Helically oriented polymer thin films by polarized UV-assisted vapor deposition polymerization

Abstract Helically oriented polymer thin films were prepared by polarized UV-assisted vapor deposition polymerization of achiral polyazomethine. Stepwise modulation of the UV polarization axis during deposition induced chiral ordering, as confirmed by circular dichroism and UV–Vis spectroscopy. The emergence of optical activity in the absence of molecular chirality, i.e. from achiral monomers, indicates the formation of pseudo-helical architectures directed solely by externally imposed linear polarization cues. This method allows programmable control of helical pitch and handedness, demonstrating a versatile strategy for constructing optically active thin films and suggesting potential for three-dimensional hierarchical chiral structures.