Vanadogermanate Cluster Anions

Abstract

Three novel vanadogermanate cluster anions have been synthesized by hydrothermal reactions. The cluster anions are derived from the (V(18)O(42)) Keggin cluster shell by substitution of V=O(2+) "caps" by Ge(2)O(OH)(2)(4+) species. In Cs(8)[Ge(4)V(16)O(42)(OH)(4)].4.7H(2)O, 1, (monoclinic, space group C2/c (No. 15), Z = 8, a = 44.513(2) A, b = 12.7632(7) A, c = 22.923(1) A, beta = 101.376(1) degrees ) and (pipH(2))(4)(pipH)(4)[Ge(8)V(14)O(50).(H(2)O)] (pip = C(4)N(2)H(10)), 2 (tetragonal, space group P4(2)/nnm (No. 134), Z = 2, a = 14.9950(7) A, c = 18.408(1) A), two and four VO(2+) caps are replaced, respectively, and each cluster anion encapsulates a water molecule. In K(5)H(8)Ge(8)V(12)SO(52).10H(2)O, 3, (tetragonal, space group I4/m (No. 87), Z = 2, a = 15.573(1) A, c = 10.963(1) A), four VO(2+) caps are replaced by Ge(2)O(OH)(2)(4+) species, and an additional two are omitted. The cluster ion in 3 contains a sulfate anion disordered over two positions. The cluster anions are analogous to the vanadoarsenate anions [V(18)(-)(n)()As(2)(n)()O(42)(X)](m)(-) (X = SO(3), SO(4), Cl; n = 3, 4) previously reported.

A Series of Vanadogermanates from 1D Chain to 3D Framework Built by Ge–V–O Clusters and Transition‐Metal‐Complex Bridges

“…In addition, the bond valence sums for terminal O18, O21, O23, and O24 atoms on the Ge atoms in 1 are less than 1, which suggests that these O atoms belong to OH groups. Similar OH groups have also been reported in other Ge-V-O clusters, such as (H 2 dab) 4 [13] It is interesting that the Cd3 atom also has significant weak Cd À O interactions of 2.856(3) , which is shorter than the sum of the van der Waals radii (< 3.7 ). [19] The relatively long Cd À O bonds may be a consequence of steric interactions between the en ligands and the Cd 2 Ge 8 V 12 clusters.…”

“…[ [13] in which one of the Ge 2 O 7 units and two VO 5 square pyramids are disordered over two positions. This disorder could be related to the weak interaction of Cs + cations and discrete Ge-V-O cluster anions.…”

“…The VÀO distances of these terminal O atoms range from 1.604(3) to 1.620(3) , whereas those for the basal, shared O atoms range from 1.912(3) to 2.006(3) . The V···V distances range from 2.8573(11) to 3.0341 (13) . In the Ge 2 O 7 fragments, the Ge À O distances vary from 1.716(3) to 1.779(3) .…”

One-pot Synthesis of Dihydropyrimidinones Using Polyoxometalate Tri-supported Transition Metal Complexes

“…[1][2][3][4][5][6][7] In these complexes, POMs can coordinate to "secondary" transition metal atoms with organic moieties using their terminal or bridging oxygen atoms to stabilize frameworks. Meanwhile, transition metal complexes with diverse structural arrangements not only serve as charge-compensating units but also modify the wide-ranging properties of POMs, such as magnetic and optical properties, electronic conductivities and electrocatalysis.…”

Hydrothermal synthesis and structure of a novel hybrid germanium vanadate: (2,2 ′ -bpy) 2 (V V O 2 ) 2 (H 2 GeO 4 ) · 6H 2 O

“…In the past few years, only four germanium vanadates were reported such as layered compounds (C 6 H 18 N 2 )Ge 2 V 4 O 12 (OH) 2 Á 2H 2 O and CsGeV 2 O 6 (OH) templated by cations [17], and discrete clusters of (pipH 2 ) 4 pipH) 4 [18]. We seek to incorporate the organic ligand into the germanium vanadate skeleton.…”