Synthesis and Redetermination of the Crystal Structure of Ammonium mu-Hydroxobis(oxodiperoxovanadate(V)) Monohydrate (NH_4)_3[{VO(O_2)_2}_2(mu-OH)] centre dot H_2O

摘要

The synthesis and X-ray structural analysis of ammonium diperoxopyrovanadate hydrate (NH_4)_3[HV_2O_(11)] centre dot H_2O (I) were performed. The structural units of crystal I are dimeric [{VO(O_2)_2}_2(mu-OH)]~(3-) complex anions, ammonium cations, and crystal water molecules. In the anionic complex, each of two metal atoms united by the hydroxo bridge is coordinated by the oxo O atom, arranged in the apex of a distorted pentagonal pyramid, and four O atoms of two eta~2-coordinated peroxo ligands and the O atom of the bridging OH group arranged in the equatorial plane. The average bond lengths are V-O(oxo) 1.602, V-O(O_2)_(cis) 1.901, V-O(O_2)_(trans) 1.878, and V-O(OH) 2.002 A. The V(1)...O(10) (2.525 A) and V(2)...O(3) (2.487 A) contacts, weakened due to the trans-effect of the multiple-bonded O(1) and O(6) oxo ligands, complete the coordination polyhedron of the vanadium atoms to a distorted pentagonal bipyramid. The complex anions, ammonium cation, and H_2O molecules are united by an extended system of hydrogen bonds.