| abstract |
(57) [Summary] Novel photochromic indeno-fused naphthopyran compounds are disclosed. This includes, for example, naphthopyran compounds having a substituted or unsubstituted indeno group, wherein the 2,1-position is fused to the naphtho position of naphthopyran. The naphthopyran has a moderate to strong electron donating substituent on a cyclic group fused to the 6- and 7-positions of the pyran ring and optionally the 8-position, or the h-side of the naphtho-position, and 3 The position also contains weak to moderate electron donating substituents. Particular substituents may include the fifth, eighth, ninth, tenth, eleventh, twelfth or thirteenth carbon atoms. Said compounds have a relative ΔOD rating of at least 80 in the saturation test and are represented by formula (I). |