catena-Poly[2,2′,2′′-nitrilo­tris­(ethan­aminium) [tri-μ-oxido-tris­[dioxido­vanadate(V)]] monohydrate]

The title compound, {(C₆H₂₁N₄)[V₃O₉]·H₂O}_n, crystallizes as a salt with [trenH₃]³⁺ cations [tren is tris­(2-amino­eth­yl)amine], and one-dimensional anionic {[V^VO₃]⁻}_n (metavanadate) chains along the c-axis direction. Three crystallographically distinct V^V sites and one occluded water mol­ecule are present for every [trenH₃]³⁺ cation in the unit cell. The {[V^VO₃]⁻}_n chains are composed of vertex-sharing [VO₄] tetra­hedra and have a repeat unit of six tetra­hedra. Each tetra­hedron in the chain contains two terminal and two μ²-bridging oxide ligands. The [trenH₃]³⁺ cations, {[V^VO₃]⁻}_n anions and occluded water mol­ecules participate in an extensive three-dimensonal hydrogen-bonding network. The three terminal ammonium sites of the [trenH₃]³⁺ cations each form strong N—H...O hydrogen bonds to terminal oxide ligands on the {[V^VO₃]⁻}_n chain. Each occluded water mol­ecule also donates two O—H...O hydrogen bonds to the terminal oxide ligands.