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Masahiro Irie - One of the best experts on this subject based on the ideXlab platform.
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A dominant factor of the Cycloreversion reactivity of diarylethene derivatives as revealed by femtosecond time-resolved absorption spectroscopy.
The Journal of chemical physics, 2020Co-Authors: Hikaru Sotome, Kanako Une, Tatsuhiro Nagasaka, Seiya Kobatake, Masahiro Irie, Hiroshi MiyasakaAbstract:Dynamics of the Cycloreversion reaction of a photochromic diarylethene derivative with a small ring-opening reaction yield (∼1%) was investigated by using femtosecond transient absorption spectroscopy. The reaction rate constant and activation barrier on the reaction coordinate were quantitatively analyzed on the basis of the temperature and excitation wavelength dependencies of the reaction yield and excited state dynamics. From the comparison of the present results with those in a more reactive derivative, we concluded that a key factor regulating the overall reaction yield is the branching ratio at the conical intersection where the excited state population is split into the product and the initial reactant. The excitation wavelength dependence of the dynamics indicated that the geometrical relaxation and vibrational cooling proceed in a few picosecond time scale behind the Cycloreversion process, and the vibrational excess energy assists the molecule to climb up the energy barrier.Dynamics of the Cycloreversion reaction of a photochromic diarylethene derivative with a small ring-opening reaction yield (∼1%) was investigated by using femtosecond transient absorption spectroscopy. The reaction rate constant and activation barrier on the reaction coordinate were quantitatively analyzed on the basis of the temperature and excitation wavelength dependencies of the reaction yield and excited state dynamics. From the comparison of the present results with those in a more reactive derivative, we concluded that a key factor regulating the overall reaction yield is the branching ratio at the conical intersection where the excited state population is split into the product and the initial reactant. The excitation wavelength dependence of the dynamics indicated that the geometrical relaxation and vibrational cooling proceed in a few picosecond time scale behind the Cycloreversion process, and the vibrational excess energy assists the molecule to climb up the energy barrier.
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multiphoton gated Cycloreversion reaction of a fluorescent diarylethene derivative as revealed by transient absorption spectroscopy
Physical Chemistry Chemical Physics, 2018Co-Authors: Tatsuhiro Nagasaka, Hikaru Sotome, Masahiro Irie, Tomohiro Kunishi, Masafumi Koga, Masakazu Morimoto, Hiroshi MiyasakaAbstract:The one- and two-photon Cycloreversion reactions of a fluorescent diarylethene derivative with oxidized benzothiophene moieties were investigated by means of ultrafast laser spectroscopy. Femtosecond transient absorption spectroscopy under the one-photon excitation condition revealed that the excited closed-ring isomer is simply deactivated into the initial ground state with a time constant of 2.6 ns without remarkable Cycloreversion, the results of which are consistent with the very low Cycloreversion reaction yield ( 1800.
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efficient Cycloreversion reaction of a diarylethene derivative in higher excited states attained by off resonant simultaneous two photon absorption
Journal of Physical Chemistry Letters, 2017Co-Authors: Hikaru Sotome, Kanako Une, Tatsuhiro Nagasaka, Seiya Kobatake, Masahiro Irie, Yukihide Ishibashi, Chiaki Okui, Kenji Kamada, Hiroshi MiyasakaAbstract:Off-resonant excitation of the closed-ring isomer of a photochromic diarylethene derivative at 730 nm induced the efficient Cycloreversion reaction with a yield of ∼20%, while the reaction yield was only 2% under one-photon excitation at 365 nm. Excitation wavelength dependence of the one-photon Cycloreversion reaction yield under steady-state irradiation in a wide wavelength range showed that the specific electronic state leading to the large Cycloreversion reaction yield, which is originally forbidden in the optical transition but partially allowed owing to the low symmetry of the molecule, is spectrally overlapped with the electronic state accessible by the allowed one-photon optical transition in the UV region. Femtosecond transient absorption spectroscopy also revealed that the off-resonant two-photon excitation preferentially pumped the molecule into the specific state, leading to the 10-fold enhancement of the Cycloreversion reaction.
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Efficient Cycloreversion Reaction of a Diarylethene Derivative in Higher Excited States Attained by Off-Resonant Simultaneous Two-Photon Absorption
2017Co-Authors: Hikaru Sotome, Kanako Une, Tatsuhiro Nagasaka, Seiya Kobatake, Masahiro Irie, Yukihide Ishibashi, Chiaki Okui, Kenji Kamada, Hiroshi MiyasakaAbstract:Off-resonant excitation of the closed-ring isomer of a photochromic diarylethene derivative at 730 nm induced the efficient Cycloreversion reaction with a yield of ∼20%, while the reaction yield was only 2% under one-photon excitation at 365 nm. Excitation wavelength dependence of the one-photon Cycloreversion reaction yield under steady-state irradiation in a wide wavelength range showed that the specific electronic state leading to the large Cycloreversion reaction yield, which is originally forbidden in the optical transition but partially allowed owing to the low symmetry of the molecule, is spectrally overlapped with the electronic state accessible by the allowed one-photon optical transition in the UV region. Femtosecond transient absorption spectroscopy also revealed that the off-resonant two-photon excitation preferentially pumped the molecule into the specific state, leading to the 10-fold enhancement of the Cycloreversion reaction
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solvent polarity dependence of photochromic reactions of a diarylethene derivative as revealed by steady state and transient spectroscopies
Journal of Physical Chemistry C, 2016Co-Authors: Yukihide Ishibashi, Hikaru Sotome, Kanako Une, Seiya Kobatake, Tetsuro Katayama, Toshiyuki Umesato, Mika Fujiwara, Yusuke Yoneda, Tsuyoshi Asahi, Masahiro IrieAbstract:Solvent polarity dependence of photochromic reactions such as cyclization and Cycloreversion of a photochromic diarylethene derivative, 1,2-bis(2-methyl-3-benzothienyl)perfluorocyclopentene, was investigated by steady-state spectroscopic and femtosecond laser photolysis methods. For the cyclization reaction, it was revealed that the quantum yield decreased with an increase in solvent polarities, mainly due to the decrease in the fraction of the conformer with C2 symmetry favorable for the cyclization. This result indicated that the branching ratio for the cyclization and the deactivation to the open-ring isomer at the conical intersection was almost independent of the solvent polarity. On the other hand, it was found for the Cycloreversion process that the closed-ring isomer in the S1 state rapidly deactivated into the ground state in competition with the activated process leading to the conical intersection providing a pathway toward both open- and closed-ring minima in the ground state. The cycloreversi...
Hiroshi Miyasaka - One of the best experts on this subject based on the ideXlab platform.
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A dominant factor of the Cycloreversion reactivity of diarylethene derivatives as revealed by femtosecond time-resolved absorption spectroscopy.
The Journal of chemical physics, 2020Co-Authors: Hikaru Sotome, Kanako Une, Tatsuhiro Nagasaka, Seiya Kobatake, Masahiro Irie, Hiroshi MiyasakaAbstract:Dynamics of the Cycloreversion reaction of a photochromic diarylethene derivative with a small ring-opening reaction yield (∼1%) was investigated by using femtosecond transient absorption spectroscopy. The reaction rate constant and activation barrier on the reaction coordinate were quantitatively analyzed on the basis of the temperature and excitation wavelength dependencies of the reaction yield and excited state dynamics. From the comparison of the present results with those in a more reactive derivative, we concluded that a key factor regulating the overall reaction yield is the branching ratio at the conical intersection where the excited state population is split into the product and the initial reactant. The excitation wavelength dependence of the dynamics indicated that the geometrical relaxation and vibrational cooling proceed in a few picosecond time scale behind the Cycloreversion process, and the vibrational excess energy assists the molecule to climb up the energy barrier.Dynamics of the Cycloreversion reaction of a photochromic diarylethene derivative with a small ring-opening reaction yield (∼1%) was investigated by using femtosecond transient absorption spectroscopy. The reaction rate constant and activation barrier on the reaction coordinate were quantitatively analyzed on the basis of the temperature and excitation wavelength dependencies of the reaction yield and excited state dynamics. From the comparison of the present results with those in a more reactive derivative, we concluded that a key factor regulating the overall reaction yield is the branching ratio at the conical intersection where the excited state population is split into the product and the initial reactant. The excitation wavelength dependence of the dynamics indicated that the geometrical relaxation and vibrational cooling proceed in a few picosecond time scale behind the Cycloreversion process, and the vibrational excess energy assists the molecule to climb up the energy barrier.
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Cycloreversion reaction of a fulgide derivative in higher excited states attained by femtosecond two photon pulsed excitation
Journal of Physical Chemistry C, 2018Co-Authors: Tatsuhiro Nagasaka, Hikaru Sotome, Yasushi Yokoyama, Yuma Yoshida, Hiroshi MiyasakaAbstract:The mechanism of the Cycloreversion reaction of a fulgide derivative in the higher excited states (Sn states) pumped by the stepwise two-photon excitation was investigated by femtosecond transient absorption spectroscopy. The first photon excitation of the ground state by the visible light led to the production of the Franck–Condon 1B state, which underwent internal conversion to the 2A state with 100 fs time constant and the structural reorganization accompanied with the vibrational cooling with 1.5 ps time constant. After these relaxation processes, the 2A state underwent the Cycloreversion reaction (11% reaction yield) with competitive nonradiative as well as radiative deactivation processes into the ground state with a time constant of 10 ps. Under the double-pulse pump condition, whereas the excitation of the 1B state induced no remarkable Cycloreversion reaction, the excitation of the 2A state resulted in the marked enhancement of the Cycloreversion reaction with a reaction quantum yield of ca. 80% ...
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multiphoton gated Cycloreversion reaction of a fluorescent diarylethene derivative as revealed by transient absorption spectroscopy
Physical Chemistry Chemical Physics, 2018Co-Authors: Tatsuhiro Nagasaka, Hikaru Sotome, Masahiro Irie, Tomohiro Kunishi, Masafumi Koga, Masakazu Morimoto, Hiroshi MiyasakaAbstract:The one- and two-photon Cycloreversion reactions of a fluorescent diarylethene derivative with oxidized benzothiophene moieties were investigated by means of ultrafast laser spectroscopy. Femtosecond transient absorption spectroscopy under the one-photon excitation condition revealed that the excited closed-ring isomer is simply deactivated into the initial ground state with a time constant of 2.6 ns without remarkable Cycloreversion, the results of which are consistent with the very low Cycloreversion reaction yield ( 1800.
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Cycloreversion Reaction of a Fulgide Derivative in Higher Excited States Attained by Femtosecond Two-Photon Pulsed Excitation
2018Co-Authors: Tatsuhiro Nagasaka, Hikaru Sotome, Yasushi Yokoyama, Yuma Yoshida, Hiroshi MiyasakaAbstract:The mechanism of the Cycloreversion reaction of a fulgide derivative in the higher excited states (Sn states) pumped by the stepwise two-photon excitation was investigated by femtosecond transient absorption spectroscopy. The first photon excitation of the ground state by the visible light led to the production of the Franck–Condon 1B state, which underwent internal conversion to the 2A state with 100 fs time constant and the structural reorganization accompanied with the vibrational cooling with 1.5 ps time constant. After these relaxation processes, the 2A state underwent the Cycloreversion reaction (11% reaction yield) with competitive nonradiative as well as radiative deactivation processes into the ground state with a time constant of 10 ps. Under the double-pulse pump condition, whereas the excitation of the 1B state induced no remarkable Cycloreversion reaction, the excitation of the 2A state resulted in the marked enhancement of the Cycloreversion reaction with a reaction quantum yield of ca. 80% in the Sn state. By summarizing the excitation wavelength dependence of the reaction amount on wavelengths of the second pump pulse, we discussed the mechanism of the effective multiphoton-gated reaction in highly excited states
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efficient Cycloreversion reaction of a diarylethene derivative in higher excited states attained by off resonant simultaneous two photon absorption
Journal of Physical Chemistry Letters, 2017Co-Authors: Hikaru Sotome, Kanako Une, Tatsuhiro Nagasaka, Seiya Kobatake, Masahiro Irie, Yukihide Ishibashi, Chiaki Okui, Kenji Kamada, Hiroshi MiyasakaAbstract:Off-resonant excitation of the closed-ring isomer of a photochromic diarylethene derivative at 730 nm induced the efficient Cycloreversion reaction with a yield of ∼20%, while the reaction yield was only 2% under one-photon excitation at 365 nm. Excitation wavelength dependence of the one-photon Cycloreversion reaction yield under steady-state irradiation in a wide wavelength range showed that the specific electronic state leading to the large Cycloreversion reaction yield, which is originally forbidden in the optical transition but partially allowed owing to the low symmetry of the molecule, is spectrally overlapped with the electronic state accessible by the allowed one-photon optical transition in the UV region. Femtosecond transient absorption spectroscopy also revealed that the off-resonant two-photon excitation preferentially pumped the molecule into the specific state, leading to the 10-fold enhancement of the Cycloreversion reaction.
Seiya Kobatake - One of the best experts on this subject based on the ideXlab platform.
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A dominant factor of the Cycloreversion reactivity of diarylethene derivatives as revealed by femtosecond time-resolved absorption spectroscopy.
The Journal of chemical physics, 2020Co-Authors: Hikaru Sotome, Kanako Une, Tatsuhiro Nagasaka, Seiya Kobatake, Masahiro Irie, Hiroshi MiyasakaAbstract:Dynamics of the Cycloreversion reaction of a photochromic diarylethene derivative with a small ring-opening reaction yield (∼1%) was investigated by using femtosecond transient absorption spectroscopy. The reaction rate constant and activation barrier on the reaction coordinate were quantitatively analyzed on the basis of the temperature and excitation wavelength dependencies of the reaction yield and excited state dynamics. From the comparison of the present results with those in a more reactive derivative, we concluded that a key factor regulating the overall reaction yield is the branching ratio at the conical intersection where the excited state population is split into the product and the initial reactant. The excitation wavelength dependence of the dynamics indicated that the geometrical relaxation and vibrational cooling proceed in a few picosecond time scale behind the Cycloreversion process, and the vibrational excess energy assists the molecule to climb up the energy barrier.Dynamics of the Cycloreversion reaction of a photochromic diarylethene derivative with a small ring-opening reaction yield (∼1%) was investigated by using femtosecond transient absorption spectroscopy. The reaction rate constant and activation barrier on the reaction coordinate were quantitatively analyzed on the basis of the temperature and excitation wavelength dependencies of the reaction yield and excited state dynamics. From the comparison of the present results with those in a more reactive derivative, we concluded that a key factor regulating the overall reaction yield is the branching ratio at the conical intersection where the excited state population is split into the product and the initial reactant. The excitation wavelength dependence of the dynamics indicated that the geometrical relaxation and vibrational cooling proceed in a few picosecond time scale behind the Cycloreversion process, and the vibrational excess energy assists the molecule to climb up the energy barrier.
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tuning of optical properties and thermal Cycloreversion reactivity of photochromic diarylbenzene by introducing electron donating substituents
The Journal of Physical Chemistry, 2019Co-Authors: Tatsumoto Nakahama, Daichi Kitagawa, Seiya KobatakeAbstract:Thermally reversible photochromic compounds having excellent physicochemical properties can be exploited for many practical applications, such as ophthalmic lenses, real-time holography, and super-resolution microscopy. In this study, we have designed and synthesized novel 1,2-diarylbenzene derivatives bearing various electron-donating substituents at the p-position of the phenyl ring to tune the optical and thermal properties for practical applications. The introduction of the electron-donating groups resulted in the red shift of the absorption spectra, an increase in the absorption coefficients of the open-ring isomers, and deceleration of the thermal Cycloreversion of the closed-ring isomers. Theoretical analysis based on Hammett’s substituent constant and density functional theory revealed that the rate of thermal Cycloreversion became lower in proportion to the electron-donating ability of the substituent. The novel 1,2-diarylbenzene derivatives synthesized here could undergo photocyclization upon irradiation with UV-A light and fast thermal Cycloreversion with a half-life of a few hundred milliseconds to seconds.
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efficient Cycloreversion reaction of a diarylethene derivative in higher excited states attained by off resonant simultaneous two photon absorption
Journal of Physical Chemistry Letters, 2017Co-Authors: Hikaru Sotome, Kanako Une, Tatsuhiro Nagasaka, Seiya Kobatake, Masahiro Irie, Yukihide Ishibashi, Chiaki Okui, Kenji Kamada, Hiroshi MiyasakaAbstract:Off-resonant excitation of the closed-ring isomer of a photochromic diarylethene derivative at 730 nm induced the efficient Cycloreversion reaction with a yield of ∼20%, while the reaction yield was only 2% under one-photon excitation at 365 nm. Excitation wavelength dependence of the one-photon Cycloreversion reaction yield under steady-state irradiation in a wide wavelength range showed that the specific electronic state leading to the large Cycloreversion reaction yield, which is originally forbidden in the optical transition but partially allowed owing to the low symmetry of the molecule, is spectrally overlapped with the electronic state accessible by the allowed one-photon optical transition in the UV region. Femtosecond transient absorption spectroscopy also revealed that the off-resonant two-photon excitation preferentially pumped the molecule into the specific state, leading to the 10-fold enhancement of the Cycloreversion reaction.
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Efficient Cycloreversion Reaction of a Diarylethene Derivative in Higher Excited States Attained by Off-Resonant Simultaneous Two-Photon Absorption
2017Co-Authors: Hikaru Sotome, Kanako Une, Tatsuhiro Nagasaka, Seiya Kobatake, Masahiro Irie, Yukihide Ishibashi, Chiaki Okui, Kenji Kamada, Hiroshi MiyasakaAbstract:Off-resonant excitation of the closed-ring isomer of a photochromic diarylethene derivative at 730 nm induced the efficient Cycloreversion reaction with a yield of ∼20%, while the reaction yield was only 2% under one-photon excitation at 365 nm. Excitation wavelength dependence of the one-photon Cycloreversion reaction yield under steady-state irradiation in a wide wavelength range showed that the specific electronic state leading to the large Cycloreversion reaction yield, which is originally forbidden in the optical transition but partially allowed owing to the low symmetry of the molecule, is spectrally overlapped with the electronic state accessible by the allowed one-photon optical transition in the UV region. Femtosecond transient absorption spectroscopy also revealed that the off-resonant two-photon excitation preferentially pumped the molecule into the specific state, leading to the 10-fold enhancement of the Cycloreversion reaction
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solvent polarity dependence of photochromic reactions of a diarylethene derivative as revealed by steady state and transient spectroscopies
Journal of Physical Chemistry C, 2016Co-Authors: Yukihide Ishibashi, Hikaru Sotome, Kanako Une, Seiya Kobatake, Tetsuro Katayama, Toshiyuki Umesato, Mika Fujiwara, Yusuke Yoneda, Tsuyoshi Asahi, Masahiro IrieAbstract:Solvent polarity dependence of photochromic reactions such as cyclization and Cycloreversion of a photochromic diarylethene derivative, 1,2-bis(2-methyl-3-benzothienyl)perfluorocyclopentene, was investigated by steady-state spectroscopic and femtosecond laser photolysis methods. For the cyclization reaction, it was revealed that the quantum yield decreased with an increase in solvent polarities, mainly due to the decrease in the fraction of the conformer with C2 symmetry favorable for the cyclization. This result indicated that the branching ratio for the cyclization and the deactivation to the open-ring isomer at the conical intersection was almost independent of the solvent polarity. On the other hand, it was found for the Cycloreversion process that the closed-ring isomer in the S1 state rapidly deactivated into the ground state in competition with the activated process leading to the conical intersection providing a pathway toward both open- and closed-ring minima in the ground state. The cycloreversi...
Jianping Lang - One of the best experts on this subject based on the ideXlab platform.
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capturing the organic species derived from the c c cleavage and in situ oxidation of 1 2 3 4 tetra pyridin 4 yl cyclobutane by cucn n based mofs
Inorganic Chemistry, 2018Co-Authors: Liang Chen, Ming Dai, Jianping LangAbstract:The solvothermal Cycloreversion and in situ oxidation of 1,2,3,4-tetra(pyridin-4-yl)cyclobutane (tpcb) within [CuCN]n-based MOFs were investigated. The radical mechanism for the Cycloreversion of tpcb ligands was supported by capturing a 1,3-butadiene species 1,2,3,4-tetra(4-pyridyl)-1,3-butadiene (tpyb) into {[Cu18(μ-CN)18(tpcb)4(tpyb)2]·H2O}n in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). Without TEMPO, a furan-based ligand 2,3,4,5-tetra(4-pyridyl)furan (tpyf) was generated within {[Cu4(μ-CN)4(tpyf)]·4MeCN}n via the C–C cleavage, followed by in situ oxidation in acidic condition.
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Capturing the Organic Species Derived from the C–C Cleavage and in Situ Oxidation of 1,2,3,4-Tetra(pyridin-4-yl)cyclobutane by [CuCN]n‑Based MOFs
2018Co-Authors: Liang Chen, Ming Dai, Jianping LangAbstract:The solvothermal Cycloreversion and in situ oxidation of 1,2,3,4-tetra(pyridin-4-yl)cyclobutane (tpcb) within [CuCN]n-based MOFs were investigated. The radical mechanism for the Cycloreversion of tpcb ligands was supported by capturing a 1,3-butadiene species 1,2,3,4-tetra(4-pyridyl)-1,3-butadiene (tpyb) into {[Cu18(μ-CN)18(tpcb)4(tpyb)2]·H2O}n in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). Without TEMPO, a furan-based ligand 2,3,4,5-tetra(4-pyridyl)furan (tpyf) was generated within {[Cu4(μ-CN)4(tpyf)]·4MeCN}n via the C–C cleavage, followed by in situ oxidation in acidic condition
Miguel A Miranda - One of the best experts on this subject based on the ideXlab platform.
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Photoinduced Electron-Transfer Cycloreversion of Thietanes: The Role of Ion−Molecule Complexes
Organic Letters, 2010Co-Authors: Juan E Arguello, Raúl Pérez-ruiz, Miguel A MirandaAbstract:Cycloreversion (CR) of thietane radical cations leads to formation of thiobenzophenone and the corresponding alkenes, eventually followed by secondary [4 + 2] cycloaddition. Final product distribution depends on the ability of fragments to escape from ion−molecule complexes (IMCs).
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Photoinduced electron-transfer Cycloreversion of thietanes: the role of ion-molecule complexes.
Organic letters, 2010Co-Authors: Juan E Arguello, Raúl Pérez-ruiz, Miguel A MirandaAbstract:Cycloreversion (CR) of thietane radical cations leads to formation of thiobenzophenone and the corresponding alkenes, eventually followed by secondary [4 + 2] cycloaddition. Final product distribution depends on the ability of fragments to escape from ion−molecule complexes (IMCs).
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Cycloreversion of azetidines via oxidative electron transfer steady state and time resolved studies
Organic Letters, 2008Co-Authors: Inmaculada Andreu, Julio Delgado, Amparo Espinos, Raul Perezruiz, Consuelo M Jimenez, Miguel A MirandaAbstract:Cycloreversion of cis- and trans-1,2,3-triphenylazetidine (c-2 and t-2) is achieved by electron transfer to (tris(4-bromophenyl)aminium radical cation (5•+). Stepwise C−N and C−C bond cleavage of a...
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Theoretical calculations on the Cycloreversion of oxetane radical cations.
Journal of Physical Chemistry A, 2005Co-Authors: M. Angeles Izquierdo, Luis R. Domingo, Miguel A MirandaAbstract:: The molecular mechanism for the Cycloreversion of oxetane radical cations has been studied at the UB3LYP/6-31G* level. Calculations support that the Cycloreversion takes place via a concerted but asynchronous process, where C-C bond breaking at the transition state is more advanced than O-C breaking. This allows a favorable rearrangement of the spin electron density from the oxetane radical cation (with the spin density located mainly on the oxygen atom) to the alkene radical cation which is one of the final products. Inclusion of solvent effects does not modify the gas-phase results.
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Chemical and transient spectroscopic evidence for C2–C3 cleavage of 2,3-diaryloxetane radical cations
Chemical Communications, 2003Co-Authors: Miguel A Miranda, M. Angeles IzquierdoAbstract:Electron transfer Cycloreversion of the methoxy substituted oxetane 1b results in the production of trans-anethole and benzaldehyde through C2–C3 bond cleavage. trans-Anethole radical cation has been detected as transient intermediate by laser flash photolysis.
