| abstract |
The present invention relates to photochromic materials that include one or more indeno-fused naphthopyrans that have particular groups at the 7, 1 1, and 13 positions thereof, and at the position alpha to the oxygen of the pyran ring thereof. With some embodiments, hydrogen or an alkoxy group is bonded to the 7 position, an optionally substituted phenyl is bonded to the 11 position, two alkyl groups are bonded to the 13 position, and two optionally substituted phenyl groups are bonded to the position alpha to the oxygen of the pyran ring of the indeno-fused naphthopyran compound. The 13 position of the indeno-fused naphthopyrans is free of ether groups in which an ether oxygen is bonded to the 13 position, and hydroxyl. The present invention also relates to photochromic articles and compositions that include such indeno-fused naphthopyrans. |