JER-LAI KUO, JAKE TAN, Institute of Atomic and Molecular Sciences Academia Sinica, Taipei 10617, Taiwan; RYUNOSUKE SHISHIDO, ASUKA FUJII, Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
In protonated binary clusters, location and magnitude of delocalization of the excess proton is shown to correlate to the difference of the proton affinities of the two components. Theoretical calculations on a series of protonated binary clusters have shown that Fermi resonance can occur in clusters containing amines. For examples, in (CH3)3N-H+-X, the N-H+ stretching frequency is high than the first overtone of N-H+ bending modes. As the N-H+ stretching frequency decreases by increasing the proton affinity of X, Fermi resonance inevitably shall occur. At least both N-H+ bending modes seem to couple with the N-H+ stretching mode; we performed multi-dimensional mode analyses to understand this coupling.