Photochromism and thermochromism of spiro[indolinoxazines] in normal and reversed and reversed micelles

Abstract

Spectra, photochromism and thermochromism of a spiro[indoline-naphthoxazine] and a spiro[indoline-phenanthroxazine] have been investigated in cationic (CTAB, hexadecyltrimethylmmonium bromide) and non-ionic (TX-100) micellar solutions and in sodium bis-2-ethylhexylsulfosuccinate (AOT)/toluene/water inverted-micelles. The spectral shifts of the photomerocyanine colour band provided information on the location of the molecules in these systems. From photokinetic study of the colour-forming and colour-fading reactions, the quantum yield and bleaching constant were determined. The thermal equilibrium constant of the spiro[indoline-phenanthroxazine] was spectrophotometrically measured. Comparison of the results obtained in microheterogeneous systems with those determined in a homogeneous solution indicated that thermo- and photo-colourability increase in TX-100 and CTAB micelles and decrease in inverted micelles.