GASEOUS F2NO- STRUCTURE AND MECHANISM OF FORMATION( CATIONS FROM THE ADDITION OF NF2+ TO N2O )

Gaseous F2NO+ cations have been obtained from the ionization of a NF3/ N2O mixture under typical chemical ionization (CI) conditions. In keep ing with previous structural studies in the solid state and in solutio n, the connectivity of these ions has been positively assigned to F2N- O+ by collisionally activated dissociation (CAD) experiments, and thei r mechanism of formation has been elucidated by Fourier transform ion cyclotron resonance (FT-ICR) and mass-analyzed ion kinetic energy (MIK E) spectrometry, complemented by ab initio calculations at the post-SC F level of theory. The F2NO+ cations originate from the ion-molecule r eaction NF2+ + N2O --> F2NO+ + N-2, the occurrence of which has been a scertained by FT-ICR experiments. The details of this ionic process ca n be satisfactorily explained in terms of a double-well potential ener gy profile, involving the formation of a (F2N/N2O)(+) adduct. This int ermediate has been actually detected in the high-pressure domain of th e CI source. It gives rise to the loss of N-2 as the only observed met astable decomposition, and the high energy difference between the invo lved transition structure and the F2NO+ and Nz fragments accounts for the corresponding dish-topped peak and large kinetic energy release.