Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807036598/dn2221sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807036598/dn2221Isup2.hkl |
CCDC reference: 634967
Key indicators
- Single-crystal X-ray study
- T = 295 K
- Mean (C-C) = 0.003 Å
- R factor = 0.022
- wR factor = 0.056
- Data-to-parameter ratio = 13.1
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ? PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.98 PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) . 2.00 Ratio PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ...... 43.24 Deg. O1 -P1 -NA1 1.555 1.555 1.555 PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ...... 43.78 Deg. O2 -P1 -NA1 1.555 1.555 4.466
Alert level G PLAT793_ALERT_1_G Check the Absolute Configuration of P1 = ... R PLAT793_ALERT_1_G Check the Absolute Configuration of C1 = ... R PLAT794_ALERT_5_G Check Predicted Bond Valency for Fe1 (2) 2.01
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 5 ALERT level C = Check and explain 3 ALERT level G = General alerts; check 3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
A mixture of 0.16 g (0.6 mmol) FeSO4.7H2O, 0.5 ml (2.0 mmol) 2-hydroxyphosphonoacetic acid (48.0 wt %) and 0.17 g (4.0 mmol) NaF (as a mineralizer) were dissolved in 10 ml of deionized water, and then 2 mol/L NaOH (aq) was added with stirring to adjust the pH of the mixture. The mixture (pH = 4) was sealed in a 20 ml Teflon-lined stainless steel autoclave, and then heated at 433 K for 72 h. Colorless block crystals were obtained, washed with distilled water, and dried in air at room temperature.
H atoms were placed in calculated positions and allaowed to ride, with C—H = 0.93 Å or O—H = and Uiso(H) = 1.2Ueq(C).
Metal phosphonates with rich composition and structural diversity have attracted considerable attention during the past few years due to their potential applications in catalysis (Clearfield, 1996), ion exchange (Alberti et al., 1999), proton conductivity (Odobel et al., 2001) and gas and liquid separations (Riou et al., 1998,2000). The strategy of attaching additional functional groups such as amine, hydroxyl and carboxylate groups to the phosphonic acid has proven to be effective for the synthesis of metal phosphonates with open-framework and microporous structures. For example, 2-hydroxyphosphonoacetic acid (H3L) with functional hydroxyl and carboxylate groups is an interesting ligand for the synthesis of metal phosphonates with open-framework structures, since it can adopt various kinds of coordination modes under different reaction conditions which may result in various interesting structures.
The title compound, (I), has been synthesized by hydrothermal technique, using 2-hydroxyphosphonoacetic acid as ligand. Analysis of the single-crystal data reveals that there are one iron(II) ion, one L3- [L = O3PCH(OH)CO2] ligand, and one Na+ ion in the asymmetric unit of (I). Each iron(II) ion is octahedrally coordinated by three phosphonate O atoms from three separate L3- ligands (Fig 1) [the Fe—O distance range from 2.032 (1) to 2.196 (1) Å], two carboxylate O atoms from two separate L3- ligands [the Fe—O bond lengths are 2.143 (1) and 2.185 (1) Å] and one hydroxyl O atom [the Fe—O bond length is 2.272 (1) Å]. These values are close to those reported for other analogous six-coordinated iron(II) phosphonates (Fu et al., 2005). As a result, all the O atoms from the L3- ligand are involved in metal coordination, and act as a monodentate connecting one iron(II) ion. The values of the O—Fe—O angles are in the range 69.39 (5)–171.49 (5)°. The overall structure can be described as a three-dimensional open-framework type with channels running along the a axis (Fig 2).
For related literature, see: Alberti et al. (1999); Clearfield (1996); Fu et al. (2005); Odobel et al. (2001); Riou et al. (1998, 2000).
Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL.
Na[Fe(C2H2O6P)] | F(000) = 912 |
Mr = 231.85 | Dx = 2.837 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 3081 reflections |
a = 10.2676 (8) Å | θ = 3.4–28.9° |
b = 9.7330 (8) Å | µ = 3.12 mm−1 |
c = 10.8624 (9) Å | T = 295 K |
V = 1085.53 (15) Å3 | Block, colourless |
Z = 8 | 0.23 × 0.17 × 0.08 mm |
Bruker SMART APEXII CCD diffractometer | 1309 independent reflections |
Radiation source: fine-focus sealed tube | 1213 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
ω scans | θmax = 28.0°, θmin = 3.4° |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2005) | h = −13→13 |
Tmin = 0.531, Tmax = 0.795 | k = −9→12 |
6143 measured reflections | l = −14→11 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.022 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.056 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0281P)2 + 1.0108P] where P = (Fo2 + 2Fc2)/3 |
1309 reflections | (Δ/σ)max = 0.001 |
100 parameters | Δρmax = 0.50 e Å−3 |
0 restraints | Δρmin = −0.36 e Å−3 |
Na[Fe(C2H2O6P)] | V = 1085.53 (15) Å3 |
Mr = 231.85 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 10.2676 (8) Å | µ = 3.12 mm−1 |
b = 9.7330 (8) Å | T = 295 K |
c = 10.8624 (9) Å | 0.23 × 0.17 × 0.08 mm |
Bruker SMART APEXII CCD diffractometer | 1309 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2005) | 1213 reflections with I > 2σ(I) |
Tmin = 0.531, Tmax = 0.795 | Rint = 0.022 |
6143 measured reflections |
R[F2 > 2σ(F2)] = 0.022 | 0 restraints |
wR(F2) = 0.056 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.50 e Å−3 |
1309 reflections | Δρmin = −0.36 e Å−3 |
100 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
Fe1 | 0.17708 (3) | 0.41645 (3) | 0.60678 (3) | 0.01090 (10) | |
P1 | 0.09669 (4) | 0.72190 (5) | 0.45975 (5) | 0.01002 (12) | |
Na1 | 0.37599 (8) | 0.58426 (8) | 0.42567 (8) | 0.01915 (19) | |
O1 | 0.17072 (14) | 0.60193 (14) | 0.51501 (14) | 0.0155 (3) | |
O2 | −0.05078 (13) | 0.71517 (14) | 0.47584 (13) | 0.0156 (3) | |
O3 | 0.14845 (13) | 0.86102 (14) | 0.50091 (13) | 0.0151 (3) | |
O4 | 0.26320 (13) | 0.72206 (14) | 0.26531 (13) | 0.0138 (3) | |
H4 | 0.2760 | 0.8109 | 0.2565 | 0.017* | |
O5 | 0.18556 (13) | 0.48131 (14) | 0.22376 (14) | 0.0162 (3) | |
O6 | −0.02360 (13) | 0.51846 (14) | 0.26669 (13) | 0.0156 (3) | |
C1 | 0.12691 (18) | 0.70391 (19) | 0.29329 (18) | 0.0108 (4) | |
H1 | 0.0737 | 0.7693 | 0.2466 | 0.013* | |
C2 | 0.09253 (18) | 0.5568 (2) | 0.25833 (18) | 0.0120 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Fe1 | 0.00952 (15) | 0.01086 (15) | 0.01232 (15) | −0.00084 (9) | −0.00043 (10) | 0.00006 (10) |
P1 | 0.0097 (2) | 0.0090 (2) | 0.0113 (2) | −0.00012 (16) | −0.00040 (17) | −0.00060 (17) |
Na1 | 0.0176 (4) | 0.0158 (4) | 0.0241 (5) | 0.0005 (3) | 0.0032 (4) | 0.0014 (3) |
O1 | 0.0161 (7) | 0.0137 (7) | 0.0168 (7) | 0.0025 (5) | 0.0003 (6) | 0.0041 (5) |
O2 | 0.0102 (6) | 0.0180 (7) | 0.0187 (7) | −0.0002 (5) | 0.0005 (5) | −0.0056 (5) |
O3 | 0.0168 (7) | 0.0114 (7) | 0.0170 (7) | −0.0017 (5) | −0.0040 (6) | −0.0014 (5) |
O4 | 0.0126 (6) | 0.0097 (6) | 0.0189 (7) | −0.0017 (5) | 0.0034 (6) | 0.0008 (5) |
O5 | 0.0155 (7) | 0.0100 (6) | 0.0230 (8) | 0.0017 (5) | 0.0065 (6) | −0.0006 (5) |
O6 | 0.0117 (6) | 0.0155 (7) | 0.0196 (7) | −0.0020 (5) | 0.0006 (5) | −0.0042 (6) |
C1 | 0.0095 (8) | 0.0104 (8) | 0.0126 (9) | 0.0011 (7) | 0.0002 (7) | 0.0005 (7) |
C2 | 0.0138 (9) | 0.0111 (9) | 0.0110 (9) | 0.0007 (7) | 0.0003 (7) | 0.0001 (7) |
Fe1—O2i | 2.0318 (14) | Na1—C2vi | 3.002 (2) |
Fe1—O1 | 2.0633 (14) | Na1—P1v | 3.2006 (10) |
Fe1—O5ii | 2.1434 (14) | Na1—Na1vii | 3.4326 (18) |
Fe1—O6i | 2.1849 (14) | Na1—Fe1viii | 3.5065 (10) |
Fe1—O3iii | 2.1960 (14) | O2—Fe1i | 2.0318 (14) |
Fe1—O4ii | 2.2713 (14) | O2—Na1iv | 2.3497 (16) |
Fe1—Na1 | 3.2725 (9) | O3—Fe1ix | 2.1960 (14) |
Fe1—Na1ii | 3.5065 (10) | O3—Na1ix | 2.3349 (16) |
P1—O1 | 1.5171 (14) | O3—Na1iv | 2.9574 (17) |
P1—O3 | 1.5218 (14) | O4—C1 | 1.443 (2) |
P1—O2 | 1.5256 (14) | O4—Fe1viii | 2.2713 (14) |
P1—C1 | 1.843 (2) | O4—H4 | 0.8797 |
P1—Na1 | 3.1868 (10) | O5—C2 | 1.262 (2) |
P1—Na1iv | 3.2006 (10) | O5—Fe1viii | 2.1434 (14) |
Na1—O1 | 2.3267 (17) | O6—C2 | 1.253 (2) |
Na1—O3iii | 2.3349 (16) | O6—Fe1i | 2.1849 (14) |
Na1—O2v | 2.3497 (16) | O6—Na1x | 2.4164 (17) |
Na1—O6vi | 2.4164 (17) | C1—C2 | 1.523 (3) |
Na1—O4 | 2.4848 (16) | C1—H1 | 0.9800 |
Na1—O3v | 2.9574 (17) | C2—Na1x | 3.002 (2) |
O2i—Fe1—O1 | 108.55 (6) | O3iii—Na1—P1v | 119.24 (5) |
O2i—Fe1—O5ii | 167.05 (6) | O2v—Na1—P1v | 26.70 (3) |
O1—Fe1—O5ii | 84.32 (6) | O6vi—Na1—P1v | 100.98 (4) |
O2i—Fe1—O6i | 90.02 (5) | O4—Na1—P1v | 106.52 (4) |
O1—Fe1—O6i | 91.57 (6) | O3v—Na1—P1v | 28.26 (3) |
O5ii—Fe1—O6i | 88.11 (5) | C2vi—Na1—P1v | 77.70 (4) |
O2i—Fe1—O3iii | 97.73 (5) | P1—Na1—P1v | 110.13 (2) |
O1—Fe1—O3iii | 89.30 (5) | O1—Na1—Fe1 | 38.81 (4) |
O5ii—Fe1—O3iii | 83.55 (5) | O3iii—Na1—Fe1 | 42.10 (4) |
O6i—Fe1—O3iii | 171.49 (5) | O2v—Na1—Fe1 | 109.92 (5) |
O2i—Fe1—O4ii | 97.64 (5) | O6vi—Na1—Fe1 | 130.83 (5) |
O1—Fe1—O4ii | 153.40 (6) | O4—Na1—Fe1 | 113.58 (4) |
O5ii—Fe1—O4ii | 69.42 (5) | O3v—Na1—Fe1 | 121.21 (4) |
O6i—Fe1—O4ii | 83.68 (5) | C2vi—Na1—Fe1 | 144.90 (5) |
O3iii—Fe1—O4ii | 91.78 (5) | P1—Na1—Fe1 | 65.06 (2) |
O2i—Fe1—Na1 | 116.58 (5) | P1v—Na1—Fe1 | 120.15 (3) |
O1—Fe1—Na1 | 44.98 (4) | O1—Na1—Na1vii | 120.74 (6) |
O5ii—Fe1—Na1 | 73.38 (4) | O3iii—Na1—Na1vii | 58.02 (4) |
O6i—Fe1—Na1 | 133.12 (4) | O2v—Na1—Na1vii | 86.87 (5) |
O3iii—Fe1—Na1 | 45.47 (4) | O6vi—Na1—Na1vii | 87.91 (5) |
O4ii—Fe1—Na1 | 125.70 (4) | O4—Na1—Na1vii | 158.98 (6) |
O2i—Fe1—Na1ii | 109.63 (4) | O3v—Na1—Na1vii | 42.05 (3) |
O1—Fe1—Na1ii | 118.30 (5) | C2vi—Na1—Na1vii | 73.81 (5) |
O5ii—Fe1—Na1ii | 61.15 (4) | P1—Na1—Na1vii | 144.47 (5) |
O6i—Fe1—Na1ii | 42.87 (4) | P1v—Na1—Na1vii | 64.75 (3) |
O3iii—Fe1—Na1ii | 130.06 (4) | Fe1—Na1—Na1vii | 86.66 (3) |
O4ii—Fe1—Na1ii | 44.91 (4) | O1—Na1—Fe1viii | 105.75 (5) |
Na1—Fe1—Na1ii | 133.773 (18) | O3iii—Na1—Fe1viii | 109.10 (5) |
O1—P1—O3 | 113.18 (8) | O2v—Na1—Fe1viii | 120.07 (5) |
O1—P1—O2 | 114.76 (8) | O6vi—Na1—Fe1viii | 37.96 (3) |
O3—P1—O2 | 110.56 (8) | O4—Na1—Fe1viii | 40.19 (3) |
O1—P1—C1 | 103.34 (8) | O3v—Na1—Fe1viii | 114.44 (4) |
O3—P1—C1 | 108.30 (8) | C2vi—Na1—Fe1viii | 57.12 (4) |
O2—P1—C1 | 105.99 (8) | P1—Na1—Fe1viii | 88.61 (2) |
O1—P1—Na1 | 43.24 (6) | P1v—Na1—Fe1viii | 119.69 (3) |
O3—P1—Na1 | 95.39 (6) | Fe1—Na1—Fe1viii | 119.73 (3) |
O2—P1—Na1 | 152.67 (6) | Na1vii—Na1—Fe1viii | 125.38 (4) |
C1—P1—Na1 | 72.21 (6) | P1—O1—Fe1 | 151.70 (9) |
O1—P1—Na1iv | 130.89 (6) | P1—O1—Na1 | 110.23 (8) |
O3—P1—Na1iv | 66.95 (6) | Fe1—O1—Na1 | 96.21 (6) |
O2—P1—Na1iv | 43.78 (6) | P1—O2—Fe1i | 127.58 (8) |
C1—P1—Na1iv | 123.83 (6) | P1—O2—Na1iv | 109.52 (7) |
Na1—P1—Na1iv | 158.45 (2) | Fe1i—O2—Na1iv | 121.38 (7) |
O1—Na1—O3iii | 79.95 (5) | P1—O3—Fe1ix | 131.10 (8) |
O1—Na1—O2v | 92.21 (6) | P1—O3—Na1ix | 133.44 (8) |
O3iii—Na1—O2v | 130.40 (7) | Fe1ix—O3—Na1ix | 92.43 (6) |
O1—Na1—O6vi | 140.06 (6) | P1—O3—Na1iv | 84.78 (6) |
O3iii—Na1—O6vi | 95.85 (6) | Fe1ix—O3—Na1iv | 125.89 (6) |
O2v—Na1—O6vi | 118.51 (6) | Na1ix—O3—Na1iv | 79.93 (5) |
O1—Na1—O4 | 80.23 (5) | C1—O4—Fe1viii | 110.42 (10) |
O3iii—Na1—O4 | 134.23 (6) | C1—O4—Na1 | 103.78 (10) |
O2v—Na1—O4 | 91.14 (5) | Fe1viii—O4—Na1 | 94.89 (5) |
O6vi—Na1—O4 | 74.68 (5) | C1—O4—H4 | 106.7 |
O1—Na1—O3v | 136.98 (6) | Fe1viii—O4—H4 | 117.4 |
O3iii—Na1—O3v | 100.07 (5) | Na1—O4—H4 | 122.5 |
O2v—Na1—O3v | 54.89 (5) | C2—O5—Fe1viii | 113.84 (12) |
O6vi—Na1—O3v | 82.95 (5) | C2—O6—Fe1i | 130.23 (13) |
O4—Na1—O3v | 122.19 (5) | C2—O6—Na1x | 105.34 (12) |
O1—Na1—C2vi | 162.81 (7) | Fe1i—O6—Na1x | 99.17 (6) |
O3iii—Na1—C2vi | 103.28 (6) | O4—C1—C2 | 106.71 (14) |
O2v—Na1—C2vi | 98.06 (6) | O4—C1—P1 | 111.00 (12) |
O6vi—Na1—C2vi | 23.73 (5) | C2—C1—P1 | 107.16 (13) |
O4—Na1—C2vi | 85.79 (5) | O4—C1—H1 | 110.6 |
O3v—Na1—C2vi | 59.66 (5) | C2—C1—H1 | 110.6 |
O1—Na1—P1 | 26.53 (4) | P1—C1—H1 | 110.6 |
O3iii—Na1—P1 | 104.70 (5) | O6—C2—O5 | 124.66 (18) |
O2v—Na1—P1 | 83.44 (4) | O6—C2—C1 | 118.85 (17) |
O6vi—Na1—P1 | 126.57 (5) | O5—C2—C1 | 116.49 (16) |
O4—Na1—P1 | 55.61 (4) | O6—C2—Na1x | 50.93 (10) |
O3v—Na1—P1 | 138.09 (4) | O5—C2—Na1x | 114.47 (13) |
C2vi—Na1—P1 | 141.39 (5) | C1—C2—Na1x | 104.71 (11) |
O1—Na1—P1v | 115.82 (5) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1/2, −y+1, z+1/2; (iii) −x+1/2, y−1/2, z; (iv) x−1/2, −y+3/2, −z+1; (v) x+1/2, −y+3/2, −z+1; (vi) x+1/2, y, −z+1/2; (vii) −x+1, −y+1, −z+1; (viii) −x+1/2, −y+1, z−1/2; (ix) −x+1/2, y+1/2, z; (x) x−1/2, y, −z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H4···O5ix | 0.88 | 1.74 | 2.6168 (19) | 173 |
Symmetry code: (ix) −x+1/2, y+1/2, z. |
Experimental details
Crystal data | |
Chemical formula | Na[Fe(C2H2O6P)] |
Mr | 231.85 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 295 |
a, b, c (Å) | 10.2676 (8), 9.7330 (8), 10.8624 (9) |
V (Å3) | 1085.53 (15) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 3.12 |
Crystal size (mm) | 0.23 × 0.17 × 0.08 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD |
Absorption correction | Empirical (using intensity measurements) (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.531, 0.795 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6143, 1309, 1213 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.660 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.022, 0.056, 1.07 |
No. of reflections | 1309 |
No. of parameters | 100 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.50, −0.36 |
Computer programs: APEX2 (Bruker, 2005), APEX2, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1997) and PLATON (Spek, 2003), SHELXTL.
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H4···O5i | 0.88 | 1.74 | 2.6168 (19) | 172.7 |
Symmetry code: (i) −x+1/2, y+1/2, z. |
Metal phosphonates with rich composition and structural diversity have attracted considerable attention during the past few years due to their potential applications in catalysis (Clearfield, 1996), ion exchange (Alberti et al., 1999), proton conductivity (Odobel et al., 2001) and gas and liquid separations (Riou et al., 1998,2000). The strategy of attaching additional functional groups such as amine, hydroxyl and carboxylate groups to the phosphonic acid has proven to be effective for the synthesis of metal phosphonates with open-framework and microporous structures. For example, 2-hydroxyphosphonoacetic acid (H3L) with functional hydroxyl and carboxylate groups is an interesting ligand for the synthesis of metal phosphonates with open-framework structures, since it can adopt various kinds of coordination modes under different reaction conditions which may result in various interesting structures.
The title compound, (I), has been synthesized by hydrothermal technique, using 2-hydroxyphosphonoacetic acid as ligand. Analysis of the single-crystal data reveals that there are one iron(II) ion, one L3- [L = O3PCH(OH)CO2] ligand, and one Na+ ion in the asymmetric unit of (I). Each iron(II) ion is octahedrally coordinated by three phosphonate O atoms from three separate L3- ligands (Fig 1) [the Fe—O distance range from 2.032 (1) to 2.196 (1) Å], two carboxylate O atoms from two separate L3- ligands [the Fe—O bond lengths are 2.143 (1) and 2.185 (1) Å] and one hydroxyl O atom [the Fe—O bond length is 2.272 (1) Å]. These values are close to those reported for other analogous six-coordinated iron(II) phosphonates (Fu et al., 2005). As a result, all the O atoms from the L3- ligand are involved in metal coordination, and act as a monodentate connecting one iron(II) ion. The values of the O—Fe—O angles are in the range 69.39 (5)–171.49 (5)°. The overall structure can be described as a three-dimensional open-framework type with channels running along the a axis (Fig 2).