Control self-assembly of hydrazide-based cyclic hexamers: in or out.

By moving the alkoxy group on the spacer from position 5 to position 4 to add another protocol for the algorithm for intermolecular and intramolecular hydrogen bonding interactions, highly regioselectivity of noncovalent synthesis of the hydrazide-based cyclic hexamers was achieved: one out of thirteen possible isomeric cyclic hexamers selectively formed and thus precise control of the two hydrazide units in the cyclic hexamers (in or out) was accomplished.