59000-86-1Relevant articles and documents
Spectroscopic, photochromic and kinetic behavior of photo conversion of Aberchrome 540 in an ionic liquid media
Aliaga,Pavez G,De la Fuente,Nú?ez,Ca?ete
, p. 125 - 130 (2018)
The photo-bleaching reaction of the chemical actinometer, Aberchrome 540, is reported for the first time in a series of ionic liquids (ILs). This fulgide in its C-form undergoes an opening reaction to yield its E-form, when it is irradiated with UV light at wavelengths >400 nm. The magnitude of bleaching was monitored spectrophotometrically and their kinetics evaluated, obtaining first-order rate constants (kobs). The results obtained in different ILs suggest that changes in the rate constants (kobs) of the opening reaction of Aberchrome 540 are mainly governed by weaker interactions such as coulombic (π* parameter) and Van der Waals interactions (δH 2, parameter). In addition, the photochemical fatigue resistance was also studied in ILs media and compared with conventional solvents (benzene, toluene, etc.). In particular, we found that three different tendencies dependent on the ILs used exist. The first group of ILs where the reversibility of the fulgide is favored (for example, [Bmim][BF4], [Bmim][PF6] and [Bmim][OTf]), behaviour similar to conventional solvents. The second group corresponds to ILs where photo reversibility is partial; and finally, other group of ILs that prevented photo reversibility. It is proposed that depending on the ILs used, the stabilization of different forms of the fulgide can be controlled, thus resulting important in terms of choosing the appropriate ILs for a specific photochemical reaction.
Ultrafast laser spectroscopic study on photochromic cycloreversion dynamics in fulgide derivatives: One-photon and multiphoton-gated reactions
Ishibashi, Yukihide,Katayama, Tetsuro,Ota, Chikashi,Kobatake, Seiya,Irie, Masahiro,Yokoyama, Yasushi,Miyasaka, Hiroshi
, p. 1409 - 1419 (2009)
Cycloreversion processes of three photochromic fulgide derivatives in toluene solution were investigated by means of picosecond and femtosecond laser photolysis methods. Femtosecond laser irradiation revealed that the cycloreversion processes upon visible one-photon excitation took place within a few ps in these three derivatives. On the other hand, drastic enhancements of the reaction yield were observed under picosecond laser exposure. Excitation intensity effect of the reaction yield and dynamic behaviors revealed that the successive two-photon absorption process leading to higher excited states opened the efficient cycloreversion channel in the three derivatives. The reaction yields in higher excited states were found to be quite large in these three systems, 0.35-0.55, while those in the S1 state were 0.048-0.21. The correlation of the reaction yield in the S1 state with that in S n states suggest the character of the electronic states connected by the optical absorption plays an important role in the control of the cycloreversion reaction. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2009.
Effects of Steric Bulkiness of Substituents on Quantum Yields of Photochromic Reactions of Furylfulgides
Yokoyama, Yasushi,Inoue, Tetsushi,Yokoyama, Masato,Goto, Takakazu,Iwai, Takeshi,et al.
, p. 3297 - 3303 (1994)
Furylfulgides with different sizes of alkyl substituents were synthesized and their photochromic properties were examined. While the quantum yield of coloring reaction increased and the quantum yield of the E-to-Z isomerization decreased as the steric bulkiness of the alkyl substituent on the 2,5-dimethyl-3-furylmethylidene moiety increased, the bleaching quantum yield increased as the isopropylidene group was replaced by an adamantylidene group. Both effects worked independently, and a furylfulgide with an isopropyl group on the furylmethylidene moiety and an adamantylidene group in one molecule showed the coloring quantum yield of 0.51 (366 nm) and the bleaching quantum yield of 0.26 (492 nm) in toluene.
Dynamics of the cyclization reaction in photochromic furyl fulgides
Handschuh,Seibold,Port,Wolf
, p. 502 - 506 (1997)
The dynamics of the photoinduced cyclization reaction of furyl fulgides has been studied applying femtosecond time-resolved transient absorption spectroscopy. For furyl fulgide 1 and adamantylidene-substituted furyl fulgide 2 in different solvents, a scheme of the reaction mechanism is set up and the reaction rates are determined by fitting individual transients. Two parallel reaction pathways can be distinguished, one of them including an intermediate state. Reaction times in the picosecond range support the application of fulgides in optical data storage media and as molecular photoswitches.
Photomechanical motion of furylfulgide crystals
Koshima, Hideko,Nakaya, Hidemitsu,Uchimoto, Hidetaka,Ojima, Naoko
, p. 107 - 109 (2012)
Plate-like microcrystals of a photochromic furylfulgide bend toward the light upon UV irradiation and then straighten upon visible light irradiation. The reversible bending was observed over 200 cycles of alternating irradiation with UV and visible light. The mechanism of bending could be explained by the X-ray crystallographic data.
Synthesis and photochromism of 1,2-bis(5-aryl-2-phenylethynylthien-3-yl)hexafluorocyclopentene derivatives
Cai, Jianxin,Farhat, Amani,Tsitovitch, Pavel B.,Bodani, Vivek,Toogood, R. Daniel,Murphy, R. Scott
experimental part, p. 176 - 182 (2010/11/05)
Photochromic dithienylethenes that possess elements of lipid complementarity, and undergo large, photoinduced changes in molecular geometry have been prepared. Further, a regioselective approach has been developed for the preparation of dithienylethenes containing phenylethynyl and various aryl substituents at C2 and C5 of the thiophene moieties, respectively. The prepared photochromic compounds were observed to undergo reversible photoisomerization. Their absorption properties, reaction quantum yields, and photoconversions were determined in n-hexane.
