Theory of a Ferroelectric Carbon Nanothread

Nanothreads are one-dimensional rigid sp3 carbon frameworks synthesized by pressure-induced polymerization of aromatic precursors such as benzene or furan. Here we predict that pyrrole-based nanothreads may exhibit ferroelectricity through reorientations of lone pairs within a 1D stack of –NH functional groups that are anchored in the rigid nanothread backbone. To help realize the stacking geometry needed for ferroelectricity, we describe a strategy of nanothread structural control based on steric crowding of bulky side groups. By this method we identify a family of pyrrole-based precursors such as 3-trifluoroumethyl-pyrrole that are energetically favored to form ferroelectric threads over non-ferroelectric isomers.