Gaseous F2NO+ cations have been obtained from the ionization of a NF3/N2O mixture under typical chemical ionization (CI) conditions. In keeping with previous structural studies in the solid state and in solution, the connectivity of these ions has been positively assigned to F2N-O+ by collisionally activated dissociation (CAD) experiments, and their mechanism of formation has been elucidated by Fourier transform ion cyclotron resonance (FT-ICR) and mass-analyzed ion kinetic energy (MIKE) spectrometry, complemented by ab initio calculations at the post-SCF level of theory. The F2NO+ cations originate from the ion-molecule reaction NF2+ + N2O --> F2NO+ + N-2, the occurrence of which has been ascertained by FT-ICR experiments. The details of this ionic process can be satisfactorily explained in terms of a double-well potential energy profile, involving the formation of a (F2N/N2O)(+) adduct. This intermediate has been actually detected in the high-pressure domain of the CI source. It gives rise to the loss of N-2 as the only observed metastable decomposition, and the high energy difference between the involved transition structure and the F2NO+ and Nz fragments accounts for the corresponding dish-topped peak and large kinetic energy release.