Observation of cation ordering and anion-mediated structure selection among the layered double hydroxides of Cu(ii) and Cr(iii)†
Abstract
Highly ordered Cl− and SO42−-intercalated layered double , a = 5.41 Å, c = 11.06 Å). In contrast the Cl−-intercalated LDH adopts the
m, a = 3.11 Å, c = 23.06 Å). The Cl−-LDH was used as a precursor to synthesize LDHs with other anions. While Br− and CO32− (molecular symmetry, D3h) select for the 3R1 polytype, the XO3− (X = Br, I) ions (molecular symmetry, C3v) select for the rare 3R2 polytype. This work demonstrates the role of the intercalated anion in structure selection of the LDH.