A porous organo-ceramic solid with cyclo-tetravanadate units, [H2pn][Mn2(C2O4)(V4O12)]

Hydrothermal synthesis using V2O5, Mn(OAc)2, 1,3-diaminopropane (pn) and oxalic acid at pH 7 and 110°C results in the formation of a hybrid organic–ceramic solid [H2pn][Mn2(C2O4)(V4O12)] 1, with an anionic open-framework composed of Mn2+ ions, oxalate and cyclotetravanadate ions. 7 Å cavities house the organic [H2pn] countercations. The crystal structure shows 1 is monoclinic, P21/m, a=8.680(2), b=11.728(2), c=9.639(2) Å, β=114.56(1)°, V=892.5(3) Å3. An isostructural material 2 [H2bn][Mn2(C2O4)(V4O12)] can be formed using 1,4-diaminobutane (bn).