On a Reinvestigation of the Structure of Dinitrogen Tetrafluoride, N2F4, by Gaseous Electron Diffraction

Abstract

Analysis of electron‐diffraction patterns from gaseous N₂F₄ at 25°C has verified conclusions from earlier work that the material contains both trans and gauche conformers. Assuming that these conformers have the same parameter values except for the torsion angle, the following principal results were obtained: ${\text{71.2\% (8.1)\hspace{0.17em}trans,\hspace{0.17em}r}}_{\mathrm{NN}}{\text{=1.492\hspace{0.17em}Å\hspace{0.17em}(0.007),\hspace{0.17em}r}}_{\mathrm{NF}}\text{=1.372\hspace{0.17em}Å\hspace{0.17em}(0.002),\hspace{0.17em}〈}\mathrm{FNF}\text{=103.1°\hspace{0.17em}(0.6),\hspace{0.17em}〈}\mathrm{NNF}\text{=101.4°\hspace{0.17em}(0.4),\hspace{0.17em}θ\hspace{0.17em}(}\mathrm{the\; dihedral\; angle}\hspace{0.17em}{\mathrm{N}}_2{\mathrm{N}}_1{\mathrm{F}}_4\mathrm{,\hspace{0.17em}}{\mathrm{N}}_1{\mathrm{N}}_2{\mathrm{F}}_1{\text{)=64.2°\hspace{0.17em}(3.7),\hspace{0.17em}l}}_{\mathrm{NN}}\text{=0.048\hspace{0.17em}Å\hspace{0.17em}(0.005),\hspace{0.17em}}\mathrm{and}{\mathrm{\hspace{0.17em}l}}_{\mathrm{NF}}\text{=0.044\hspace{0.17em}Å\hspace{0.17em}(0.002).}$ These distances and root‐mean‐square amplitudes are r_a and l_a values; the errors are 2σ and include estimates of systematic error. The diffraction results indicate that the energy difference E_g—E_t is roughly less than 1.0 kcal but that the rotational barrier may be several kilocalories.