Despite the crystal-chemical similarities between copper and silver ions, t
here is no known silver copper oxide, neither natural nor synthetic. In thi
s work, we present the synthesis at room-temperature of the first silver co
pper oxide of formula Ag2Cu2O3 (tetragonal, a=5.8857(3)Angstrom, c=10.6868(
7)Angstrom, space group I41/amd, Z=4). It should be noted that the thermal
stability of this new oxide is enhanced with respect to Ag2O or even CuO. T
he structure consists of alternating chains of edge-sharing square planar C
u(II) and zigzag chains of linearly coordinated Ag(I) ions.