Solid- and gas-phase structures and spectroscopic and chemical properties of tris(pentafluorosulfanyl)amine, N(SF5)3, and bis(pentafluorosufanyl)aminyl radical, [rad]N(SF5)2

Abstract

Tris(pentafluorosulfanyl)amine, N(SF5)3, and the bis(pentafluorosulfanyl)aminyl radical, N(SF5)2, have been synthesized and characterized by gas electron diffraction, single crystal XRD, NMR, EPR, FT-IR, Raman, and UV–vis spectroscopy, and by their thermal decompositions. The amine possesses a planar molecular structure of D3 symmetry with an unusually long NS bond of 1.829(6) Å. The long NS bonds are in accordance with the small Arrhenius activation barrier for the decay into N(SF5)2 and SF5 radicals of 6.9 kcal mol−1, and its half-life at room temperature is only 50 min. The aminyl radical possesses C2 symmetry with NS = 1.692(4) Å and SNS = 135.1(5)°, and its structure is similar to that of FN(SF5)2. This radical is much more stable than the amine (half-life at room temperature is 130 min). Dimerization and formation of the corresponding hydrazine, (SF5)2NN(SF5)2, was not observed, nor was the nitrene:NSF5 or its isomer FNSF4.