93633-69-3

Upstream product

• 16111-07-2 2-(3',3'-dimethyl-6-nitro-3'H-spiro[chromene-2,2'-indol]-1'-yl)-ethanol 
• 1417158-14-5 C₂₀H₂₁N₂O₄⁽¹⁺⁾*C₂₈H₂₀O₁₆S₄^(4-) 

Downstream Products

• 16111-07-2 2-(3',3'-dimethyl-6-nitro-3'H-spiro[chromene-2,2'-indol]-1'-yl)-ethanol 

Relevant academic research and scientific papers

Reverse photochromism of spiropyran in silica

The high thermal stability of the photomerocyanine-form (PMC-form) of spiropyran (SP) dispersed in perhydropolysilazane (PHPS), which converted to silica at ambient temperature, was investigated. PHPS was converted to silica by the de-ammonium reaction wi

A Multiswitchable Poly(terthiophene) Bearing a Spiropyran Functionality: Understanding Photo- and Electrochemical Control

An electroactive nitrospiropyran-substituted polyterthiophene, poly(2-(3,3′′-dimethylindoline-6′-nitrobenzospiropyranyl) ethyl 4,4′′-didecyloxy-2,2′:5′,2′′- terthiophene-3′-acetate), has been synthesized for the first time. The spiropyran, incorporated into the polymer backbone by covalent attachment to the alkoxyterthiophene monomer units, leads to multiple colored states as a result of both photochemical and electrochemical isomerization of the spiropyran moiety to merocyanine forms as well as electrochemical oxidation of the polyterthiophene backbone and the merocyanine substituents. While electrochemical polymerization of the terthiophene monomer can take place without oxidation of the spiropyran, increasing the oxidation potential leads to complex electrochemistry that clearly involves this substituent. To understand this complex behavior, the first detailed electrochemical study of the oxidation of the precursor spiropyran, 1-(2-hydroxyethyl)-3,3-dimethylindoline-6′- nitrobenzospiropyran, was undertaken, showing that, in solution, an irreversible electrochemical oxidation of the spiropyran occurs leading to reversible redox behavior of at least two merocyanine isomers. With these insights, an extensive electrochemical and spectroelectrochemical study of the nitrospiropyran- substituted polyterthiophene films reveals an initial irreversible electrochemical oxidative ring-opening of the spiropyran to oxidized merocyanine. Subsequent reduction and cyclic voltammetry of the resulting nitromerocyanine-substituted polyterthiophene film gives rise to the formation of both merocyanine π-dimers or oligomers and π-radical cation dimers, between polymer chains. Although merocyanine formation is not electrochemically reversible, the spiropyran can be photochemically regenerated, through irradiation with visible light. Subsequent electrochemical oxidation of the nitrospiropyran-substituted polymer reduces the efficiency of the spiropyran to merocyanine isomerization, providing electrochemical control over the polymer properties. SEM and AFM images support the conclusion that the bulky spiropyran substituent is electrochemically isomerized to the planar merocyanine moiety, affording a smoother polymer film. The conductivity of the freestanding polymer film was found to be 0.4 S cm-1.(Figure Presented)

Study of the Possibility of Functionalization of Graphene Oxide Nanoplatelets with Photochromic Chromene and Spiropyrans in Solutions

Abstract: Spectral and kinetic studies of the interaction of the surface groups of graphene oxide nanoplatelets with the molecules of photochromic compounds from the classes of chromenes and spiropyrans in solutions were carried out. It was shown that the

Negative Photochromism of Solutions of Functionalized Spiropyrans in a Water—Acetonitrile Mixture

A spectral-kinetic study of photochromic functionalized nitro-substituted indoline spiropyrans in water-acetonitrile mixtures has allowed to observe for the first time the effect of negative photochromism due to the self-assembly of photochromic molecules in a mixed solvent with the formation of hydrogen bonds and proton complexes.

Transmission spectroscopy and kinetics in crystalline solids using aqueous nanocrystalline suspensions: The spiropyran-merocyanine photochromic system

A comparison of the solution and solid state thermal decay kinetics of five photochromic spiropyrans with different N-Alkyl groups (SP1-SP5) was carried out in acetonitrile and nanocrystalline suspensions at 298 K. The change in absorbance at ca. 550 nm was measured as a function of time for the merocyanine (MC) using transmission UV-vis spectroscopy. We found that the thermal decay kinetics are slower and follow a biexponential decay in the solid state compared to a faster, monoexponential decay that was measured in solution. We observed that, while the kinetic range measured in solution varies by a factor of 13, the decay kinetics in the solid state cover a range of ca. 150, indicating that crystal packing has an influence much greater than that of the effects of N-Alkyl substitution. A fluorescence analysis of irradiated samples of SP1 in solution could be used to determine the formation of the MC species and its subsequent decay. By contrast, a similar analysis of nanocrystalline suspensions displayed changes as a function of time that are consistent with selfquenching.

Synthesis of zinc chlorin-spiropyran dyads and their self-aggregation properties

A photochromic spiropyran moiety has been covalently linked to a self-aggregative zinc analog of chlorophyllous pigments. Semi-synthetic zinc chlorins possessing a 31-hydroxy- or 31-methoxy group were used as the chlorophyll model, and the spiropyran part was introduced at the 17-position of the chlorin macrocycle. The spiropyran moiety reversibly isomerized to its opened merocyanine form in the dyads. The photoisomerization induced drastic change in electric dipole moment of the side chain, and photoswitchable chlorophyll aggregation was found in the pigment conjugates.

Photochromism of a merocyanine dye bound to sulfonatocalixarenes: Effect of ph and the size of macrocycle on the kinetics

The effect of 1:1 complex formation on the photochromic behavior of the merocyanine isomer of a nitro-substituted spirobenzopyran dye was studied in aqueous solution using 4-sulfonatocalixarene (SCXn) cavitands possessing four or eight phenol units. The binding constants were independent of the size of the macrocycle, and about 7-fold more stable associates were produced at pH 2.3 than in slightly alkaline solution. The complexation with SCXn diminished the acidity of protonated merocyanine (trans-MCH+) and precluded its photoinitiated transition to spirobenzopyran form, but did not affect the reactions in basic media. Upon exposure to light, the complexed trans-MCH + was converted to cis isomer. The association with 4-sulfonatocalix[4]arene slowed down the thermal back reaction in the dark to a larger extent than the confinement to 4-sulfonatocalix[8]arene. Both the activation energy and the Arrhenius A factor were significantly larger when the smaller, more rigid macrocycle served as a host.

Physicochemical study of spiropyran-terthiophene derivatives: Photochemistry and thermodynamics

The photochemistry and thermodynamics of two terthiophene (TTh) derivatives bearing benzospiropyran (BSP) moieties, 1-(3,3″-dimethylindoline- 6′-nitrobenzospiropyranyl)-2-ethyl 4,4″-didecyloxy-2,2′: 5′,2″-terthiophene-3′-acetate (BSP-2) and 1-(3,3″- dimethylindoline-6′-nitrobenzospiropyranyl)-2-ethyl 4,4″-didecyloxy- 2,2′:5′,2″-terthiophene-3′-carboxylate (BSP-3), differing only by a single methylene spacer unit, have been studied. The kinetics of photogeneration of the equivalent merocyanine (MC) isomers (MC-2 and MC-3, respectively), the isomerisation properties of MC-2 and MC-3, and the thermodynamic parameters have been studied in acetonitrile, and compared to the parent, non-TTh-functionalised, benzospiropyran derivative, BSP-1. Despite the close structural similarity of BSP-2 and BSP-3, their physicochemical properties were found to differ significantly; examples include activation energies (Ea(MC-2) = 75.05 kJ mol-1, Ea(MC-3) = 100.39 kJ mol-1) and entropies of activation (ΔS?MC-2 = 43.38 J K-1 mol-1, ΔS?MC-3 = 37.78 J K-1 mol-1) for the thermal relaxation from MC to BSP, with the MC-3 value much closer to the unmodified MC-1 value (46.48 J K-1 mol -1) for this latter quantity. The thermal relaxation kinetics and solvatochromic behaviour of the derivatives in a range of solvents of differing polarity (ethanol, dichloromethane, acetone, toluene and diethyl ether) are also presented. Differences in the estimated values of these thermodynamic and kinetic parameters are discussed with reference to the molecular structure of the derivatives.

Microwave-assisted crystallization inclusion of spiropyran molecules in indium trimesate films with antidromic reversible photochromism

An indium trimesate metal-organic framework (JUC-120) which possesses a cubic zeolitic MTN topology, as a new analogue to MIL-100(Al, Fe or Cr) compounds, has been successfully synthesized. Its structure exhibits a mesoporous cage (26 A) and high thermal stability. The assembly of nitrobenzospiropyran derivatives (BSP) into JUC-120 nanocrystals (BSP/JUC-120) is achieved by a microwave-assisted crystallization inclusion approach. The BSP/JUC-120 films have been prepared on quartz wafers by a spin-coating method. The successful encapsulation of BSP molecules into the mesopores of the JUC-120 structure has been verified by N2 adsorption and TGA measurements. The photochromic properties of BSP/JUC-120 films are studied by the UV-Vis and fluorescence spectroscopies. More interestingly, metastable open merocyanine (OMC) species are directly generated from the closed spiropyran form (CSP) without photoirradiation and stabilized for a long period in the BSP/JUC-120 film. The open merocyanine isomer bleaches to the closed spiropyran form by ultraviolet or visible light, and the coloration is regained upon standing in the dark, exhibiting antidromic photochromism. Moreover, the BSP/JUC-120 film shows high reversibility and thermal stability of photochromism. This highly efficient MOF film is expected to be promising in the applications of optical devices.

Photochromism in cucurbit[8]uril cavity: Inhibition of hydrolysis and modification of the rate of merocyanine-spiropyran transformations

The effect of inclusion complex formation on the photochromic behavior of a spirobenzopyran dye and its merocyanine isomer was studied in aqueous solution using cucurbit[8]uril (CB8) as a host. The merocyanine (MC) and protonated merocyanine (MCH+) were the most stable forms both in water and inside the cavity of CB8. The equilibrium constant of 1:1 complexation with CB8 was found to be 1.7 × 105 and 2.0 × 106 M -1 for the former and latter species, respectively. The encapsulation led to significant change in the rate of the photoinduced and thermal photochromic transformations and hindered the hydrolysis of MC. The effect of CB8 on the reaction kinetics strongly altered with pH. The transition from the spiropyran form to trans-MC in a thermal reaction had 33 kJ mol-1 lower activation energy and more than 5 orders of magnitude smaller Arrhenius pre-exponential factor in CB8 than in water.