Synthesis, Structure, and Electron-Donating Ability of 2,2′:6′,2″-Dioxatriphenylamine and Its Sulfur Analogue

Abstract 2,2′:6′,2″-Dioxa- and dithia-triphenylamines 4a and 4b were prepared. Both compounds had a C2-like structure. The sulfur compound 4b had a more twisted structure than 4a; the dihedral angle between two edge phenyl rings was 43° for 4a, and 62° for 4b. The oxygen compound 4a had a reversible oxidation wave at +0.81 V vs SCE, whereas 4b had an irreversible peak at +1.14 V.