  Nanothreads are 1D carbon-based nanomaterials produced by pressure-induced
polymerization of multiply unsaturated (and typically aromatic) precursors with
multiple bonds between adjacent precursors. We computationally design
non-covalent interactions between functional groups on thread-forming monomers
to control the relative stabilities of different nanothread backbones. In
particular, functionalized furan or thiophene precursors are identified that
favor nanothreads with oxygen or sulfur atoms arrayed along the same side of
the thread backbone, rather than on alternating sides as currently seen
experimentally for threads formed from unfunctionalized furan or thiophene.
This heteroatom chain provides opportunities for unusual properties arising
from a sterically compressed one-dimensional chain of p orbitals.
