  Van der Waals epitaxy on the surface of two-dimensional (2D) layered crystals
has gained significant research interest for the assembly of well-ordered
nanostructures and fabrication of vertical heterostructures based on 2D
crystals. Although van der Waals epitaxial assembly on the hexagonal phase of
transition metal dichalcogenides (TMDCs) has been relatively well
characterized, a comparable study on the distorted octahedral phase (1T' or Td)
of TMDCs is largely lacking. Here we investigate the assembly behavior of
one-dimensional (1D) AgCN microwires on various distorted TMDC crystals, namely
1T'-MoTe2, Td-WTe2, and 1T'-ReS2. The unidirectional alignment of AgCN chains
is observed on these crystals, reflecting the symmetry of underlying distorted
TMDCs. Polarized Raman spectroscopy and transmission electron microscopy
directly confirm that AgCN chains display the remarkable alignment behavior
along the distorted chain directions of underlying TMDCs. The observed
unidirectional assembly behavior can be attributed to the favorable adsorption
configurations of 1D chains along the substrate distortion, which is supported
by our theoretical calculations and observation of similar assembly behavior
from different cyanide chains. The aligned AgCN microwires can be harnessed as
facile markers to identify polymorphs and crystal orientations of TMDCs.
