Semipermanent merocyanines of spirocyclic compounds: photochromic “balance”

Abstract Synthesis methods have been developed, and new spiropyrans of the benzophenazine series have been obtained. In solution, all of the new compounds appear as semipermanent merocyanines. Spirobenzopyrans of the benzophenazine series demonstrate both positive and negative photochromic properties, thus enabling the approach of photochromic “balance” to be realized.