In my first project were studied relative energies of H and D bonds. They differ due to differences in zero-point vibrational energy (ZPVE). Ab-initio calculations (on HF and MP2 levels, with 6-31G** basis set) were used to calculate ZPVE of all possible H and D substitutions in complexes of water dimer and trimer, methanol dimer cation and water dimer anion and cation.
ZPVE of D-bond was found to be lower then that of the H-bond for the neutral complexes, the difference being traced to be caused mostly by one particular vibrational mode, displacement of bridging atom away from O-O axis. The situation is reversed in ionic complexes. Total ZPVE is higher if the complex is D-bonded, difference caused by several intramolecular modes. Intermolecular decrease of ZPVE remains same as in the neutral complexes.
Paper, written by Prof. Scheiner was accepted by J. Am. Chem. Soc.
SIUC / Chemistry & Biochemistry / Martin Cuma / 2-Jan-96 / mc