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Spiropyran structure

Structure A spiropyran is a 2H- pyran isomer that has the hydrogen atom at position two replaced by a second ring system linked to the carbon atom at position two of the pyran molecule in a spiro way. So there is a carbon atom which is common on both rings, the pyran ring and the replaced ring Poly(spiropyran-glutamate) | C85H89N9O20 | CID 11980092 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological. Spiropyran (SP) closed-ring structure and its stimuli-induced open-ring zwitterionic and quinoidal isomers (MC). 4.7 Although the majority of publications highlight the photochemical features of spiro compounds, less attention has been paid on their electrochemical behavior Discovery of the spiropyran structure The versatility of the spiropyran class of photochromes we know today was not immediately apparent when their basic structures were first described. The non-photochromic spiropyrans that preceded the multifunctional indoline-pyran hybrid were reported first by Decker in 1908,.

The photochemical and structural characteristics of two organic photochromes, specifically indoline-spiro-benzopyran and benzothiazoline-spiro-benzopyran, have been studied by computational chemistry techniques. Both quantum mechanical and classical methods were used A total of five new structures were obtained via isothermal evaporation experiments under different conditions, namely 1,3,3-Trimethylindolino-benzopyrylospiran (I), 1,3,3-Trimethylindolinonaphtospirooxaxine (II), 1- (2-Hydroxyethyl)-3,3-dimethylindolino-6′-nitrobenzopyrylospiran (III), and 1,3,3-Trimethylindolino-8′-methoxybenzopyrylospiran (IVa and IVb)

Spiropyran - Wikipedi

  1. The structural formula of the parent closed-ring isomer of spiropyran is represented as 1 in Fig. 1A. The molecule comprises an indoline and a chromene moiety bound together via a spiro junction and oriented perpendicular with respect to one another
  2. General structure of the spiropyran. Nonplanar indoline and benzopyrene fragments are located in a molecule approximately orthogonal to each other. A dihedral angle between planes О (30)-С (25)-С (26) of the benzopyrene and N (11)-C (25)-C (26) of the indoline cycles at the spiroatom С (25) is 86.3°
  3. Spiropyrans are a class of photochromic compounds that feature two main isoforms, a closed spiropyran (SP) and an open merocyanine (MC), which are inter-switchable with UV and visible light. The double bond containing MC isomer has several resonance forms with different optical spectra
  4. f Two views of the X-ray crystal structure 5 ⊂ 4 (the cartoons show the orientation of the cage). The hydrogen atoms were removed for clarity. g The 4-induced ring-opening isomerization of.
Proton-conduction photomodulation in spiropyran

@misc{etde_21522545, title = {Electronic structure of a spiropyran derived molecular switch in direct contact with the Au(111) surface} author = {Bronner, Christopher, Schulze, Gunnar, Franke, Katharina J, Pascual, Jose Ignacio, and Tegeder, Petra} abstractNote = {As nanometer scale phenomena advance into the grasp of technological application, the potential building blocks of molecular. Photochromic spiropyrans undergo drastic structural changes between closed spiropyran (SP) and open merocyanine (MC) isoforms. Due to their photo-switching properties, spiropyran derivatives have a wide range of applications, from design of smart nanomaterials to optical regulation of biomacromolecules [ 12 ] The chemical structure of both SP and MC were successfully elucidated with the aid of 1H-NMR and IR spectroscopies. Infrared spectroscopy was employed to confirm the structural changes of before and after the irradiation took place of spiropyran compound. The ring opening process of SP is believed to take place after th Trimethylindolino-8′-methoxybenzopyrylospiran (IVa and IVb). Since the basic structure of a spiropyran/-oxazine does not present typical hydrogen bond accepting and donating groups, this study illustrates the importance of additional functional groups connected to this kind of molecules to induce specific intermolecular interactions spiropyran where the emphasis is on their structure. Spiropyran polymeric systems can be used for a variety of applications, showing that by combining the key advantages of the spiropyran moiety with the smart engineering of spiropyran based polymers, new materials with designed macroscopic properties can be obtained

A one-pot synthesis and structure study of a new salt spiropyran of the indoline series containing 2H-chromene vinyl-3H-indolium moiety as a substituent at the 8'-position are described. The structure was confirmed by 1H and 13C NMR and IR spectroscopy and high-resolution mass spectrometry. The single crystals of the compound were investigated by X-ray diffraction analysis The basic structure of the ring-closed spiropyran (SP) and the ring-opened merocyanine (MC), along with the derivatives examined herein, are shown in Scheme 1. The primary features of interest for these systems are the bonding character of the spirocarbon of the pyran ring and the ethylene bridge geometry with bonds denoted (α), (β) and (γ. The common structure of spiropyran is composed of two aromatic rings: benzopyran and indole, connected by a sp 3 hybrid spiro-C atom. The two aromatic rings are orthogonal to each other, and the closed-ring spiropyran molecule is unconjugated and colorless We have studied the structures and absorption spectra of merocyanine, the photoresponsive isomer of the spiropyran (SP) −merocyanine (MC) pair, in chloroform and in water solvents using a combined hybrid QM/MM Car−Parrinello molecular dynamics (CP-QM/MM) and ZINDO approach. We report remarkable differences in the molecular structure and charge distribution of MC between the two solvents.

Among such materials, spiropyran is one of the most attractive compounds because the structure and polarity of the material are dramatically changed after photo irradiation, unlike other materials. In this work, we designed and synthesized a spiropyran derivative (SpMA) with a methacryloyl group on the nitrobenzene ring of a spiropyran skeleton Chemical structure of the spiropyran (SP) mechanophore and its transformation into the merocyanine (MC) form Description. Spiropyran hexyl methacrylate is used for spiropyran-based polymeric hydrogel for light-activated mechanical actuation [1] . Molecular Weight. 431.57. Formula. C₂₈H₃₃NO₃

Solvent dependence of structure, charge distribution, and absorption spectrum in the photochromic merocyanine-spiropyran pair. Murugan NA(1), Chakrabarti S, Ågren H. Author information: (1)Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden. murugan@theochem.kth.s Two tetraphenylethene (TPE)-functionalized spiropyran (SP) molecules with very similar structure were designed and synthesized. The two molecules exhibit aggregation-induced emission (AIE) properties, as well as multistimuli-responsive color-changing properties, such as photochromism and acidchromism This demonstrates that in the polymer brush structures, which are densely packed with spiropyran moieties, there is no evidence of steric hindrance of the characteristic SP- MC photo-switching in response to UV and white light irradiation. When in the merocyanine form, the polymer coatings show an absorbance band with a (A) Molecular structure of the photoexpanding hydrogel containing a spiropyran moiety substituted by two sulfonate groups and photographs depicting the light-triggered expansion of the gel. (B) Molecular structure of photocontracting hydrogel containing a spiropyran moiety and photographs of the light-triggered contraction of the gel

Poly(spiropyran-glutamate) C85H89N9O20 - PubChe

  1. A reversible rearrangement of micellar junctions through loop-bridge or bridge-loop transitions is proposed to interpret the influence of photoisomerozation of spiropyran groups on the associative structure and rheological properties of the polymer solution
  2. The crystalline structure of salts I and II differs from that of the neutral SP being formed by the cationic layers separated by I - ions, thus providing a sufficient volume for spiropyran phototransformations. Photochromism of I and II single crystals has been first studied
  3. Spiropyran salts and their neutral precursors: synthesis, crystal structure, photochromic transformations in solutions and solid state E.A. Yurieva and S.M. Aldoshin Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka 142432, Moscow Region, Russian Federatio

Electrochemical Characterization of Spiropyran Structures

  1. Since the basic structure of a spiropyran/-oxazine does not present typical hydrogen bond accepting and donating groups, this study illustrates the importance of additional functional groups connected to this kind of molecules to induce specific intermolecular interactions
  2. The spiropyran structure chosen has reduced sensitivity to the effect of secondary electrochemical processes such as H+ production and provides transient access to a decreased thermal Z-E isomerization barrier in the one electron oxidized state, akin to that achieved in the corresponding photochemical path. Thus, we show that the energy needed.
  3. Chemical structure of the spiropyran and merocyanine isomers. (a) STM image of spiropyran islands on Bi(110) grown at room temperature and (b) its close-up view . The inset shows the STM image of a SP island obtained on Au(111) , for comparison. The unit cell is marked by a dotted rectangle
  4. Spiropyran, a molecule that reacts to external force, changes color when it is physically stimulated due to a change in its chemical structure. When injected into concrete or silicone, it reacts.

The evolution of spiropyran: fundamentals and progress of

A spiropyran is composed of two subunits (indole and chromene) connected by a spiro carbon atom, and practically uncoupled, from the electronic point of view. 14,15 14. S is the linker between corning crystal and spiropyran molecule. Figure 1 show the spiropyran molecular structure used in this work and their corresponding merocyanine form after UV illumination. For multilayer generation, a solution of 10 ml of pyridine and 90 ml of dimethilformamide was used as linker between the spiropyran multilayers Synthesis of Spiropyran Monomer Our Approach • polymer brushes • high loading of spiropyran molecule • 3D arrangement - spiropyran molecule Micro-capillary : Convenient platform for rapid analysis and detection Advantages • act as a mechanical support for the optically sensitive layer • represents an optical waveguide structure diffraction structure of SP2 and SP3; b) Reversible isomerization of spiropyran between SP and MC form under UV and visible light irradiation. Combined photochromism with TADF or RTP was a slick way to manipulate the delayed emission because of the responsiveness of photochromic materials. Very recently, our group have copolymerized spiropyran an Facile Isolation of Functionalized Spiropyran Mechanophores without Recrystallization . prepared by James F Berry . SURVICE Engineering . 4695 Millennium Drive . Belcamp, MD . The true structure of the merocyanine is likely an average of the two isomers. Accompanying this transformation is a change in color to a shade of deep blue/purple.

adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86 Spiropyran, a molecule that reacts to external force, changes color when it is physically stimulated due to a change in its chemical structure. When this substance is injected in concrete or. Read Conformational dimorphism of the spiropyran 1′,3′,3′‐trimethylspiro[2H‐1‐benzopyran‐2,2′‐indoline]‐6‐carbaldehyde), Acta Crystallographica Section C: Structural Chemistry on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips

Spectrum and Structure of Spiropyra

  1. 1. Chemistry. 2013 Nov 11;19(46):15726-34. doi: 10.1002/chem.201302640. Epub 2013 Oct 2. Spiropyran photoswitches in the context of DNA: synthesis and photochromic.
  2. The observed photochromism in modified paper was related to the grafted SPMA. Spiropyran is a group of colorless, light-sensitive molecule that can absorb ultraviolet (UV) light. Under UV irradiation, the colorless, closed SP structure was isomerized to a merocyanine (MC) structure and showed color again
  3. F : General structure of the spiropyran. are o ered. Probably, the authors of work [ ]aretheclosest toasolution,butthereisstillafeelingthatade nitiveanswer has not been received yet. Conformational transitions between rotamers have not been fully investigated, the routes of the transition processe

A Structural Analysis of Spiropyran and Spirooxazine

[23] P. Naumov, P. Yu and K. Sakurai, Electronic Tera-Order Stabilizationof Photoinduced Metastable Species: Structure of the PhotochromicProduct of Spiropyran Determined with in situ SingleCrystal X-ray Photodiffraction, J. Phys. Chem. A 112, 2008, 5810.[WoS light-responsive spiropyran molecular switches. The encapsula-tion is accompanied by isomerization of the guest to its otherwise unstable form. X-ray crystal structure of the inclusion complex reveals that upon binding of the guest, the cage undergoes a significant structural deformation. Owing to its flexibility, th

@misc{etde_21197250, title = {Switching of spiropyran molecules on a Au(111) surface} author = {Schulze, Gunnar, Karcher, Michael, Franke, Katharina, Ruedt, Christoph, Fumagalli, Paul, and Pascual, Jose Ignacio} abstractNote = {The photon and electron mediated conversion of the molecule 3-methyl-6-nitro-spiropyran (SP) into its merocyanine isomer were investigated on a Au(111) surface by means. A gene delivery system using spiropyran as a photoswitchable photosensitizer for the controlled photochemical internalization effect was developed by engineering the outer coating of a polyethylenimine/DNA complex with a small amount of spiropyran-containing cationic copolymers. The successful bindi The ideal monomer molecular structure, whereby (1) attaching norbornene on both sides of the rhodamine dye and (2) methylene spacers between the dye and norbornenes on both sides afforded the nonpareil polymer structure that was capable of thermoreversible mechanochromic and photochromic features, and irreversible thermochromic features

Photochromic spiropyran- and spirooxazine-homopolymers in

and their ability to plasticise the gel polymer structure.17 Secondly, the spiropyran isomerisation kinetics (and conse-quently the ionogel actuation kinetics) can be strongly in!u-enced by the ionic liquid used to form the ionogel.16,18 Despite the enormous potential of these photoresponsive actuators, they have not as yet been broadly. Modifying spiropyran with coordinating sidechains controls the ratio of spiropyran molecules to metal ions such that two or more spiropyran molecules coordinate to a single ion. In polymers containing modified spiropyran, this multiple spiropyran to ion coordination allows the formation of ionic crosslink Spiropyran (SP) with hexyl acrylate on the SP ring (SP-8-hexyl acrylate, Figures 1A, 2) exhibits efficient photo switching while covalently incorporated within a p-NIPAM hydrogel, particularly when substituted at the 8' position (Dunne et al., 2016b). The length of the alkyl chain spacer appears to play a significant role in providing. Such structure rearrangement results from isomerization between transparent spiropyran and colored merocyanine (MC) upon cleavage/formation of the C-O spiro bond and ring opening/closing. On the other side, replacing the complex chemical synthesis by simple blending of the polymer and PMs may provide a simple solution for the fabrication of.

Development of light-responsive porous polycarbonate

The dynamic processes of colorization under an excitation light were investigated using the two copolymers. One copolymers contained methylmethacrylate (MMA) and methacrylate-spiropyran (MA-spiropyran) as comonomers and other structure was kept methacrylate-spiropyran and methacrylate-chalcone (MA-chalcone) The novel behavior of the photoswitch incorporated in the covalent network was predicted by coarse-grained simulations of the system's chemical structure. Using pH control and polymeric structures that differ in lower critical solution temperature, we were able to develop hydrogels with highly tunable volumetric expansion Spiropyran is a prototype molecular switch which undergoes a reversible ring-opening reaction by photoinduced cleavage of a C-O bond in the spiropyran (SP) to the merocyanine (MC) isomer. While the electronic states and switching behavior are well characterized in solution, adsorption on metal surfaces crucially affects these properties. Using two-photon photoemission and scanning tunneling. This clearly demonstrates our ability to synthesize our described sandwich structured UCNPs. To utilize 808 nm NIR as a light source for the spiropyran based photo-switching reactions, an efficient NIR to the Visible converter is needed. A similar 808nm excitable UCNP with the aforementioned structure is designed

Spiropyran-Coated Surfaces Rohit Rosario, structure is a major contributor to the structure of the open form, because, in the neutral structure, the aroma-ticityoftheoxygen-bearingringislost.Thus,themolecules may be switched from closed to open with UV light (o Upon ultraviolet irradiation this spiropyran converts into a photomerocyanine structure with an absorbance in the visible region. This chromophore can be detected and the decay rate of the photomerocyanine to the spiropyran form in the dark is directly related to the specific intermolecular interactions within the monolayer

Surfaces were modified by the Langmuir-Blodgett (LB) deposition of a mixed monolayer of a spiropyran derivative (SP1822) and n-octadecane (C18). The LB film exhibited a reversible change in its structure between the SP form (neutral closed form) and the PMC form (zwitterionic open form) upon irradiation by light at specific wavelengths, which. The spiropyran group of M4Sp is converted to a zwitterionic merocyanin group upon UV-light irradiation, and an amphiphilic property of M4Sp is strengthened. Amphiphilic peptides disturb the membrane structure resulting in enhancement of CF leakage [34]. M7Sp possesses an amphiphilicity more or less in either spiropyran or merocyanin form, and.

Spiropyran-based dynamic materials - Chemical Society

Photochromism is accompanied by a large change in the structure and the dipole moment. These changes suggest that such molecules might be useful in light-controlled, 'smart surface' applications. This study examines the effect of the microenvironment near the surface-bound spiropyran on its photochemistry Step 1 (irradiation of the spiropyran modified micro-capillary with UV light) and 5 (irradiation of spiropyran modified micro-capillary with white light) are depicted in the scheme; Figure S8: Absorbance at 510 nm recorded on a USB400 spectrometer using the set-up depicted in Figure S7 during experimental steps 1-6

Conformational States of the Spiropyran Molecul

The evolution of spiropyran: fundamentals and progress of

Chemo- and biosensing applications of spiropyran and its

Quantum-Chemical Investigation of Molecular Structure and Thermodynamic Properties of Spiropyran Molecules. Monday, 14 May 2018: 14:40. Room 620 (Washington State Convention Center) ABSTRACT WITHDRAWN A crystal structure of the dinitro analogue establishes the trans stereochemistry. This product zwitterion is highly coloured (blue-purple) unlike the colourless reactant. The rate at which this colour clears can be easily measured in a UV/visible spectrometer, and from this activation parameters are inferred as a function of the solvent Structure and isomerization of a spiropyran derivative (left) and the corresponding absorption and emission changes (right). The absorption spectrum of the closed spiro form 1c is shown in blue. The corresponding spectrum of the open merocyanine form 1o is shown in red A NOVEL SPIROPYRAN-CONDUCTING POLYMER BIOSENSOR CHIP WITH ELECTROCHEMICAL AND PHOTOCHEMICAL SENSING PROPERTIES Michele Zanoni 1, Robert Gorkin III2, David L. Officer2, Klaudia Wagner2, Sanjeev Gambhir2, Gordon G. Wallace2 and Dermot Diamond1 1 CLARITY: Centre for Sensor Web Technologies, NCSR, Dublin City University, IRELAND and 2 ARC Centre of Excellence for Electromaterials Science, IPRI.

Reversible chromism of spiropyran in the cavity of a

Quasi-crystals are supramolecular aggregates exhibiting both crystalline (solid) properties as well as amorphous, liquid-like properties.. Self-organized structures termed quasi-crystals were originally described in 1978 by the Israeli scientist Valeri A. Krongauz of the Weizmann Institute of Science, in the Nature paper, Quasi-crystals from irradiated photochromic dyes in an applied. ground state energies of the closed and open forms of spiropyran for difierent basis sets. The frequency dependent linear polarizability of spiropyran and derivatives were obtained and plotted. The found absorption peaks are difierent for the closed and the open structures of the spiropyran molecule. PACS numbers: 31.15.A{, 32.10.Dk, 33.15.Kr 1 of a spiropyran mechanophore in real-time. Measurements of reaction kinetics with polymer tethers of varying repeating unit structure demonstrate that degree of polymerization is the key descriptor of mechanochemical activity, independent of molecular weight and pendant group constitution. These results hav For fabricating photoresponsive multifunctional materials, we have developed the potassium salt of a new anionic spiropyran, 1′,3′,3′-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2′-indoline]-5′-sulfonate (1 −), with the sulfonate group present on the indoline moiety and whose crystal structure was revealed by single-crystal X-ray diffraction analysis adsorbed spiropyran molecules. In contrast to covalent functionalization, the van der Waals interaction is less invasive and only slightly changes the electronic structure of the tube [4]. To obtain a realistic description of the adsorbtion of molecules including their position on the CNT surface and the resulting dipole fields, density

spiropyran respectively. They are organic compounds with a closed ring form (Figure 1), which change into an open ring form called merocyanine under UV exposure. Spirooxazine is colorless in its closed ring form and be- comes blue [12] under UV irradiation (open ring form), and spiropyran is pale yellow in its closed ring form an influence of the attached spiropyran molecule on the electro nic structure of the substrate CNT is small, i.e. the band structure and the wave function remain approximately unchanged [3]. As a result, it is sufficientto investigatethe behavior of a p ristineCNT located in a static dipole field induced by the attached molecules Dubois, Kevin, Spectroscopic investigations of the photochemical properties of I. Spiropyran on y zeolite for photochromic applications II. Rhenium(I) bipyridyl tricarbonyl on mesoporous ZSM-5 zeolite and silica for photocatalytic reduction of carbo CDs have a rigid and well defined structure with a hydro-phobic cavity. A variety of organic and inorganic guest molecules have been inserted into its cavity, resulting in the formation of Scheme 1 Spiropyran-merocyanine structures in equilibrium under UV-visible light irradiation. aLaboratorio de Encapsulamento Molecular e Biomateriais.

Electronic structure of a spiropyran derived molecular

Moreover, the structure of spiropyran resembles the potent Eg5 inhibitor ispinesib (Fig. 8C). Consequently, it is strongly expected that the photochromic Eg5 inhibitor composed of spiropyran will have a significant change in its inhibitory activity correlating with its isomerization. In fact, the spiropyran derivative, DSPPA, inhibited Eg5 In order to prevent thermal isomerization the skeletal modification of spiropyran structure and/or the introduction of a substituent group as well as the selection of a medium is carried out. Where an improved compound is incorporated into a polymer matrix or Langmuir-Brodgett film, the thermal stability of the composite material may be increased

Spiropyran as a potential molecular diagnostic tool for

binding properties of two novel spiropyran derivatives with differences in both the substitution pattern and the pKa-value. A 4-state model has been used to quantitatively account for the difference in binding affinity between the MC and the MCH+ forms, and qualitative arguments are used to explain these differences in terms of structure and charg The thermal and photochemical ring opening and ring closure of the spiropyran/merocyanine couple of three nitro-substituted spiropyrans (6-NO2: 6, 7 and 8-NO2: 8) were studied and the results were compared with those of other 6-NO2 spirobenzopyranindolines (BIPS) (1-5). The photocolouration, which occurs in the triplet manifold throughout, and the photochemical conversion and thermal. spiropyran mechanophore are given in Fig. 1. Active polymers (shown in Fig. 1a and b) consisted of difunctional spiropyran (1) as the mechanophore and EGDMA (3), PEG550 (4) or PEG750 (5) as the primary crosslinker. Here, polymer was linked to the 50 and 8 attachment points of spi-ropyran as shown in Fig. 1a, allowing force transfer across th

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spiropyran films are a deep blue color, but when that same film relaxes, the color turns purple. The activated film reversibly structure and, therefore, intended function. Second, the reversibility of the secondary color transition offers an opportunity for new, high-resolution spectroscopic probes o Enabling Room-Temperature Mechanochromic Activation in a Glassy Polymer: Synthesis and Characterization of Spiropyran Polycarbonate Yuval Vidavsky,†,∥ Steven J. Yang,†,∥ Brooks A. Abel,‡ Iris Agami,§ Charles E. Diesendruck,§ Geoffrey W. Coates,‡ and Meredith N. Silberstein*,† †Sibley School of Mechanical and Aerospace Engineering, and ‡Department of Chemistry and Chemical. The conformational flexibility of nitrospiropyran, which was altered by modifying the structure of the background ligand, had a profound impact on the self-assembly process. By coating the nanoparticles with a spiropyran lacking the nitro group, a conceptually different self-assembly system, relying on a reversible proton transfer, was realized

One-Pot Synthesis and Structure Study of a New Indoline

Abstract. Side chain liquid crystal polymers containing spiropyran and mesogenic units give photo- and thermo-chromic mesophases. Structural changes of the mesomorphic systems can be induced by the reversible spiropyran-merocyanine dye conversion Present invention provides an ionic spiropyran compounds having a long-chain alkyl group or groups at both or either of the 1- and 2-positions of 3',3'-dimethyl-6-nitrospiroÄ2H-1-benzopyran-2',2'-indol composite material conjugated the said ionic spiropyran compound with clay mineral Fig. 1 Molecular structure and isomerisation of 1-(2-hydroxyethyl)-3,3-dimethylindoline-6. 0-nitrobenzospiropyran (BSP-1) spiropyran. Fig. 2 Structures of the TTh and TTh-BSP derivatives studied: methyl 4,4. 00--didecyloxy Iron mixed-valence complex, (n-G 3 H 7) 4 N[Fe ll Fe lll (dto) 3](dto = C 2 O 2 S 2), shows a spin entropy- driven phase transition called charge transfer phase transition in [Fe ll Fe lll (dto) 3]-∞ around 120 K and a ferromagnetic transition at 7 K.These phase transitions remarkably depend on the hexagonal ring size in the two-dimensional honeycomb network structure of [Fe ll lll m (dto)

Solid-state photochromism and acidochromism

closed spiropyran form due to the polarity of the solvent stabilizing the closed spiropyran form [24, 25]. Conse-quently, the spiropyran moiety opens in such a miniscule proportion in hexane that it is almost impossible to detect the rate constant for merocyanine ring closing. In com-parison, when in a relatively polar environment such a Due to the presence of the photochromic spiropyran molecule in the polymer structure, these hydrogels reversibly shrink and swell in aqueous environments when exposed to different light conditions. When placed onto a ratcheted surface, the actuation of the bipedal gel produces a walking motion by taking a series of steps in a give US8236914B2 US12/693,801 US69380110A US8236914B2 US 8236914 B2 US8236914 B2 US 8236914B2 US 69380110 A US69380110 A US 69380110A US 8236914 B2 US8236914 B2 US 8236914B2 Authority US United States Prior art keywords polymer stress mechanophore mechanochromic spiropyran Prior art date 2007-07-27 Legal status (The legal status is an assumption and is not a legal conclusion

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