Abstract:
Precise control over the supramolecular organization
of organic semiconducting materials guiding to exclusive
face-on or edge-on orientation is a challenging
task. In the present work, we study the preferential packing
of thiophene oligomers induced through rational molecular
designing and self-assembly. The acceptor–donor–
acceptor-type oligomers having 2-(1,1-dicyano-methylene)
rhodanine as acceptor (OT1) favored a face-on packing,
whereas that of functionalized with N-octyl rhodanine
(OT2) preferred an edge-on packing as evident from 2Dgrazing
incidence angle X-ray diffraction, tapping-mode
atomic force microscopy (AFM) and Raman spectroscopy
analyses. The oligomers exhibited anisotropic conductivity
in the self-assembled state as an outcome of the preferred
orientation, revealed by the conducting AFM experiment.
