The near-IR spectrum of NO((X)over-tilde(2)Pi)-He detected through excitation into the (A)over-tilde-state continuum: A joint experimental and theoretical study

摘要

We present the first measurement of a bound-state spectrum of the NO-He complex. The recorded spectrum is associated with the first overtone transition of the NO moiety. The IR absorption is detected by exciting the vibrationally excited complex to the (A) over tilde -state dissociation continuum. The resulting NO(A) fragment is subsequently ionized in the same laser pulse. We recorded two bands centered around the NO monomer rotational lines, Q(11)(0.5) and R-11(0.5), consistent with an almost free rotation of the NO fragment within the complex. The origin of the spectrum is found at 3724.06 cm(-1) blue shifted by 0.21 cm(-1) from the corresponding NO monomer origin. The rotational structures of the spectrum are found to be in very good agreement with calculated spectra based on bound states derived from a set of high level ab initio potential energy surfaces [Klos et al. J. Chem. Phys. 112, 2195 (2000)]. Published by AIP Publishing.