Discrete GeF₅^– Anion Structurally Characterized with a Readily Synthesized Imidazolium Based Naked Fluoride Reagent

Abstract

The recently prepared novel naked fluoride reagent 1,3-bis(2,6-diisopropylphenyl)imidazolium fluoride ([(L)H][F]), treated with an excess of MF (M = Si, Ge), results in isolation of [(L)H][MF] products with the elusive trigonal bipyramidal MF anions. Specific steric characteristics of the [(L)H] cation readily support isolation of monomeric and discrete trigonal bipyramidal fluorido anions of silicon and germanium. Based on combination of experimental results and DFT calculations, we demonstrate that the role of bulky cation is not solely due to steric hindering but also due to electrostatic effects, which are important in the design of such uncommon species. The discrete GeF anion was characterized by X-ray single-crystal diffraction for the first time. We report the missing F NMR entries for the discrete GeF and GeF anions in acetonitrile. All the products were also characterized by Raman spectroscopy and elemental analysis and supported by quantum-mechanical calculations.

C−F Bond Activation by a Saturated N‐Heterocyclic Carbene: Mesoionic Compound Formation and Adduct Formation with B(C6F5)3

“…The molecular structure of 5 is shown in Figure . The 19 F NMR spectrum of 5 shows a peak at δ =−124.61 ppm, which is in good agreement with that reported by the groups of Tavčar and Atwood . The C1–C4 bond length is 1.485(4) Å, which is in good agreement with that in 2 .…”

C−F Bond Activation by a Saturated N‐Heterocyclic Carbene: Mesoionic Compound Formation and Adduct Formation with B(C6F5)3

“…Themolecular structure of 5 is shown in Figure 5. The 19 FNMR spectrum of 5 shows ap eak at d = À124.61 ppm, which is in good agreement with that reported by the groups of Tavčar [28] and Atwood. [29] TheC 1-C4 bond length is 1.485(4) ,which is in good agreement with that in 2.…”

Reactions of ClF3 with Main Group and Transition Metal Oxides: Access to Dioxychloronium(V) Fluoridometallates and Oxidofluoridometallates

“…The structures of [SnF 5 ] − anions in the [NF 4 ] + , [N 2 F 3 ] + , and [N 5 ] + salts were previously derived from vibrational and/or 19 F NMR spectroscopy in the solid‐state or solution, respectively [70–72] . Only crystal structures with discrete [SiF 5 ] − anions have been reported for the homologous pentafluoridosilicate(IV) anion [73–76] . Whereas the homologous pentafluoridogermanate(IV) anion can either be discrete, as a [GeF 5 ] − anion in the 1,3‐bis(2,6‐diisopropylphenyl)imidazolium salt or a [Ge 3 F 16 ] 4− anion in [C(NH 2 ) 2 NH 3 ] 2 [Ge 3 F 16 ]⋅ n HF ( n =1, 2), or “polymerize” to form the anion [42,77,78] .…”

“…[70][71][72] Only crystal structures with discrete [SiF 5 ] À anions have been reported for the homologous pentafluoridosilicate(IV) anion. [73][74][75][76] Whereas the homologous pentafluoridogermanate(IV) anion can either be discrete, as a [GeF 5 ] À anion in the 1,3-bis(2,6-diisopropylphenyl)imidazolium salt or a [Ge 3 F 16 ] 4À anion in [C(NH 2 ) 2 NH 3 ] 2 [Ge 3 F 16 ]•nHF (n = 1, 2), or "polymerize" to form the 1 1 GeF 2=2 F 4=1 � � À anion. [42,77,78] The [42,78] For the Sn system, anions with higher Sn content such as [Sn 2 F 9 ] À and [Sn 5 F 24 ] 4À were described and they were either characterized by vibrational spectroscopy or single-crystal X-ray diffraction.…”