Synthesis and Photochromic Properties of Annellated Benzo [1, 2, 3-kl: 4, 5, 6-k'l'] dixanthene and Their Endoperoxides

Abstract

10, 20-Dioxadinaphtho [1, 2-a : 1', 2'-j] perylene [1c] and 10, 20-dioxadinaphtho [2, 1-a : 2', 1'-j] perylene [1d] were synthesized by cyclization of 1, 5-bis (1- or 2-naphthyloxy) anthraquinones, which were prepared from 1, 5-dichloroanthraquinone and 2-naphthol (or 1-naphthol). The electronic absorption spectrum of [1c] or [1d] showed some resemblance to that of benzo [1, 2, 3-kl : 4, 5, 6-k'l'] dixanthene [1a] except for a considerable red shift (-30 nm). The photooxidation of the above red compounds [Ic] - [1d] at 541 nm gave colorless endoperoxides [2c] - [2d]. Photooxidati, on of [1c], which is the most sterically hindered derivative, proceeded about 2 times faster than that of [1a] or [1d]. The photochemical and thermal properties of [2c] - [2d] were also investigated.