Cover illustration: The intermolecular interactions in 2,3-dichloro-6-nitrobenzylaminium chloride, including the three-center hydrogen-bond configuration. For clarity, only relevant H atoms and intramolecular interactions are shown. See Rathore, Narasimhamurthy, Vijay, Yathirajan & Nagaraja [Acta Cryst. (2006), C62, o36-o38].
Tricesium lithium dicobalt tetrakis(tetraoxomolybdate), Cs3LiCo2(MoO4)4, and trirubidium lithium dizinc tetrakis(tetraoxomolybdate), Rb3LiZn2(MoO4)4, are isotypic with Cs6Zn5(MoO4)8 and contain frameworks of MoO4 and (M2/3Li1/3)O4 tetrahedra (M = Co and Zn) with alkaline cations in cuboctahedral cavities. The frameworks are close to that of 12CaO·7Al2O3 and the cations repeat the Y3Au3Sb4 structure.
PbZn2(BO3)2 crystallizes in the space group Pccn, with the Pb atom at a site with imposed twofold symmetry. The compound represents a new structure type in which ZnBO3 layers are bridged by Pb2+ cations, giving rise to a three-dimensional framework.