P 4008 (OTTO) Poly(3-hexylthiophene-2,5-diyl) electronic grade, 99.995% trace metals basis, average Mn 15,000-45,000 Cas 104934-50-1 - used in organic electronics primarily because of its regular end-to-end arrangement of side chain, which allows efficient Π-Π stacking of the conjugated backbones.