Using Systematic Comparisons of 2D and 3D Structures To Reveal Principles of Molecular Organization. Tetraesters of Linear Bisisophthalic Acids

Linear bisisophthalic acids 1 and 2 and
analogous structures are known to be adsorbed on graphite
to give nanopatterns that are programmed by the concerted effects
of topology and hydrogen bonding. For comparison, we have now studied
the corresponding tetraesters 3–7, which have similar topologies and affinities for graphite but cannot
form strong intermolecular interactions. As a result, they fail to
crystallize in 2D and 3D according to consistent patterns. The sharply
contrasting behavior of the tetraacids and tetraesters provides compelling
evidence for the hypothesis that molecular organization is best controlled
in both 2D and 3D by using topology and strong directional interactions
in tandem to control the relative orientation of neighbors. When topology
and dominant intermolecular interactions are in harmony, then organization
can be expected to follow reliable patterns within a related series
of compounds, and structures in 2D and 3D can be designed to show
high levels of homology.