CRYSTAL STRUCTURE OF A NEW MAGNESIUM PARATUNGSTATE SALT (CH3NH3)4[(Mg(H2O)5)2H6W12O42]Br2×8H2O
A. V. Anyushin1,2, A. I. Smolentsev1, M. N. Sokolov1,2
1Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk National Research State University, Novosibirsk, Russia
Keywords: полиоксометаллаты, паравольфрамат Б, магний, кристаллическая структура, polyoxometalates, paratungstate B, magnesium, crystal structure
Abstract
The X-ray crystal structure of (CH3NH3)4[(Mg(H2O)5)2(H6W12O42)]Br2×8H2O (1) obtained by a reaction of Li2WO4×H2O and Mg(NO3)2×6H2O in the presence of MeNH3Br is reported. Crystallographic parameters are: triclinic, space group P-1, a = 10.8280(4) Å, b = 12.4866(5) Å, c = 12.6201(5) Å, α = 108.501(1)°, β = 111.542(1)°, γ = 91.139(1)°, V = 1486.98(10) Å3, Z = 1, C4H66Br2Mg2N4O60W12, dx = 3.959 g/cm3, T = 150 K, R1 = 0.030 for 9914 Fo > 4δ(F) until 2θmax = 66.6° The structure contains tetraprotonated [H2W12O42]10- anions coordinated with {Mg(H2O)5}2+ cations as ditopic ligands via terminal oxygen atoms. The crystal structure also incorporates outer-sphere CH3NH3+ and Br- ions. The Mg2+ cations are in the octahedral environment, Mg-O(H2O) and Mg-O(W) bond lengths being 2.102(5)÷2.044(5) Å and 2.071(5) Å, respectively.
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