Intermolecular Network Analysis of the Liquid and Vapor Interfaces of Pentane and Water: Microsolvation Does Not Trend with Interfacial Properties

Type r 0 (Å) Type θ 0 (°) k θ (kcal/mol/rad) 2 Type k 1 (kcal/mol) k 2 (kcal/mol) k 3 (kcal/mol) a) Form of the bonded potential: í µí±¢ = í µí±(í µí± ‒ í µí± 0) 2 b) Form of the angular potential: í µí±¢ = í µí± í µí¼ (í µí¼ ‒ í µí¼ 0) 2 c) Form of the torsional potential: í µí±¢ = 1 2 í µí± 1 (1 + cos í µí¼) + 1 2 í µí± 2 (1 ‒ cos 2í µí¼) + 1 2 í µí± 3 (1 + cos 3í µí¼)

) Form of the angular potential:  =   ( - 0 ) 2 c) Form of the torsional potential: Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics.This journal is © the Owner Societies 2014 of the bonded potential:  = ( - 0 ) 2 b

Figure S1 .
Figure S1.Order parameter, S z , as a function of θ in degrees, defined by the three vectors of n-pentane.

Figure S2 .
Figure S2.Geometric criterion that defines a hydrogen bond.

Figure S3 .
Figure S3.(A) Definition of dipole moment orientation of H2O with respect to a solute.(B) The special case where the solute is a water molecule (reference H2O).For the water molecule donating a H-bond to the reference H 2 O, the angle is called alpha (α) wherein a value of 180° indicates alignment of the dipole moment vector along the axis of the hydrogen bond.For a water molecule accepting a H-bond from the reference H 2 O, the angle is referred to as (β) wherein a value of 0° indicates perfect alignment of the dipole moment vector along the H-bond.

Figure S4 .
Figure S4.Radial distribution functions ( O-O and  O-H ) of TIP3P/Ew H 2 O at 273 K and 298 K.

Figure S9 .
Figure S9.A) Potential of mean force for water migration across the water:pentane or water:vapor interfaces and b) pentane traveling across the water:pentane and pentane:vapor interfaces in kcal/mol.

Figure S10 .
Figure S10.Distributions of (A) the number of neopentane molecules that solvate individual H 2 O, and (B) the number of water molecules that solvate individual neopentane at 273 K and 298 K.

Table S2 .
Lennard-Jones parameters and charges for C 5 H 12 and H 2 O. a,b C

Table S3 .
Gibbs dividing surface position for water and alkane in different systems in Å.

Table S4 .
Density in g/cm 3 and diffusion coefficient, D, in cm 2 /sec for H 2 O and C 5 H 12 at different temperatures.

Table S5 .
Hydrogen bond distribution and its statistical error for bulk water as well as vapor and organic interfaces for both 273 and 298K.

Table S6 .
Cross correlation of each instance of hydrogen bond breakage and formation with the change in O..O distance in H 2 O:vapor at 298K.

Table S7 .
Liquid density (  L ) and vapor density (  V ) of C 5 H 12 :vapor and H 2 O:vapor interfaces studies in g/cm 3 .

Table S8 .
Complete list of surface tensions and interfacial widths for all vapor systems using all fitting methods.

Table S9 .
Diffusion coefficients in (10 -5 cm 2 /sec) and liquid density densities of H 2 O:C 5 H 12 in this work in g/cm 3 .

Table S10 .
Cross correlation of each instance of hydrogen bond breakage and formation with the change in O..O distance in H 2 O:pentane at 298K.