Ionic spiropyran compound and photochromic material conjugated it with clay

摘要

Present invention provides an ionic spiropyran compounds having a long-chain alkyl group or groups at both or either of the 1- and 2-positions of 3',3'-dimethyl-6-nitrospiroÄ2H-1-benzopyran-2',2'-indol composite material conjugated the said ionic spiropyran compound with clay mineral. Said composite material is capable of forming a transparent thin film photo-interconvertible between the said spiropyran structure and the corresponding merocyanine structure.