Photochromic Behavior and Its Stability of a New Bifunctional Dye Composed of Spirobenzopyran and a Cinnamoyl Moiety

Shen Kaihua,Kim Jae Hong,Kim Go Woon,Cho Min Ju,Lee Sang Kyu,Choi Dong Hoon The Polymer Society of Korea 2005 Macromolecular Research Vol.13 No.3

A novel bifunctional dye composed of spirobenzopyran and a cinnamoyl moiety was prepared and its photochromic behavior under the illumination of monochromatic UV light was investigated. This colorless bifunctional dye exhibits typical photochromism in both the film and in solution, through the structural and geometrical transformation from spirobenzopyran to merocyanine accompanied by a photocrosslinking reaction between the cinnamoyl moieties. Two kinds of photochemical reaction were selectively achieved by irradiation with monochromatic UV light at wavelengths of 275 and 365 nm, respectively. The effect of the selective photochemical reaction on the photochromism of the dye and its decaying behavior was investigated.

High contrast fluorescence switching based on CH₃NH₃PbBr₃ perovskite nanoparticles in photochromic composites

Kim, Sung-Hoon,Yun, Seokjin,Choi, Jihoon,Kim, Jong H. Elsevier Sequoia 2018 Journal of photochemistry and photobiology Chemist Vol. No.

<P><B>Abstract</B></P> <P>In this work, we report on the photo-induced fluorescence switching film by using CH<SUB>3</SUB>NH<SUB>3</SUB>PbBr<SUB>3</SUB> perovskite nanoparticle fluorophore and spironaphthoxazine photochromic dye for the first time. Attributed to the effective spectral overlap between absorption of spironaphthoxazine in ring-opened merocyanine form and emission of CH<SUB>3</SUB>NH<SUB>3</SUB>PbBr<SUB>3</SUB> energy transfer-induced fluorescence switching film is demonstrated. In addition, both highly luminescent optical property of CH<SUB>3</SUB>NH<SUB>3</SUB>PbBr<SUB>3</SUB> and efficient photochromic reactivity of spironaphthoxazine, enabled high emission on/off emission contrast (>10.0) and fast emission turn on (4.0s). Finally, modulation of the switching speed is successfully achieved by introducing the chelating agent into the photochrmic film, which effectively retards the rate of photochromic reaction of spironaphthoxazine.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fluorescence photo-switch is developed using perovskite nanoparticle fluorophore and photochromic photochromic dye. </LI> <LI> On/off contrast over >10.0 is achieved by taking advantage of highly luminescent property of perovskite nanoparticles. </LI> <LI> Turn on speed is effectively modulated by introducing the chelating additive that can retard photochromic reaction. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>High on/off contrast photo-switchable fluorescence is demonstrated by combining highly luminescent fluorophore, CH<SUB>3</SUB>NH<SUB>3</SUB>PbBr<SUB>3</SUB> perovskite nanoparticles and photochromic dye, spironaphthoxazine.</P> <P>[DISPLAY OMISSION]</P>

Size and Crystal Structure Dependence of Photochromism of Nanocrystalline WO3 and MoO3 Prepared by Acid-Precipitation Method

곽준영,정영희,김영일 대한화학회 2023 대한화학회지 Vol.67 No.1

Nanocrystallne WO3 and MoO3 with several different sizes and crystal structures were prepared by simple acid precipitation and subsequent heat treatment. The photochromic (PC) properties of these samples were comparatively investi- gated in powder state by monitoring diffuse reflectance spectral changes after bandgap irradiation. The PC effect of hexago- nal WO3 and monoclinic WO3 strongly depended upon crystallite size rather than crystal structure. The smaller the crystallite size, the better the PC effect. However, orthorhombic WO·H2O and MoO3 having hexagonal and orthorhombic structures did not follow this trend. One consistent result for all WO3 and MoO3 samples is that the heat treatment in air, which changes crystallinity, whether it changes the crystal structure or only the crystallite size, reduces the PC effect. Since the thermal treat- ment reduces the surface oxygen defect sites, we believe that the PC effect of WO3 and MoO3 depends critically on the sur- face oxygen defect sites that serve as deep trap sites for photogenerated electrons and oxygen radical holes. We also found that the proton insertion claimed by double charge injection model is not critical for the PC effect.

Photochromism of A Styrene-Derived Polymer Having Pendant Phenoxyanthraquinones

Ju, Sang-Yong,Ahn, Kwang-Duk,Han, Dong-Keun,Suh, Dong-Hack,Kim, Jong-Man Korean Society of Photoscience 2000 Journal of Photosciences Vol.7 No.4

A Styrene-derived polymer having pendent phenoxyanthraquinones for photochromism was prepared by AIBN-initiated radical polymerization. Syntgesus of the monomers was straightforward and the polymer was obtained in 65% yield. Photoinduced rearrangement from the “trans” quinone forms to the “ana” quinone forms readily occurred both in solution and in film when the polymer was irradiated with UV light.

Photochromic Polysiloxanes Substituted with 1,2-Bis(2-methyIbenzo[b]thiophene-3-yl)hexafluorocyclopentene

Shin, Hee-Won,Kim, Yong-Rok,Kim, Eun-Kyoung The Polymer Society of Korea 2005 Macromolecular Research Vol.13 No.4

Photochromic diarylethene polymers (DPs) in which 1,2-bis(2-methylbenzo[b ]thiophene-3-yl)hexafluorocyclopentene (BTF6) were covalently grafted onto the polymer main chain as pendant photochromic units were newly synthesized and their photochromic properties were investigated using steady-state and picosecond timeresolved spectroscopies. Polysiloxanes substituted with BTF6 molecules were prepared by sol-gel process using a mixture of tetraethoxysilane (TEOS), a silylated BTF6, and an organically modified silane precursor in the presence of HCl. The polysiloxane film (DP1) prepared from $\omega-methoxy$ poly(ethylene glycol) 3-(triethoxysilyl) propylcarbainate (MPGSC) as the silane precursor showed a much lower glass transition temperature than that (DP2) from heptadecafluorodecyltrimethoxysilane (HDFTMS). The ring-closure quantum yields of DP1 and DP2 were determined to be 0.20 and 0.02, respectively. Such a large difference in the quantum yield was attributed to the polymer matrix environment of the free inner volume.

Photochromic photography with hackmanite obtained by large-scale synthesis

Sami Vuori,Hannah Byron,Isabella Norrbo,Minnea Tuomisto,Mika Lastusaari 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Hackmanite (Na8Al6Si6O24(Cl,S)2) is an intelligent mineral that changes its color from white to pink uponexposure to UV radiation, X-rays, or gamma radiation and reverts to white by exposure to visible light orheat. This reversible photochromism can be used in e.g. solar UV indexing, X-ray imaging, gamma radiationdetection, and intelligent clothing. Hackmanite is conventionally synthesized in a laboratory withyields measured in grams, which is low in an industrial aspect when considering the material’s vast applicationportfolio. In this work, we show that it is possible to produce hackmanite in an industrial scalewith the final product yield of up to 1 kg marking a significant advance towards the commercial use ofhackmanite. We also show yet another novel application invention: a photochromic photographic filmthat can be reused indefinitely due to hackmanite’s coloration ability that does not weaken with repeateduse.

A New Diarylethene with Donor-acceptor Group for Reversible Photo-induced Electrochemical Switching

Kim, Eun-Kyoung,Kim, Mi-Young,Kim, Kyong-Tae Korean Chemical Society 2008 Bulletin of the Korean Chemical Society Vol.29 No.4

A new diarylethene compound with donor and acceptor substituent was synthesized from 2,3-bis(2-methylbenzo[b]thiophene-3-yl)hexafluorocyclopentene (BTF) over 5 steps. The donor-acceptor structured BTF compound (TBTFE) showed spectral change to a longer wavelength through photochromism with a high cyclization quantum yield (0.56). The 3,4-ethylenedioxythiophene (T) and carboethoxy (E) groups directly connected to BTF unit promoted electrical change accompanied with the photoisomerization of the BTF unit. Photo-induced electrical switching was achieved from a photocell containing TBTFE doped polymer film, which showed reversible and stable current change over repeated cycles by the alternative UV/Vis irradiation, as estimated by the I-V plot.

Fabrication of Patterned Images in Photochromic Organic Microfibers

Lee, Jung,Lee, Chan-Woo,Kim, Jong-Man WILEY-VCH Verlag 2010 Macromolecular rapid communications Vol.31 No.11

<P>Photochromic spiropyran molecules were embedded in electrospun polymer microfibers. Electrospinning of a clear viscous chloroform solution containing a spiropyran and a matrix polymer, such as polystyrene and polyethylene oxide, affords polymer microfibers that are photoswitchable. Photomasked, 365 nm UV irradiation of the microfibers results in the generation of patterned color images owing to the selective transformation of the spiropyran molecules from their ring-closed SP to ring-opened MC form. The UV-irradiated areas display brilliant red fluorescence, which changes to green fluorescence upon prolonged irradiation.</P><P> <img src='wiley_img_2010/10221336-2010-31-11-MARC201000019-gra001.gif' alt='wiley_img_2010/10221336-2010-31-11-MARC201000019-gra001'> </P> <B>Graphic Abstract</B> <P>Electrospun fibers embedded with photochromic spiropyran were fabricated and a photomasked UV irradiation afforded patterned color images that could be erased by heat treatment. The UV irradiated areas display brilliant red fluorescence, which changes to green fluorescence upon prolonged irradiation. <img src='wiley_img_2010/10221336-2010-31-11-MARC201000019-content.gif' alt='wiley_img_2010/10221336-2010-31-11-MARC201000019-content'> </P>

A New Diarylethene with Donor-acceptor Group for Reversible Photo-induced Electrochemical Switching

김은경,김경태,Miyoung Kim 대한화학회 2008 Bulletin of the Korean Chemical Society Vol.29 No.4

A new diarylethene compound with donor and acceptor substituent was synthesized from 2,3-bis(2-methylbenzo[b]thiophene-3-yl)hexafluorocyclopentene (BTF) over 5 steps. The donor-acceptor structured BTF compound (TBTFE) showed spectral change to a longer wavelength through photochromism with a high cyclization quantum yield (0.56). The 3,4-ethylenedioxythiophene (T) and carboethoxy (E) groups directly connected to BTF unit promoted electrical change accompanied with the photoisomerization of the BTF unit. Photo-induced electrical switching was achieved from a photocell containing TBTFE doped polymer film, which showed reversible and stable current change over repeated cycles by the alternative UV/Vis irradiation, as estimated by the I-V plot.

광변색성 2-(1',2'-dimethyl-3'-indolyl)-3-(2"-methyl-3"-benzo〔b〕thiophenyl) maleic anhydride의 합성과 특성 연구

김홍두,안광현,김준원 慶熙大學校 레이저 工學硏究所 1995 레이저공학 Vol.6 No.-

Photochromic 2-(1', 2'-dimethyl-3'-indolyl)-3-(2"-methyl-3"-benzo[b]thiophenyl) maleic anhydride(DIMBMA) was synthesized by electrocyclic reaction. The new synthesis route gave a better yield than previously reported thio-Claisen rearrangement method by Irie. DIMBMA in benzene solution or polymer film turned to the cyclic form by 488nm wavelength and using 632.8nm or ambient light it was easily reverted. Without light, the reverse reaction did not proceed and its life time seemed quite long. The forced Raylegh scattering was used to measure the diffusion coefficient and DIMBMA showed good holographic efficiency.