D 1437 (OTTO) 1,8-Dibromooctane, 98% Cas 4549-32-0 - used as an additive in the preparation poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]]:[6,6]-phenylC71-butyric acid methyl ester, which finds application in the fabrication of organic photovoltaics (OPVs).