SOLVENT EFFECT ON ACID-BASE CLUSTERING BETWEEN ACETIC-ACID AND PYRIDINE

The solvent effect on the acid-base interaction between acetic acid an d pyridine has been studied by the mass spectrometric analysis of clus ters isolated from liquid droplets, The clusters resulting from the ac etic acid-pyridine, acid-base, interaction in water are quite differen t from those in acetonitrile solvent, In water (acetic acid:pyridine:w ater = 1:1:10) the acid-base interaction occurs through the interclust er interaction between acetic acid and pyridine clusters, On the other hand, in acetonitrile (acetic acid:pyridine:acetonitrile = 1:1:10), t he acid-base interaction proceeds through an intermonomer interaction between an acetic acid molecule and pyridine molecule, and the cluster s 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 acet onitrile solvent.