Poly[[[μ3-N′-(carboxymethyl)ethylenediamine-N,N,N′-triacetato]dysprosium(III)] trihydrate]

In the title coordination polymer, {[Dy(C10H13N2O8)]·3H2O}n, the dysprosium(III) ion is coordinated by two N atoms and six O atoms from three different (carboxymethyl)ethylenediaminetriacetate ligands in a distorted square-antiprismatic geometry. The ligands connect the metal atoms, forming layers parallel to the ab plane. O—H⋯O hydrogen bonds further assemble adjacent layers into a three-dimensional supramolecular network.

In the title coordination polymer, {[Dy(C 10 H 13 N 2 O 8 )]Á3H 2 O} n , the dysprosium(III) ion is coordinated by two N atoms and six O atoms from three different (carboxymethyl)ethylenediaminetriacetate ligands in a distorted square-antiprismatic geometry. The ligands connect the metal atoms, forming layers parallel to the ab plane. O-HÁ Á ÁO hydrogen bonds further assemble adjacent layers into a three-dimensional supramolecular network.

Experimental
A mixture of Dy 2 O 3 (0.189 g, 0.5 mmol), ethylenediaminetetraacetic acid (0.146 g, 0.5 mmol), and H 2 O (10 mL) was sealed in a 20 mL Teflon-lined reactor, which was heated in an oven to 423 K for 36 h and then cooled to room temperature at a rate of 5 K h -1 . Colourless crystals were obtained in a yield of 46% based on Dy.

Refinement
All water H atoms were tentatively located in difference density Fourier maps and were refined with O-H distance restraints of 0.85 (2) Å and with U iso (H) = 1.5 U eq (O). In the last stage of refinement, they were treated as riding on their parent O atoms. All H atoms attached to C atoms were fixed geometrically and treated as riding with C-H = 0.97 Å, and U iso (H) = 1.2U eq (C). Fig. 1. The asymmetric unit of the title compound, with displacement ellipsoids drawn at the 50% probability level. Symmetry codes: (ii) 1/2-x, -1/2+y, z; (iii) 1/2+x, y, 1/2-z.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.