3.1.1 Dimer:
It has been shown earlier that three different conformers are possible
for CHD homo dimer,58out of which dimer3 has all four carbonyl groups H-bonded and dimer1 and
dimer2 have one carbonyl group on each monomeric moiety free (Figure
S1). The relative orientation of the two free carbonyl groups are cis
(designated as C-conformer) and trans (T-conformer) to each other in
dimer1 and dimer2, respectively. These free carbonyl groups are key to
allow for chain propagation, resulting in higher order cluster
formation. This is why dimer3, with all the four carbonyl groups being
H-bonded, results in a closed structure and cannot give rise to higher
order cluster formation. The energetics of all the conformers are given
in Table 1. From the table, it can be found out that dimer3 is most
stable among all the possible conformers, while the C and T dimer are
energetically very close to each other.