Quantum mechanical estimation of Abraham hydrogen bond parameters using 1:1 donor-acceptor complexes
Obaidur Rahaman, Douglas J. Doren, Dominic M. Di Toro · Journal of Physical Organic Chemistry · 2014
Hydrogen bond donor strength () and acceptor strength () have been successfully used in models of many environmental and chemical systems, and a number of computational methods have been developed to predict them. In this work, a quantum chemical Møller–Plesset perturbation (MP2) method is applied to estimate the binding free energies (ΔGhbond) of several 1:1 hydrogen-bonded complexes. A correlation between the binding free energies and hydrogen bond strength is established. This relationship can be used to develop an accurate computational model for predicting and using binding free energies. The accuracy of the method in predicting Abraham (root mean squared deviation (RMSD) = 0.0693) and (RMSD = 0.0677) are comparable to the empirical, fragment-based ABSOLV method (RMSD = 0.1144 and 0.1281 for and , respectively). The binding free energy has been decomposed into its thermodynamic components, and it is demonstrated that the linear relationships in the dataset and the existence of magic point can be attributed to a constant entropy of reaction. Copyright © 2014 John Wiley & Sons, Ltd.