Intense Colouring Photochromic 2H-Naphtho[1,2-b]pyrans and Heterocyclic Pyrans

A naphtho [1,2-$i(b)] pyran of general formula (I), wherein one or both of R?1¿ and R?2¿ is a 4-aminoaryl group; R?5¿ is selected from linear or branched C¿1?-C¿10? alkyl, C¿1?-C¿20? cycloalkyl, C¿1?-C¿20? bicycloalkyl, C¿1?-C¿20? polycycloalkyl, linear or branched C¿1?-C¿10? haloalkyl, linear or branched C¿1?-C¿10? perhaloalkyl, linear or branched C¿1?-C¿10? perhaloalkenyl, linear or branched C¿1?-C¿10? alkenyl, C¿1?-C¿10? alkynyl, linear or branched C¿1?-C¿10? alkoxy, linear or branched C¿1?-C¿10? alkylthio, linear or branched C¿1?-C¿10? alkoxy (linear or branched C¿1?-C¿10? alkyl), linear or branched C¿1?-C¿10? hydroxyalkyl, linear or branched C¿1?-C¿10? aminoalkyl, aryl, phenyl, heteroaryl, halogen, nitrile, nitro, amino, linear or branched C¿1?-C¿20? alkoxycarbonyl, hydroxyl, formyl, acetyl, amido, C¿1?-C¿5? alkylamido, C¿1?-C¿5? dialkylamido, aroyl, benzoyl, alkyl C¿1?-C¿5? amino, dialkyl C¿1?-C¿5? amino, arylamino, diarylamino, aryl C¿1?-C¿5? alkylamino and cyclicamino groups; arylsulfinyl, arylsulfanyl, arylsulfonyl, linear or branched C¿1?-C¿10? alkylsulfonyl, P(O)(O-C¿1?-C¿10? alkyl)¿2? or is the alkenyl function (II), wherein R?11¿ and/or R?12¿ and/or R?13¿ is hydrogen or is as defined for R?5¿, and R?3¿, R?4¿ and R?6¿-R?10¿ are each hydrogen or as defined R?1¿, R?2¿ or R?5¿. The compounds may be combined with a polymeric host material such as a plastic or a glass to make a sunglass lens, an ophthalmic lens or a window.