Diprotonation of Guanidine in Superacidic Solutions

Abstract

Guanidinium chloride reacts with the superacidic solutions HF/MF (M=As, Sb) at a molar ratio of 1:2 under formation of the diprotonated guanidinium salts [C(NH ) (NH )][AsF ] and [C(NH ) (NH )][SbF ] . The compounds were characterized by using infrared and Raman spectroscopy. Furthermore, single-crystal X-ray structure analysis of the guanidinium(2+) salts [C(NH ) (NH )][SbF ] ⋅HF, [C(NH ) (NH )] [Ge F ]⋅HF, and [C(NH ) (NH )] [Ge F ]⋅2 HF and the guanidinium(1+) salt [C(NH ) ][SbF ] is reported. The discussion of the experimental data is supported by quantum-chemical calculations of the [C(NH ) (NH )] and [C(NH ) ] ions to investigate the modification of the resonance stabilization during the protonation process at the PBE1PBE/6-311G++(3df,3pd) level of theory. The planar CN skeleton of the guanidinium(2+) ion has two carbon-nitrogen bonds in the range 1.286(4)-1.293(4) Å and one carbon-nitrogen bond of 1.453(4) Å, which can be explained with a decreased resonance stabilization relative to the guanidinium(1+) ion.

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

“…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] . The [GeF 6 ] polyhedra in the latter can either be trans ‐bridged to a linear chain as in [XeF 5 ][GeF 2/2 F 4/1 ] or cis ‐bridged to helical chains as in [ClO 2 ][GeF 2/2 F 4/1 ] or O 2 [GeF 5 ]⋅HF [42,78] .…”

“…[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. [78][79][80] The , in which the anion also forms a layer-motif.…”

Mixed Group 14–15 Metalates as Model Compounds for Doped Lead Halide Perovskites

“…Pb and Bi cannot be differentiated during crystal structure refinement, but the isomorphous nature of 1 and 2 and the results of elemental analysis strongly suggest that the arrangement of E and Pb atoms is the same in both compounds. Trinuclear halogenido metalates with corner‐sharing octahedra are rare, but have been reported before [55–57] . The organic cations separate the individual anions in such a way that no short intermolecular iodine−iodine contacts are observed in 1 and 2 .…”

Gemischte Gruppe‐14‐15‐Metallate als Modellverbindungen für dotierte Bleihalogenidperowskite

“…Pb und Bi können kristallographisch nicht unterschieden werden, die isomorphe Natur von 1 und 2 und die Ergebnisse der Elementaranalyse lassen jedoch stark vermuten, dass die Anordnung der E‐ und Pb‐Atome in beiden Verbindungen identisch ist. Dreikernige Halogenidometallate mit eckenverknüpften Oktaedern sind selten, es wurden jedoch schon Beispiele berichtet [55–57] . Die organischen Kationen ordnen sich so zwischen den einzelnen Anionen an, dass keine kurzen intermolekularen Iod‐Iod‐Kontakte in 1 und 2 beobachtet werden können.…”

“…Dreikernige Halogenidometallate mit eckenverknüpften Oktaedern sind selten, es wurden jedoch schon Beispiele berichtet. [55][56][57] Die organischen Kationen ordnen sich so zwischen den einzelnen Anionen an, dass keine kurzen intermolekularen Iod-Iod-Kontakte in 1 und 2 beobachtet werden kçnnen. Abbildung 2. a) Ausschnitt aus der Kristallstruktur von 1.…”