Hydration Equilibrium Constants of Aldehydes, Ketones and Quinazolines

SPARC chemical reactivity and physical processes models were coupled and extended to calculate hydration equilibrium constants for aldehydes, ketones, quinazoline and substituted quinazolines compounds from molecular structure. The energy differences between the initial (anhydrible) and the final (hydrated) states in the gas phase for a molecule of interest were calculated using SPARC mechanistic perturbation models. These perturbations models quantify the interactions of the appended perturber (P) with the carbonyl reaction center of the aldehydes or ketones or with the imine reaction center of the quinazolines. The perturbations of the reaction center were factored into mechanistic components of electrostatic, resonance and steric effects in the gas phase. The solvation energy (Henry's constant) of the anhydrible and the hydrated states on going from the gas phase to the aqueous phase were calculated using SPARC physical processes models. These physical processes models quantify the intermolecular interactions between the solute and the solvent molecules upon placing a solute molecule in the aqueous phase. The intermolecular interactions are factored into dispersion, induction, dipole-dipole and H-bonding interaction mechanisms. The RMS deviation error was 0.36 pKhydration units for 36 aldehyde and ketone compounds and 0.43 pKhydration units for quinazoline and 31 substituted quinazoline compounds.