Freeze-drying synthesis of an amorphous Zn2+ complex and its transformation to a 2-D coordination framework in the solid state

Abstract

An amorphous and metastable precursor for a Zn two-dimensional coordination framework was synthesised via freeze drying. The precursor comprises randomly packed discrete clusters of a Zn complex. The amorphous-to-crystalline framework transformation, which was triggered by the gentle application of heat or pressure, was accompanied by a change in the coordination geometry of the Zn²⁺ ions from tetrahedral to octahedral symmetry.