Raman spectra of glucose and fructose are reported in the region 20-4000 cm −1 . The spectra were recorded for the crystalline sugars, amorphous sugars with varying water contents and aqueous solutions with varying sugar contents. The Raman spectra of amorphous carbohydrates have not been reported previously. They are very similar to those of the aqueous solutions. Several vibrational bands were found to be sensitive to water, especially for the amorphous samples containing small amounts of water.

The far-infrared and Raman spectra of 1,3-benzodioxole vapor have been recorded and analyzed. Forty-one infrared and six Raman bands were assigned to transitions between the various ring-puckering energy levels in the ground and excited ring-flapping states. The determination of the energy levels was assisted by analysis of the single vibronic level fluorescence spectra of the jet-cooled molecules. The puckering levels change substantially in the flapping excited state, indicating substantial interaction between the two vibrational modes. From the spectroscopic data, a two-dimensional vibrational potential energy surface was determined. This has a barrier to planarity of 164 cm-1 and energy minima at puckering and flapping angles of ±24° and ∓3°, respectively. This molecule has a lower barrier to planarity than 1,3-dioxole, reflecting the influence of the benzene ring on the anomeric effect. Nevertheless, the anomeric effect is clearly the origin of the nonplanarity of this bicyclic ring system.

A method, based on classical physics, to utilize the first four even moments of the depolarized collision induced light scattering spectrum to derive an empirical model for the pair polarizability anisotropy of interacting molecules, with only one adjustable parameter, is described and applied to the spectra of Ne, Ar, Kr, Xe, and CH4. Good agreement with ab initio results in the literature is obtained and profiles calculated with these models are in excellent agreement with experiment.

The vapor-phase far-infrared, mid-infrared, ultraviolet, Raman, and laser-induced fluorescence spectra of indan have been recorded and analyzed. The far-infrared spectra, which are very similar to those previously reported, together with the Raman and dispersed fluorescence (SVLF) spectra of the jet-cooled molecules were used to reassign the ring-puckering and ring-flapping energy levels for the S0 ground state. These were then utilized to calculate a two-dimensional vibrational potential energy surface (PES) which nicely fits all of the assigned puckering and flapping levels. The PES has a barrier of 488 cm−1 as compared to a previously reported value of 1979 cm−1, which was based on a one-dimensional analysis and earlier assignments. The dihedral angle of puckering is ±30°. Fluorescence excitation spectra of jet-cooled indan together with ultraviolet absorption spectra were used to assign the flapping and puckering levels in the S1(π,π*) electronic excited state. The PES for this state has a barrier of 441 cm−1 and the energy minima correspond to puckering angles of ±39°. The flapping frequency and the stiffness of the PES along the flapping coordinate both decrease substantially in the excited state. The barriers to planarity for both states are higher than those for analogous molecules due to the two –CH2–CH2– torsional interactions. Ab initio calculations do a fairly good job of predicting the experimental barriers for indan and related molecules in their S0 and S1 states.