93633-69-3Relevant articles and documents
Reverse photochromism of spiropyran in silica
Kinashi,Nakamura,Ono,Ishida,Ueda
, p. 136 - 140 (2010)
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
Study of the Possibility of Functionalization of Graphene Oxide Nanoplatelets with Photochromic Chromene and Spiropyrans in Solutions
Barachevsky, V. A.,Gorelik, A. M.,Khuzin, A. A.,Tuktarov, A. R.,Venidiktova, O. V.
, p. 2640 - 2646 (2022/01/22)
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
Transmission spectroscopy and kinetics in crystalline solids using aqueous nanocrystalline suspensions: The spiropyran-merocyanine photochromic system
Breslin, Vanessa M.,Garcia-Garibay, Miguel A.
, p. 637 - 642 (2017/02/10)
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.
Photochromism of a merocyanine dye bound to sulfonatocalixarenes: Effect of ph and the size of macrocycle on the kinetics
Miskolczy, Zsombor,Biczók, László
, p. 648 - 653 (2013/03/14)
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.
