摘要 |
A photochromic chromene compound which develops a color of a neutral tint, has high color optical density, a high fading speed and high durability, and has an indeno(2,1-f)naphtho(1,2-b)pyran structure represented by the following formula as the basic skeleton, wherein a sulfur-containing substituent selected from thiol group, alkylthio group, alkoxyalkylthio group, haloalkylthio group, cycloalkylthio group, arylthio group and heteroarylthio group is bonded to the 6-position and/or 7-position carbon atom(s). |