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.