High yield room temperature syntheses of KAgF4 and AgF3 and the preparation and unit cell of LiAgF4

AgF2 dissolves at similar to 20 degrees C in liquid anhydrous hydrogen fluoride (aHF), containing either LiF or KF, with sunlight or ultraviolet (UV)-irradiated F-2. Concentrated KF-aHF solutions quickly give a nearly quantitative conversion to KAgF4. Preparation of LiAgF4 is less efficient, but it can be prepared in high purity. It is isomorphous with LiAuF4, and has a monoclinic unit cell: a = 4.87(1); b = 5.93(1); c = 10.08(1) Angstrom; beta = 93.0(1)degrees; V = 291(1) Angstrom(3), z = 4. KHF2 impurity in KAgF4 can be removed as KPF6 with PF5 at 0 degrees C. Preparation of AgF3, with minimum contamination by Ag3F8, is achieved at 0 degrees C using GeF4 as F- acceptor. The high solubility of the salt K2GeF6 makes this possible. (C) 1998 Elsevier Science S.A. All rights reserved.