A series of novel spirooxazine（SPO） derivatives containing nitrogen heterocycles was synthesized and characterized by 1H NMR spectra, Fourier transform infrared（FTIR） spectra, mass spectra（MS） and elemental analy- sis, and their photochromic behaviors were fully investigated in solvents and polymer media. In solvents, they dis- played excellent photochromism properties such as high photochromic response and fast thermal bleaching rate. Es- pecially, compounds 1 and 4 exhibited strong fluorescence intensities in dichloromethane solution. It was additionally found that compound 4 showed high fatigue resistence in poly（methyl methacrylate）（PMMA） film, and the thermal decay curves were fitted with biexponential function in PMMA film.
A series of naphthopyrans with hydrazone unit （8a-8m）, were synthesized and characterized by 1H NMR, 13C NMR, IR and HRMS. The photochromic properties were investigated under continuous irradiation, in particular re- gard to the fatigue resistance and the lifetime of the colored open form in solution and polymers. The results showed that these compounds had both good photochromic properties and high fatigue resistance. Detailed studies showed that representative compound 8d （3,3-di-4-methoxybenzoic acid methylenehydrazino-[3H]-naphtho [2,1-b]pyran） had good photochromic properties in THF solution, in solid state, and in polymers, and exhibited a significant ba- thochromic shift in the spectra of the open forms compared to known naphthopyrans 9 （3,3-diphenyl-[3H]- naphtho[2,1-b]pyran）. On the other hand, the higher melting points of target compounds are promising for the polymer film preparation through hot-melt method.
