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The Raman spectrum of gaseous N2F4 at a pressure of 760 Torr was recorded with a spectral slit width of 3 kaysers. Ten of the expected eleven fundamentals of the symmetric motions of both the gauche and trans isomers give rise to strongly polarized Raman lines. These new data require a reassignment of some of the fundamentals for both the C2 and C2h conformers. The Raman of the solid at 18 K was also recorded. Both conformers were found in the solid even after annealing the sample for 9 hr at a temperature of 101.6 K and 3 hr at a temperature of 106.8 K. Bands attributable to the gauche isomer became more intense relative to those for the trans isomer after several hours of annealing.

The medium resolution Raman spectrum of gaseous phenol has been recorded between 4000 and 50 cm−1 using the 5145 A line of an argon laser. A number of a′ bands have been observed which correspond to previously assigned normal modes, but lines at 1388 and 1285 cm−1, which are not normally observed in the infrared spectrum of the gas, have been assigned as fundamentals. In addition, a strong Raman band at 1007 cm−1 is probably an overtone of an out-of-plane vibration at 503 cm−1 in resonance with a nearby a′ fundamental. Two bands at 824 and 810 cm−1 were both found to belong to the symmetric a′ species. Previous assignments have dealt with these two bands as having different symmetries. A reassignment of some of the fundamentals of phenol may be necessary to account for these Raman observations.

The Raman spectra of gaseous hydrazine and hydrazine-d4 have been recorded from 40 to 3500 cm−1. For the ‘light’ molecule, strongly polarized lines at 3398, 3329 and 1076 cm−1 have been assigned to the NH antisymmetric stretch, NH symmetric stretch, and NN stretch, respectively. For the hydrazine-d4 molecule, strongly polarized lines at 2442, 2422, 1031, 930 and 749 cm−1 have been assigned to the ND antisymmetric stretch, ND symmetric stretch, NN stretch, ND2 was and ND2 rock, respectively. The Raman spectra of both solid hydrazine and hydrazine-d4 have been recorded and the splitting in the intramolecular fundamental region indicates that there are at least four molecules per primitie cell. In the lattice region of the spectra the optical translations and librations are assigned and the number of lattice modes rules out both of the space groups previously proposed for hydrazine from scattering studies.

The infrared (200–3500 cm−1) and Raman (50–3500 cm−1) spectra of two isotopic species of tetramethylbiphosphine-bisborane, (CH3)4P2·2BH3 and (CH3)4P2·2BD3, in the solid state at low temperatures have been recorded. The spectra have been interpreted in detail on the basis ofC 2h molecular symmetry. The P-B stretching modes were assigned to bands at 599 and 567 cm−1 in the Raman and infrared spectra of the “light” compound, respectively. Only one P-P stretching mode was observed in the Raman spectra. The vibrational data appear to be consistent with the presence of only one conformer in the solid state, which is at variance with the conclusions from an X-ray study. Considerable splitting of the low-frequency bending modes was observed for both compounds; this splitting has been attributed to the factor group.

Although the equilibrium structure of four-membered ring systems can be understood in terms of a balance between the ring-strain and torsional forces, the resulting conformation of fluorinated derivatives of cyclobutane is more difficult to quantify. For example, the introduction of a CF2 group in cyclobutane reduces the barrier to planarity from 503 cm−1 (c-C4H8) to 241 cm−1 (c-C4H6F2). Since a similar reduction in barrier heights has also been reported for trimethylene oxide and 3,3-difluoroxetane, efforts have been initiated to understand these changes by considering variations in the torsional forces for fluorine-containing cyclic and open chain molecules. To complement our work in this area, the present vibrational study of Perfluorocyclobutanone (c-C4F6O) was undertaken in order to determine the skeletal structure of this molecule.

A rotating sample holder that rotates the sample rapidly out of the laser beam before decomposition from heating can take place.