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Estimation of Henry's Law Constant for a Diverse Set of Organic Compounds from Molecular Structure
Citation:
HILAL, S. H., A. N. Saravanaraj, AND L. A. Carreira. Estimation of Henry's Law Constant for a Diverse Set of Organic Compounds from Molecular Structure. Presented at 236th ACS National Meeting & Exposition, Philadelphia, PA, August 17 - 21, 2008.
Impact/Purpose:
The research goal of this subtask is driven by the need for chemical property information at a wide range of environmental conditions (e.g., temperature, pressure, media, pH) where reliable literature data do not exist and for new chemicals with few existing literature values.
Description:
The SPARC (SPARC Performs Automated Reasoning in Chemistry) vapor pressure and activity coefficient models were coupled to estimate Henry’s Law Constant (HLC) in water and in hexadecane for a wide range of non-polar and polar organic compounds without modification or additional parameterization of the vapor pressure or activity coefficient models. The vapor pressure model describes the solute-solute intermolecular interactions in the pure liquid phase while the activity coefficient model describes the solute-solvent and solvent-solvent intermolecular interactions upon placing solute, i, in solvent, j. These intermolecular interactions are factored into dispersion, induction, H-bonding and dipole-dipole components upon moving a solute molecule from the gas to the liquid phase. These models were tested and validated on the largest experimental HLC data set to date. 1353 organic solutes, spanning a wide range of functional groups, dipolarities, and hydrogen-bonding capabilities. The RMS deviation error for the SPARC-calculated versus the experimental log HLC for 1220 compounds in water and for 562 compounds in hexadecane were 0.456 and 0.192 (log (mole/L)/(mole/L)), respectively.