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

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2019-01-01

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en

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8

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Chemistry: A European Journal, Volume 25, issue 13, pp. 3310-3317

Abstract

The crystal structures of α-F 2 and β-F 2 have been reinvestigated using neutron powder diffraction. For the low-temperature phase α-F 2 , 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 3 , 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 2 , stable between circa 45.6 K and the melting point of 53.53 K, crystallizes in the cubic primitive space group Pm (Formula presented.) n with the lattice parameter a=6.5314(15) Å, V=278.62(11) Å 3 , cP16, Z=8, at 48 K. β-F 2 is isotypic to γ-O 2 and δ-N 2 . The centres of gravity of the F 2 molecules are arranged like the atoms in the Cr 3 Si structure type.

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crystal structure, fluorine, neutron diffraction, quantum chemical calculations, FREQUENCIES, EXCITATION, TRIPLE, PERTURBATION, NEUTRON-DIFFRACTION, SINGLE-CRYSTAL, BASIS-SETS, SPECTRUM, MATRIX-ISOLATION, DERIVATIVES

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Citation

Ivlev, S I, Karttunen, A J, Hoelzel, M, Conrad, M & Kraus, F 2019, ' The Crystal Structures of α- and β-F 2 Revisited ', Chemistry: A European Journal, vol. 25, no. 13, pp. 3310-3317 . https://doi.org/10.1002/chem.201805298