Photochromic Substituted 2H-Naphtho[1,2-b]pyrans

A 2$i(H)-naphtho[1,2-$i(b)]pyran of general formula (I) wherein R?5¿ is substituted and where R?8¿ is selected from the substituents including hydrogen, linear or branched C¿1?-C¿20? alkyl, C¿3?-C¿20? cycloalkyl, C¿4?-C¿20? bicycloalkyl, C¿5?-C¿20? polycycloalkyl, linear or branched C¿1?-C¿20? haloalkyl, linear or branched C¿1?-C¿20? perhaloalkyl, linear or branched C¿2?-C¿20? alkenyl, linear or branched C¿4?-C¿20? polyalkenyl, linear or branched C¿2?-C¿20? alkynyl, linear or branched C¿4?-C¿20? polyalkynyl, linear or branched C¿1?-C¿20? hydroxyalkyl, linear or branched C¿1?-C¿20? alkylcarbonyl, linear or branched C¿1?-C¿20? polyhydroxyalkyl, linear or branched C¿1?-C¿20? alkoxy, linear of branched C¿1?-C¿20? alkylthio, linear or branched C¿1?-C¿20?(C¿1?-C¿5? or C¿1?-C¿10?alkoxy)alkyl, linear or branched C¿1?-C¿20?(C¿1?-C¿5? or C¿1?-C¿10?alkylthio)alkyl, benzoyl, aroyl, heteraroyl, phenyl, aryl, heteroaryl, halogen, hydroxyl, formyl, acetyl, linear or branched C¿3?-C¿20? alkenoyl, linear or branched C¿5?-C¿20? polyalkenoyl, nitrile, carboxyl, C¿1?-C¿20? or C¿1?-C¿5? alkoxycarbonyl, C¿1?-C¿20? $i(N)-alkylamido, C¿1?-C¿20? or C¿1?-C¿5? $i(N, N)-dialkylamido, amido, nitro, amino, C¿1?-C¿20? or C¿1?-C¿5? alkylamino, C¿1?-C¿20? dialkylamino, C¿2?-C¿20? dialkenylamino, C¿4?-C¿20?di(polyalkenyl)amino, arylamino, diarylamino, C¿1?-C¿20? alkylarylamino, cyclic-amino groups, arylsulfanyl, aryloxy, arylsulfinyl, arylsulfonyl, linear or branched C¿1?-C¿20? alkylsulfonyl, and di-(C¿1?-C¿10? or C¿1?-C¿20? alkoxyalkyl)phosphonyl and X includes O, S, NH, or the function R?8¿X is selected from aziridino, mono- or poly- substituted linear or branched C¿1?-C¿20? alkyl aziridino, pyrrolidino, mono- or poly- substituted linear or branched C¿1?-C¿20? alkyo pyrrolidino, piperidino, mono- or poly- substituted linear or branched C¿1?-C¿20? alkyl piperidino, morpholino, mono- or poly- substituted linear or branched C¿1?-C¿20? alkyl morpholino, thiomorpholino, mono- or poly- substituted linear or branched C¿1?-C¿20? alkyl thiomorpholino, indolino, mono- or poly- substituted linear or branched C¿1?-C¿20? alkyl indolino, piperazino, mono- or poly- substituted linear or branched C¿1?-C¿20? alkyl piperazino, linear or branched C¿1?-C¿20?$i(N)-alkylpiperazino, linear or branched C¿1?-C¿20?$i(N)-hydroxyalkylpiperazino, $i(N)-phenylpiperazino, $i(N)-aryliperazino, homopiperidino, mono- or poly- substituted linear or branched C¿1?-C¿20? alkyl homopiperidino, $i(N)-indolinyl, $i(N)-1,2,3,4-tetrahydroquinolinyl, $i(N)-1,2,3,4,4a-hexahydrocarbazolyl. The compounds may be combined with polymeric host material such as plastic or glass or make a sunglass lens, an ophthalmic lens or a window. The compounds may also be included in an ink or a fuel.