Materials Data on FeN2F5 by Materials Project
(Fe2NF8)2N2(NF)4 crystallizes in the orthorhombic Pbcn space group. The structure is two-dimensional and consists of four ammonia molecules; eight monofluoroamine molecules; and two Fe2NF8 sheets oriented in the (0, 0, 1) direction. In each Fe2NF8 sheet, Fe3+ is bonded to five F1- atoms to form corner-sharing FeF5 trigonal bipyramids. There are a spread of Fe–F bond distances ranging from 1.80–2.10 Å. N1+ is bonded in a linear geometry to two equivalent F1- atoms. Both N–F bond lengths are 1.77 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to one Fe3+ and one N1+ atom. In the second F1- site, F1- is bonded in a linear geometry to two equivalent Fe3+ atoms. In the third F1- site, F1- is bonded in a single-bond geometry to one Fe3+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Fe3+ atom. In the fifth F1- site, F1- is bonded in a linear geometry to two equivalent Fe3+ atoms.