Theoretical prediction of hydrogen bond donor capacity

Ab initio calculations on over fifty hydrogen bond donor molecules, and their complexes with a reference hydrogen bond acceptor, are reported. Properties calculated for the molecules and complexes are assessed for their ability to correlate and predict experimentally derived values of hydrogen bond donor capacity, α. Two such properties stand out as excellent predictors of α: both the electrostatic potential at the donor H nucleus and the hydrogen bond stabilization energy correlate α to close to the estimated experimental error. Several other calculated properties, including atomic charges and multipoles on the donor H, the extent of charge transfer from acceptor to donor, and topological properties of the electron density, are also correlated with α