When molecules assemble in self-assembled molecular networks
on
highly oriented pyrolytic graphite, typically six orientational domains
are formed, which can be grouped into two sets of three, each set
characteristic of a packing chirality. Under dynamic nanoconfinement
conditions, where the scanning tunneling microscopy (STM)-based lithography
process gradually increases the area available for molecule adsorption
and self-assembly, the orientational domain equivalence is often disrupted.
Additionally, this phenomenon can sometimes be accompanied by the
selective formation of one of the two enantiomorphic packings. Until
now, the preferential orientation of domains, sometimes accompanied
by the favored formation of enantiomorphic packing patterns, has been
investigated for anisotropic molecules with a single alkyl chain.
We reasoned that a system where different alkyl chains may adsorb
along various directions on the substrate, while also adopting different
orientations concerning the line-wise movement of the STM tip, can
potentially hinder molecular alignment in the nanocorrals and eventually
limit the extent of enantiomorph-selective adsorption. To address
this hypothesis, in this study, we investigate the self-assembly of
an achiral molecule with four alkyl chains, in pairs directed along
two different directions, under dynamic nanoconfinement conditions.
Despite of this increased molecular structural complexity, dynamic
nanoconfinement conditions lead to a clear bias in the formation of
rotational domains, as well as partial chiral selection, although
in a complex fashion. The factors that contribute to this bias are
discussed. This highlights the significance of utilizing dynamic nanoconfinement
conditions to control domain orientation and to disturb chirality
equivalence, even for intricate systems.