Described are novel reversible photochromic naphthopyran compounds having at least one ortho substituted phenyl group at the 3-position of the pyran ring. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indolino)-oxazine type compounds, are also described.
                            描述了一种新型可逆光致变色的
萘吡喃化合物,其在
吡喃环的3位具有至少一个邻位取代的苯基团。还描述了含有这种化合物或涂有这种化合物的有机宿主材料。还描述了包含新型
萘吡喃化合物或与互补光致变色化合物(例如螺(indolino)-氧嗪型化合物)组合的物品,如眼镜镜片或其他塑料透明物。