Hindered rotation in ion-neutral molecular complexes: The n1 vibration of H2–HCO
نویسندگان
چکیده
Infrared spectra of the mass selected ionic complexes H2–HCO 1 and D2–DCO 1 have been recorded in the vicinity of their n1 vibrations ~H2 /D2 stretch! by means of photofragmentation spectroscopy. The anomalous rotational constants obtained by fitting the observed line positions to a semirigid Watson A-type Hamiltonian reflect the appreciable zero-point excursions of the H2 /D2 molecule. Barriers for this internal motion are estimated utilizing a simple atom–diatom hindered rotor Hamiltonian. According to this one-dimensional model, the barrier increases by about 15% upon vibrational excitation which is mainly attributed to electrostatic effects. © 1997 American Institute of Physics. @S0021-9606~97!00344-9#
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