The reaction behavior of xenon difluoride, XeF2, toward HN3, NaN3, and NaOCN was investigated in H2O, aHF (anhydrous HF), and SO2ClF solution. The analysis of the final reaction products (XeF2 + HN3 (NaN3) in H2O --> HF, N-2, N2O, Xe; XeF2 + HN3 in aHF --> N-2, Xe, N2F2; XeF2 + HOCN (NaOCN) in H2O --> HF, N-2, N2O NHS, CO2, Xe) indicated the intermediate formation of FXe(N-3) and FXe(NCO) and revealed different reaction mechanisms for both compounds. Both intermediates, FXe(N-3) and FXe(NCO), were studied on the basis of ab initio computations at HF and correlated MP2 levels using a quasirelativistic LANL2DZ pseudopotential for Xe. Both were shown to possess stable minima at HF and MP2 levels (no imaginary frequencies) with the following structural parameters (MP2/LANL2DZ). FXe(N-3) : C-s; d(F-Xe) = 2.051, d(Xe-N1) = 2.318, d(N1-N2) = 1.241, d(N2-N3) = 1.180 Angstrom; angle(FXeN1) = 178.1, angle(XeN1N2)= 112.2, angle(N1N2N3) = 174.7 degrees. FXe(NCO) : C-s; d(F-Xe) = 2.024, d(Xe-N) = 2.206, d(N-C) = 1.194, d(C-N) = 1.231 Angstrom; angle(FXeN) = 178.7, angle(XeNC) = 125.4, angle(NCO) = 174.2 degrees. The experimentally unobserved cyanate isomer, FXe(OCN), was calculated to be higher in energy than the isocyanate isomer FXe(NCO) : Delta E = 19.8 (HF), 18.3 (MP2) kcal mol(-1).