Reassessment of hydrophobic bonding

Abstract

Hydrophobic bonding theory is re-examined in the light of ¹³C relaxation time (T₁) measurements, which indicate that water is unique in its ability to restrict the motion of hydrophobic parts of solute molecules. The motional restriction is shown to account for most of the entropy change on solution that has hitherto been ascribed to “structure making.” A simple theory of the restriction mechanism is advanced which also explains the observed enthalpies of solution and the isotope effects.