Preparation and crystal structure of the ammonium cobalt carbonate hydroxide hydrate (NH 4) 2Co 8(CO 3) 6(OH) 6·4H 2O

Abstract

(NH 4) 2Co 8(CO 3) 6(OH) 6 · 4H 2O was prepared by digesting Co 2( OH) 2 CO 3 · xH 2 O in water solution of NH 4HCO 3. Chemical analyses, diffuse reflectance spectroscopy and XRD data proved that this compound, like Na 2Co 8(CO 3) 6(OH) 6 · 6H 2O and K 2Co 8(CO 3) 6(OH) 6 · 4H 2O, is a derivative of the kambaldaite Na 2Ni 8(CO 3) 6(OH) 6 · 6H 2O, a mineral with an unique channel structure which had no other synthetic or natural analogues.