Solvent effect on acid-base clustering between acetic acid and pyridine

The solvent effect on the acid-base interaction between acetic acid and pyridine has been studied by the mass spectrometric analysis of clusters isolated from liquid droplets, The clusters resulting from the acetic acid-pyridine, acid-base, interaction in water are quite different from those in acetonitrile solvent, In water (acetic acid:pyridine:water = 1:1:10) the acid-base interaction occurs through the intercluster interaction between acetic acid and pyridine clusters, On the other hand, in acetonitrile (acetic acid:pyridine:acetonitrile = 1:1:10), the acid-base interaction proceeds through an intermonomer interaction between an acetic acid molecule and pyridine molecule, and the clusters are produced through the aggregation of a polar (acetic acid)(delta-)(pyridine)(delta+) complex, This solvent effect is mainly attributed to the cluster structure of acetic acid and pyridine in water and acetonitrile solvent.