Switching properties of fluorescent photochromic poly(methyl methacrylate) with spironaphthoxazine and D-π-A type pyran-based fluorescent dye.
Fluorescent photochromic poly(methyl methacrylate) (PMMA) with spironaphthoxazine (SPO) and D-π-A type pyran-base fluorescent dye as a fluorophore was synthesized by typical free radical copolymerization. The poly(MMA-co-SPO-co-fluorophore) in both solution and solid film exhibited excellent photoregulated fluorescence switching behavior and reversible modulation of fluorescence intensity using alternating irradiation with UV and visible light. The poly(MMA-co-SPO-co-fluorophore) also showed viscosity and conductivity switching behaviors along with photoresponse.
Synthesis and X-ray structural characterization of new spiroxazine
Abstract A novel spiroxazine containing a mesogenic group has been prepared. The colourless spiroxazine exhibit photochromism through ring opening of the oxazine ring. The crystal structure was determined by X-ray crystallography and the crystal was found to exist in the triclinic space group P1 (No. 1).
Kinetic matrix effects (response and density distribution functions): ring closure. Reaction of indolinobenzospiropyrans in glassy poly(alkyl methacrylates)
The ring closure (bleaching) reaction of photochromic indolinobenzospirans is a fast unimolecular process with a finite activation volume. When the reagent is immobilised in a rigid matrix, the isomerization is controlled by the amount of free volume in the neighbourhood of the reacting molecule and so the distribution of reaction rates reflects the density distribution in the matrix. The theory of such kinetic matrix effects is presented and methods of evaluating the reagent response and matrix density distribution functions are discussed. Ring closure reactions of three such compounds in four polymeric matrices are reported and the complete functions evaluated for 8-bromo-2′,2′-dimethyl-6-nitro-1′-phenyl-(2H-[1]benzospiropyran-2,2′indoline) in poly(methyl methacrylate).