Synthesis and photochromic properties of new spiro [azahomoadamantane-naphthoxazines]

The coupling of various nitrosonaphthols with 4,5-dimethyl-4-azahomoadamantane-4-enium iodide, in the presence of an equimolar amount of triethylamine, affords new spiro [azahomoadamantane-naphthoxazines]. The study of their photochromic properties by flash photolysis shows special features, particularly a hypsochromic shift of the wavelength of absorption of the colored forms, when compared to well known spiro[indolinenaphthoxazines], and also an obvious decrease in the thermal bleaching kinetics.