The Tetrakis‐(trifluoromethanesulfonato)‐aurate Anion: Syntheses and Properties of M[Au(CF3SO3)4] (M = Li – Rb, Ag). Issue 3 (18th February 2013)

• Record Type: Journal Article
• Authors: Logemann, Christian; Klüner, Thorsten; Wickleder, Mathias S.
• Is Part Of: Zeitschrift für anorganische und allgemeine Chemie. Volume 639:Issue 3/4(2013)
• Page Start: 485
• Page End: 492
• Publication Date: 2013-02-18
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/zaac.201300025
• Languages: English
• ISSNs: 0044-2313

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The reaction of Au(OH)<sub>3</sub> and trifluoromethanesulfonic acid (triflic acid) in the presence of <italic>M</italic><sub>2</sub>CO<sub>3</sub> (<italic>M</italic> = Li, Na, K, Rb) and Ag(CF<sub>3</sub>SO<sub>3</sub>), respectively, yielded yellow single crystals of <italic>M</italic>[Au(CF<sub>3</sub>SO<sub>3</sub>)<sub>4</sub>] (<italic>M</italic> = Li, Na, K, Rb, Ag). They exhibit the [Au(CF<sub>3</sub>SO<sub>3</sub>)<sub>4</sub>]<sup>–</sup> anion with the gold atom in a square‐planar coordination of four monodentate triflate ions. The structural characteristics of the anion are well reproduced by theoretical calculations that allowed also for a reliable assignment of observed IR energies. Charge compensation for the anions is achieved by different <italic>M</italic><sup>+</sup> counter cations. According to their coordination requirements different crystal structures are adopted. For <italic>M</italic> = Li, Na, the compounds are triclinic [<italic>M</italic> = Li/Na: triclinic, <italic>P</italic><tex-math notation="tex"><![CDATA[$\bar{1}$]]></tex-math><inline-graphic xlink:href="ark:/27927/pgg1vb451rt" mimetype="image" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />, <italic>Z</italic> = 1, <italic>a</italic> = 509.92(2)/525.43(2), <italic>b</italic> = 854.08(3)/902.08(4), <italic>c</italic> = 1044.67(4)/1080.28(5) pm, <italic>α</italic> = 94.006(2)/104.367(2)°, <italic>β</italic> = 92.935(2)/93.602(3)°, <italic>γ</italic> = 93.841(2)/90.706(2)°, <italic>V</italic> = 452.12(3)/494.83(4) Å<sup>3</sup>] and octahedral coordination of the cations is observed. The monoclinic Ag[Au(CF<sub>3</sub>SO<sub>3</sub>)<sub>4</sub>] [<italic>C</italic>2/<italic>c</italic>, <italic>Z</italic> = 4, <italic>a</italic> = 2218.83(5), <italic>b</italic> = 499.19(1), <italic>c</italic> = 1751.73(4) pm, <italic>β</italic> = 104.736(1)°, <italic>V</italic> = 1876.43(7) Å<sup>3</sup>] shows the Ag<sup>+</sup> ion in trigonal prismatic surrounding of oxygen atoms. A coordination number of eight is found for K[Au(CF<sub>3</sub>SO<sub>3</sub>)<sub>4</sub>] [orthorhombic, <italic>Pbcn</italic>, <italic>Z</italic> = 4, <italic>a</italic> = 904.32(4), <italic>b</italic> = 1050.64(4), <italic>c</italic> = 2120.71(9) pm, <italic>V</italic> = 2014.92(15) Å<sup>3</sup>] and also for Rb[Au(CF<sub>3</sub>SO<sub>3</sub>)<sub>4</sub>] [monoclinic, <italic>P</italic>2<sub>1</sub>/<italic>n</italic>, <italic>Z</italic> = 4, <italic>a</italic> = 919.80(3), <italic>b</italic> = 2121.77(6), <italic>c</italic> = 1083.40(3) pm, <italic>β</italic> = 90.120(2)°, <italic>V</italic> = 2114.36(11) Å<sup>3</sup>]. In both cases the [<italic>M</italic>O<sub>8</sub>] polyhedra have dodecahedral shape. The thermal decomposition of selected compounds was monitored up to 1050 °C and shows that a mixture of elemental gold and the respective alkaline metal sulfate is the residue. For <italic>M</italic> = Ag elemental silver is formed instead of a sulfate.</p> </abstract>