Role of the Methoxy Substituents on the Photochromic Indolyfulgides. Absorption Maximum <i>vs.</i> Molar Absorption Coefficient of the Colored Form

Abstract

Abstract While the introduction of a methoxy group to C-5 of the indole ring of the indolylfulgide caused a large bathochromic shift of the absorption maximum of its colored form, introduction of a methoxy group to C-6 resulted in enlargement of the molar absorption coefficient of the colored form. The 5,6-dimethoxy-substituted indolylfulgide has both properties.