49756-76-5Relevant academic research and scientific papers
Crystal structures of XeF5+MF4- (M = Ag, Au) and their relevance to the basicity and oxidizability of MF4-
Lutar, Karel,Jesih, Adolf,Leban, Ivan,Zemva, Boris,Bartlett, Neil
, p. 3467 - 3471 (1989)
XeF5+AuF4- has been prepared from BrF3·AuF3 by displacement of BrF3 with XeF6. The salt interacts quantitatively with KrF2 in anhydrous HF, below 0°C, to yield XeF5+AuF6-. XeF5AuF4 (I) is isostructural with XeF5AgF4 (II), and these compounds crystallize in space group I4/m with the following unit cell dimensions: I, ao = 5.735 (5) A?, co = 20.007 (17) A?, V = 658 (2) A?3, Z = 4; II, ao = 5.593 (2) A?, co = 20.379 (5) A?, V = 637.5 (8) A?3, Z = 4. The structure of II was solved by the Patterson method and refined to conventional R and Rw values of 0.077 and 0.090, respectively. The structure contains double layers of XeF5+ and layers of AgF4- ions, all layers being parallel to the ab plane. The XeF5+ ion had C4v symmetry with Xe-F(axial) = 1.853 (19) A?, Xe-F(equatorial) = 1.826 (9) A?, and F(axial)-Xe-F(equatorial) = 77.7 (3)°. The anion (site symmetry D2h), which is not significantly different from O4h symmetry, has Ag-F = 1.902 (11) A?. Differences between the XeF5AgF4 and XeF5AuF4 structures are attributed to lower ligand charges in the anion of the former, relative to those in the latter, and these in turn are related to observed differences in the basicity and oxidizability of the anions.
