Research Article: MnBa2(HPO4)2(H2PO4)2

Date Published: June 01, 2012

Publisher: International Union of Crystallography

Author(s): Wei Sun, Li-Zhi Sun, Teng-Teng Zhu, Biao-Chun Zhao, Jin-Xiao Mi.


Crystals of manganese(II) dibarium bis­(hydrogenphosphate) bis­(dihydrogenphosphate), MnBa2(HPO4)2(H2PO4)2, were obtained by hydro­thermal synthesis. The title compound is isotypic with its CdII and CaII analogues. The structure is built up of an infinite {[Mn(HPO4)2(H2PO4)2]4−}n chain running along [100], which consists of alternate MnO6 octa­hedra and [PO4] tetra­hedra, in which the centrosymmetric MnO6 octa­hedra share their four equatorial O-atom corners with tetra­hedral [PO3(OH)] groups and their two axial apices with tetra­hedral [PO2(OH)2] groups. These chains are held together by BaO9 coordination polyhedra, developing into a three-dimensional structure. The O—H⋯O hydrogen bonds additionally stabilize the structural set-up. Due to the ionic radius of Mn2+ being much smaller than those of Ca2+ and Cd2+, this may imply that their adopted structure type has a great tolerance for incorporating various ions and the exploitation of more diverse compounds in the future is encouraged.

Partial Text

For background to transition metal phosphates, see: Cheet­ham et al. (1999 ▶); Mao et al. (2000 ▶); Mi et al. (2000 ▶); Sun et al. (2012 ▶); Escobal et al. (1999 ▶). For isotypic structures, see: Ben Taher et al. (2001 ▶) for CdBa2(HPO4)2(H2PO4)2; Ben Tahar et al. (1999 ▶) and Toumi et al. (1997 ▶) for CaBa2(HPO4)2(H2PO4)2. For the bond-valence method, see: Brown (2002 ▶). For ionic radii, see: Shannon (1976 ▶).