Synthesis and photochromic properties of novel spiro[indoline-quinoline]oxazine derivatives

• Seven novel spirooxazine derivatives containing nitrogen heterocycles were designed and synthesized.
• The absorption spectra in different solvents and polymeric films was analyzed.
• The compounds of spirooxazine derivatives exhibited significantly photochromic properties and excellent fatigue resistance.

A series of novel spirooxazine derivatives containing nitrogen heterocycles have been synthesized and characterized by 1H NMR, 13C NMR, IR and HRMS in this paper, and the photochromic behaviors of the compounds have been studied in different solutions and the compounds were embedded into a poly(methylmethacrylate) and poly(vinyl butyral) matrix (PMMA, PVB). In solutions, they showed thermochromism and acidichromism. Embedded into polymeric films, the photochromic kinetics of the thermal decoloration of the compounds significantly changed and it was found that the decoloration curves fitted biexponential function. Detailed studies showed that representative compound 1 [1,3,3-trimethyl-6′-piperidino-spiro(indoline-2,3′-[3H]-quinolino[2,1-b][1,4]oxazine)] exhibited high fatigue resistance in poly(methylmethacrylate) and poly(vinyl butyral) matrix.