Knowledge Bank

“With the aid of matrix $(N2$, or $Ar, 20^{\circ} K $) and pure solid spectra, new low frequency fundamentals have been found for both $ketene1,2$ and diazomethane. Vibrational assignments for both molecules and their mono-and didiutero isotopically substituted forms have been made. Analysis of gas phase perpendicular absorptions has given accurate values for the smallest moment of intertia. Valence force fields and been fitted to the experimental frequencies. Several unusual features of the potential functions will be discussed in terms of the bonding. For instance, the out-of-plane $CH2$ bending force constants are very much lower than those in such molecules as ethylene or formaldehyde.”