Oligo (p-phenylene) s containing hydroxyl group (s), namely, OPP (n)-OH (n= 3, 4, and 5; n denotes the number of benzene rings), HO-OPP (3)-OH, and 1, 3, 5-tri (4-biphenyl) phenol TBP-OH were synthesized in high yields by the Suzuki coupling reaction. Absorption maxima (λmaxs) of OPP (n)-OHs shifted progressively toward long wavelengths due to the expansion of the π-conjugation system with an increase in the number of benzene rings. ...