Synthesis
and Lewis Acid Properties of (ReO<sub>3</sub>F)<sub>∞</sub> and the X‑ray Crystal Structures of (HF)<sub>2</sub>ReO<sub>3</sub>F·HF and [N(CH<sub>3</sub>)<sub>4</sub>]<sub>2</sub>-[{ReO<sub>3</sub>(μ-F)}<sub>3</sub>(μ<sub>3</sub>‑O)]·CH<sub>3</sub>CN
Maria V. Ivanova
Tobias Köchner
Hélène
P. A. Mercier
Gary J. Schrobilgen
10.1021/ic302221y.s001
https://acs.figshare.com/articles/journal_contribution/Synthesis_and_Lewis_Acid_Properties_of_ReO_sub_3_sub_F_sub_sub_and_the_X_ray_Crystal_Structures_of_HF_sub_2_sub_ReO_sub_3_sub_F_HF_and_N_CH_sub_3_sub_sub_4_sub_sub_2_sub_ReO_sub_3_sub_F_sub_3_sub_sub_3_sub_O_CH_sub_3_sub_CN/2559628
A high-yield,
high-purity synthesis of (ReO<sub>3</sub>F)<sub>∞</sub> has
been achieved by solvolysis of Re<sub>2</sub>O<sub>7</sub> in anhydrous
HF (aHF) followed by reaction of the water formed with dissolved F<sub>2</sub> at room temperature. The improved synthesis has allowed the
Lewis acid and fluoride ion acceptor properties of (ReO<sub>3</sub>F)<sub>∞</sub> to be further investigated. The complex, (HF)<sub>2</sub>ReO<sub>3</sub>F·HF, was obtained by dissolution of (ReO<sub>3</sub>F)<sub>∞</sub> in aHF at room temperature and was characterized
by vibrational spectroscopy and single-crystal X-ray diffraction at
−173 °C. The HF molecules are F-coordinated to rhenium,
representing the only known example of a HF complex with rhenium.
The trirhenium dianion, [{ReO<sub>3</sub>(μ-F)}<sub>3</sub>(μ<sub>3</sub>-O)]<sup>2–</sup>, was obtained as the [N(CH<sub>3</sub>)<sub>4</sub>]<sup>+</sup> salt by the reaction of stoichiometric
amounts of (ReO<sub>3</sub>F)<sub>∞</sub> and [N(CH<sub>3</sub>)<sub>4</sub>]F in CH<sub>3</sub>CN solvent at −40 to −20
°C. The anion was structurally characterized in CH<sub>3</sub>CN solution by <sup>19</sup>F NMR spectroscopy and in the solid state
by Raman spectroscopy and a single-crystal X-ray structure determination
of [N(CH<sub>3</sub>)<sub>4</sub>]<sub>2</sub>[{ReO<sub>3</sub>(μ-F)}<sub>3</sub>(μ<sub>3</sub>-O)]·CH<sub>3</sub>CN at −173 °C. The structural
parameters and vibrational frequencies of the [{MO<sub>3</sub>(μ-F)}<sub>3</sub>(μ<sub>3</sub>-O)]<sup>2–</sup> and [{MO<sub>3</sub>(μ-F)}<sub>3</sub>(μ<sub>3</sub>-F)]<sup>−</sup> anions (M = Re, Tc) were calculated using density functional theory.
The calculated geometries of [{ReO<sub>3</sub>(μ-F)}<sub>3</sub>(μ<sub>3</sub>-O)]<sup>2–</sup> and [{TcO<sub>3</sub>(μ-F)}<sub>3</sub>(μ<sub>3</sub>-F)]<sup>−</sup>, are in very good
agreement with their experimental geometries. Calculated vibrational
frequencies and Raman intensities have been used to assign the Raman
spectra of (HF)<sub>2</sub>ReO<sub>3</sub>F·HF and [N(CH<sub>3</sub>)<sub>4</sub>]<sub>2</sub>[{ReO<sub>3</sub>(μ-F)}<sub>3</sub>(μ<sub>3</sub>-O)]·CH<sub>3</sub>CN. The X-ray crystal
structures of the byproducts, [N(CH<sub>3</sub>)<sub>4</sub>][ReO<sub>4</sub>] and KF·4HF, were also determined in the course of this
work.
2013-06-17 00:00:00
Raman
2O
KF
CH 3CN solution
fluoride ion acceptor properties
HF
ReO 3F
MO
vibrational frequencies
19 F NMR spectroscopy
room temperature