Synthesis and optical properties of poly(thiophene) derivatives with benzothiazole moiety

A series of poly(thiophene)s, poly(3-(2-benzothiazolyl)thiophene) (PBTT) and poly(3-(2-benzothiazolyl)oxyethyl thiophene) (PBTOET), containing a benzothiazole moiety in the side chain have been synthesized by a cross-coupling reaction using Ni catalyst. PBTT and PBTOET were characterized by FT-IR and 1H-NMR spectra. Both polymers showed fluorescence peaks in the visible region. The HOMO and LUMO energies were estimated by cyclic voltammetry. PBTT was more suitable as a hole transporting material than PBTOET. The turn-on voltages of PBTT and PBTOET single layer EL devices were 5.0 V and 6.5 V, respectively.