The title complex, {[Fe(C4H4O4)(H2O)4]}n, is an infinite polymeric compound bridged by the succinate dianion. Two carboxylate groups coordinate in a monodentate manner to the FeII atom, in a trans fashion, with an O—Fe—O bond angle of 175.72 (6)° and Fe—O distances of 2.0886 (14) and 2.1008 (15) Å. One of the uncoordinated carboxylate O atom forms an intramolecular hydrogen bond with a coordinated water molecule. Extensive hydrogen bonding between parallel polymeric complex chains results in a three-dimensional supramolecular structure.
Supporting information
CCDC reference: 201268
An acetonitrile solution (20 ml) containing succinic acid (0.12 g, 1 mmol),
FeCl3·6H2O (0.27 g, 1 mmol) and NaOH (0.08 g, 2 mmol) was refluxed
for 1 h. The resulting dark-yellow solution was cooled to room temperature and
filtered. Orange crystals were obtained from the filtrate after one week.
The methylene H atoms were placed in calculated positions (C—H = 0.97 Å) and
included in the final cycles of refinement as riding, with Uiso(H) =
1.2Ueq of the carrier atom. The H atoms of the coordinated water
molecules were located in a difference Fourier map and were refined with fixed
positional parameters and Uiso(H) values of 0.08 Å2.
Data collection: MSC/AFC Diffractometer Control Software
(Molecular Structure Corporation, 1992); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1985); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994).
Crystal data top
[Fe(C4H4O4)(H2O)4] | F(000) = 504 |
Mr = 243.99 | Dx = 1.929 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71069 Å |
Hall symbol: -P 2ybc | Cell parameters from 20 reflections |
a = 7.4046 (10) Å | θ = 4.5–10.0° |
b = 14.7960 (13) Å | µ = 1.81 mm−1 |
c = 7.7788 (11) Å | T = 298 K |
β = 99.727 (12)° | Prism, orange |
V = 839.98 (18) Å3 | 0.45 × 0.40 × 0.35 mm |
Z = 4 | |
Data collection top
Rigaku AFC-7S diffractometer | 1496 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.018 |
Graphite monochromator | θmax = 26.0°, θmin = 2.8° |
ω/2θ scans | h = 0→9 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→18 |
Tmin = 0.443, Tmax = 0.509 | l = −9→9 |
1778 measured reflections | 3 standard reflections every 150 reflections |
1651 independent reflections | intensity decay: 0.1% |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.027 | H-atom parameters constrained |
wR(F2) = 0.076 | w = 1/[σ2(Fo2) + 0.3528P] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max = 0.001 |
1651 reflections | Δρmax = 0.42 e Å−3 |
119 parameters | Δρmin = −0.79 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.025 (2) |
Crystal data top
[Fe(C4H4O4)(H2O)4] | V = 839.98 (18) Å3 |
Mr = 243.99 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.4046 (10) Å | µ = 1.81 mm−1 |
b = 14.7960 (13) Å | T = 298 K |
c = 7.7788 (11) Å | 0.45 × 0.40 × 0.35 mm |
β = 99.727 (12)° | |
Data collection top
Rigaku AFC-7S diffractometer | 1496 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.018 |
Tmin = 0.443, Tmax = 0.509 | 3 standard reflections every 150 reflections |
1778 measured reflections | intensity decay: 0.1% |
1651 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.027 | 0 restraints |
wR(F2) = 0.076 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.42 e Å−3 |
1651 reflections | Δρmin = −0.79 e Å−3 |
119 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Fe | 0.57091 (4) | 0.644517 (17) | 0.81242 (3) | 0.01580 (14) | |
O1 | 0.3698 (2) | 0.66723 (11) | 0.59398 (18) | 0.0259 (3) | |
O2 | 0.2599 (2) | 0.52946 (10) | 0.53014 (19) | 0.0332 (4) | |
O3 | −0.2376 (2) | 0.62833 (11) | 0.04247 (19) | 0.0276 (3) | |
O4 | 0.0191 (2) | 0.63257 (11) | −0.0694 (2) | 0.0298 (4) | |
O5 | 0.38358 (19) | 0.66013 (10) | 0.98199 (19) | 0.0248 (3) | |
O6 | 0.5205 (2) | 0.50515 (11) | 0.79900 (19) | 0.0332 (4) | |
O7 | 0.7687 (2) | 0.62922 (10) | 0.64283 (19) | 0.0245 (3) | |
O8 | 0.6345 (2) | 0.78344 (10) | 0.82042 (18) | 0.0290 (3) | |
C1 | 0.2663 (3) | 0.61177 (14) | 0.4984 (2) | 0.0215 (4) | |
C2 | 0.1461 (3) | 0.65115 (14) | 0.3387 (3) | 0.0268 (5) | |
H2A | 0.2226 | 0.6842 | 0.2707 | 0.032* | |
H2B | 0.0610 | 0.6937 | 0.3761 | 0.032* | |
C3 | 0.0386 (3) | 0.58003 (14) | 0.2235 (3) | 0.0261 (4) | |
H3A | 0.1227 | 0.5338 | 0.1972 | 0.031* | |
H3B | −0.0475 | 0.5516 | 0.2878 | 0.031* | |
C4 | −0.0660 (3) | 0.61693 (13) | 0.0537 (2) | 0.0208 (4) | |
H51 | 0.3684 | 0.7167 | 1.0231 | 0.080* | |
H52 | 0.2689 | 0.6442 | 0.9477 | 0.080* | |
H61 | 0.4286 | 0.5031 | 0.7072 | 0.080* | |
H62 | 0.5228 | 0.4641 | 0.8756 | 0.080* | |
H71 | 0.7755 | 0.5772 | 0.5920 | 0.080* | |
H72 | 0.8693 | 0.6369 | 0.7262 | 0.080* | |
H81 | 0.6847 | 0.8077 | 0.9245 | 0.080* | |
H82 | 0.6787 | 0.8189 | 0.7387 | 0.080* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Fe | 0.01218 (19) | 0.02061 (19) | 0.01357 (19) | −0.00070 (9) | −0.00082 (12) | 0.00106 (9) |
O1 | 0.0239 (8) | 0.0285 (7) | 0.0216 (7) | −0.0030 (6) | −0.0067 (6) | 0.0010 (6) |
O2 | 0.0394 (9) | 0.0270 (8) | 0.0276 (8) | −0.0027 (7) | −0.0102 (7) | 0.0010 (6) |
O3 | 0.0176 (8) | 0.0446 (9) | 0.0191 (7) | 0.0044 (6) | −0.0008 (6) | 0.0017 (6) |
O4 | 0.0164 (7) | 0.0463 (9) | 0.0258 (8) | −0.0037 (6) | 0.0008 (6) | 0.0029 (6) |
O5 | 0.0152 (7) | 0.0320 (7) | 0.0268 (8) | 0.0004 (6) | 0.0030 (6) | −0.0036 (6) |
O6 | 0.0371 (9) | 0.0261 (8) | 0.0322 (8) | −0.0030 (7) | −0.0062 (7) | 0.0055 (6) |
O7 | 0.0230 (8) | 0.0276 (7) | 0.0220 (7) | 0.0007 (6) | 0.0013 (6) | −0.0010 (5) |
O8 | 0.0372 (9) | 0.0264 (7) | 0.0225 (7) | −0.0084 (7) | 0.0021 (6) | −0.0005 (5) |
C1 | 0.0162 (9) | 0.0288 (10) | 0.0185 (9) | 0.0000 (8) | 0.0005 (7) | −0.0010 (8) |
C2 | 0.0271 (12) | 0.0279 (10) | 0.0221 (10) | 0.0000 (8) | −0.0054 (9) | −0.0008 (7) |
C3 | 0.0212 (10) | 0.0278 (10) | 0.0257 (10) | −0.0016 (8) | −0.0060 (8) | 0.0035 (8) |
C4 | 0.0167 (9) | 0.0222 (9) | 0.0218 (9) | −0.0022 (8) | −0.0013 (7) | −0.0021 (7) |
Geometric parameters (Å, º) top
Fe—O5 | 2.0821 (15) | O6—H62 | 0.85 |
Fe—O1 | 2.0886 (14) | O7—H71 | 0.87 |
Fe—O6 | 2.0951 (16) | O7—H72 | 0.91 |
Fe—O3i | 2.1008 (15) | O8—H81 | 0.91 |
Fe—O8 | 2.1074 (15) | O8—H82 | 0.93 |
Fe—O7 | 2.1424 (16) | C1—C2 | 1.517 (3) |
O1—C1 | 1.273 (3) | C2—C3 | 1.518 (3) |
O2—C1 | 1.245 (3) | C2—H2A | 0.970 |
O3—C4 | 1.269 (3) | C2—H2B | 0.970 |
O4—C4 | 1.254 (2) | C3—C4 | 1.516 (3) |
O5—H51 | 0.91 | C3—H3A | 0.97 |
O5—H52 | 0.88 | C3—H3B | 0.97 |
O6—H61 | 0.90 | | |
| | | |
O5—Fe—O1 | 92.17 (6) | Fe—O7—H72 | 96.4 |
O5—Fe—O6 | 90.50 (6) | H71—O7—H72 | 109.4 |
O1—Fe—O6 | 91.22 (6) | Fe—O8—H81 | 118.0 |
O5—Fe—O3i | 84.21 (6) | Fe—O8—H82 | 129.5 |
O1—Fe—O3i | 175.72 (6) | H81—O8—H82 | 104.5 |
O6—Fe—O3i | 91.10 (6) | O2—C1—O1 | 123.63 (18) |
O5—Fe—O8 | 92.44 (6) | O2—C1—C2 | 120.09 (18) |
O1—Fe—O8 | 89.55 (6) | O1—C1—C2 | 116.28 (18) |
O6—Fe—O8 | 176.94 (6) | C1—C2—C3 | 113.19 (17) |
O3i—Fe—O8 | 88.32 (6) | C1—C2—H2A | 108.9 |
O5—Fe—O7 | 178.66 (5) | C3—C2—H2A | 108.9 |
O1—Fe—O7 | 89.06 (6) | C1—C2—H2B | 108.9 |
O6—Fe—O7 | 89.99 (6) | C3—C2—H2B | 108.9 |
O3i—Fe—O7 | 94.54 (6) | H2A—C2—H2B | 107.8 |
O8—Fe—O7 | 87.05 (6) | C4—C3—C2 | 113.86 (17) |
C1—O1—Fe | 130.35 (14) | C4—C3—H3A | 108.8 |
C4—O3—Feii | 126.69 (14) | C2—C3—H3A | 108.8 |
Fe—O5—H51 | 117.4 | C4—C3—H3B | 108.8 |
Fe—O5—H52 | 119.4 | C2—C3—H3B | 108.8 |
H51—O5—H52 | 100.6 | H3A—C3—H3B | 107.7 |
Fe—O6—H61 | 100.2 | O4—C4—O3 | 123.30 (18) |
Fe—O6—H62 | 133.4 | O4—C4—C3 | 118.90 (18) |
H61—O6—H62 | 117.1 | O3—C4—C3 | 117.78 (18) |
Fe—O7—H71 | 118.1 | | |
| | | |
O5—Fe—O1—C1 | −91.29 (18) | O1—C1—C2—C3 | 175.25 (19) |
O6—Fe—O1—C1 | −0.75 (18) | C1—C2—C3—C4 | −173.67 (18) |
O8—Fe—O1—C1 | 176.29 (18) | Feii—O3—C4—O4 | 15.6 (3) |
O7—Fe—O1—C1 | 89.22 (18) | Feii—O3—C4—C3 | −162.60 (13) |
Fe—O1—C1—O2 | 5.5 (3) | C2—C3—C4—O4 | 78.9 (3) |
Fe—O1—C1—C2 | −174.65 (14) | C2—C3—C4—O3 | −102.8 (2) |
O2—C1—C2—C3 | −4.9 (3) | | |
Symmetry codes: (i) x+1, y, z+1; (ii) x−1, y, z−1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H51···O1iii | 0.91 | 1.80 | 2.706 (2) | 172 |
O5—H52···O4iv | 0.88 | 1.84 | 2.692 (2) | 163 |
O6—H61···O2 | 0.90 | 1.74 | 2.620 (2) | 165 |
O6—H62···O5v | 0.85 | 2.20 | 2.996 (2) | 157 |
O7—H71···O2vi | 0.87 | 1.84 | 2.697 (2) | 169 |
O7—H72···O4i | 0.91 | 1.78 | 2.655 (2) | 161 |
O8—H81···O7iii | 0.91 | 1.95 | 2.847 (2) | 173 |
O8—H82···O3vii | 0.93 | 1.91 | 2.823 (2) | 169 |
Symmetry codes: (i) x+1, y, z+1; (iii) x, −y+3/2, z+1/2; (iv) x, y, z+1; (v) −x+1, −y+1, −z+2; (vi) −x+1, −y+1, −z+1; (vii) x+1, −y+3/2, z+1/2. |
Experimental details
Crystal data |
Chemical formula | [Fe(C4H4O4)(H2O)4] |
Mr | 243.99 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 298 |
a, b, c (Å) | 7.4046 (10), 14.7960 (13), 7.7788 (11) |
β (°) | 99.727 (12) |
V (Å3) | 839.98 (18) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.81 |
Crystal size (mm) | 0.45 × 0.40 × 0.35 |
|
Data collection |
Diffractometer | Rigaku AFC-7S diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.443, 0.509 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1778, 1651, 1496 |
Rint | 0.018 |
(sin θ/λ)max (Å−1) | 0.617 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.076, 1.04 |
No. of reflections | 1651 |
No. of parameters | 119 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.42, −0.79 |
Selected geometric parameters (Å, º) topFe—O5 | 2.0821 (15) | Fe—O7 | 2.1424 (16) |
Fe—O1 | 2.0886 (14) | O1—C1 | 1.273 (3) |
Fe—O6 | 2.0951 (16) | O2—C1 | 1.245 (3) |
Fe—O3i | 2.1008 (15) | O3—C4 | 1.269 (3) |
Fe—O8 | 2.1074 (15) | O4—C4 | 1.254 (2) |
| | | |
O5—Fe—O1 | 92.17 (6) | O1—Fe—O8 | 89.55 (6) |
O1—Fe—O6 | 91.22 (6) | O3i—Fe—O8 | 88.32 (6) |
O5—Fe—O3i | 84.21 (6) | O1—Fe—O7 | 89.06 (6) |
O1—Fe—O3i | 175.72 (6) | O3i—Fe—O7 | 94.54 (6) |
O6—Fe—O3i | 91.10 (6) | | |
Symmetry code: (i) x+1, y, z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H51···O1ii | 0.91 | 1.80 | 2.706 (2) | 172 |
O5—H52···O4iii | 0.88 | 1.84 | 2.692 (2) | 163 |
O6—H61···O2 | 0.90 | 1.74 | 2.620 (2) | 165 |
O6—H62···O5iv | 0.85 | 2.20 | 2.996 (2) | 157 |
O7—H71···O2v | 0.87 | 1.84 | 2.697 (2) | 169 |
O7—H72···O4i | 0.91 | 1.78 | 2.655 (2) | 161 |
O8—H81···O7ii | 0.91 | 1.95 | 2.847 (2) | 173 |
O8—H82···O3vi | 0.93 | 1.91 | 2.823 (2) | 169 |
Symmetry codes: (i) x+1, y, z+1; (ii) x, −y+3/2, z+1/2; (iii) x, y, z+1; (iv) −x+1, −y+1, −z+2; (v) −x+1, −y+1, −z+1; (vi) x+1, −y+3/2, z+1/2. |
The succinate dianion has been used as a bridging ligand in the preparation of multinuclear metal complexes. A variety of bridging modes, including µ2–, µ3– and µ4, has been found (Ng, 1998; Rastsvetaeva et al., 1996; Ng & Kumar Das, 1993). Some recent structure determinations have shown that the coordination mode of the succinate dianion is affected by hydrogen bonding between water and one of the carboxylate group (Liu et al., 2002).
A section of the structure of the title compound, (I), is shown in Fig. 1. Two succinate O atoms, related by the translation symmetry, and four water molecules coordinate to the FeII center with normal octahedral coordination geometry. The succinate carbon skeleton assumes a trans-planar conformation, with a C1—C2—C3—C4 torsion angle of -173.67 (18)°. This skeleton is approximately coplanar with the coordination plane formed by atoms O1, O3i, O6 and O8 [symmetry code: (i) 1 + x, y, 1 + z] and perpendicular to the coordination plane formed by atoms O1, O3i, O5 and O7; the dihedral angles between the succinate carbon skeleton and the two coordination planes are 6.08 (11) and 89.84 (19)°, respectively. The two carboxylate groups of the same succinate dianion are nearly perpendicular to one another [dihedral angle 75.98 (17)°]. One of the carboxylate groups is nearly coplanar with the carbon skeleton [dihedral angle 4.5 (3)°], while the other is nearly perpendicular to it [dihedral angle 79.5 (2)°]. A search in Cambridge Structural Database (Allen, 2002) showed that this perpendicular geometry of the two carboxylate groups is different from the situation in µ2-succinate–metal complexes, including the similar NiII complex tetraaqua(µ2-succinato)nickel(II) (Gupta et al., 1983). Two separate intramolecular hydrogen bonds are observed between the carboxylate groups and coordinated water molecules (Fig. 1), which may be responsible for the nearly perpendicular arrangement of the carboxylate groups.
The succinate dianions act as bridging ligands in the structure, linking neighboring FeII atoms related by translational symmetry to form infinite polymeric complex chains spreading along the [101] direction. Each carboxylate group of the succinate dianion acts is monodentate, perhaps owing to the intramolecular hydrogen bonding between the coordinated carboxylate groups and coordinated water molecules.
An extensive hydrogen-bonding network exists in the crystal structure of (I), involving all carboxylate O atoms. The uncoordinated carboxylate atoms O2 and O4 are involved in the hydrogen bonding, intramolecularly to a neighboring coordinated water molecules, as mentioned above, and intermolecularly to adjacent polymeric chains. The water atoms O5 and O7 act as both donors and acceptors in the hydrogen bonding. The polymeric chains are interlinked via hydrogen bonding, resulting in a three-dimensional supramolecular structure.