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Saito K, Miyazawa T, Fujiwara A, Hishida M, Saitoh H, Massalska-Arodź M, Yamamura Y. Reassessment of structure of smectic phases: Nano-segregation in smectic E phase in 4-n-alkyl-4′-isothiocyanato-1,1′-biphenyls. J Chem Phys 2013; 139:114902. [DOI: 10.1063/1.4821162] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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2
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Sorai M, Nakazawa Y, Nakano M, Miyazaki Y. Update 1 of: Calorimetric Investigation of Phase Transitions Occurring in Molecule-Based Magnets. Chem Rev 2013; 113:PR41-122. [DOI: 10.1021/cr300156s] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michio Sorai
- Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yasuhiro Nakazawa
- Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Motohiro Nakano
- Department of Applied Chemistry,
Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871,
Japan
| | - Yuji Miyazaki
- Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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Ikeuchi S, Yamamura Y, Yoshida Y, Mitsumi M, Toriumi K, Saito K. Calorimetric Study of Correlated Ligand Dynamics in Mixed-Valence MMX Chain Complex [{Ni2(n-BuCS2)4}I]. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2010. [DOI: 10.1246/bcsj.20090301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Naumov P, Sakurai K, Ishikawa T, Takahashi J, Koshihara SY, Ohashi Y. Intramolecular Nitro-Assisted Proton Transfer in Photoirradiated 2-(2‘,4‘-Dinitrobenzyl)pyridine: Polarized Optical Spectroscopic Study and Electronic Structure Calculations. J Phys Chem A 2005; 109:7264-75. [PMID: 16834092 DOI: 10.1021/jp0520392] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nitro-assisted proton transfer (NAPT), responsible for the photoactivity of ortho-nitrobenzylpyridines and a model for the nitro-based caged compounds, is studied along with the parent compound 2-(2',4'-dinitrobenzyl)pyridine (DNBP) with polarized optical spectroscopy and theoretical calculations. The transition dipole moments of a DNBP single-crystal identified oriented molecules of the long-lived enamine tautomer (NH), rather than of the aci-nitro tautomer (OH), as carriers of the photoinduced blue coloration. It is clarified that the blue second singlet transition owes to intramolecular charge transfer from the allyl-pyridinium part to the dinitrophenyl fragment of NH. The theoretical modeling of the ground-state potential energy surface showed that while NH and OH can interconvert by means of direct proton transfer, such a process between the initial form CH and either OH and NH would require significant rotation of the aromatic rings. In the ground state, OH is less stable but the kinetically preferred product over NH. Once created, regardless of whether via ground-state or excited-state routes, the aci-nitro group of OH undergoes energetically inexpensive rotation to deliver the proton to the nitrogen acceptor. The "softening" of the energy surface around OH due to its structural flexibility, that is, mediation of the proton transfer by the nitro group, is crucial to overcome the high barrier for a direct proton jump from CH to NH, even in cases of unfavorable donor-acceptor geometry. The very small structural change experienced by the surrounding of a molecule undergoing NAPT is promising for the design of photoactive systems which retain their crystallinity during a prolonged operation.
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Affiliation(s)
- Pance Naumov
- ICYS, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
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Ikeuchi S, Miyazaki Y, Takeda S, Akutagawa T, Nishihara S, Nakamura T, Saito K. Cooperativity of dynamics of 18-crown-6 molecule forming one-dimensional chain in Cs2(18-crown-6)3[Ni(dmit)2]2. J Chem Phys 2005; 123:044514. [PMID: 16095376 DOI: 10.1063/1.1979481] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Heat capacity of Cs2(18-crown-6)3[Ni(dmit)2]2 was measured by adiabatic calorimetry. A broad thermal anomaly was observed around 225 K. The entropy gain (about 52 J K(-1) mol(-1)) is much larger than that expected for twofold disordering of 18-crown-6 assumed in the previous structure analysis. The shape of thermal anomaly was qualitatively explained by a linear Ising model developed for cooperative disordering in polymers. The 18-crown-6 molecules forming a one-dimensional chain in the crystal are orientationally disordered with moderate cooperativity.
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Affiliation(s)
- Satoaki Ikeuchi
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, 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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Saito K, Ikeuchi S, Nakazawa Y, Sato A, Mitsumi M, Yamashita T, Toriumi K, Sorai M. Alkyl Group as Entropy Reservoir in an MMX Chain Complex, Pt2(n-PenCS2)4I. J Phys Chem B 2005; 109:2956-61. [PMID: 16851309 DOI: 10.1021/jp046187o] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Heat capacity of halogen-bridged one-dimensional binuclear metal complex (so-called MMX chain) having four n-pentyl groups, Pt2(n-PenCS2)4I, was measured by adiabatic calorimetry. A first-order phase transition was observed at 207.4 K when measurement was made after cooling from room temperature. The enthalpy and entropy of transition were determined to be 10.19 kJ mol(-1) and 49.1 J K(-1) mol(-1), respectively. A monotropic phase transition was observed at 324 K on heating, and the entropy of transition was essentially null. The sample once heated above 324 K never returned to the initial phase at room temperature and underwent a higher-order phase transition at 173 K and a first-order phase transition at 220.5 K. The enthalpy and entropy of the first-order phase transition were estimated to be 11.6 kJ mol(-1) and 52.4 J K(-1) mol(-1), respectively. The magnitude of the entropy gain at the phase transition from the initial room-temperature phase to the high-temperature phase at 324 K shows that in Pt2(n-PenCS2)4I a large amount of entropy reserved in alkyl chain is transferred to dithiocarboxylato groups upon the phase transition, as in the cases of Pt2(n-PrCS2)4I and Pt2(n-BuCS2)4I.
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Affiliation(s)
- Kazuya Saito
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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Khuong TAV, Zepeda G, Sanrame CN, Dang H, Bartberger MD, Houk KN, Garcia-Garibay MA. Crankshaft Motion in a Highly Congested Bis(triarylmethyl)peroxide. J Am Chem Soc 2004; 126:14778-86. [PMID: 15535703 DOI: 10.1021/ja046987c] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Crankshaft motion has been proposed in the solid state for molecular fragments consisting of three or more rotors linked by single bonds, whereby the two terminal rotors are static and the internal rotors experience circular motion. Bis-[tri-(3,5-di-tert-butyl)phenylmethyl]-peroxide 2 was tested as a model in search of crankshaft motion at the molecular level. In the case of peroxide 2, the bulky trityl groups may be viewed as the external static rotors, while the two peroxide oxygens can undergo the sought after internal rotation. Evidence for this process in the case of peroxide 2 was obtained from conformational dynamics determined by variable-temperature (13)C and (1)H NMR between 190 and 375 K in toluene-d(8). Detailed spectral assignments for the interpretation of two coalescence processes were based on a correlation between NMR spectra obtained in solution at low temperature, in the solid state by (13)C CPMAS NMR, and by GIAO calculations based on a B3LYP/6-31G structure of 2 obtained from its X-ray coordinates as the input. Evidence supporting crankshaft rotation rather than slippage of the trityl groups was obtained from molecular mechanics calculations.
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Affiliation(s)
- Tinh-Alfredo V Khuong
- Department of Chemistry and Biochemistry, University of California-Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1569, USA
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Harada J, Ogawa K. X-ray diffraction analysis of nonequilibrium states in crystals: observation of an unstable conformer in flash-cooled crystals. J Am Chem Soc 2004; 126:3539-44. [PMID: 15025482 DOI: 10.1021/ja038203l] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Some molecules with a molecular skeleton similar to that of stilbenes and azobenzenes show orientational disorder in the crystals. If the disorder is dynamic, a conformational interconversion takes place through a pedal motion. In this study X-ray diffraction analyses of (E)-stilbene (1) and azobenzene (2) were carried out at various temperatures. We succeeded in observing thermodynamic nonequilibrium states that were generated by fast freezing of the conformational interconversion at low temperatures. The populations of the two conformers in crystals of 1 at 90 K varied with the cooling rate. Flash cooling of a crystal of 2 from room temperature to 90 K made it possible to observe the minor unstable conformer that does not exist in the equilibrium state at the same temperature.
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Affiliation(s)
- Jun Harada
- Department of Chemistry, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
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Saito K, Massalska-Arodz M, Ikeuchi S, Maekawa M, Sciesinski J, Sciesinska E, Mayer J, Wasiutynski T, Sorai M. Thermodynamic Study on a Chiral Glass Former, 4-(1-Methylheptyloxy)-4‘-cyanobiphenyl. J Phys Chem B 2004. [DOI: 10.1021/jp049777v] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kazuya Saito
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Maria Massalska-Arodz
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Satoaki Ikeuchi
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Masashi Maekawa
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Jacek Sciesinski
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Ewa Sciesinska
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Jacek Mayer
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Tadeusz Wasiutynski
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Michio Sorai
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, and The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
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Saito K, Okada M, Akutsu H, Sato A, Sorai M. Freezing of Crankshaft Motion of trans-Stilbene Molecule in Charge-Transfer Complexes, STB-TCNQ and STB-TCNQF4. J Phys Chem B 2004. [DOI: 10.1021/jp036630f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kazuya Saito
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Mizuho Okada
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Hiroki Akutsu
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Akane Sato
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Michio Sorai
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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Ikeuchi S, Saito K, Nakazawa Y, Mitsumi M, Toriumi K, Sorai M. Calorimetric Study of a Halogen-Bridged MMX Chain Complex Having Alkyl Chains, Pt2(n-PrCS2)4I (n-Pr = Propyl Group). J Phys Chem B 2003. [DOI: 10.1021/jp035835l] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Satoaki Ikeuchi
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Department of Chemistry, Graduate School of Science and Technology, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8850, Japan, Department of Material Science, Himeji Institute of Technology, Harima Science Park City, Hyogo 678-1297, Japan
| | - Kazuya Saito
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Department of Chemistry, Graduate School of Science and Technology, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8850, Japan, Department of Material Science, Himeji Institute of Technology, Harima Science Park City, Hyogo 678-1297, Japan
| | - Yasuhiro Nakazawa
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Department of Chemistry, Graduate School of Science and Technology, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8850, Japan, Department of Material Science, Himeji Institute of Technology, Harima Science Park City, Hyogo 678-1297, Japan
| | - Minoru Mitsumi
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Department of Chemistry, Graduate School of Science and Technology, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8850, Japan, Department of Material Science, Himeji Institute of Technology, Harima Science Park City, Hyogo 678-1297, Japan
| | - Koshiro Toriumi
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Department of Chemistry, Graduate School of Science and Technology, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8850, Japan, Department of Material Science, Himeji Institute of Technology, Harima Science Park City, Hyogo 678-1297, Japan
| | - Michio Sorai
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Department of Chemistry, Graduate School of Science and Technology, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8850, Japan, Department of Material Science, Himeji Institute of Technology, Harima Science Park City, Hyogo 678-1297, Japan
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Sorai M, Saito K. Alkyl chains acting as entropy reservoir in liquid crystalline materials. CHEM REC 2003; 3:29-39. [PMID: 12552529 DOI: 10.1002/tcr.10046] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The roles played by the conformational disordering of alkyl chains in determining the aggregation states of matter are reviewed for liquid crystalline materials from a thermodynamic perspective. Entropy, which is one of the most macroscopic concepts but which has a clear microscopic meaning, provides crucial microscopic information for complex systems for which a microscopic description is hard to establish. Starting from structural implication by absolute (third-law) entropy for crystalline solids, the existence of successive phase transitions caused by the successive conformational melting of alkyl chains in discotic mesogens is explained. An experimental basis is given for the "quasi-binary picture" of thermotropic liquid crystals, i.e., the highly disordered alkyl chains behave like a second component (solvent). A novel entropy transfer between the "components" of a molecule and the resulting "alkyl chains as entropy reservoir" mechanism are explained for cubic mesogens.
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Affiliation(s)
- Michio Sorai
- Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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Harada J, Ogawa K. Invisible but common motion in organic crystals: a pedal motion in stilbenes and azobenzenes. J Am Chem Soc 2001; 123:10884-8. [PMID: 11686690 DOI: 10.1021/ja011197d] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Some molecules that have a molecular skeleton similar to stilbenes and azobenzenes are known to show an orientational disorder in the crystals. Some of the disorders are known to be dynamic and mediated by a pedal motion in crystals. Dynamic processes of (E)-stilbene (1) and (E)-3,3',4,4'-tetramethylazobenzene (2) in the crystals were investigated by X-ray diffraction analyses. The dynamic disorder and the pedal motion were detected at higher temperature, even in the molecules that showed no traces of the disorder at room temperature. The results demonstrated that the pedal motion should always be taken into account, even if no disorder is detected. The reasons for the nonoccurrence of the disorder and for the prevalence of the pedal motion are also discussed.
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Affiliation(s)
- J Harada
- Department of Chemistry, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan
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