Density functional study of hydrogen-bonded acetonitrile-water complex

We report the interaction of acetonitrile with one, two, and three water molecules using the Density Functional Theory method and the 6-31+G* basis set. Different conformers were studied and the most stable conformer of acetonitrile-(water)n complex has total energies -209.1922504, -285.6224478, and -362.068728 hartrees with one, two, and three water molecules, respectively. The corresponding binding energy for these three structures is 4.52, 8.34, and 22.48 kcal/mol. The hydrogen-bonding results in blue, blue, and redshift in C equivalent to N stretching mode in acetonitrile with one, two, and three water molecules, respectively, whereas there was a redshift in O-H symmetric stretching mode of water. (C) 2004 Wiley Periodicals, Inc. Int J Quantum Chem 102: 106-111, 2005.