Synthesis, Structure, and π-Donor Properties of Tris(ethylenedioxy)benzene and Bis(ethylenedioxy)thiophene

Abstract

Tris(ethylenedioxy)benzene 3 and bis(ethylenedioxy)thiophene 4 have been synthesized starting from 2,3-dibromo-1,4-dioxene in 25 and 38% overall yields, respectively. These ethylenedioxy-fused benzene and thiophene can be easily oxidized to produce the corresponding radical cations 3 •+ and 4 •+ because of their high-lying HOMO levels. Interestingly, the radical cation 3 •+ exhibits a fairly strong fluorescent emission at max 602 and 590 nm (F = 0.40 in MeCN and 0.50 in H2SO4).