Brief summaries are given of work on the vibrational spectra of the following compounds. (1)N(SiH3)3. A Raman study of the 14N-15N isotopic shift of the totally symmetric NSi3 stretching mode confirms that the heavy atom skeleton is planar in the gas phase. In condensed phases it is slightly distorted from D3h in some undetermined manner. (2) Si(NCO)4, Ge(NCO)4, and Ge(N3)4. Each of these molecules has some Raman bands with depolarization ratios between 0 and 0.75, showing that the molecules are not tetrahedral. (3) Cyclopropenone-d0 and -d2. A good assignment of the fundamentals has been made, and the forms of the normal modes calculated. The hands at 1483 cm−1 (d0) and 1409 cm−1 (d2) are nearly pure C=C stretches, making them the lowest such modes known. (4, 5) Tetramethylenecyclobutane and its perchloro derivative. The former is planar (D4h); the latter is not (D2d). (6) F2C=C=C=CF2. This is planar (D2d). (7) B4Cl4. This has an unusual B4 tetrahedral cage. A reliable set of assignments has been made and force constants determined. (8) Trithiadiborolanes. The B2S3 ring is planar.
Foil A. Miller, "Molecules We Have Recently Met," Appl. Spectrosc. 29, 461-469 (1975)