This invention has for its object to provide a novel spiro compound and photochromic materials prepared by bonding covalently the spiro compound to zirconium stratiform substance via a phosphoric atom. The invention includes 1',3',3'-trimethyl-spiro[2H-1-benzopyran-2,2'-indoline]-6-methylphosphonic acid represented by the following formula (I) and its salts, and photochromic materials comprising the said compound.
这项发明旨在提供一种新型的
螺环化合物和光致变色材料,通过
磷原子将
螺环化合物与
锆层状物质共价键合而制备而成。该发明包括以下式子(I)所表示的1',3',3'-三甲基螺[2H-1-苯并
吡喃-2,2'-
吲哚]-6-
甲基膦酸及其盐,以及含有该化合物的光致变色材料。