New structure types of polymeric chain anions in the crystal structures of complex zirconium fluorides

Abstract

The crystal structures of complex zirconium fluorides (C2H5N4)2Zr2F10·H2O and (H3O)3(NEt4)2Zr4F21·3H2O synthesized for the first time are determined. The formation of new structure types of polymeric chain complex anions is found in them. Two crystallographically independent zigzag-like polymeric chains ∞(ZrF5)− composed of pentagonal bipyramidal polyhedra of Zr atoms sharing F-F edges form a polymeric chain complex anion in the (C2H5N4)2Zr2F10·H2O structure. The polymeric chain complex anion in the (H3O)3(NEt4)2Zr4F21·3H2O structure is formed of tetranuclear -Zr(1)F7-Zr(2)F8-Zr(3)F8-Zr(4)F7- moieties in which Zr(2)F8 and Zr(3)F8 polyhedra are linked by a common thiangular face and Zr(1)F7 and Zr(4)F7 polyhedra are bonded to Zr(2)F8 and Zr(3)F8 polyhedra by common edges. In the polymeric chain of the complex [Zr4F21]5− anion the tetranuclear fragments share edges. The structural fragments of the compounds are combined in three-dimensional units by a branched system of N-H⋯O, N-H⋯F, and O-H⋯F hydrogen bonds.