Knowledge Bank

From the infrared spectral data of gaseous difluoramine ($NF2H$) and difluoramine-d ($NF\_\{2)D$), the potential energy constants for the two molecules have been obtained. The N-H (or N-D) and N-F stretching force constants are respectively 5.6474 and $4.0681md/\backslash AA$. These values are consistent with the larger N-H (or N-D) and N-F distances measured from microwave experiments for these molecules compared to the corresponding distances in $NH3(orND3)$ and $NF3$. The constants for the F-N-H (or F-N-D) and H-N-H (or D-N-D) angle bending are respectively 1.0726 and $1.9000md\backslash AA/rad2$. The coupling between the N-H (or N-D) stretching and the F-N-H (or F-N-D) bending modes is rather high, according to the potential energy constant calculation. The determination of the rotational distortion constants, mean square amplitudes, and thermodynamic properties for the two molecules is in progress.