| abstract |
A compound according to Formula IA and IB, reversibly convertible under photochromic and electrochromic conditions between a ring-open isomer A and a ring-closed isomer B is provided. For substitutent groups, Z is N, O or S; each R 1 is independently selected from the group consisting of H, or halo; each R 2 is independently selected from the group consisting of H, halo, a polymer backbone, alkyl or aryl; or, when both R 2 together form -CH=CH- and form part of a polymer backbone; each R3 is independently selected from the group consisting of H, halo, alkyl, alkoxy, thioalkyl or aryl; each R 4 is aryl; and each R 5 is independently selected from the group consisting of H, halo, alkyl, alkoxy, thioalkyl or aryl. |