TY  - JOUR
A1  - Godec, Aljaz
A1  - Smith, Jeremy C.
A1  - Merzel, Franci
T1  - Soft Collective Fluctuations Governing Hydrophobic Association
JF  - PHYSICAL REVIEW LETTERS
N2  - The interaction between two associating hydrophobic particles has traditionally been explained in terms of the release of entropically frustrated hydration shell water molecules. However, this picture cannot account for the kinetics of hydrophobic association and is therefore not capable of providing a microscopic description of the hydrophobic interaction (HI). Here, Monte Carlo simulations of a pair of molecular-scale apolar solutes in aqueous solution reveal the critical role of collective fluctuations in the hydrogen bond (HB) network for the microscopic picture of the HI. The main contribution to the HI is the relaxation of solute-water translational correlations. The existence of a heat capacity maximum at the desolvation barrier is shown to arise from softening of non-HB water fluctuations and the relaxation of many-body correlations in the labile HB network. The microscopic event governing the kinetics of hydrophobic association has turned out to be a relatively large critical collective fluctuation in hydration water displacing a substantial fraction of HB clusters from the inner to the outer region of the first hydration shell.
Y1  - 2013
U6  - https://doi.org/10.1103/PhysRevLett.111.127801
SN  - 0031-9007
VL  - 111
IS  - 12
PB  - AMER PHYSICAL SOC
CY  - COLLEGE PK
ER  -