A Strategy for Revealing the Packing in Semicrystalline π‐Conjugated Polymers: Crystal Structure of Bulk Poly‐3‐hexyl‐thiophene (P3HT)

To tilt or not to tilt: The crystal structure for bulk P3HT (phase I) was determined by "multi-technique crystallography", which combines X-ray diffraction, solid-state NMR spectroscopy, and DFT calculations. The results showed that this semiconducting polymer crystallizes in the monoclinic space group P2(1)/c with nontilted π-stacks at a distance of 3.9 Å (see picture).