Poly[guanidinium [tri-μ-formato-κ⁶O:O′-formato-κ²O,O′-yttrium(III)]]

In the title coordination polymer, {(CH₆N₃)[Y(CHO₂)₄]}_n, the yttrium(III) ion is coordinated by one O,O-bidentate formate ion and six μ₂ bridging formate ions, generating a square-anti­prismatic YO₈ coordination polyhedron. The bridging formate ions connect the metal ions into an anionic, three-dimensional network. Charge compensation is provided by guanidinium ions, which inter­act with the framework by way of N—H...O hydrogen bonds. The guanidine molecules reside in porous channels of 3.612 by 8.189 Å, when considering the van der Waals radii of the nearest atoms (looking down the a-axis).