Co-reporter:Hikaru Sotome, Tatsuhiro Nagasaka, Kanako Une, Soichiro Morikawa, Tetsuro Katayama, Seiya Kobatake, Masahiro Irie, and Hiroshi Miyasaka
Journal of the American Chemical Society November 29, 2017 Volume 139(Issue 47) pp:17159-17159
Publication Date(Web):November 6, 2017
DOI:10.1021/jacs.7b09763
Two-color, two-pulse femtosecond pulsed excitation was applied to the elucidation of the dynamics and mechanism of cycloreversion reaction of a diarylethene derivative in the higher excited states. Transient absorption spectroscopy under one-photon visible excitation revealed that the 1B state produced by the excitation undergoes the internal conversion into the 2A state with a time constant of 200 fs. Geometrical rearrangement of the 2A state takes place concomitantly with the vibrational cooling with a time constant of 3 ps. The resultant 2A state undergoes the transition into the conical intersection point in competition with nonradiative as well as radiative deactivation into the ground state with a time constant of 12 ps. The second pulse excitation of the 2A state, especially the geometrically relaxed 2A state, led to the significant enhancement of the cycloreversion reaction through the large reaction quantum yield of ca. 50–90% in the higher excited state (Sn state), while the excitation of the 1B state, leading to the Sn′ state, did not induce such enhancement. By integrating with the excitation wavelength dependence of the second pump laser pulse, we discussed the chemical reactivity of diarylethene derivatives in terms of the symmetry of the electronic states.
Co-reporter:Ryota Kashihara, Masakazu Morimoto, Syoji Ito, Hiroshi Miyasaka, and Masahiro Irie
Journal of the American Chemical Society November 22, 2017 Volume 139(Issue 46) pp:16498-16498
Publication Date(Web):November 7, 2017
DOI:10.1021/jacs.7b10697
Photoswitchable turn-on mode fluorescent molecules have been so far successfully used in super-resolution fluorescence microscopies. Here, we report on fluorescence photoswitching of 1,2-bis(2-ethyl-6-phenyl-1-benzothiophene-1,1-dioxide-3-yl)perfluorocyclopentene (1) by irradiation with single-wavelength visible (420 nm < λ < 470 nm) light, the wavelength of which is longer than the 0–0 transition of open-ring isomer 1a, without UV light excitation. By absorbing very weak hot bands or Urbach tails 1a underwent a cyclization reaction to produce fluorescent closed-ring isomer 1b. Both cyclization and cycloreversion reactions of 1 took place with the visible light in the far off-resonance region of the absorption edge. Based on numerical simulations of the formation process of 1b from 1a by irradiation with 450 nm light, weak absorption coefficients at 450 nm in n-hexane and CCl4 were estimated to be 0.084 and 0.19 M–1 cm–1, respectively. The reversible fluorescence photoswitching with the single visible light is advantageously applicable to super-resolution fluorescence imaging in biological systems.
Co-reporter:Benoît Roubinet, Michael Weber, Heydar Shojaei, Mark Bates, Mariano L. Bossi, Vladimir N. Belov, Masahiro Irie, and Stefan W. Hell
Journal of the American Chemical Society May 17, 2017 Volume 139(Issue 19) pp:6611-6611
Publication Date(Web):April 24, 2017
DOI:10.1021/jacs.7b00274
A modular assembly of water-soluble diarylethenes (DAEs), applicable as biomarkers for optical nanoscopy, is reported. Reversibly photoswitchable 1,2-bis(2-alkyl-6-phenyl-1-benzothiophene-1,1-dioxide-3-yl)perfluorocyclopentenes possessing a fluorescent “closed” form were decorated with one or two methoxy group(s) attached to the para-position(s) of phenyl ring(s) and two, four, or eight carboxylic acid groups. Antibody conjugates of these DAEs feature low aggregation, efficient photoswitching in aqueous buffers, specific staining of cellular structures, and photophysical properties (high emission efficiencies and low cycloreversion quantum yields) enabling their application in superresolution microscopy. Images of tubulin, vimentin, and nuclear pore complexes are presented. The superresolution images can also be acquired by using solely 488 nm light without additional photoactivation with UV light. These DAEs exhibit reversible photoswitching without requiring any additives to the imaging media and open new paths toward the modular design of fluorescent dyes for bioimaging with optical superresolution.
Co-reporter:Hikaru Sotome, Tatsuhiro Nagasaka, Kanako Une, Chiaki Okui, Yukihide Ishibashi, Kenji Kamada, Seiya Kobatake, Masahiro Irie, and Hiroshi Miyasaka
The Journal of Physical Chemistry Letters July 20, 2017 Volume 8(Issue 14) pp:3272-3272
Publication Date(Web):July 5, 2017
DOI:10.1021/acs.jpclett.7b01388
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.
Co-reporter:Yuta Takagi, Masakazu Morimoto, Ryota Kashihara, Sae Fujinami, Syoji Ito, Hiroshi Miyasaka, Masahiro Irie
Tetrahedron 2017 Volume 73, Issue 33(Issue 33) pp:
Publication Date(Web):17 August 2017
DOI:10.1016/j.tet.2017.03.040
Turn-on mode fluorescence switching molecules are applicable to super-resolution fluorescence microscopy, such as PALM (photoactivation localization microscopy), STORM (stochastic optical reconstruction microscopy) or RESOLFT (reversible saturable (switchable) optical linear fluorescence transitions) microscopy. Here we report on a molecular design strategy to control the cycloreversion quantum yield of the turn-on mode fluorescent diarylethenes, 1,2-bis(2-ethyl-6-aryl-1-benzothiophene-1,1-dioxide-3-yl)perfluorocyclopentenes. Diarylethene derivatives having ortho-substituted phenyl rings at 6- and 6′-positions of 1,2-bis(2-ethyl-1-benzothiophene-1,1-dioxide-3-yl)perfluorocyclopentene were synthesized and their photophysical and photochemical properties were evaluated. The ortho-substitution of the phenyl rings with fluorine or methyl groups decreases the extension of π-conjugation length, resulting in a small blue shift of the absorption spectrum and a substantial increase in the cycloreversion quantum yield from 10−4 to 10−2 without significant influence on the fluorescence quantum yield. Water-soluble derivatives having sodium sulfonate groups were also synthesized. These derivatives fulfill requirements necessary for the application to RESOLFT super-resolution fluorescence microscopy.Download high-res image (150KB)Download full-size image
Co-reporter:Yuhei Arai;Syoji Ito;Hajime Fujita;Yusuke Yoneda;Takahiro Kaji;Satoshi Takei;Ryota Kashihara;Masakazu Morimoto;Hiroshi Miyasaka
Chemical Communications 2017 vol. 53(Issue 29) pp:4066-4069
Publication Date(Web):2017/04/06
DOI:10.1039/C6CC10073B
We demonstrated one-colour control of activation, excitation and deactivation of a fluorescent diarylethene derivative by using a 532 nm CW laser at a weak output power. This one-colour control method was applied to single-molecule tracking in polymer films over a total duration of a few hours at room temperature and PALM for the nanostructures of polymer systems.
Co-reporter:Yukihide Ishibashi
The Journal of Physical Chemistry C 2016 Volume 120(Issue 2) pp:1170-1177
Publication Date(Web):December 29, 2015
DOI:10.1021/acs.jpcc.5b08504
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 cycloreversion reaction quantum yield also decreasing with an increase in the solvent polarity was attributed to larger increase of the direct deactivation into the ground state from the excited state minimum of the closed-ring isomer.
Co-reporter:Satoko Ohshima, Masakazu Morimoto and Masahiro Irie
Chemical Science 2015 vol. 6(Issue 10) pp:5746-5752
Publication Date(Web):14 Jul 2015
DOI:10.1039/C5SC01994J
Mixed crystals composed of 1,2-bis(2-methyl-5-(p-methoxyphenyl)-3-thienyl)perfluorocyclopentene (1a) and 1,2-bis(5-methyl-2-(p-methoxyphenyl)-4-thiazolyl)perfluorocyclopentene (2a) were prepared, and their photochromic as well as light-driven bending performance was studied to reveal how shape changes of individual molecules cause the bending response. 1a and 2a molecules, having similar geometrical structures, randomly mix with each other in a single crystal. The absorption spectra of the closed-ring isomers 1b and 2b were, however, distinctly different. The difference of the spectra made it possible to discriminate the cycloreversion reactions of 1b and 2b in the mixed crystals by irradiation with 750 nm light. The bending response of the mixed crystals by the selective photoisomerization revealed that the local shape change of each molecule is additively linked to the macroscopic deformation of the crystals.
Co-reporter:Takaki Sumi, Tomohiro Kaburagi, Masakazu Morimoto, Kanako Une, Hikaru Sotome, Syoji Ito, Hiroshi Miyasaka, and Masahiro Irie
Organic Letters 2015 Volume 17(Issue 19) pp:4802-4805
Publication Date(Web):September 16, 2015
DOI:10.1021/acs.orglett.5b02361
A new fluorescent photochromic diarylethene that can be activated by irradiation with 405 nm light was synthesized. The turn-on mode switching of fluorescence with visible light is favorable for application to biological systems. The fluorescence quantum yield of the photogenerated closed-ring isomer was as high as 0.8 in less or medium polar solvents, and even in polar acetonitrile the yield was higher than 0.6.
Co-reporter:Masahiro Irie, Tuyoshi Fukaminato, Kenji Matsuda, and Seiya Kobatake
Chemical Reviews 2014 Volume 114(Issue 24) pp:12174
Publication Date(Web):December 16, 2014
DOI:10.1021/cr500249p
Co-reporter:Tuyoshi Fukaminato ; Takashi Hirose ; Takao Doi ; Masaki Hazama ; Kenji Matsuda
Journal of the American Chemical Society 2014 Volume 136(Issue 49) pp:17145-17154
Publication Date(Web):November 12, 2014
DOI:10.1021/ja5090749
Photoactive molecules that reversibly switch upon visible light irradiation are one of the most attractive targets for biological as well as imaging applications. One possible approach to prepare such photoswitches is to extend π-conjugation length of molecules and shift the absorption bands to longer wavelengths. Although several attempts have been demonstrated based on this approach for diarylethene (DAE) photoswitches, photoreactivity of the DAE derivatives is dramatically suppressed when the conjugation length is extended by connecting aromatic dyes at the side positions of aryl groups in the DAE unit. In this study, we successfully prepared a visible-light reactive DAE derivative by introducing an aromatic dye at the reactive carbon atom of the DAE unit, optimizing orbital level of each component, and controlling the mutual orientation of the aromatic dye and the DAE unit. The DAE derivative (3) undergoes a photocyclization reaction upon irradiation with 560 nm light and the closed-isomer converts to the open-ring isomer upon irradiation with 405 nm light. The high photoconversion yields (>90%) were achieved for both photocyclization and photocycloreversion reactions. The photoreactivity induced by visible light irradiation and the molecular design strategy were discussed based on theoretical calculations.
Co-reporter:Takaki Sumi, Yuta Takagi, Akira Yagi, Masakazu Morimoto and Masahiro Irie
Chemical Communications 2014 vol. 50(Issue 30) pp:3928-3930
Publication Date(Web):05 Mar 2014
DOI:10.1039/C4CC00396A
The cycloreversion quantum yields of compounds 1b and 2b increased upon irradiation with light at shorter wavelengths. The irradiation wavelength dependence is ascribed to the energy barrier on the 2A potential energy surface in the excited electronic state.
Co-reporter:Tomohiro Ichikawa, Masakazu Morimoto and Masahiro Irie
Photochemical & Photobiological Sciences 2014 vol. 13(Issue 2) pp:199-204
Publication Date(Web):19 Sep 2013
DOI:10.1039/C3PP50239B
A photochromic diarylethene having 2-methyl-4-pyridyl groups formed chiral cocrystals with (R)- or (S)-1,1′-bi-2-naphthol (BINOL). X-ray crystal structure analysis revealed that the diarylethene forms O–H⋯N type hydrogen bonds with BINOL and the central hexatriene moiety is fixed in P- or M-helix conformation in the cocrystals. The diarylethene molecules underwent reversible cyclization reactions in the single-component crystal as well as in the cocrystals upon alternate irradiation with ultraviolet (UV) and visible light. In the chiral cocrystals, a highly enantioselective photocyclization reaction took place owing to the conformational confinement.
Co-reporter:Yuichiro Shoji;Akira Yagi;Masahiro Horiuchi;Masakazu Morimoto
Israel Journal of Chemistry 2013 Volume 53( Issue 5) pp:303-311
Publication Date(Web):
DOI:10.1002/ijch.201300018
Abstract
Photochromic diarylethene derivatives bearing hydrophilic N,N-bis(2-(2-(2-methoxyethoxy)ethoxy)ethyl)sulfonamide (SO2NTEG2) (1–3) or myo-inositol (4–6) substituents were synthesized. Although the solubility in aqueous solution of the derivatives containing the four tri(ethylene glycol) chains was relatively poor, the solubility was improved by introducing two myo-inositol residues. The derivatives could be dissolved even in pure water and underwent photochromism upon alternate irradiation with ultraviolet (UV) and visible light, in both organic and aqueous solutions. The absorption maxima of the open- and closed-ring isomers of these derivatives and the photostationary conversion ratios from the open- to the closed-ring isomers upon UV irradiation did not change much, even when the solvent polarity was changed. These results indicate that the diarylethene derivatives are mono-molecularly dissolved in aqueous solution and that intermolecular interactions between the derivatives are negligible when the concentration is less than 1×10−4 mol⋅L−1.
Co-reporter:Yuta Takagi, Tomohiro Kunishi, Tetsuro Katayama, Yukihide Ishibashi, Hiroshi Miyasaka, Masakazu Morimoto and Masahiro Irie
Photochemical & Photobiological Sciences 2012 vol. 11(Issue 11) pp:1661-1665
Publication Date(Web):02 Jul 2012
DOI:10.1039/C2PP25078K
The sulfone derivatives of 1,2-bis(2-alkyl-6-phenyl-1-benzothiophen-3-yl)perfluorocyclopentene having various short alkyl chain substituents at reactive carbons were prepared and the effect of alkyl substitution on the fluorescence property of the closed-ring isomers was studied. Upon irradiation with ultraviolet (UV) light the derivatives exhibit a brilliant green fluorescence under irradiation with visible (> 400 nm) light, while the fluorescence disappears upon irradiation with visible (> 400 nm) light alone. The fluorescence quantum yield of the methyl substituted derivative (1b) dramatically decreases from 0.84 to 0.15 when the solvent is changed from hexane to acetonitrile, while the changes of ethyl, n-propyl and n-butyl substituted derivatives (2b)–(4b) are moderate. The quantum yields of (2b)–(4b) are kept to values close to 0.7 even in polar acetonitrile. The fluorescence lifetime measurement revealed that efficient non-radiative decay processes took place in (1b) in polar solvent, while their contribution to the deactivation was not so large in (2b)–(4b). The neighboring short alkyl chains at the connecting carbons are considered to defend the sulfone units against the attack of polar solvent molecules and weaken the solvent polarity effect.
Co-reporter:Yukihide Ishibashi ; Toshiyuki Umesato ; Seiya Kobatake ; Masahiro Irie ;Hiroshi Miyasaka
The Journal of Physical Chemistry C 2012 Volume 116(Issue 7) pp:4862-4869
Publication Date(Web):February 1, 2012
DOI:10.1021/jp2107632
Temperature dependencies of cyclization and cycloreversion processes of a photochromic diarylethene derivative, 1,2-bis(2-methyl-3-benzothienyl)perfluorocyclopentene (BT), were investigated by steady-state spectroscopy and femtosecond laser photolysis methods. Steady-state measurements revealed that the cyclization reaction quantum yield and the fraction of the conformer with C2v symmetry favorable for the cyclization (antiparallel, AP conformer) were independent of temperature in the range of 253–343 K. These results indicated that the cyclization reaction of the AP conformer in the open-ring isomer in the excited state had no apparent temperature dependence and suggested that the fate of the excited AP conformer in the open-ring isomer, such as cyclization or deactivation to the ground state, was determined at the conical intersection. On the other hand, the cycloreversion reaction was dependent on the temperature; the reaction quantum yield increased together with a decrease in the lifetime of the excited state of the closed-ring isomer with increasing temperature. On the basis of the adiabatic energy surface for the reaction profiles, it was deduced that the rapid deactivation into the ground state took place in the S1 state in competition with the activated pathways leading to the conical intersection where the cycloreversion occurred.
Co-reporter:Fumitaka Terao;Dr. Masakazu Morimoto ;Dr. Masahiro Irie
Angewandte Chemie International Edition 2012 Volume 51( Issue 4) pp:901-904
Publication Date(Web):
DOI:10.1002/anie.201105585
Co-reporter:Fumitaka Terao;Dr. Masakazu Morimoto ;Dr. Masahiro Irie
Angewandte Chemie International Edition 2012 Volume 51( Issue 4) pp:
Publication Date(Web):
DOI:10.1002/anie.201107570
Co-reporter:Fumitaka Terao;Dr. Masakazu Morimoto ;Dr. Masahiro Irie
Angewandte Chemie 2012 Volume 124( Issue 4) pp:
Publication Date(Web):
DOI:10.1002/ange.201107570
Co-reporter:Fumitaka Terao;Dr. Masakazu Morimoto ;Dr. Masahiro Irie
Angewandte Chemie 2012 Volume 124( Issue 4) pp:925-928
Publication Date(Web):
DOI:10.1002/ange.201105585
Co-reporter:Kazuya Mori ; Yukihide Ishibashi ; Hirohisa Matsuda ; Syoji Ito ; Yutaka Nagasawa ; Hirotomo Nakagawa ; Kingo Uchida ; Satoshi Yokojima ; Shinichiro Nakamura ; Masahiro Irie ;Hiroshi Miyasaka
Journal of the American Chemical Society 2011 Volume 133(Issue 8) pp:2621-2625
Publication Date(Web):February 4, 2011
DOI:10.1021/ja108992t
One-color control of colorization/decolorization reactions of diarylethene molecules was attained by using nonresonant high-order multiphoton absorption processes with a near-infrared (NIR) femtosecond laser pulse at 1.28 μm with 35 fs full width at half-maximum (fwhm). The intensity of a rather weak laser pulse (<1 nJ/pulse) can induce the simultaneous three-photon absorption leading to the colorization, while much weaker intensity induces two-photon absorption resulting in the decolorization. The spatial patterning concomitant with higher-order multiphoton absorption processes was also demonstrated.
Co-reporter:Tuyoshi Fukaminato ; Takao Doi ; Nobuyuki Tamaoki ; Katsuki Okuno ; Yukihide Ishibashi ; Hiroshi Miyasaka
Journal of the American Chemical Society 2011 Volume 133(Issue 13) pp:4984-4990
Publication Date(Web):March 10, 2011
DOI:10.1021/ja110686t
Single-molecule fluorescence photoswitching plays an essential role in ultrahigh-density (Tbits/inch2) optical memories and super-high-resolution fluorescence imaging. Although several fluorescent photochromic molecules and fluorescent proteins have been applied, so far, to optical memories and super-high-resolution imaging, their performance is unsatisfactory because of the absence of “non-destructive fluorescence readout capability”. Here we report on a new molecular design principle of a molecule having non-destructive readout capability. The molecule is composed of acceptor photochromic diarylethene and donor fluorescent perylenebisimide units. The fluorescence is reversibly quenched when the diarylethene unit converts between the open- and the closed-ring isomers upon irradiation with visible and UV light. The fluorescence quenching is based on an electron transfer from the donor to the acceptor units. The fluorescence photoswitching and non-destructive readout capability were demonstrated in solution (an ensemble state) and at the single-molecule level. Femtosecond time-resolved transient and fluorescent lifetime measurements confirmed that the fluorescence quenching is attributed to the intramolecular electron transfer.
Co-reporter:Kakishi Uno ; Hiroyuki Niikura ; Masakazu Morimoto ; Yukihide Ishibashi ; Hiroshi Miyasaka
Journal of the American Chemical Society 2011 Volume 133(Issue 34) pp:13558-13564
Publication Date(Web):August 5, 2011
DOI:10.1021/ja204583e
Photoswitchable or photoactivatable fluorescent dyes are potentially applicable to ultrahigh density optical memory media as well as super-resolution fluorescence imaging when the dyes are highly fluorescent and have large absorption coefficients. Here, we report on highly fluorescent photochromic dyes, which are initially nonluminous in solution under irradiation with visible light but activated to emit green or red fluorescence upon irradiation with ultraviolet (UV) light. The dyes 5a–9a are sulfone derivatives of 1,2-bis(2-ethyl-6-phenyl(or thienyl)-1-benzothiophen-3-yl)perfluorocyclopentene. It was found that substitution of phenyl or thiophene rings at 6 and 6′ positions of the benzothiophene-1,1-dioxide groups is effective to increase the fluorescence quantum yields of the closed-ring isomers over 0.7 and absorption coefficients over 4 × 104 M–1 cm–1. The phenyl-substituted derivatives 5a–7a undergo photocyclization reactions to produce yellow closed-ring isomers 5b–7b, which emit brilliant green fluorescence at around 550 nm (ΦF = 0.87–0.88) under irradiation with 488 nm light. Any absorption intensity change of the closed-ring isomers was not observed even after 100 h storage in the dark at 80 °C. The closed-ring isomers slowly returned to the initial open-ring isomers upon irradiation with visible (λ > 480 nm) light. The ring-opening quantum yields (ΦC→O) were measured to be (1.6–4.0) × 10–4. When the phenyl substituents are replaced with thiophene rings, such as compounds 8a and 9a, the absorption bands of the closed-ring isomers shift to longer than 500 nm. The closed-ring isomers exhibit brilliant red fluorescences at around 620 nm (ΦF = 0.61–0.78) under irradiation with 532 nm light. The ring-opening reactions are very slow (ΦC→O < 1 × 10–5). The fluorescence lifetimes of these sulfone derivatives were measured to be around 2–3 ns, which is much longer than the value of the closed-ring isomer of 1,2-bis(2-methyl-1-benzothiophen-3-yl)perfluorocyclopentene (τF = 4 and 22 ps). The closed-ring isomer 8b in 1,4-dioxane exhibits excellent fatigue resistant property under irradiation with visible light (λ > 440 nm) superior to the stability of Rhodamine 101 in ethanol.
Co-reporter:Hidetaka Nakai, Shinobu Uemura, Yousuke Miyano, Motohiro Mizuno, Masahiro Irie and Kiyoshi Isobe
Dalton Transactions 2011 vol. 40(Issue 10) pp:2177-2179
Publication Date(Web):04 Feb 2011
DOI:10.1039/C0DT01645D
A photoreactive rhodium dithionite complex [(RhCpEt)2(μ-CH2)2(μ-O2SSO2)] (1Et) with CpEt (η5-C5Me4Et) ligands was newly synthesized. Upon short-time irradiation with low intensity light, two kinds of stepwise surface morphology changes of the crystal 1Et were observed. Prolonged irradiation with high intensity light caused cracking and breaking down of the crystal.
Co-reporter:Yukihide Ishibashi, Mika Fujiwara, Toshiyuki Umesato, Hisayuki Saito, Seiya Kobatake, Masahiro Irie, and Hiroshi Miyasaka
The Journal of Physical Chemistry C 2011 Volume 115(Issue 10) pp:4265-4272
Publication Date(Web):February 21, 2011
DOI:10.1021/jp112370a
Cyclization reaction of a photochromic diarylethene derivative, 1,2-bis(2-methyl-3-benzothienyl)perfluorocyclopentene (BT), in nonpolar alkane solutions with different viscosity was investigated by means of femtosecond−microsecond transient absorption spectroscopy and a time-correlated single-photon counting method. Transient absorption measurements revealed that a ring closure rapidly occurred with a time constant of 450 fs. In addition to this rapid cyclization, transient species with longer lifetimes (ca. 150 ps and ca. 1 μs) were observed. The faster time constant of 150 ps was independent of the solvent viscosity and was assigned to the fluorescence lifetime of a conformer with molecular geometry unfavorable for the ring closure. The longer component was strongly quenched in the solution purged with O2 and was attributed to the triplet state of the open-ring form. Steady-state measurement and nanosecond transient absorption spectroscopy revealed that the cyclization process did not occur via the triplet state of BT. These results indicate that only the rapid reaction taking place in subpicosecond time region was responsible for the cyclization process. The key factors regulating the cyclization reaction of diarylethene derivatives were discussed on the basis of the solvent viscosity dependence, by comparing the present results with those obtained for other diarylethene derivatives.
Co-reporter:Masakazu Morimoto
Journal of the American Chemical Society 2010 Volume 132(Issue 40) pp:14172-14178
Publication Date(Web):September 21, 2010
DOI:10.1021/ja105356w
The photomechancial effect of a rectangular plate two-component cocrystal composed of a photochromic diarylethene derivative, 1,2-bis(2-methyl-5-(1-naphthyl)-3-thienyl)perfluorocyclopentene (1o), and perfluoronaphthalene (FN) has been examined. The crystal of 1o·FN with the size of 1−5 mm in length exhibits reversible bending motion upon alternate irradiation with ultraviolet (UV) and visible light. The reversible bending could be repeated over 250 times. In situ X-ray crystallographic analysis revealed that the deformation of the crystal is due to the elongation of the b-axis of the unit cell, which corresponds to the long axis of the plate crystal, induced by the shape change of component diarylethene molecules upon photocyclization. The bending motion was observed even at 4.7 K, and dynamic measurement of the bending proved that the anisotropic expansion of the crystal takes place in the microsecond time scale at the low temperature. Molecular crystal cantilevers made of 1o·FN can lift metal balls, the weight of which is 200−600 times heavier than the weight of the crystal, upon UV irradiation. The maximum stress generated by UV irradiation was estimated to be 44 MPa, which is 100 times larger than that of muscles (∼0.3 MPa) and comparable to that of piezoelectric crystals, such as lead zirconate titanate (PZT) (∼50 MPa).
Co-reporter:Masahiro Irie
Photochemical & Photobiological Sciences 2010 vol. 9(Issue 12) pp:1535-1542
Publication Date(Web):19 Oct 2010
DOI:10.1039/C0PP00251H
Photochromism is characterized as a reversible colour change of a chemical species upon photoirradiation. Although vast numbers of photochromic molecules have been so far synthesized, molecules which exhibit thermally irreversible photochromic reactivity are limited within a few families of compounds. Among the thermally irreversible photochromic molecules, diarylethene derivatives are the most promising candidates for applications to opto-electronic devices because of their fatigue resistance, high sensitivity and rapid response. In this review, characteristic photochromic performances of the derivatives, detection and analysis of the photochromic reactions at a single-molecule level and application of the single-crystalline photochromism to molecular machinery will be described.
Co-reporter:Lumi Kuroki, Shizuka Takami, Kenji Yoza, Masakazu Morimoto and Masahiro Irie
Photochemical & Photobiological Sciences 2010 vol. 9(Issue 2) pp:221-225
Publication Date(Web):13 Jan 2010
DOI:10.1039/B9PP00093C
Correlation between the photoinduced shape changes of diarylethene single crystals and their molecular packing in the crystals was studied. Crystals of 1,2-bis(5-ethyl-2-phenyl-4-thiazolyl)perfluorocyclopentene (3a) and 1,2-bis(2-isopropyl-5-phenyl-3-thienyl)perfluorocyclopentene (4a) showed similar photoinduced deformation from square to lozenge as that of 1,2-bis- (2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene (1a). Although these three diarylethenes have different electronic structures and exhibit different colours upon UV irradiation, the crystallographic structures and molecular packing of the crystals are very similar to each other. The result indicates that the deformation mode is determined by the packing mode of component molecules in the crystal. X-Ray crystallographic analysis of a micrometre-sized crystal 1a (20 × 15 × 8 μm) prepared by sublimation revealed that the small-size crystal, which shows photoinduced deformation, has the same crystal structure as that of the large bulk crystal.
Co-reporter:Tuyoshi Fukaminato, Masaaki Tanaka, Takao Doi, Nobuyuki Tamaoki, Tetsuro Katayama, Arabinda Mallick, Yukihide Ishibashi, Hiroshi Miyasaka and Masahiro Irie
Photochemical & Photobiological Sciences 2010 vol. 9(Issue 2) pp:181-187
Publication Date(Web):06 Jan 2010
DOI:10.1039/B9PP00131J
A fluorescent photochromic molecule, which is composed of a photochromic diarylethene (DE) and a fluorescent perylenebisimide (PBI), was synthesized and its fluorescence photoswitching was studied. The fluorescence quantum yield of the open-ring isomer is constant irrespective of solvent polarity, while that of the closed-ring isomer decreases with an increase in the dielectric constant of solvents. Femtosecond time-resolved transient and fluorescence lifetime measurements revealed that the fluorescence quenching of the closed-ring isomer is attributed to the intramolecular electron transfer from the PBI chromophore to the DE unit.
Co-reporter:Yukihide Ishibashi, Masayuki Mukaida, Magnus Falkenström, Hiroshi Miyasaka, Seiya Kobatake and Masahiro Irie
Physical Chemistry Chemical Physics 2009 vol. 11(Issue 15) pp:2640-2648
Publication Date(Web):20 Feb 2009
DOI:10.1039/B818591C
A cycloreversion reaction of a photochromic diarylethene derivative, 1-(2-methyl-3-benzothienyl)-2-(2,4-dimethyl-5-phenyl-3-thienyl)perfluorocyclopentene, with asymmetrical structure, in n-hexane solution, was investigated by means of picosecond and femtosecond laser spectroscopic methods. Femtosecond laser spectroscopy revealed that the excited state (S1) of the closed form with a lifetime of 1.3 ps undergoes the cycloreversion reaction in competition with the internal conversion and the apparent reaction yield was independent of the excitation intensity. On the other hand, picosecond laser excitation at 532 nm led to the drastic enhancement of the cycloreversion reaction yield by a successive two-photon absorption process via the S1 state, leading to higher excited states with a large cycloreversion yield of 0.60 ± 0.1. For the multiphoton-enhanced cycloreversion reaction, we reported that the efficient cycloreversion reaction of a diarylethene derivative with C2v symmetry could occur by stepwise, visible two-photon excitation but did not take place by UV one-photon absorption to a higher excited state. In the present asymmetrical system, both UV one-photon and visible two-photon absorption opened the efficient cycloreversion reaction. Similarities and differences of the reaction profiles in higher excited states between diarylethene derivatives with symmetrical and asymmetrical structures are discussed from the viewpoint of the selection rule of optical transition and its dependence on molecular structures.
Co-reporter:Masakazu Morimoto, Masahiro Irie
Tetrahedron Letters 2009 50(26) pp: 3404-3407
Publication Date(Web):
DOI:10.1016/j.tetlet.2009.02.139
Co-reporter:Tuyoshi Fukaminato, Takao Doi, Masaaki Tanaka and Masahiro Irie
The Journal of Physical Chemistry C 2009 Volume 113(Issue 27) pp:11623-11627
Publication Date(Web):June 10, 2009
DOI:10.1021/jp902880d
Two types of fluorescent diarylethene−perylenebisimide dyads were synthesized and their photochromic performance was studied. The dyads showed an unexpected photochromic reactivity. The photocyclization reaction takes place upon irradiation with visible light (>500 nm), where the diarylethene unit has no absorption. Inferring from the excitation wavelength dependence and oxygen effect, the triplet states of the diarylethene unit are considered to play an essential role in the photocyclization reaction with visible (>500 nm) light.
Co-reporter:Masashi Saitoh, Tuyoshi Fukaminato, Masahiro Irie
Journal of Photochemistry and Photobiology A: Chemistry 2009 Volume 207(Issue 1) pp:28-31
Publication Date(Web):5 September 2009
DOI:10.1016/j.jphotochem.2009.03.010
A photochromic diarylethene, 1,2-bis(3-methyl-2-thienyl)perfluorocyclopentene (1) was encapsulated into water-soluble nano-cavitand 2 to induce the photochromic performance in aqueous solution. 1H NMR measurements confirmed the formation of 1:1 complex between 1 and 2 in a D2O solution. Upon irradiation with UV and visible light, encapsulated diarylethene within nano-cavitand exhibited reversible and efficient photochromic reactions even in the aqueous solution. The photocyclization and photocycloreversion quantum yields are almost similar to those observed in organic solvents. The efficient photochromic performance of the diarylethene in aqueous solution is attributed to the fact that the empty pore of 2 selectively captures the hydrophobic perfluorocyclopentene moiety and the reactive thiophene moieties are free from the cavity, as evidenced by 1H NOESY measurement.
Co-reporter:Tuyoshi Fukaminato, Masaaki Tanaka, Lumi Kuroki and Masahiro Irie
Chemical Communications 2008 (Issue 33) pp:3924-3926
Publication Date(Web):02 Jul 2008
DOI:10.1039/B804137G
Diarylethene derivatives with oxidized thiophene rings shift their absorption band to a shorter wavelength in the UV region upon photocyclization; no color change was observed during the photochromic reaction, and the invisible photochromism is advantageous for devices used under room light.
Co-reporter:Masakazu Morimoto, Seiya Kobatake and Masahiro Irie
Chemical Communications 2008 (Issue 3) pp:335-337
Publication Date(Web):25 Oct 2007
DOI:10.1039/B713694C
A photochromic diarylethene containing naphthyl groups formed a chiral crystal when co-crystallized with octafluoronaphthalene, although both molecules are achiral, and underwent highly enantioselective photocyclization owing to the conformational confinement in the crystal.
Co-reporter:Masato Ohsumi, Masaki Hazama, Tuyoshi Fukaminato and Masahiro Irie
Chemical Communications 2008 (Issue 28) pp:3281-3283
Publication Date(Web):19 May 2008
DOI:10.1039/B802780C
Photochromism of a symmetric diarylmaleimide derivative, having two thiophene rings (1), and a non-symmetric derivative having a S,S-dioxide thiophene ring and a thiophene ring (2) as the aryl moieties, was studied in various solvents. The photocyclization quantum yield of 1 gradually decreased with increasing the solvent polarity and the reaction was not observed in polar solvents, such as ethanol and acetonitrile; on the other hand, such a strong solvent dependence of the photocyclization reaction was not observed for 2; the different behavior is attributed to the weaker electron donating ability of the S,S-dioxide thiophene ring.
Co-reporter:Kensuke Tani, Yukihide Ishibashi, Hiroshi Miyasaka, Seiya Kobatake and Masahiro Irie
The Journal of Physical Chemistry C 2008 Volume 112(Issue 30) pp:11150-11157
Publication Date(Web):July 2, 2008
DOI:10.1021/jp8003272
Cyclization and cycloreversion reactions of a photochromic diarylethene derivative, bis(2-methyl-5-phenylthiophen-3-yl)perfluorocyclopentene, in crystalline phase were investigated by means of picosecond laser spectroscopy. Rapid cyclization within a few picoseconds, as comparable to that in solution phase, was confirmed for the colorization reaction in the crystalline phase. On the other hand, cycloreversion reaction took place with a time constant of 25 ps. In addition, nonlinear enhancement of the cycloreversion process was observed. The excitation intensity dependence of the reaction profiles and the correlation of the apparent reaction yield with the time interval of two pulses employed for the excitation clearly revealed that the successive two-photon absorption process via the S 1 state, leading to higher excited states, opened the efficient cycloreversion process. The dynamics and mechanisms of the multiphoton-gated reaction in the crystalline phase were discussed by comparing the present results with those in solution phase.
Co-reporter:Nobuaki Soh, Kenji Yoshida, Hizuru Nakajima, Koji Nakano, Toshihiko Imato, Tuyoshi Fukaminato and Masahiro Irie
Chemical Communications 2007 (Issue 48) pp:5206-5208
Publication Date(Web):12 Oct 2007
DOI:10.1039/B713663C
A fluorescent photochromic compound, composed of diarylethene, fluorescein and succinimidyl ester units, was developed for the controllable fluorescent labeling of biomolecules based on a small molecule.
Co-reporter:Seiya Kobatake;Shunpei Kuma
Journal of Physical Organic Chemistry 2007 Volume 20(Issue 11) pp:960-967
Publication Date(Web):9 MAY 2007
DOI:10.1002/poc.1196
New types of diarylethene dimers bridged by a spiro structure were synthesized. One of their dimers formed three kinds of polymorphic forms by recrystallization from different solvents: hexane (1a-α), acetone (1a-β), and acetonitrile (1a-γ). In crystals of 1a-α and 1a-β the molecules are packed in solvent-free crystal structures, whereas crystal 1a-γ includes acetonitrile molecules in the crystal. The difference of significant photochromic reactivities in their polymorphic crystals was observed for photocoloration reactions. Crystals 1a-β and 1a-γ showed photochromism in the single-crystal phase, but 1a-α did not do so. Their photochromic reactivity was found to depend on the distance between the reactive carbon atoms by X-ray crystallographic analysis. When the distance is less than 4.2 Å in the antiparallel conformation, the molecule can undergo photochromism in the crystal. On the other hand, crystals of bromo-substituted diarylethene dimer (2a) cannot be suitable for X-ray crystallographic analysis when it was recrystallized from hexane, acetone, and acetonitrile. However, it formed single crystal by recrystallization from p-xylene, which showed photochromism in the crystalline phase. The edge-to-face aromatic interaction between p-xylene molecules assisted the crystal growth of the diarylethene dimer. Upon irradiation with ultraviolet light, two kinds of the enantiomers, (M,SS)- and (P,RR)-2b, are produced. Partial photobleaching reactions of either of the two enantiomers by irradiation with linearly polarized visible light were confirmed by polarized absorption spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.
Co-reporter:Shizuka Takami
Journal of Physical Organic Chemistry 2007 Volume 20(Issue 11) pp:894-899
Publication Date(Web):31 MAY 2007
DOI:10.1002/poc.1204
Dithiazolylethenes 1a and 2a having 4- or 3-pyridyl groups and 3a having N-methylpyridinium groups at thiazole rings were prepared and their photochromic performance was examined. Upon irradiation with 313 nm light the colorless acetonitrile solutions of 1a and 2a turned violet, which show the absorption maxima at 538 and 530 nm, respectively. The violet color is due to the closed-ring isomers 1b and 2b. The violet color disappeared upon irradiation with visible light (λ > 480 nm). When the pyridine rings were converted to N-methylpyridinium ions, the colorless acetonitrile solution of 3a turned blue (λmax = 596 nm) upon irradiation with 365 nm light. The absorption maximum of the closed-ring isomer 3b showed a bathochromic shift as much as 58 nm relative to the maximum of 1b. In methanol 3a changed to green (λmax = 750 nm) upon irradiation with 365 nm light. It was suggested J-aggregates of 3b are formed in methanol. Copyright © 2007 John Wiley & Sons, Ltd.
Co-reporter:Tuyoshi Fukaminato, Masaaki Tanaka, Lumi Kuroki and Masahiro Irie
Chemical Communications 2008(Issue 33) pp:NaN3926-3926
Publication Date(Web):2008/07/02
DOI:10.1039/B804137G
Diarylethene derivatives with oxidized thiophene rings shift their absorption band to a shorter wavelength in the UV region upon photocyclization; no color change was observed during the photochromic reaction, and the invisible photochromism is advantageous for devices used under room light.
Co-reporter:Takaki Sumi, Yuta Takagi, Akira Yagi, Masakazu Morimoto and Masahiro Irie
Chemical Communications 2014 - vol. 50(Issue 30) pp:NaN3930-3930
Publication Date(Web):2014/03/05
DOI:10.1039/C4CC00396A
The cycloreversion quantum yields of compounds 1b and 2b increased upon irradiation with light at shorter wavelengths. The irradiation wavelength dependence is ascribed to the energy barrier on the 2A potential energy surface in the excited electronic state.
Co-reporter:Masakazu Morimoto, Seiya Kobatake and Masahiro Irie
Chemical Communications 2008(Issue 3) pp:NaN337-337
Publication Date(Web):2007/10/25
DOI:10.1039/B713694C
A photochromic diarylethene containing naphthyl groups formed a chiral crystal when co-crystallized with octafluoronaphthalene, although both molecules are achiral, and underwent highly enantioselective photocyclization owing to the conformational confinement in the crystal.
Co-reporter:Hidetaka Nakai, Shinobu Uemura, Yousuke Miyano, Motohiro Mizuno, Masahiro Irie and Kiyoshi Isobe
Dalton Transactions 2011 - vol. 40(Issue 10) pp:NaN2179-2179
Publication Date(Web):2011/02/04
DOI:10.1039/C0DT01645D
A photoreactive rhodium dithionite complex [(RhCpEt)2(μ-CH2)2(μ-O2SSO2)] (1Et) with CpEt (η5-C5Me4Et) ligands was newly synthesized. Upon short-time irradiation with low intensity light, two kinds of stepwise surface morphology changes of the crystal 1Et were observed. Prolonged irradiation with high intensity light caused cracking and breaking down of the crystal.
Co-reporter:Satoko Ohshima, Masakazu Morimoto and Masahiro Irie
Chemical Science (2010-Present) 2015 - vol. 6(Issue 10) pp:NaN5752-5752
Publication Date(Web):2015/07/14
DOI:10.1039/C5SC01994J
Mixed crystals composed of 1,2-bis(2-methyl-5-(p-methoxyphenyl)-3-thienyl)perfluorocyclopentene (1a) and 1,2-bis(5-methyl-2-(p-methoxyphenyl)-4-thiazolyl)perfluorocyclopentene (2a) were prepared, and their photochromic as well as light-driven bending performance was studied to reveal how shape changes of individual molecules cause the bending response. 1a and 2a molecules, having similar geometrical structures, randomly mix with each other in a single crystal. The absorption spectra of the closed-ring isomers 1b and 2b were, however, distinctly different. The difference of the spectra made it possible to discriminate the cycloreversion reactions of 1b and 2b in the mixed crystals by irradiation with 750 nm light. The bending response of the mixed crystals by the selective photoisomerization revealed that the local shape change of each molecule is additively linked to the macroscopic deformation of the crystals.
Co-reporter:Masato Ohsumi;Masaki Hazama;Tuyoshi Fukaminato
Chemical Communications 2008(Issue 28) pp:
Publication Date(Web):2008/07/11
DOI:10.1039/B802780C
Photochromism of a symmetric diarylmaleimide derivative, having two thiophene rings (1), and a non-symmetric derivative having a S,S-dioxide thiophene ring and a thiophene ring (2) as the aryl moieties, was studied in various solvents. The photocyclization quantum yield of 1 gradually decreased with increasing the solvent polarity and the reaction was not observed in polar solvents, such as ethanol and acetonitrile; on the other hand, such a strong solvent dependence of the photocyclization reaction was not observed for 2; the different behavior is attributed to the weaker electron donating ability of the S,S-dioxide thiophene ring.
Co-reporter:Nobuaki Soh, Kenji Yoshida, Hizuru Nakajima, Koji Nakano, Toshihiko Imato, Tuyoshi Fukaminato and Masahiro Irie
Chemical Communications 2007(Issue 48) pp:NaN5208-5208
Publication Date(Web):2007/10/12
DOI:10.1039/B713663C
A fluorescent photochromic compound, composed of diarylethene, fluorescein and succinimidyl ester units, was developed for the controllable fluorescent labeling of biomolecules based on a small molecule.
Co-reporter:Yuhei Arai, Syoji Ito, Hajime Fujita, Yusuke Yoneda, Takahiro Kaji, Satoshi Takei, Ryota Kashihara, Masakazu Morimoto, Masahiro Irie and Hiroshi Miyasaka
Chemical Communications 2017 - vol. 53(Issue 29) pp:NaN4069-4069
Publication Date(Web):2017/02/20
DOI:10.1039/C6CC10073B
We demonstrated one-colour control of activation, excitation and deactivation of a fluorescent diarylethene derivative by using a 532 nm CW laser at a weak output power. This one-colour control method was applied to single-molecule tracking in polymer films over a total duration of a few hours at room temperature and PALM for the nanostructures of polymer systems.
Co-reporter:Yukihide Ishibashi, Masayuki Mukaida, Magnus Falkenström, Hiroshi Miyasaka, Seiya Kobatake and Masahiro Irie
Physical Chemistry Chemical Physics 2009 - vol. 11(Issue 15) pp:NaN2648-2648
Publication Date(Web):2009/02/20
DOI:10.1039/B818591C
A cycloreversion reaction of a photochromic diarylethene derivative, 1-(2-methyl-3-benzothienyl)-2-(2,4-dimethyl-5-phenyl-3-thienyl)perfluorocyclopentene, with asymmetrical structure, in n-hexane solution, was investigated by means of picosecond and femtosecond laser spectroscopic methods. Femtosecond laser spectroscopy revealed that the excited state (S1) of the closed form with a lifetime of 1.3 ps undergoes the cycloreversion reaction in competition with the internal conversion and the apparent reaction yield was independent of the excitation intensity. On the other hand, picosecond laser excitation at 532 nm led to the drastic enhancement of the cycloreversion reaction yield by a successive two-photon absorption process via the S1 state, leading to higher excited states with a large cycloreversion yield of 0.60 ± 0.1. For the multiphoton-enhanced cycloreversion reaction, we reported that the efficient cycloreversion reaction of a diarylethene derivative with C2v symmetry could occur by stepwise, visible two-photon excitation but did not take place by UV one-photon absorption to a higher excited state. In the present asymmetrical system, both UV one-photon and visible two-photon absorption opened the efficient cycloreversion reaction. Similarities and differences of the reaction profiles in higher excited states between diarylethene derivatives with symmetrical and asymmetrical structures are discussed from the viewpoint of the selection rule of optical transition and its dependence on molecular structures.
