Stepwise Unidirectional Synthesis of Oligo Phenylene Vinylenes with a Series of Monomers. Use in Plastic Solar Cells

Four new monomers for directional stepwise synthesis of oligophenylenevinylenes (OPVs) (4-{2-[4-(5,5-dimethyl[1,3]dioxan-2-yl)-2,5-dipropoxyphenyl]vinyl}benzyl)phosphonic acid diethyl ester, (5-{2-[4-(5,5-dimethyl[1,3]dioxan-2-yl)-2,5-dipropylphenyl]vinyl}thiophene-2-ylmethyl)phosphonic acid diethyl ester, (5-{2-[4-(5,5-dimethyl[1,3]dioxan-2-yl)-2,5-dipropoxyphenyl]vinyl}thiophene-2-ylmethyl)phosphonic acid diethyl ester, and (7-{2-[4-(5,5-dimethyl[1,3]dioxan-2-yl)-2,5-dipropylphenyl]vinyl}benzo[1,2,5]thiadiazol-4-ylmethyl)phosphonic acid diethyl ester have been prepared. Trimeric OPVs were then synthesized and tested as active materials in photovoltaic cells. Conversion efficiencies in the range of 0.5−1% were obtained in blends with the soluble C60 derivative PCBM. A terpyridine end-functionalized trimer and a heterotrimer with a mixed composition of monomers were also prepared.