Exploring new belousovite-related zinc and cadmium alkali sulfate halides: synthesis and structural variability.

Fourteen new belousovite-related compounds, AZn(TO4)X (A = K, Rb, Cs, Tl, NH4; T = S, Se; X = Cl, Br, I) have been prepared via melt and evaporation techniques by reacting AX and ZnTO4 either at high temperatures or in hot aqueous solutions. They adopt the layered structure of the belousovite archetype, and constitute a morphotropic series. The apophyllite-type layers in these structures undergo different corrugations, most pronounced in the case of CsZn(SO4)I. In addition, during the study two species unrelated to belousovite, namely Na4Zn(SO4)2Cl2 and Cs2Cd3(SO4)4, were found with framework crystal structures having different topology and belonging to new structure types.

Pb6O5(NO3)2: A Nonlinear Optical Oxynitrate Structurally Based on Lead Oxide Framework.

A high second harmonic generation response is demonstrated by a Pb6O5(NO3)2 lead oxynitrate whose identity was verified upon reinvestigation of the PbO-Pb(NO3)2 system. Its crystal structure exhibits a unique cationic [Pb6O5]2+ framework hosting orientationally ordered NO3- triangles in the channels. Easy preparation and high thermal stability (until ∼500 °C in air) suggest it to be a new promising NLO material.