Poly[diaqua­(μ₆-benzene-1,2,4,5-tetra­carboxyl­ato)(μ₆-2,5-dicarboxy­benzene-1,4-dicarboxyl­ato)disamarium]

The title compound, [Sm₂(C₁₀H₂O₈)(C₁₀H₄O₈)(H₂O)₂]_n or [Sm₂(btec)(H₂btec)(H₂O)₂]_n, was synthesized hydro­­thermally by the reaction of Sm₂O₃ with 1,2,4,5-ben­zene­tetra­carboxylic acid (H₄btec). The Sm atom is coordinated by nine O atoms, three from H₂btec²⁻, five from btec⁴⁻ and one from a coordinated water mol­ecule. Sm—O distances range from 2.376 (3) to 2.558 (5) Å.