ION-EXCHANGE REACTIONS AND PHYSICAL-PROPERTIES OF THE MICA ANALOG KNIASO4

Exchange of RNH//3** plus and H//3O** plus for K** plus in the mica analog KNiAsO//4 has been investigated by chemical analysis, X-ray powder diffraction, infrared spectroscopy, and thermal analysis. For R equals C//nH//2//n// plus //1 with n equals 1-10, the alkyl chains form ordered arrays between the inorganic layers and hydrogen bonding occurs between the minus NH//3** plus and the oxygen atoms of the arsenate groups. Warming KNiAsO//4 with 1 M HCl leads to partial replacement of K** plus by H** plus (H//2O)//y but prolonged boiling with 1 M HCl removes all K** plus to give Ni//3(AsO//4)//26H//2O.