1 research outputs found
One-Pot Synthesis and AFM Imaging of a Triangular Aramide Macrocycle
Macrocyclizations in exceptionally
good yields were observed during
the self-condensation of <i>N</i>-benzylated phenyl <i>p</i>-aminobenzoates in the presence of LiHMDS to yield three-membered
cyclic aramides that adopt a triangular shape. An <i>ortho</i>-alkyloxy side chain on the <i>N</i>-benzyl protecting
group is necessary for the macrocyclization to occur. Linear polymers
are formed exclusively in the absence of this Li-chelating group.
A model that explains the lack of formation of other cyclic congeners
and the demand for an <i>N-</i>(<i>o</i>-alkoxybenzyl)
protecting group is provided on the basis of DFT calculations. High-resolution
AFM imaging of the prepared molecular triangles on a calcite(10.4)
surface shows individual molecules arranged in groups of four due
to strong surface templating effects and hydrogen bonding between
the molecular triangles