A new polymeric chain in the dihydrogendecavanadate(V)–decavanadate(V) [NH2(CH2)4]5[V10O28H2]0.5[V10O28]0.5 obtained by in situ synthesis of the organic cation

A new polymeric compound, [NH2(CH2)4]5[V10O28H2]0.5[V10O28]0.5, was obtained by in situ synthesis of the organic cation from an aqueous solution of V2O5–HCl–NH2(CH2)4NH2. The crystal structure was solved by single-crystal X-ray diffraction. [NH2(CH2)4]5[V10O28H2]0.5[V10O28]0.5 consists of dihydrogendecavanadate(V), [H2V10O28]4−, and decavanadate(V), [V10O28]6−, units assembled in one-dimensional arrays by interanionic hydrogen bonds O–H⋯O and cation-anion N–H⋯O interactions. The latter involve pyrrolidinium cations, which were obtained in the compound instead of the starting butane-1,4-diamine. Pyrrolidinium cations further connect the polymeric chains into a three-dimensional network. The presence of the two types of units, [HnV10O28](6−n)− with n = 0 and n = 2, in one compound was not yet observed and is herein reported for the first time.