Interaction of water with the phenylenediamine isomers - Ab initio potential evaluation and molecular dynamics simulation

The interaction of water with the three phenylenediamine isomers, whose solubility in water is remarkably different, has been investigated by performing quantum mechanical ab initio MO calculations and molecular dynamics simulations, with the aim of studying the properties of their first hydration shells. Results are discussed in relation to the different mutual positions of the hydrophilic groups on the aromatic ring, which characterise the isomers. In particular, findings based on ab initio potentials evidence that the hydration features of the meta-isomer are somewhat different from those of the ortho- and para-isomers of phenylenediamine.