The minimum-energy structure of the 7HQ-(H2O)(n) (n 1-3) complexes (where 7HQ is 7-hydroxyquinoline) and the potential energy surfaces governing triple proton transfer in 7HQ-(H2O)(2) and quadruple proton transfer in 7HQ-(H2O)(3) have been characterized by means of different ab initio quantum mechanical methods. The solvent effects on the structures and reactivity of the complexes have been studied through the use of Onsager self-consistent reaction field models. A comparison was made between the calculated results and experimental data where available. The role of electron correlation in describing geometric features and the proton-transfer reactions was discussed in detail.