Chemical design enables the control of conformational polymorphism in functional 2,3-thieno(bis)imide-ended materialsElectronic supplementary information (ESI) available: Details of synthesis, structure determination from single crystal and powder X-Ray diffraction, photoluminescence of C4-NT4N powder, DSC curves, theoretical calculations, thin deposit preparation, thermal processing and XRD. CCDC 1033185-1033188. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.10

We report a successful chemical design strategy based on the even-odd alkyl end tailoring, which allows us to promote and control conformational polymorphism in single crystal and thin deposits of thienoimide-based molecular semiconductors (C x -NT4N). We introduce a chemical design strategy to control conformational polymorphism in 2,3-thienoimide based molecular materials.