Planar coordination of the group I B elements: crystal structure of Ag (II) oxide

Abstract

The authors investigated the crystal structure of AgO in order to determine the type of coordination and the bond distances of Ag (II). The X-ray analysis by the powder method shows that the compound is monoclinic, spatial group C 6 2 h = C 2/ c, with the following parameters: a = 5.85 2A b = 3.47 0 A c = 5,49 5 A β = 107·30′ V = 106,7 A 2, Z = 4 The structure is very similar to that of tenorite CuO. The positions of the atoms are the following. 4 Ag in 1/4 1/4 0; 3/4 1/4 1/2 + (000: 1/2 1/2 0) 4 O in O y 1/4; O y 3/4 + (000: 1/2 1/2 0) The most probable value of the parameter y is 0.084. The authors discuss the presence, in the structure, of two distances. Ag O : 1) 2.04 Å 2) 2.35 Å which are commonly found in the silver compounds with formal valence (1) and (II). Of the hybridization dsp 2, which should characterize Ag (II), only the planarity of the Silver-Oxygen groups is maintained.