RELATIVE INVESTIGATION OF THE PROPERTIES FOR MONOMER AND DIMER PHOTOCHROMIC SPIROCOMPOUNDS

Compounds containing two photochromic fragments have been investigated . The structure and solvent effects on the absorption spectra and kine tic of the thermal relaxation of the colored form produced under UV ir radiation were studied. The hypsochromic displacement of the absorptio n bands and the increase of the life - time of the open form for the d imer spirobenzopyran as compared with the monomer analog was found. Th is data indicate that the closed and opened forms are interacted with each other. For the dimer spironaphthoxazines similar interaction is n ot found. The photodegradation for these compounds under UV light are also studied.