US Patent 7527754 Photochromic indeno-fused naphthopyrans

Photochromic materials comprising indeno-fused naphthopyrans having substituents comprising a 4-fluorophenyl group and a 4-aminophenyl group bonded to the 3-position of the indeno-fused naphthopyran are disclosed. The photochromic materials may exhibit faster fade rates as compared to similar indeno-fused naphthopyrans without a 4-fluorophenyl group and a 4-aminophenyl group bonded to the 3-position of the indeno-fused naphthopyran. Substituted 2-propyn-1-ols utilized for the synthesis of the indeno-fused naphthopyrans disclosed herein are disclosed. Photochromic compositions and articles, such as optical elements, incorporating the photochromic materials disclosed herein are also disclosed.