High-resolution Raman spectra of nu(2) and associated hot bands of (C2D2)-C-12

The Raman spectra of the Q branch of the nu (2) band of (C2D2)-C-12 and ass ociated hot bands (nu (2) + nu (4) - nu (4), nu (2) + nu (5) - nu (5), nu ( 2) + 2 nu (4) - 2 nu (4), nu (2) + 2 nu (5) - 2 nu (5), nu (2) + nu (4) + n u (5) - (nu (4) + nu (5)), and 2 nu (2) - nu (2)) have been recorded with a n instrumental resolution of about 3 x 10(-3) cm(-1) and analyzed. All of t hem have been recorded using high resolution inverse Raman spectroscopy. Fo r 2 nu (2) - nu (2), this technique has been combined with stimulated Raman pumping in order to populate the nu (2) = 1 state. A simultaneous analysis of all the observed Raman transitions and of the nu (2) - nu (5) band reco rded in the infrared region has been per-formed on the basis of a theoretic al model which takes into account the rotational and vibrational l-type res onances within each vibrational manifold and the Darling-Dennison anharmoni c resonance between the nu (2) + 2 nu (4) and nu (2) + 2 nu (5) states. The determined parameters reproduce the assigned wavenumbers with a standard d eviation of the same order of magnitude as the experimental uncertainty. (C ) 2001 Academic Press.