Reversible repositioning of zinc atoms within single crystals of a zinc polycarboxylate with an open-framework structure

The results of using tetrahydrofuran-2,3,4,5-tetracarboxylic acid C4H4O(COOH)4 with nine coordinating oxygen atoms to link Co and Zn, in extended open-framework structures, are presented. It was observed that upon heating under vacuum, the zinc compound not only loses water but some of the zinc atoms move to different positions in the structure while preserving the crystallinity of the single crystals.