Valence bond studies of N2F+

The results of STO-6G valence bond (VB) calculations for the linear cation N2F+ show that (a) the dominant Lewis-type VB structures involve a single positive charge which is located on either of the nitrogen atoms, and (b) a small amount of N-F pi-bonding arises primarily from the formation of one-electron N-F pi-bonds. It is suggested that N-F pi-bonding is one of several factors which are responsible for the shortening of the N-F bond of N2F+ relative to that of NF4+. Valence bond and bond length considerations imply that the extent of N-O pi-bonding in N2O and NO43- exceeds the degree of N-F pi-bonding in N2F+ and NF4+.