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Sun Jong Baek - One of the best experts on this subject based on the ideXlab platform.
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Conformationally specific vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of alkanethiols: structure and ionization of Conformational Isomers of ethanethiol, isopropanethiol, 1-propanethiol, tert-butanethiol, and 1-butanethiol.
The journal of physical chemistry. A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong Baek, Songhee Han, Doo-sik Ahn, Sang Kyu KimAbstract:Conformational Isomers of alkanethiols are isolated in the molecular beam, and the conformer-specific ionization dynamics have been investigated using vacuum ultraviolet mass-analyzed threshold ionization (MATI) spectroscopy. Only a single conformer of ethanethiol is observed to give the adiabatic ionization potential (IP) of 9.2922 +/- 0.0007 eV for the gauche conformer. For isopropanethiol, IP is found to be 9.1426 +/- 0.0006 for the trans conformer and 9.1559 +/- 0.0006 eV for the gauche conformer. Only two major Conformational Isomers are identified for 1-propanethiol, giving an IP of 9.1952 +/- 0.0006 for the trans-gauche conformer and 9.2008 +/- 0.0006 eV for the gauche-gauche conformer. The tert-butanethiol, as expected, has a single conformer with an IP of 9.0294 +/- 0.0006 eV. For 1-butanethiol, there are a number of conformers, and the assignment of the MATI bands to each conformer turns out to be nontrivial. The spectral simulation using the Franck-Condon analysis based on the density functional theory (DFT) calculations has been used for the identification of each Conformational Isomer in the MATI spectrum. Each conformer undergoes its unique structural change upon ionization, as revealed in the vibration resolved MATI spectrum, providing the powerful method for the spectral identification of a specific Conformational Isomer. The conformer specificity in the ionization-driven structural change reflects the role of the electron of the highest occupied molecular orbital (HOMO) in the Conformational preference.
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ionization spectroscopy of Conformational Isomers of propanal the origin of the Conformational preference
Journal of Physical Chemistry A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong BaekAbstract:Two different Conformational Isomers of propanal, cis and gauche, are investigated by the vacuum-UV mass-analyzed threshold ionization (VUV-MATI) spectroscopy to give accurate adiabatic ionization potentials of 9.9997 ± 0.0006 eV and 9.9516 ± 0.0006 eV, respectively. cis-Propanal, which is the more stable conformer in the neutral state, becomes less stable in the cation compared to gauche-propanal. Vibrational structures revealed in the MATI spectra indicate that cis and gauche Isomers undergo their unique structural changes upon ionization. The ionization of gauche-propanal induces a geometrical change along the Conformational coordinate, suggesting that the steric effect in the ground state is diminished upon ionization. Natural bonding orbital (NBO) calculations provide the extent of hyperconjugation in each Conformational Isomer of propanal.
Sun Young Choi - One of the best experts on this subject based on the ideXlab platform.
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Conformationally specific vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of alkanethiols: structure and ionization of Conformational Isomers of ethanethiol, isopropanethiol, 1-propanethiol, tert-butanethiol, and 1-butanethiol.
The journal of physical chemistry. A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong Baek, Songhee Han, Doo-sik Ahn, Sang Kyu KimAbstract:Conformational Isomers of alkanethiols are isolated in the molecular beam, and the conformer-specific ionization dynamics have been investigated using vacuum ultraviolet mass-analyzed threshold ionization (MATI) spectroscopy. Only a single conformer of ethanethiol is observed to give the adiabatic ionization potential (IP) of 9.2922 +/- 0.0007 eV for the gauche conformer. For isopropanethiol, IP is found to be 9.1426 +/- 0.0006 for the trans conformer and 9.1559 +/- 0.0006 eV for the gauche conformer. Only two major Conformational Isomers are identified for 1-propanethiol, giving an IP of 9.1952 +/- 0.0006 for the trans-gauche conformer and 9.2008 +/- 0.0006 eV for the gauche-gauche conformer. The tert-butanethiol, as expected, has a single conformer with an IP of 9.0294 +/- 0.0006 eV. For 1-butanethiol, there are a number of conformers, and the assignment of the MATI bands to each conformer turns out to be nontrivial. The spectral simulation using the Franck-Condon analysis based on the density functional theory (DFT) calculations has been used for the identification of each Conformational Isomer in the MATI spectrum. Each conformer undergoes its unique structural change upon ionization, as revealed in the vibration resolved MATI spectrum, providing the powerful method for the spectral identification of a specific Conformational Isomer. The conformer specificity in the ionization-driven structural change reflects the role of the electron of the highest occupied molecular orbital (HOMO) in the Conformational preference.
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ionization spectroscopy of Conformational Isomers of propanal the origin of the Conformational preference
Journal of Physical Chemistry A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong BaekAbstract:Two different Conformational Isomers of propanal, cis and gauche, are investigated by the vacuum-UV mass-analyzed threshold ionization (VUV-MATI) spectroscopy to give accurate adiabatic ionization potentials of 9.9997 ± 0.0006 eV and 9.9516 ± 0.0006 eV, respectively. cis-Propanal, which is the more stable conformer in the neutral state, becomes less stable in the cation compared to gauche-propanal. Vibrational structures revealed in the MATI spectra indicate that cis and gauche Isomers undergo their unique structural changes upon ionization. The ionization of gauche-propanal induces a geometrical change along the Conformational coordinate, suggesting that the steric effect in the ground state is diminished upon ionization. Natural bonding orbital (NBO) calculations provide the extent of hyperconjugation in each Conformational Isomer of propanal.
Sang Kyu Kim - One of the best experts on this subject based on the ideXlab platform.
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Spatial Isolation of Conformational Isomers of Hydroquinone and Its Water Cluster Using the Stark Deflector.
The journal of physical chemistry. A, 2018Co-Authors: Hyun Sik You, Songhee Han, Doo-sik Ahn, Junggil Kim, Jean Sun Lim, Sang Kyu KimAbstract:Conformational Isomers of hydroquinone and their 1:1 clusters with water have been spatially separated using a Stark deflector in a supersonic jet. trans-Hydroquinone (HyQ) conformer with zero dipole moment is little influenced by inhomogeneous electric fields, whereas cis conformer with nonzero dipole moment (2.38 D) is significantly deflected from the molecular beam axis into the direction along which the strong field gradient is applied. Resonant two photon ionization carried out by shifting the laser position perpendicular to the molecular beam axis after the Stark deflector then gives an exclusive S1-S0 excitation spectrum of the cis conformer only, making possible immaculate conformer-specific spectroscopy and dynamics. As the spatial separation is apparently proportional to the effective dipole moment strength, Conformational assignment could be absolute in the Stark deflector, which contrasts with the hole-burning spectroscopic technique where identification of a Conformational Isomer is intrinsically not unambiguous. trans- and cis-HyQ-H2O clusters have also been spatially separated according to their distinct effective dipole moment strengths to give absolute spectroscopic identification of each cluster Isomer, nailing down the otherwise disputable Conformational assignment. This is the first report for the spatial separation of Conformational cluster Isomers.
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Conformationally specific vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of alkanethiols: structure and ionization of Conformational Isomers of ethanethiol, isopropanethiol, 1-propanethiol, tert-butanethiol, and 1-butanethiol.
The journal of physical chemistry. A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong Baek, Songhee Han, Doo-sik Ahn, Sang Kyu KimAbstract:Conformational Isomers of alkanethiols are isolated in the molecular beam, and the conformer-specific ionization dynamics have been investigated using vacuum ultraviolet mass-analyzed threshold ionization (MATI) spectroscopy. Only a single conformer of ethanethiol is observed to give the adiabatic ionization potential (IP) of 9.2922 +/- 0.0007 eV for the gauche conformer. For isopropanethiol, IP is found to be 9.1426 +/- 0.0006 for the trans conformer and 9.1559 +/- 0.0006 eV for the gauche conformer. Only two major Conformational Isomers are identified for 1-propanethiol, giving an IP of 9.1952 +/- 0.0006 for the trans-gauche conformer and 9.2008 +/- 0.0006 eV for the gauche-gauche conformer. The tert-butanethiol, as expected, has a single conformer with an IP of 9.0294 +/- 0.0006 eV. For 1-butanethiol, there are a number of conformers, and the assignment of the MATI bands to each conformer turns out to be nontrivial. The spectral simulation using the Franck-Condon analysis based on the density functional theory (DFT) calculations has been used for the identification of each Conformational Isomer in the MATI spectrum. Each conformer undergoes its unique structural change upon ionization, as revealed in the vibration resolved MATI spectrum, providing the powerful method for the spectral identification of a specific Conformational Isomer. The conformer specificity in the ionization-driven structural change reflects the role of the electron of the highest occupied molecular orbital (HOMO) in the Conformational preference.
Kyowon Choi - One of the best experts on this subject based on the ideXlab platform.
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Conformationally specific vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of alkanethiols: structure and ionization of Conformational Isomers of ethanethiol, isopropanethiol, 1-propanethiol, tert-butanethiol, and 1-butanethiol.
The journal of physical chemistry. A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong Baek, Songhee Han, Doo-sik Ahn, Sang Kyu KimAbstract:Conformational Isomers of alkanethiols are isolated in the molecular beam, and the conformer-specific ionization dynamics have been investigated using vacuum ultraviolet mass-analyzed threshold ionization (MATI) spectroscopy. Only a single conformer of ethanethiol is observed to give the adiabatic ionization potential (IP) of 9.2922 +/- 0.0007 eV for the gauche conformer. For isopropanethiol, IP is found to be 9.1426 +/- 0.0006 for the trans conformer and 9.1559 +/- 0.0006 eV for the gauche conformer. Only two major Conformational Isomers are identified for 1-propanethiol, giving an IP of 9.1952 +/- 0.0006 for the trans-gauche conformer and 9.2008 +/- 0.0006 eV for the gauche-gauche conformer. The tert-butanethiol, as expected, has a single conformer with an IP of 9.0294 +/- 0.0006 eV. For 1-butanethiol, there are a number of conformers, and the assignment of the MATI bands to each conformer turns out to be nontrivial. The spectral simulation using the Franck-Condon analysis based on the density functional theory (DFT) calculations has been used for the identification of each Conformational Isomer in the MATI spectrum. Each conformer undergoes its unique structural change upon ionization, as revealed in the vibration resolved MATI spectrum, providing the powerful method for the spectral identification of a specific Conformational Isomer. The conformer specificity in the ionization-driven structural change reflects the role of the electron of the highest occupied molecular orbital (HOMO) in the Conformational preference.
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ionization spectroscopy of Conformational Isomers of propanal the origin of the Conformational preference
Journal of Physical Chemistry A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong BaekAbstract:Two different Conformational Isomers of propanal, cis and gauche, are investigated by the vacuum-UV mass-analyzed threshold ionization (VUV-MATI) spectroscopy to give accurate adiabatic ionization potentials of 9.9997 ± 0.0006 eV and 9.9516 ± 0.0006 eV, respectively. cis-Propanal, which is the more stable conformer in the neutral state, becomes less stable in the cation compared to gauche-propanal. Vibrational structures revealed in the MATI spectra indicate that cis and gauche Isomers undergo their unique structural changes upon ionization. The ionization of gauche-propanal induces a geometrical change along the Conformational coordinate, suggesting that the steric effect in the ground state is diminished upon ionization. Natural bonding orbital (NBO) calculations provide the extent of hyperconjugation in each Conformational Isomer of propanal.
Tae Yeon Kang - One of the best experts on this subject based on the ideXlab platform.
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Conformationally specific vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of alkanethiols: structure and ionization of Conformational Isomers of ethanethiol, isopropanethiol, 1-propanethiol, tert-butanethiol, and 1-butanethiol.
The journal of physical chemistry. A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong Baek, Songhee Han, Doo-sik Ahn, Sang Kyu KimAbstract:Conformational Isomers of alkanethiols are isolated in the molecular beam, and the conformer-specific ionization dynamics have been investigated using vacuum ultraviolet mass-analyzed threshold ionization (MATI) spectroscopy. Only a single conformer of ethanethiol is observed to give the adiabatic ionization potential (IP) of 9.2922 +/- 0.0007 eV for the gauche conformer. For isopropanethiol, IP is found to be 9.1426 +/- 0.0006 for the trans conformer and 9.1559 +/- 0.0006 eV for the gauche conformer. Only two major Conformational Isomers are identified for 1-propanethiol, giving an IP of 9.1952 +/- 0.0006 for the trans-gauche conformer and 9.2008 +/- 0.0006 eV for the gauche-gauche conformer. The tert-butanethiol, as expected, has a single conformer with an IP of 9.0294 +/- 0.0006 eV. For 1-butanethiol, there are a number of conformers, and the assignment of the MATI bands to each conformer turns out to be nontrivial. The spectral simulation using the Franck-Condon analysis based on the density functional theory (DFT) calculations has been used for the identification of each Conformational Isomer in the MATI spectrum. Each conformer undergoes its unique structural change upon ionization, as revealed in the vibration resolved MATI spectrum, providing the powerful method for the spectral identification of a specific Conformational Isomer. The conformer specificity in the ionization-driven structural change reflects the role of the electron of the highest occupied molecular orbital (HOMO) in the Conformational preference.
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ionization spectroscopy of Conformational Isomers of propanal the origin of the Conformational preference
Journal of Physical Chemistry A, 2008Co-Authors: Sun Young Choi, Tae Yeon Kang, Kyowon Choi, Sun Jong BaekAbstract:Two different Conformational Isomers of propanal, cis and gauche, are investigated by the vacuum-UV mass-analyzed threshold ionization (VUV-MATI) spectroscopy to give accurate adiabatic ionization potentials of 9.9997 ± 0.0006 eV and 9.9516 ± 0.0006 eV, respectively. cis-Propanal, which is the more stable conformer in the neutral state, becomes less stable in the cation compared to gauche-propanal. Vibrational structures revealed in the MATI spectra indicate that cis and gauche Isomers undergo their unique structural changes upon ionization. The ionization of gauche-propanal induces a geometrical change along the Conformational coordinate, suggesting that the steric effect in the ground state is diminished upon ionization. Natural bonding orbital (NBO) calculations provide the extent of hyperconjugation in each Conformational Isomer of propanal.