Details

Autor(en) / Beteiligte

• Ivlev, Sergei I
• Karttunen, Antti J
• Hoelzel, Markus
• Conrad, Matthias
• Kraus, Florian

Titel

The Crystal Structures of α- and β-F 2 Revisited

Ist Teil von

• Chemistry : a European journal, 2019-03, Vol.25 (13), p.3310-3317

Ort / Verlag

Germany

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• The crystal structures of α-F and β-F have been reinvestigated using neutron powder diffraction. For the low-temperature phase α-F , which is stable below circa 45.6 K, the monoclinic space group C2/c with lattice parameters a=5.4780(12), b=3.2701(7), c=7.2651(17) Å, β=102.088(18)°, V=127.26(5) Å , mS8, Z=4 at 10 K can now be confirmed. The structure model was significantly improved, allowed for the anisotropic refinement of the F atom, and an F-F bond length of 1.404(12) Å was obtained, which is in excellent agreement with spectroscopic data and high-level quantum chemical predictions. The high-temperature phase β-F , stable between circa 45.6 K and the melting point of 53.53 K, crystallizes in the cubic primitive space group Pm n with the lattice parameter a=6.5314(15) Å, V=278.62(11) Å , cP16, Z=8, at 48 K. β-F is isotypic to γ-O and δ-N . The centres of gravity of the F molecules are arranged like the atoms in the Cr Si structure type.