MOLECULAR SELF-ASSEMBLY COMPOSED OF AROMATIC HYDROGEN-BOND DONOR-ACCEPTOR COMPLEXES

Molecular self-assembling systems derived from the clustering of acid and base molecules have been investigated by mass spectrometric analys is of clusters isolated hem liquid droplets. N-H ... N and O-H ... N h ydrogen-bonded acid-base systems were compared When heteroaromatic N-H ... N hydrogen-bonding acid-base: systems, such as 7-azaindole dimer, the indole-quinoline pair, etc. were used as acid-base pairs, the clu sters composed of equimolar acid and base molecules were generated. Th is means that the hydrogen-bonding acid-base complex, N-H ... N, behav es like a single molecule in cluster formation. On the other hand, clu stering of the aromatic O-H ... N hydrogen-bonding systems, such as ph enol-pyridine, phenol-pyrazine, etc., was controlled by the acid-base interaction determined by the pK(a) values, giving a multilayer struct ure for a relatively strong acid-base pair and a monolayer structure f or a relatively weak acid-base pair. Molecular self-assembling systems containing hydrogen-bond donor and acceptor molecules have been syste matically described here.