Proton-stabilized three-dimensional anionic framework in H[Zn6O2(BO3)3]

A three-dimensional anionic framework built up from [ZnO4] tetrahedra and planar [BO3] groups, stabilized by H atoms, has been found for hydrogen zinc oxide borate, H[Zn6O2(BO3)(3)]. Boron and one of the borate O atoms are on 18e ( 2) positions. Triple units of [ ZnO4] tetrahedra sharing a common oxygen vertex on a 12c ( 3) site and strong asymmetrical linear hydrogen bonds with the H atom [ on a 12c ( 3) position] disordered over a twofold axis are specific structural features of this zincoborate. There is evidence that the reported Zn4O(BO3)(2) [Harrison, Gier & Stuky (1993). Angew. Chem. Int. Ed. Engl. 32, 724 - 726] corresponds to this structure.