Hydrogen bonding and π–π stacking in hexa­aqua­iron(II) bis­(4′,7-dimethoxy­isoflavone-3′-sulfonate) octa­hydrate

In the structure of the title compound, [Fe(H₂O)₆](C₁₇H₁₃O₇S)₂·8H₂O, 16 hydrogen bonds exist between the centrosymmetric [Fe(H₂O)₆]²⁺ cation, the isoflavone-3′-sulfonate anions and the coordinated and solvent water mol­ecules. π–π stacking inter­actions between the isoflavone units, hydrogen bonding and electrostatic inter­actions result in a three-dimensional supramolecular structure.

S1. Comment

Dimethoxydaidzein (4',7-dimethoxyisoflavone) is found mainly in Leguminosae plants, such as Wisteria brachybotrys (Konoshima et al., 1988), the root of Glycyrrhiza pallidiflora Maxim (Fukai et al., 1990) and the fruits of Amorpha fruticosa (Petkov et al., 1983). It has been shown to be pharmacologically active as an inhibitor of phosphodiesterase (Petkov et al., 1983) and of the Epstein–Barr virus (Konoshima et al., 1988). Oka et al. (1989) also found that dimethoxydaidzein can be used to inhibit cancer cells. The biological utilization rate of isoflavonid is low and the dose is high because of its poor solubility. Thus, it is necessary to synthesize a water-soluble derivative of dimethoxydaidzein in order to study its possible biological effects. We have synthesized several derivatives of daidzein, namely sodium 7-methoxy-4'-hydroxyisoflavone-3'-sulfonate (Zhang et al., 2002), sodium 4',7-dihydroxyisoflavone-3'-sulfonate (Zhang et al., 2003) and sodium 5,7-dihydroxy-4',6-dimethoxyisoflavone-3'-sulfonate (Zhang et al., 2004), and have studied their crystal structures and biological activities. The results show that isoflavonesulfonates possess better biological activities than their parent compounds. The title compound, (I), is a water-soluble derivative of isoflavone with potential medical applications.

A molecular representation of the structure of (I) is shown in Fig. 1. The Fe^II atom lies on an inversion centre and is coordinated by six water molecules, which form a slightly distorted octahedron. The Fe—O bond lengths fall in the range 2.043 (3)–2.155 (3) Å, close to those in [Fe(H₂O)₆](C₆H₂N₃O₇)₂·2H₂O and [Fe(H₂O)₆](NO₃)₂·2C₆H₁₂N₄·4H₂O [2.024 (1)–2.164 (2) Å; Honda et al. (2003) and Zhu et al. (2003), respectively].

In the anion, the bond lengths and angles of the isoflavone units are similar to those in the isomorphic compounds [Co(H₂O)₆]X₂·8H₂O (Zhang et al., 2002) and [Ni(H₂O)₆]X₂·8H₂O (Wang & Zhang, 2005) (X is 4',7-dimethoxyisoflavone-3'-sulfonate). The atoms of the benzopyranone moiety containing rings A (C4–C9) and C (C1–C4/C9/O1) display an almost coplanar configuration, with a mean deviation from the least-squares planes of 0.010 (3) Å. To avoid steric conflict, the two rigid ring systems, namely benzene ring B (C10–C15) and the benzopyranone moiety, are rotated by 58.09 (13)° with respect to each other. The methoxy atoms C17 and O4 bonded to atom C13 are nearly coplanar with the attached ring B, with mean deviations from the least-squares plane of 0.013 (4) and 0.012 (3) Å, respectively. Atom O3 of the other methoxy group bonded to atom C7 is nearly coplanar with its attached A/C rings, with a mean out-of-plane deviation of 0.012 (2) Å, while atom C16 of this methoxyl group is slightly out of the plane [0.094 (4) Å].

One hydrogen-bond chain exists between carbonyl atom O2 and the Fe^II-coordinated water molecule O8, bridged by O11—H25···O2, O11—H26···O13, O13—H29···O14 and O8—H20···O14 hydrogen bonds (Fig. 1). Water atom O14 and sulfonate atom O6 are bifurcated and trifurcated, respectively, by hydrogen bonds (Table 2).

The isoflavone skeletons are arranged in an anti-parallel fashion, with π–π stacking interactions between rings A in a column along the b axis (Fig. 2.). A normal range for such interactions is 3.3–3.8 Å (Janiak, 2000). In (I), rings A of the isoflavone skeleton form stacks with Cg···Cgⁱ = 3.683 (2) Å and Cg···Cgⁱⁱ = 3.799 (2) Å, where Cg, Cgⁱ and Cgⁱⁱ are the centroids of rings A at (x, y, z), (1 − x, −y, 2 − z) and (1 − x, 1 − y, 2 − z), respectively. The C16—H16A···O5^vi hydrogen bond [symmetry code: (vi) Please complete] between isoflavone units builds a supramolecular R₂²(28) synthon (Etter, 1990). These isoflavone columns are also cross-linked by a C8—H8···O7^v hydrogen bond [symmetry code: (v) Please complete].

Thus, in the crystal structure of (I), the hydrophilic regions are dominated by classical hydrogen bonds, while the columns of isoflavone moieties generate hydrophobic areas, with the sulfonate group bridging the two regions. This combination of hydrogen bonds, π–π stacking and electrostatic interactions between the cations and anions leads to the formation of a three-dimensional supramolecular structure.

S2. Experimental

Sodium 4',7-dimethoxyisoflavone-3'-sulfonate was synthesized according to the method of Wang & Zhang (2005). Sodium 4',7-dimethoxyisoflavone-3'-sulfonate (1.0 g) was dissolved in water (10 ml) and then mixed with a saturated solution (5 ml) of FeSO₄·7H₂O in Solvent?. Crystals of the title compound were obtained after 1 d. On recrystallization from water, single crystals of (I) suitable for X-ray diffraction analysis were obtained by slow evaporation (m.p. 593 K; decomposes).

S3. Refinement

Water H atoms were located in a difference Fourier map and their positions were refined, with O—H distances in the range 0.72 (4)–0.97 (4) Å. They were constrained with a common U_iso(H) = 0.080 Ų. [Please check added text] All other H atoms were placed in calculated positions and treated as riding, with C—H distances in the range 0.93–0.96 Å and with U_iso(H) = 1.2U_eq(C), or 1.5U_eq(C) for methyl H atoms.

Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SMART; data reduction: SAINT-Plus (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. Thin dashed lines indicate hydrogen bonds. For clarity, the H atoms of the isoflavone skeletons have been omitted.
	Fig. 2. A partial packing diagram for (I), viewed appoximately along the a axis. Thin dashed lines indicate hydrogen bonds and π–π interactions.

Hexaaquairon(II) bis(4',7-dimethoxyisoflavone-3'-sulfonate) octahydrate

Crystal data

[Fe(H2O)6](C17H13O7S)2·8H2O	F(000) = 1080
Mr = 1030.74	Dx = 1.504 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2854 reflections
a = 18.892 (7) Å	θ = 2.4–23.6°
b = 7.336 (3) Å	µ = 0.52 mm^−1
c = 18.357 (7) Å	T = 298 K
β = 116.552 (5)°	Needle, colourless
V = 2275.8 (15) Å^3	0.46 × 0.18 × 0.16 mm
Z = 2

Data collection

Bruker SMART CCD area-detector diffractometer	4000 independent reflections
Radiation source: fine-focus sealed tube	2643 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
ϕ and ω scans	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 1999)	h = −22→19
Tmin = 0.797, Tmax = 0.922	k = −8→8
11468 measured reflections	l = −16→21

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.113	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0498P)^2 + 0.9561P] where P = (Fo^2 + 2Fc^2)/3
4000 reflections	(Δ/σ)max < 0.001
337 parameters	Δρmax = 0.29 e Å^−3
37 restraints	Δρmin = −0.32 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.55831 (12)	0.1756 (3)	0.89512 (12)	0.0455 (6)
O2	0.32825 (13)	0.2899 (4)	0.83678 (13)	0.0590 (7)
O3	0.63099 (14)	0.2406 (3)	1.17776 (13)	0.0585 (7)
O4	0.20929 (13)	0.2127 (3)	0.45852 (12)	0.0460 (6)
O5	0.22848 (14)	0.6887 (3)	0.60148 (13)	0.0558 (7)
O6	0.12787 (13)	0.4958 (3)	0.50765 (15)	0.0575 (7)
O7	0.22723 (14)	0.6130 (3)	0.47266 (13)	0.0536 (6)
O11	0.18072 (15)	0.1818 (3)	0.72658 (15)	0.0556 (7)
O12	0.10666 (18)	0.4873 (5)	0.30998 (17)	0.0711 (9)
S1	0.20970 (5)	0.55516 (11)	0.53763 (5)	0.0383 (2)
C1	0.50141 (18)	0.1791 (5)	0.81726 (18)	0.0438 (8)
H1	0.5168	0.1509	0.7770	0.053*
C2	0.42489 (17)	0.2193 (4)	0.79258 (18)	0.0357 (7)
C3	0.39813 (18)	0.2578 (4)	0.85406 (18)	0.0392 (8)
C4	0.45915 (17)	0.2521 (4)	0.93798 (17)	0.0352 (7)
C5	0.44210 (19)	0.2841 (5)	1.00360 (19)	0.0490 (9)
H5	0.3904	0.3091	0.9939	0.059*
C6	0.5004 (2)	0.2792 (5)	1.0815 (2)	0.0522 (9)
H6	0.4882	0.3012	1.1245	0.063*
C7	0.57855 (19)	0.2414 (4)	1.09754 (19)	0.0430 (8)
C8	0.59740 (18)	0.2068 (4)	1.03452 (18)	0.0409 (8)
H8	0.6491	0.1805	1.0445	0.049*
C9	0.53676 (18)	0.2123 (4)	0.95578 (18)	0.0361 (7)
C10	0.36767 (17)	0.2146 (4)	0.70502 (17)	0.0337 (7)
C11	0.32168 (16)	0.3664 (4)	0.66634 (17)	0.0343 (7)
H11	0.3264	0.4720	0.6962	0.041*
C12	0.26918 (16)	0.3625 (4)	0.58447 (17)	0.0306 (7)
C13	0.26148 (17)	0.2054 (4)	0.53842 (18)	0.0332 (7)
C14	0.30607 (18)	0.0535 (4)	0.57656 (18)	0.0388 (8)
H14	0.3013	−0.0525	0.5469	0.047*
C15	0.35776 (18)	0.0590 (4)	0.65871 (18)	0.0390 (8)
H15	0.3867	−0.0448	0.6836	0.047*
C16	0.7118 (2)	0.2118 (6)	1.1984 (2)	0.0683 (12)
H16A	0.7423	0.2146	1.2565	0.102*
H16B	0.7300	0.3060	1.1745	0.102*
H16C	0.7180	0.0953	1.1781	0.102*
C17	0.1978 (2)	0.0536 (5)	0.4097 (2)	0.0592 (10)
H17A	0.1596	0.0790	0.3547	0.089*
H17B	0.1789	−0.0442	0.4311	0.089*
H17C	0.2471	0.0191	0.4103	0.089*
H25	0.230 (2)	0.202 (5)	0.758 (2)	0.080*
H26	0.156 (2)	0.272 (6)	0.706 (2)	0.080*
H27	0.134 (2)	0.433 (6)	0.288 (2)	0.080*
H28	0.135 (3)	0.500 (6)	0.353 (3)	0.080*
Fe1	0.0000	1.0000	0.5000	0.0421 (2)
O8	−0.04029 (18)	0.8245 (5)	0.55955 (18)	0.0792 (10)
O10	0.11841 (14)	0.9613 (4)	0.59238 (16)	0.0578 (7)
H19	−0.072 (2)	0.743 (5)	0.540 (2)	0.080*
H20	−0.027 (3)	0.817 (6)	0.605 (2)	0.080*
H23	0.142 (2)	1.027 (5)	0.634 (2)	0.080*
H24	0.153 (2)	0.883 (6)	0.591 (2)	0.080*
O9	0.01432 (17)	0.7765 (4)	0.43155 (19)	0.0781 (10)
H21	0.053 (2)	0.712 (6)	0.452 (2)	0.080*
H22	−0.020 (2)	0.708 (6)	0.416 (3)	0.080*
O13	0.1013 (2)	0.4825 (5)	0.6551 (2)	0.0801 (10)
H29	0.087 (2)	0.590 (5)	0.678 (2)	0.080*
H30	0.112 (3)	0.523 (6)	0.626 (3)	0.080*
O14	0.0310 (2)	0.7164 (5)	0.7174 (2)	0.0861 (10)
H31	0.061 (2)	0.797 (6)	0.762 (2)	0.080*
H32	−0.005 (2)	0.658 (6)	0.729 (2)	0.080*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0325 (12)	0.0692 (16)	0.0332 (12)	0.0088 (10)	0.0134 (10)	0.0024 (11)
O2	0.0309 (13)	0.094 (2)	0.0479 (14)	0.0075 (12)	0.0141 (11)	−0.0103 (13)
O3	0.0573 (16)	0.0711 (17)	0.0364 (14)	0.0044 (13)	0.0113 (12)	0.0004 (12)
O4	0.0552 (14)	0.0364 (13)	0.0344 (12)	0.0041 (10)	0.0095 (11)	−0.0033 (10)
O5	0.0733 (17)	0.0374 (13)	0.0452 (13)	0.0178 (12)	0.0163 (12)	−0.0062 (11)
O6	0.0348 (13)	0.0469 (14)	0.0790 (17)	0.0084 (10)	0.0148 (12)	0.0055 (12)
O7	0.0711 (16)	0.0447 (14)	0.0506 (14)	0.0098 (12)	0.0323 (12)	0.0149 (11)
O11	0.0423 (15)	0.0578 (17)	0.0544 (16)	−0.0009 (12)	0.0105 (12)	−0.0049 (13)
O12	0.068 (2)	0.090 (2)	0.0506 (17)	0.0126 (16)	0.0218 (14)	0.0034 (17)
S1	0.0381 (5)	0.0316 (4)	0.0410 (5)	0.0055 (3)	0.0140 (4)	0.0023 (4)
C1	0.044 (2)	0.053 (2)	0.0348 (18)	0.0030 (16)	0.0184 (15)	0.0037 (15)
C2	0.0339 (17)	0.0365 (18)	0.0359 (17)	0.0013 (13)	0.0147 (14)	0.0026 (14)
C3	0.0331 (18)	0.0418 (19)	0.0412 (19)	−0.0008 (14)	0.0152 (15)	−0.0007 (15)
C4	0.0339 (17)	0.0367 (18)	0.0344 (17)	0.0019 (13)	0.0149 (14)	−0.0009 (14)
C5	0.041 (2)	0.061 (2)	0.048 (2)	0.0050 (16)	0.0221 (17)	−0.0041 (17)
C6	0.060 (2)	0.061 (2)	0.039 (2)	0.0037 (18)	0.0250 (18)	−0.0065 (17)
C7	0.047 (2)	0.0393 (19)	0.0363 (19)	0.0002 (15)	0.0129 (16)	0.0019 (15)
C8	0.0335 (17)	0.0433 (19)	0.0395 (19)	0.0034 (14)	0.0107 (15)	0.0023 (15)
C9	0.0412 (18)	0.0316 (17)	0.0372 (18)	0.0014 (13)	0.0191 (15)	0.0027 (14)
C10	0.0318 (16)	0.0337 (17)	0.0363 (17)	−0.0009 (13)	0.0159 (13)	0.0011 (14)
C11	0.0338 (16)	0.0305 (16)	0.0385 (17)	−0.0004 (13)	0.0163 (14)	−0.0054 (14)
C12	0.0302 (16)	0.0291 (16)	0.0363 (17)	0.0016 (12)	0.0183 (13)	0.0024 (13)
C13	0.0314 (16)	0.0323 (17)	0.0369 (17)	−0.0016 (13)	0.0163 (14)	0.0024 (14)
C14	0.0444 (19)	0.0296 (17)	0.0438 (19)	0.0004 (14)	0.0210 (15)	−0.0054 (14)
C15	0.0393 (18)	0.0328 (17)	0.0409 (19)	0.0071 (14)	0.0144 (15)	0.0034 (15)
C16	0.055 (2)	0.084 (3)	0.045 (2)	0.013 (2)	0.0039 (18)	0.010 (2)
C17	0.072 (3)	0.049 (2)	0.045 (2)	0.0003 (18)	0.0150 (19)	−0.0101 (17)
Fe1	0.0322 (4)	0.0379 (4)	0.0474 (4)	0.0018 (3)	0.0098 (3)	−0.0041 (3)
O8	0.0641 (19)	0.087 (2)	0.0697 (19)	−0.0291 (15)	0.0148 (17)	0.0081 (19)
O10	0.0348 (14)	0.0595 (17)	0.0581 (16)	0.0106 (11)	0.0019 (12)	−0.0199 (12)
O9	0.0524 (18)	0.068 (2)	0.082 (2)	0.0201 (14)	0.0011 (16)	−0.0260 (16)
O13	0.085 (2)	0.076 (2)	0.094 (3)	0.0157 (17)	0.0536 (19)	0.0141 (18)
O14	0.099 (3)	0.082 (2)	0.088 (2)	−0.0217 (18)	0.051 (2)	−0.0146 (18)

Geometric parameters (Å, º)

O1—C1	1.351 (3)	C10—C11	1.395 (4)
O1—C9	1.372 (3)	C11—C12	1.382 (4)
O2—C3	1.235 (3)	C11—H11	0.9300
O3—C7	1.359 (4)	C12—C13	1.398 (4)
O3—C16	1.416 (4)	C13—C14	1.383 (4)
O4—C13	1.354 (3)	C14—C15	1.383 (4)
O4—C17	1.428 (4)	C14—H14	0.9300
O5—S1	1.445 (2)	C15—H15	0.9300
O6—S1	1.457 (2)	C16—H16A	0.9600
O7—S1	1.437 (2)	C16—H16B	0.9600
O11—H25	0.87 (4)	C16—H16C	0.9600
O11—H26	0.80 (4)	C17—H17A	0.9600
O12—H27	0.87 (4)	C17—H17B	0.9600
O12—H28	0.73 (4)	C17—H17C	0.9600
S1—C12	1.771 (3)	Fe1—O8^i	2.043 (3)
C1—C2	1.340 (4)	Fe1—O8	2.043 (3)
C1—H1	0.9300	Fe1—O10	2.138 (2)
C2—C3	1.456 (4)	Fe1—O10^i	2.138 (2)
C2—C10	1.483 (4)	Fe1—O9^i	2.155 (3)
C3—C4	1.455 (4)	Fe1—O9	2.155 (3)
C4—C9	1.383 (4)	O8—H19	0.80 (2)
C4—C5	1.399 (4)	O8—H20	0.76 (4)
C5—C6	1.361 (4)	O10—H23	0.84 (4)
C5—H5	0.9300	O10—H24	0.88 (4)
C6—C7	1.397 (5)	O9—H21	0.81 (4)
C6—H6	0.9300	O9—H22	0.77 (4)
C7—C8	1.378 (4)	O13—H29	0.99 (4)
C8—C9	1.387 (4)	O13—H30	0.72 (4)
C8—H8	0.9300	O14—H31	0.97 (4)
C10—C15	1.385 (4)	O14—H32	0.90 (4)
C1—O1—C9	118.1 (2)	O4—C13—C14	124.3 (3)
C7—O3—C16	117.8 (3)	O4—C13—C12	116.8 (2)
C13—O4—C17	118.7 (2)	C14—C13—C12	118.9 (3)
H25—O11—H26	114 (4)	C15—C14—C13	120.1 (3)
H27—O12—H28	104 (5)	C15—C14—H14	119.9
O7—S1—O5	114.14 (15)	C13—C14—H14	119.9
O7—S1—O6	111.97 (15)	C14—C15—C10	122.0 (3)
O5—S1—O6	110.10 (15)	C14—C15—H15	119.0
O7—S1—C12	107.89 (13)	C10—C15—H15	119.0
O5—S1—C12	105.95 (13)	O3—C16—H16A	109.5
O6—S1—C12	106.29 (13)	O3—C16—H16B	109.5
C2—C1—O1	126.1 (3)	H16A—C16—H16B	109.5
C2—C1—H1	116.9	O3—C16—H16C	109.5
O1—C1—H1	116.9	H16A—C16—H16C	109.5
C1—C2—C3	118.4 (3)	H16B—C16—H16C	109.5
C1—C2—C10	121.0 (3)	O4—C17—H17A	109.5
C3—C2—C10	120.5 (3)	O4—C17—H17B	109.5
O2—C3—C4	121.8 (3)	H17A—C17—H17B	109.5
O2—C3—C2	122.7 (3)	O4—C17—H17C	109.5
C4—C3—C2	115.5 (3)	H17A—C17—H17C	109.5
C9—C4—C5	117.4 (3)	H17B—C17—H17C	109.5
C9—C4—C3	120.7 (3)	O8^i—Fe1—O8	180.000 (1)
C5—C4—C3	121.9 (3)	O8^i—Fe1—O10	90.02 (12)
C6—C5—C4	120.7 (3)	O8—Fe1—O10	89.98 (12)
C6—C5—H5	119.7	O8^i—Fe1—O10^i	89.98 (12)
C4—C5—H5	119.7	O8—Fe1—O10^i	90.02 (12)
C5—C6—C7	120.6 (3)	O10—Fe1—O10^i	180.000 (1)
C5—C6—H6	119.7	O8^i—Fe1—O9^i	90.37 (15)
C7—C6—H6	119.7	O8—Fe1—O9^i	89.63 (15)
O3—C7—C8	124.9 (3)	O10—Fe1—O9^i	89.90 (10)
O3—C7—C6	114.8 (3)	O10^i—Fe1—O9^i	90.10 (10)
C8—C7—C6	120.3 (3)	O8^i—Fe1—O9	89.63 (15)
C7—C8—C9	117.8 (3)	O8—Fe1—O9	90.37 (15)
C7—C8—H8	121.1	O10—Fe1—O9	90.10 (10)
C9—C8—H8	121.1	O10^i—Fe1—O9	89.90 (10)
O1—C9—C4	121.1 (3)	O9^i—Fe1—O9	180.000 (1)
O1—C9—C8	115.7 (3)	Fe1—O8—H19	127 (3)
C4—C9—C8	123.2 (3)	Fe1—O8—H20	128 (4)
C15—C10—C11	117.6 (3)	H19—O8—H20	105 (5)
C15—C10—C2	121.1 (3)	Fe1—O10—H23	126 (3)
C11—C10—C2	121.3 (3)	Fe1—O10—H24	127 (2)
C12—C11—C10	121.2 (3)	H23—O10—H24	107 (4)
C12—C11—H11	119.4	Fe1—O9—H21	120 (3)
C10—C11—H11	119.4	Fe1—O9—H22	114 (3)
C11—C12—C13	120.3 (3)	H21—O9—H22	104 (4)
C11—C12—S1	120.2 (2)	H29—O13—H30	103 (5)
C13—C12—S1	119.5 (2)	H31—O14—H32	108 (4)

Symmetry code: (i) −x, −y+2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O11—H25···O2	0.87 (4)	1.88 (4)	2.729 (3)	166 (4)
O11—H26···O13	0.80 (4)	1.86 (4)	2.661 (4)	178 (5)
O12—H27···O11^ii	0.87 (4)	1.92 (4)	2.785 (4)	172 (4)
O12—H28···O7	0.73 (4)	2.27 (4)	2.979 (4)	165 (5)
O8—H19···O6^iii	0.80 (2)	2.03 (3)	2.820 (4)	166 (4)
O8—H20···O14	0.76 (4)	1.99 (4)	2.711 (4)	157 (5)
O9—H21···O6	0.81 (4)	2.06 (4)	2.849 (3)	162 (4)
O9—H22···O13^iii	0.77 (4)	2.05 (4)	2.794 (5)	161 (5)
O10—H23···O11^iv	0.84 (4)	1.90 (4)	2.735 (4)	172 (4)
O10—H24···O5	0.88 (4)	1.96 (4)	2.836 (3)	172 (4)
O13—H29···O14	0.99 (4)	1.78 (4)	2.716 (5)	156 (3)
O13—H30···O6	0.72 (4)	2.33 (4)	2.966 (4)	149 (5)
O14—H31···O12^v	0.97 (4)	1.83 (4)	2.736 (4)	156 (3)
O14—H32···O12^iii	0.90 (4)	2.03 (4)	2.843 (5)	149 (4)
C8—H8···O7^vi	0.93	2.54	3.444 (5)	164
C16—H16A···O5^vii	0.96	2.51	3.405 (4)	155

Symmetry codes: (ii) x, −y+1/2, z−1/2; (iii) −x, −y+1, −z+1; (iv) x, y+1, z; (v) x, −y+3/2, z+1/2; (vi) −x+1, y−1/2, −z+3/2; (vii) −x+1, −y+1, −z+2.