The Experts below are selected from a list of 602583 Experts worldwide ranked by ideXlab platform
Kaho Nakatani - One of the best experts on this subject based on the ideXlab platform.
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quantum chemical study on the high Pressure Effect for 4 4 retrocycloaddition of anthracene cyclophane photodimer
Journal of Physical Chemistry C, 2019Co-Authors: Ryoichi Fukuda, Kaho NakataniAbstract:The [4 + 4] retrocycloaddition of bis anthracene photodimer yields anthracene cyclophane. The carbon–carbon bond cleavage in this reaction is significantly accelerated by applying high Pressure. We elucidate the origin of the Pressure Effect using the quantum chemical method considering the high-Pressure Effect with the extreme Pressure polarizable continuum model. The confinement by high-Pressure medium significantly deforms and destabilizes the photodimer structure, and this destabilization reduces the activation energy of the bond cleavage. The Pressure Effect significantly depends on the shapes of the solvation cavity, indicating that the Pressure Effect is specific to the orientation of the molecule with respect to the surrounding matrix. This finding clearly explains the observed biexponential behavior of the reaction rate that indicates the coexistence of Pressure-sensitive and Pressure-insensitive components. During deformation, the bridging sp3 carbons in photodimer involve sp2 character, and it ...
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quantum chemical study on the high Pressure Effect for 4 4 retrocycloaddition of anthracene cyclophane photodimer
The Journal of Physical Chemistry, 2019Co-Authors: Ryoichi Fukuda, Kaho NakataniAbstract:The [4 + 4] retrocycloaddition of bis anthracene photodimer yields anthracene cyclophane. The carbon–carbon bond cleavage in this reaction is significantly accelerated by applying high Pressure. We elucidate the origin of the Pressure Effect using the quantum chemical method considering the high-Pressure Effect with the extreme Pressure polarizable continuum model. The confinement by high-Pressure medium significantly deforms and destabilizes the photodimer structure, and this destabilization reduces the activation energy of the bond cleavage. The Pressure Effect significantly depends on the shapes of the solvation cavity, indicating that the Pressure Effect is specific to the orientation of the molecule with respect to the surrounding matrix. This finding clearly explains the observed biexponential behavior of the reaction rate that indicates the coexistence of Pressure-sensitive and Pressure-insensitive components. During deformation, the bridging sp³ carbons in photodimer involve sp² character, and it promotes the bond cleavage. From the mechanochemical point of view, a sizable mechanical force acts on atoms distanced from the reaction center, and the remote force assists the bond cleavage. This mechanism has an analogy to the principle of leverage. We also elucidate the Pressure Effects on ultraviolet–visible and infrared spectroscopies by quantum chemical computations for exploring the analysis methods in high-Pressure chemistry.
Ryoichi Fukuda - One of the best experts on this subject based on the ideXlab platform.
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quantum chemical study on the high Pressure Effect for 4 4 retrocycloaddition of anthracene cyclophane photodimer
Journal of Physical Chemistry C, 2019Co-Authors: Ryoichi Fukuda, Kaho NakataniAbstract:The [4 + 4] retrocycloaddition of bis anthracene photodimer yields anthracene cyclophane. The carbon–carbon bond cleavage in this reaction is significantly accelerated by applying high Pressure. We elucidate the origin of the Pressure Effect using the quantum chemical method considering the high-Pressure Effect with the extreme Pressure polarizable continuum model. The confinement by high-Pressure medium significantly deforms and destabilizes the photodimer structure, and this destabilization reduces the activation energy of the bond cleavage. The Pressure Effect significantly depends on the shapes of the solvation cavity, indicating that the Pressure Effect is specific to the orientation of the molecule with respect to the surrounding matrix. This finding clearly explains the observed biexponential behavior of the reaction rate that indicates the coexistence of Pressure-sensitive and Pressure-insensitive components. During deformation, the bridging sp3 carbons in photodimer involve sp2 character, and it ...
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quantum chemical study on the high Pressure Effect for 4 4 retrocycloaddition of anthracene cyclophane photodimer
The Journal of Physical Chemistry, 2019Co-Authors: Ryoichi Fukuda, Kaho NakataniAbstract:The [4 + 4] retrocycloaddition of bis anthracene photodimer yields anthracene cyclophane. The carbon–carbon bond cleavage in this reaction is significantly accelerated by applying high Pressure. We elucidate the origin of the Pressure Effect using the quantum chemical method considering the high-Pressure Effect with the extreme Pressure polarizable continuum model. The confinement by high-Pressure medium significantly deforms and destabilizes the photodimer structure, and this destabilization reduces the activation energy of the bond cleavage. The Pressure Effect significantly depends on the shapes of the solvation cavity, indicating that the Pressure Effect is specific to the orientation of the molecule with respect to the surrounding matrix. This finding clearly explains the observed biexponential behavior of the reaction rate that indicates the coexistence of Pressure-sensitive and Pressure-insensitive components. During deformation, the bridging sp³ carbons in photodimer involve sp² character, and it promotes the bond cleavage. From the mechanochemical point of view, a sizable mechanical force acts on atoms distanced from the reaction center, and the remote force assists the bond cleavage. This mechanism has an analogy to the principle of leverage. We also elucidate the Pressure Effects on ultraviolet–visible and infrared spectroscopies by quantum chemical computations for exploring the analysis methods in high-Pressure chemistry.
Hidenori Takagi - One of the best experts on this subject based on the ideXlab platform.
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gigantic anisotropic uniaxial Pressure Effect on superconductivity within the cuo2 plane of la1 64eu0 2sr0 16cuo4 strain control of stripe criticality
Journal of the Physical Society of Japan, 2004Co-Authors: Nao Takeshita, T Sasagawa, Takenari Sugioka, Yoshinori Tokura, Hidenori TakagiAbstract:The Effect of uniaxial Pressure on superconductivity was examined for high- T c cuprate La 1.64 Eu 0.2 Sr 0.16 CuO 4 , which is located at the boundary between the superconducting and stripe phases. We found markedly large anisotropy of the uniaxial Pressure Effect not only between the in-plane and out-of-plane Pressures but also within the tetragonal CuO 2 plane . When the Pressure is applied along the [110] direction, we found the largest Pressure Effect ever observed in cuprates, d T c /d P [110] ∼2.5 K/kbar, while the change in T c was not appreciable when the Pressure is applied along [100]. This substantial in-plane anisotropy is attributed to an intimate link between the symmetry of one-dimensional stripes and that of the strain produced within the CuO 2 plane.
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gigantic anisotropic uniaxial Pressure Effect on superconductivity within the cuo2 plane of la1 64eu0 2sr0 16cuo4 strain control of stripe criticality
arXiv: Strongly Correlated Electrons, 2003Co-Authors: Nao Takeshita, T Sasagawa, Takenari Sugioka, Yoshinori Tokura, Hidenori TakagiAbstract:The Effect of uniaxial Pressure on superconductivity was examined for a high-Tc cuprate La1.64Eu0.2Sr0.16CuO4, which is located at the boundary between the superconducting and stripe phases. We found remarkably large anisotropy of the uniaxial Pressure Effect not only between the in-plane and out-of-plane Pressures but also within the CuO2-plane. When the Pressure is applied along the tetragonal [110] direction, we found the largest Pressure Effect ever observed in cuprates, dTc/dP - 2.5 K/kbar, while the change of Tc was not appreciable when applied along [100]. This substantial in-plane anisotropy is attributed to an intimate link between the symmetry of the one-dimensional stripes and that of the strain produced within the CuO2 plane.
Markku Kulmala - One of the best experts on this subject based on the ideXlab platform.
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re evaluation of the Pressure Effect for nucleation in laminar flow diffusion chamber experiments with fluent and the fine particle model
Journal of Physical Chemistry A, 2009Co-Authors: Erik Herrmann, A P Hyvarinen, D Brus, H Lihavainen, Markku KulmalaAbstract:This study is an investigation of the Effect of total Pressure on homogeneous nucleation rates of n-butanol in helium and n-pentanol in helium and argon in a laminar flow diffusion chamber (LFDC). To verify earlier findings, experimental data was re-evaluated using the computational fluid dynamics (CFD) software FLUENT in combination with the fine particle model (FPM) for aerosol dynamics calculations. This approach has been introduced in an earlier paper [Herrmann, E.; Lihavainen, H.; Hyvarinen, A.-P.; Riipinen, I.; Wilck, M.; Stratmann, F.; Kulmala, M. J. Phys. Chem. A 2006, 110, 12448]. As a result of our evaluation, a flaw in the femtube2 code was found which had been used in the original data analysis [Hyvarinen, A.-P.; Brus, D.; Ždimal, V.; Smolik, J.; Kulmala, M.; Viisanen, Y.; Lihavainen, H. J. Chem. Phys. 2006, 124, 224304]. The FLUENT analysis yielded a weak positive Pressure Effect for the nucleation of n-butanol in helium at low nucleation temperatures (265−270 K). n-Pentanol in helium showed ...
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the carrier gas Pressure Effect in a laminar flow diffusion chamber homogeneous nucleation of n butanol in helium
Journal of Chemical Physics, 2006Co-Authors: A P Hyvarinen, Markku Kulmala, David Brus, Vladimir Zdimal, J Smolik, Yrjo Viisanen, H LihavainenAbstract:Homogeneous nucleation rate isotherms of n-butanol+helium were measured in a laminar flow diffusion chamber at total Pressures ranging from 50to210kPa to investigate the Effect of carrier gas Pressure on nucleation. Nucleation temperatures ranged from 265to280K and the measured nucleation rates were between 102 and 106cm−3s−1. The measured nucleation rates decreased as a function of increasing Pressure. The Pressure Effect was strongest at Pressures below 100kPa. This negative carrier gas Effect was also temperature dependent. At nucleation temperature of 280K and at the same saturation ratio, the maximum deviation between nucleation rates measured at 50 and 210kPa was about three orders of magnitude. At nucleation temperature of 265K, the Effect was negligible. Qualitatively the results resemble those measured in a thermal diffusion cloud chamber. Also the slopes of the isothermal nucleation rates as a function of saturation ratio were different as a function of total Pressure, 50kPa isotherms yielded th...
H Lihavainen - One of the best experts on this subject based on the ideXlab platform.
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re evaluation of the Pressure Effect for nucleation in laminar flow diffusion chamber experiments with fluent and the fine particle model
Journal of Physical Chemistry A, 2009Co-Authors: Erik Herrmann, A P Hyvarinen, D Brus, H Lihavainen, Markku KulmalaAbstract:This study is an investigation of the Effect of total Pressure on homogeneous nucleation rates of n-butanol in helium and n-pentanol in helium and argon in a laminar flow diffusion chamber (LFDC). To verify earlier findings, experimental data was re-evaluated using the computational fluid dynamics (CFD) software FLUENT in combination with the fine particle model (FPM) for aerosol dynamics calculations. This approach has been introduced in an earlier paper [Herrmann, E.; Lihavainen, H.; Hyvarinen, A.-P.; Riipinen, I.; Wilck, M.; Stratmann, F.; Kulmala, M. J. Phys. Chem. A 2006, 110, 12448]. As a result of our evaluation, a flaw in the femtube2 code was found which had been used in the original data analysis [Hyvarinen, A.-P.; Brus, D.; Ždimal, V.; Smolik, J.; Kulmala, M.; Viisanen, Y.; Lihavainen, H. J. Chem. Phys. 2006, 124, 224304]. The FLUENT analysis yielded a weak positive Pressure Effect for the nucleation of n-butanol in helium at low nucleation temperatures (265−270 K). n-Pentanol in helium showed ...
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the carrier gas Pressure Effect in a laminar flow diffusion chamber homogeneous nucleation of n butanol in helium
Journal of Chemical Physics, 2006Co-Authors: A P Hyvarinen, Markku Kulmala, David Brus, Vladimir Zdimal, J Smolik, Yrjo Viisanen, H LihavainenAbstract:Homogeneous nucleation rate isotherms of n-butanol+helium were measured in a laminar flow diffusion chamber at total Pressures ranging from 50to210kPa to investigate the Effect of carrier gas Pressure on nucleation. Nucleation temperatures ranged from 265to280K and the measured nucleation rates were between 102 and 106cm−3s−1. The measured nucleation rates decreased as a function of increasing Pressure. The Pressure Effect was strongest at Pressures below 100kPa. This negative carrier gas Effect was also temperature dependent. At nucleation temperature of 280K and at the same saturation ratio, the maximum deviation between nucleation rates measured at 50 and 210kPa was about three orders of magnitude. At nucleation temperature of 265K, the Effect was negligible. Qualitatively the results resemble those measured in a thermal diffusion cloud chamber. Also the slopes of the isothermal nucleation rates as a function of saturation ratio were different as a function of total Pressure, 50kPa isotherms yielded th...
