1485-92-3Relevant articles and documents
Improving the synthesis of spiropyran derivatives using microwave irradiation method
Rohadi, Atisya,Hasbullah, Siti Aishah,Lazim, Azwan Mat,Nordin, Rumaisa
, p. 1017 - 1024 (2014)
A solvent free synthesis of spiropyran derivatives has been developed from the condensation of indoline and salicylaldehyde using a microwave irradiation method. This method starts from readily available starting materials and provides biologically interesting products. The microwave irradiation method was remarkably successful and gave spiropyran derivatives in higher yield (72-99%) with a much shorter reaction time (10-15 min) compared to the conventional heating method. The chemical structures of the compounds prepared were characterized through IR, 1H NMR and 13C NMR spectral data.
Proton-Stabilized Photochemically Reversible E/ Z Isomerization of Spiropyrans
Kortekaas,Chen,Jacquemin,Browne
, p. 6423 - 6430 (2018)
Spiropyrans undergo Cspiro-O bond breaking to their ring-open protonated E-merocyanine form upon protonation and irradiation via an intermediate protonated Z-merocyanine isomer. We show that the extent of acid-induced ring opening is controlled by matching both the concentration and strength of the acid used and with strong acids full ring opening to the Z-merocyanine isomer occurs spontaneously allowing its characterization by 1H NMR spectroscopy as well as UV/vis spectroscopy, and reversible switching between Z/E-isomerization by irradiation with UV and visible light. Under sufficiently acidic conditions, both E- and Z-isomers are thermally stable. Judicious choice of acid such that its pKa lies between that of the E- and Z-merocyanine forms enables thermally stable switching between spiropyran and E-merocyanine forms and hence pH gating between thermally irreversible and reversible photochromic switching.
'Ship-in-a-bottle' synthesis and photochromism of spiropyrans encapsulated within zeolite Y supercages
Casades, Isabel,Constantine, Steven,Cardin, David,García, Hermenegildo,Gilbert, Andrew,Márquez, Francisco
, p. 6951 - 6956 (2000)
The ship-in-a-bottle synthesis of three spiropyrans inside the NaY supercages was carried out by the condensation of 2-methylene-1,3,3-trimethylindoline with the appropriate substituted benzaldehyde. After the reaction, spiropyrans were detected in the supernatant and the zeolites became coloured. Combustion chemical and thermogravimetric analyses confirmed the presence of organic material within the solid. UV-Vis and Raman spectroscopies are compatible with the formation of the merocyanine form of the spiropyran photochromic system. Upon visible irradiation the solids bleach, and in some cases the coloration is regained upon standing in the dark for long periods. This abnormal photochromic behaviour is the reverse of that observed for the spiropyran/merocyanine system in ethanol and illustrates the possibility of zeolites as media to alter the molecular properties of incorporated guests. (C) 2000 Elsevier Science Ltd.
Studies on adsorptiochromism I: Binding of adsorptiochromic spiropyrans to some pharmaceutically useful solids
Connors,Jozwiakowski
, p. 892 - 897 (1987)
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Sublimation thermodynamics of indoline and benzoxazine based spiropyrans
Dunaev, A. M.,Govorov, D. N.,Kudin, L. S.,Kuzmin, N. A.,Lukyanov, B. S.,Lukyanova, M. B.,Motalov, V. B.
, (2021/10/29)
Sublimation of 1,3,3,6′-tetramethyl-8′-formyl-spiroindoline-2,2′-[2H] -chromene (SP-1) and 3,6′-dimethyl-8′-formyl-spiro (4-oxo-3,4-dihydro-2H-1,3-benzoxazine)-2,2′-[2H] -chromene (SP-2) was studied by Knudsen effusion mass spectrometry in the temperature range 309–363 K and 331–384 K, respectively. It has been shown that, in the temperature range under study, both spiropyrans are thermally stable and sublime congruently in the form of monomeric molecules. The dependences of the saturated vapor pressure (Pa) on temperature are described by the equations: lg p (SP-1) = – (6.239±0.093)?103?T–1+ (15.832±0.278), lg p (SP-2) = – (6.625±0.111)?103?T–1 + (15.459±0.312). The sublimation enthalpies have been evaluated by the second law method as ΔsH°(298.15 K) = 119±5 kJ?mol–1 (SP-1) and ΔsH°(298.15 K) = 128±5 kJ?mol–1 (SP-2). The enthalpies of formation of spiropyran molecules in the ideal gas state, ΔfH°g(298.15 K) = 199±9 kJ?mol–1 (SP-1) and ΔfH°g(298.15 K) = –296±10 kJ?mol–1 (SP-2), have been calculated using isodesmic reactions method implying quantum chemical calculations. Combining the latter values with the corresponding sublimation enthalpies the enthalpies of formation for crystalline state spiropyrans were determined: ΔfH°cr(298.15 K) = 80±10 kJ?mol–1 (SP-1) and ΔfH°cr(298.15 K) = –424±11 kJ?mol–1 (SP-2).
