catena-Poly[2,2',2''-nitrilo-tris-(ethan-aminium) [tri-μ-oxido-tris-[dioxido-vanadate(V)]] monohydrate]

The title compound, {(C6H21N4)[V3O9]·H2O} n , crystallizes as a salt with [trenH3](3+) cations [tren is tris-(2-amino-eth-yl)amine], and one-dimensional anionic {[V(V)O3](-)} n (metavanadate) chains along the c-axis direction. Three crystallographically distinct V(V) sites and one occluded water mol-ecule are present for every [trenH3](3+) cation in the unit cell. The {[V(V)O3](-)} n chains are composed of vertex-sharing [VO4] tetra-hedra and have a repeat unit of six tetra-hedra. Each tetra-hedron in the chain contains two terminal and two μ(2)-bridging oxide ligands. The [trenH3](3+) cations, {[V(V)O3](-)} n anions and occluded water mol-ecules 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(V)O3](-)} n chain. Each occluded water mol-ecule also donates two O-H⋯O hydrogen bonds to the terminal oxide ligands.