Title: Examination of Low-Lying Rovibrational States of D3h Oblate Top Molecules Using High Resolution FTIR and Coherent Anti-Stokes Raman Spectroscopies

Interesting rovibrational characteristics of two D3h oblate symmetric top molecules were studied. Hamiltonian models for the fine rovibrational level structure of [1.1.1]propellane (propellane) were obtained for many low-lying modes. Ground state parameters (GSP) that are not exclusively K2n dependent were obtained. Initially, the GSP were used in conjunction with density functional (DFT) values of the exclusively K2n dependent parameters C0, and De. Coriolis h1,1 (K = 1, l = 1) interactive fundamentals 15 and12 were analyzed; complementary use of transition energies and line intensities allowed an experimental value of the Coriolis parameter to be assessed. In another phase of the project, a global fit of the 10, 11, and 14 fundamental bands and the 11-18 and 10-18 bands was performed. The h1,1 interaction between the close proximity rovibrational states of 11 and 14 results in energy shifts and large distortions of line intensities in the 11 band, and these characteristics were reproduced. Splitting of the otherwise degenerate A1 and A2 states that are the highest in frequency for a given J manifold was observed for the h1,1 coupled 11 /14 triad composed of the |k | = 3 levels of 14, the kl = + 4 levels of 11