Ab initio molecular orbital calculations on complexes of chloride ion with acetonitrile and vibrational spectroscopic studies

3-21G and 6-31 + G ab initio molecular orbital calculations have been performed on the (CH3CN)Cl- complex with three different configurations. A comparison of calculated harmonic frequencies and IR intensities of acetonitrile in the CH stretching region thus obtained in the gas phase with the experimental results for (CH3CN)X- systems in the liquid phase suggests that the halide ions interact with acetonitrile linearly through its CH bonds in the Cs configuration. © 1994.