58273-90-8Relevant articles and documents
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.
SYNTHESIS AND PHOTOCHROMIC PROPERTIES OF INDOLINOSPIROCHROMENES WITH BENZYL, ETHYL, AND ACETONYL GROUPS ATTACHED TO THE NITROGEN ATOM
Lazarenko, I. B.,Przhiyalgovskaya, N. M.,Gal'bershtam, M. A.,Bobyleva, G. K.,Suvorov, N. N.
, p. 1054 - 1057 (2007/10/02)
A number of photochromic indoline spirochromenes with benzyl, acetonyl, and etyl substituents attached to the nitrogen atom in the indoline part of the molecule were synthesized.The introduction of a benzyl group at the nitrogen atom in place of the methyl group does not change the rate constants of the dark decolorization of the photomerocyanines, whereas an acetonyl group increases them, and an ethyl group decrease them.The introduction of the indicated substituents in the 1 position gives rise to a bathochromic shift (up to 18 nm) of the long-wave absorption band of the merocyanine form of the spirochromene.