Applications of advanced experimental techniques: high pressure NMR and computer simulationsBased on the presentation given at Dalton Discussion No. 4, 10–13th January 2002, Kloster Banz, Germany.

The usefulness of pressure variation for the elucidation of mechanisms of solvent exchange reactions on metal ions is discussed. Even if the distinction between a limiting and an interchange mechanism, based on the magnitude of the activation volumes, is not straightforward, the activation mode, associative or dissociative, can be assigned from the sign of ΔV‡. The use of quantum mechanical calculations has also become a valuable tool in studies of exchange reactions. These calculations can be performed on the ground state and on transition states or intermediates with increased or decreased coordination number. They are useful for distinguishing between possible pathways and/or to give insight on the mechanism, not available experimentally.