The influence of the OHO angle on the proton valency in inter- and intra-molecular hydrogen bonds

The influence of the OHO angle in the hydrogen bond on the potential-energy surface has been studied. The OHO angle has been artificially changed from 140° to 180° to study the influence of the angle on the location of the energy minimum relative to QMRC, the minimum energy reaction path, and BORC, the bond-order reaction path. In the intermolecular hydrogen bond QMRC and BORC are identical, independent on the OHO angle. The intramolecular hydrogen bond is very sensitive to a change in the OHO angle. The agreement between the theoretical results is confirmed by available experimental neutron data.