| 摘要 |
A photochromic compound having a high color-developing sensitivity, a large fading rate and good durability of photochromic property. A novel chromene compound is, for example, represented by the following formula,and in which, as a basic structure, a condensed ring having a particular divalent group bonded to carbon atoms at the fourth and fifth positions of a fluoreno group is spiro-bonded to the first position of an indene ring, a particular divalent group is bonded to carbon atoms at the fifth and sixth positions of a chromene ring to form a condensed ring, and particular substituents are bonded to a carbon atom at the second position of the chromene ring.
|
