Synthesis of Highly Soluble and Oxidatively Stable Tetraceno[2,3-b]thiophenes and Pentacenes
journal contributionposted on 17.08.2007, 00:00 by Sujeewa S. Palayangoda, Rajib Mondal, Bipin K. Shah, Douglas C. Neckers
A comparative study of suitably functionalized, highly soluble tetraceno[2,3-b]thiophenes (1−3) and pentacenes (4−6) that show higher photoxidative stability than that of unfunctionalized corresponding acenes is reported. The absorption and emission of 1−3 (Amax = 624−656 nm, λmax = 634−672 nm, ΦF ≈ 10%) and 4−6 (Amax = 672−704 nm, λmax = 682−718 nm, ΦF ≈ 10%) were found to be systematically red-shifted by the substitution in the order of the tert-butylethynyl < triisopropylsilylethynyl < phenylethynyl groups. The oxidation potentials of these compounds were similar (E1/2 ≈ 0.70 V), except for 4, which showed lower oxidation potential (E1/2 ≈ 0.63 V).