Abstract The secondary structure of a dissymmetric and chiral poly(diphenylacetylene) (PDPA) is elucidated by combining the data from NMR experiments (regioregular head to tail structure), Raman IR studies ( E configuration polyene double bonds), high‐resolution AFM images (helical pitch, packing angle orientation external helix). As result, an E‐transoidal backbone describing three coaxial hel...