Spiropyrans and spirooxazines 8. 5��-(1,3-Benzothiazol-2-yl)-substituted spiro[indoline-2,3��-naphthopyrans]: synthesis and spectral and photochromic properties

Novel photochromic 5??-(1,3-benzothiazol-2-yl)-substituted spiro[indoline-2,3??-naphthopyrans] possessing luminescence properties in both the cyclic and merocyanine forms were synthesized. Unlike the 8??-(1,3-benzothiazol-2-yl)-substituted benzopyran analogs, the synthesized compounds are characterized by the lower relative stability of the merocyanine isomers.     

Synthesis and photochromic properties of spiropyrans containing a fused benzopyranone fragment

New spiro compounds of the indole, phthalazine, isobenzofuran, and benzopyran series, containing a fused benzopyranone fragment in the chromene moiety, were synthesized. Indole derivatives were found to exhibit photochromic properties under stationary conditions at 293 K. The thermal stability of merocyanine isomers sharply decreases upon introduction of electron-withdrawing nitro group into the indole fragment and fusion of a benzene ring to the chromene fragment.     

Synthesis and structure of indoline spiropyrans based on benzo[f]coumarin

Russian Chemical Bulletin - Indoline spiropyrans containing benzo[f]coumarin moiety annulated to the 2H-pyran cycle were synthesized. The obtained compounds exist in solutions as a tautomeric...     

Spiropyrans and spirooxazines 5. Synthesis of photochromic 8-(4,5-diphenyl-1,3-oxazol-2-y1)-substituted spiro[indoline-benzopyrans]

Photochromic spiro[indoline-benzopyrans] containing 4,5-diphenyloxazolyl group at position 8 of the benzopyran fragment have been obtained. New diphenyloxazolyl-substituted spiropyrans manifest considerably higher thermal stability of the merocyanine isomers than their naphthopyran analogs.     

The Chebyshev-Markov-Krein algorithm for analyzing microphysical processes in hail clouds

A modified Chebyshev-Markov-Krein algorithm is proposed for controlling processes governed by kinetic equations.