gómez-García CJ, Casado J, Tovar JD. Innentitelbild: An Unusually Small Singlet-Triplet Gap in a Quinoidal 1,6-Methano[10]annulene Resulting from Baird’s 4 nπ-Electron Triplet Stabilization (Angew. Chem. 20/2015). Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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121
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Montes R, Rodríguez I, Casado J, López-Sabater M, Cela R. Determination of the cardiac drug amiodarone and its N-desethyl metabolite in sludge samples. J Chromatogr A 2015; 1394:62-70. [DOI: 10.1016/j.chroma.2015.03.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 12/22/2022]
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122
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Varnavski O, Abeyasinghe N, Aragó J, Serrano-Pérez JJ, Ortí E, López Navarrete JT, Takimiya K, Casanova D, Casado J, Goodson T. High Yield Ultrafast Intramolecular Singlet Exciton Fission in a Quinoidal Bithiophene. J Phys Chem Lett 2015; 6:1375-84. [PMID: 26263138 DOI: 10.1021/acs.jpclett.5b00198] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We report the process of singlet exciton fission with high-yield upon photoexcitation of a quinoidal thiophene molecule. Efficient ultrafast triplet photogeneration and its yield are determined by photoinduced triplet-triplet absorption, flash photolysis triplet lifetime measurements, as well as by femtosecond time-resolved transient absorption and fluorescence methods. These experiments show that optically excited quinoidal bithiophene molecule undergoes ultrafast formation of the triplet-like state with the lifetime ∼57 μs. CASPT2 and RAS-SF calculations have been performed to support the experimental findings. To date, high singlet fission rates have been reported for crystalline and polycrystalline materials, whereas for covalently linked dimers and small oligomers it was found to be relatively small. In this contribution, we show an unprecedented quantum yield of intramolecular singlet exciton fission of ∼180% for a quinoidal bithiophene system.
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Streifel BC, Zafra JL, Espejo GL, Gómez-García CJ, Casado J, Tovar JD. Inside Cover: An Unusually Small Singlet-Triplet Gap in a Quinoidal 1,6-Methano[10]annulene Resulting from Baird’s 4nπ-Electron Triplet Stabilization (Angew. Chem. Int. Ed. 20/2015). Angew Chem Int Ed Engl 2015. [DOI: 10.1002/anie.201502710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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124
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Streifel BC, Zafra JL, Espejo GL, Gómez-García CJ, Casado J, Tovar JD. An Unusually Small Singlet-Triplet Gap in a Quinoidal 1,6-Methano[10]annulene Resulting from Baird’s 4nπ-Electron Triplet Stabilization. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201500879] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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125
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Streifel BC, Zafra JL, Espejo GL, Gómez-García CJ, Casado J, Tovar JD. An Unusually Small Singlet-Triplet Gap in a Quinoidal 1,6-Methano[10]annulene Resulting from Baird’s 4nπ-Electron Triplet Stabilization. Angew Chem Int Ed Engl 2015; 54:5888-93. [DOI: 10.1002/anie.201500879] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Indexed: 11/05/2022]
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