Vibrational potential function and structure of nitrosyl hypofluorite by normal coordinate analysis

While the nitrosyl hypofluorite molecule has previously been identified as a product in the reaction between fluorine and nitrogen dioxide in matrix isolation experiments, the bonding characteristics of the molecule were not investigated, and assignments of four infrared absorption bands were not clearly established. Normal coordinate analysis has now allowed determination of the bonding characteristics and definite assignment of the absorption bands. The fluorine atom in ONOF is loosely bonded to one oxygen of an NO2 radical. The central NO bond is strong, with a bond order of about 1.5 while the terminal NO bond is very strong (bond order about 2.0). The ONO bond angle is intermediate between those of NO2 and NO2+. The absorption band at 1716 cm−1 has been assigned to terminal NO bond stretch, that at 1200 cm−1 to central NO bond stretch, and that at 412 cm−1 to OF bond stretch. The band at 702 cm−1 is due to bending of the ONO group. Torsional and NOF bending frequencies are too low to be observed with conventional infrared spectrophotometers.