An oxo-centred trinuclear Fe^III complex: tri­aqua­hexakis([mu]₂-betaine-O:O')-[mu]₃-oxo-triiron(III) bis­(tetra­chloro­manganate) trichloride ­hexahydrate

The title compound, [Fe₃(C₅H₁₁NO₂)₆O(H₂O)₃](MnCl₄)₂Cl₃·6H₂O, contains a triiron core linked by a [mu]₃-bridging oxide ion. Each of the iron(III) ions has a distorted octahedral environment, being coordinated, in addition to the oxide ion, by four neutral betaine mol­ecules and one water mol­ecule. The N-alkyl­ated [alpha]-amino acid betaine is present in the dipolar zwitterionic form and chelates pairs of Fe atoms at the vertices of the triangular [Fe₃O]⁷⁺ ionic core. The Fe complex has a crystallographically imposed D3 symmetry. The water mol­ecules fully exhaust their potential as hydrogen donors, forming a two-dimensional hydrogen-bond network in planes parallel to (001).

S1. Comment

Within a project to study the structure and physical properties of low-dimensional magnetic compounds, we have synthesized the title compound, (I), which contains a trinuclear oxo-bridged complex of Fe^III with the N-substituted α-aminoacid betaine [betaine=trimethylglycine; IUPAC: 1-carboxy-N,N,N-trimethylmethanaminium] as chelating agent. It is well known that betaine chelates p-, d- and 4f-metals via the carboxy group and several crystal structures of coordination compounds of betaine have been reported (Chen & Mak, 1991; Chen et al., 1995). According to a recent search of the Cambridge Structural Database (CSD; release October 2000; Allen & Kennard, 1993), this paper reports the first crystal structure of a coordination compound of iron and betaine. \sch

Trinuclear iron compounds raise a lot of interest because oxo-bridged polynuclear Fe^III centers have been found to perform important biological functions such as oxygen storage and transport in a variety of proteins. These compounds initially attracted interest as a model for the unusual magnetic properties of ferritin, a family of iron-storage proteins that sequester iron inside a protein coat (Holt et al., 1974). The ferric core of ferritin exhibits superparamagnetism (Allen et al., 1998), a magnetic behaviour found in clusters with a large number of magnetic ions, where the thermal dependence of the magnetization in the paramagnetic region is similar to that of a classic ensemble of non-interacting moments. Due to a balance between the magnitude of the pairwise exchange interactions and the size of a given magnetic domain, the available orientations of the magnetic moments may be so close together as to appear continuous. Several studies have shown that not only the magnetic but also the spectroscopic, electronic and structural properties of compounds containing triangular oxo-bridged complexes of transition metal atoms are very interesting (Cannon & White, 1988). In particular, a lot of attention has been paid to mixed-valence trinuclear carboxylate complexes of iron with the general formula [Fe^IIFe^IIIO(R—CO₂)6(L)₃].nS. These complexes are formed with a variety of carboxylate ligands (R—CO₂), monodentate ligands (L), and solvate molecules (S) (Oh et al., 1984; Woehler, Wittebort et al., 1987; Sato et al., 1996). Focus has been put on the interactions among the three iron atoms via the bridging ligands and the kinetics and mechanisms of electron transfer which have been studied by several techniques, including IR spectroscopy, NMR, Mössbauer spectroscopy and neutron diffraction (Cannon et al., 1991).

In mixed-valence iron acetate complexes and mono-oxidized biferrocene derivatives, phase transitions related to valence trapping have been observed at low temperature (Oh et al., 1984). The onset of such transitions appear to involve the cooperative effect of the dynamics of the ligand and/or solvate molecules (Woehler, Wittebort et al., 1987; Cannon et al., 1991). It has been found that the solvate molecules have a dramatic effect on the electron-transfer rate for a given mixed-valence complex, either by affecting the magnitude of the Fe₃O intermolecular interactions, or, in a more subtle way, by lowering the symmetry of the environment around the Fe₃O core (Woehler, Richard et al., 1987). It is well established that in both (Fe^II/Fe^III) mixed-valence and Fe^III compounds, the metal ions in the tri-iron oxo-centered units are antiferromagnetically coupled and spin frustration occurs due to the triangular geometry of the Fe₃O core. An equilateral triangular geometry is unstable and a lower energy is obtained by lifting the degeneracy of the ground state in what has been called a "magnetic Jahn-Teller" effect (Cannon & White, 1988). In several crystallographic studies of carboxylate complexes of oxo-centered trinuclear iron compounds with orthorhombic or monoclinic structures a rather close noncrystallographic threefold symmetry of the complex was found, and in a few reported crystal structures there is an exact, crystallographic imposed, C₃ or even higher D_{3 h} symmetry. However, inelastic neutron scattering experiments performed in two such compounds of trigonal symmetry indicate that the three magnetic coupling constants in the iron core are not equal (Cannon et al., 1994). These inequalities may reflect the expected small structural differences in the metal environment due to the "magnetic Jahn-Teller effect" and it has been argued that the crystal symmetry of these compounds might be higher than the molecular symmetry, and correspond to an average, disordered structure. Therefore, accurate structural data is demanded for this type of compounds in order to understand their electronic and magnetic properties.

In the title compound, the [Fe₃O(BET)₆(H₂O)₃]⁷⁺ cation has a crystallographic imposed D₃ symmetry. The central [Fe₃O]⁷⁺ ion and the oxygen atoms of the coordinating water molecule, trans to the central oxide ion, are strictly planar. Each of the Fe^III ions is coordinated by four betaine molecules, one water molecule and the bridging oxide ion, in a slightly distorted octahedral environment. The complex ion has its charge balanced by three chlorine and two tetrachloromanganese(II) counterions. In addition, the structure contains six solvate water molecules per formula unit. Each pair of Fe^III ions is bridged by two betaine molecules related by a twofold axis via the carboxy groups, one above and another below the Fe₃O plane.

The coordination polyhedron of the iron atoms is slightly distorted from the ideal octahedral geometry, with the iron atom lying 0.1651 (18) Å above the oxygen basal plane. The angles O4—Fe—O1 and O4—Fe—O2 deviate 3.21 (7) and 6.22 (7)°, respectively, from the ideal value of 90°. The distances in the basal plane between the iron and the carboxy oxygen atoms show a significant asymmetry [1.990 (2) and 2.051 (2) Å]. The shortest Fe—Fe distance is 3.3179 (9) Å, a value which is sufficiently large to preclude direct metal-metal bonding. The antiferromagnetic coupling between the moments of the metal ions in such triangular bridged complexes is usually attributed to an indirect exchange mechanism via both the oxide ion and the carboxylate groups. The Fe—O distances are in the range 1.9156 (7)–2.051 (2) Å, the shortest distance being that to the central O^2- ion, which is believed to be the main magnetic superexchange pathway between the Fe atoms (Cannon et al., 1994). The geometry of the inner core of the complex is similar to that in other carboxylate tri-nuclear complexes of Fe^III such as [Fe₃O(OOCCH₃)₆(H₂O)₃]Cl·6H₂O (Anso et al., 1997) and [Fe₃O(C₂H₅O₂N)₆·3(H₂O)₃](ClO₄)₇ (Thundathil et al., 1977).

The betaine molecules are present in the neutral, zwitterionic form, featuring a strong dipole moment due to a tetravalent N atom carrying the positive charge and a negatively charged deprotonated carboxylic group. The carboxylate C–O distances are almost identical with a value typical for a delocalized double bond and an O–C–O angle of 126.8 (3)°. The main skeleton of the betaine molecule defined by atoms C1, C2, N1 and C4 is planar, the deviations of these atoms from the least-squares plane being less than 0.006 (3) Å. The carboxylate group is only slightly rotated from this plane around the C1–C2 bond by 2.9 (5)°. The C3 and C5 methyl groups lie above and below the plane of the skeleton with distances of 1.235 (7) and 1.210 (7) Å, respectively. The small asymmetry corresponds to a slight rotation of ca 1% of the trimethylammonium group around the C2–N1 bond. It is worthwhile mentioning that the value of the C2—N1—C4 angle [105.8 (3)°] is peculiar because it is not only shorter than the ideal tetrahedral value but also much shorter than that observed in pure betaine (Viertorinne et al., 1999), showing the flexibility of the aminoacid molecule in adapting its shape to different crystal environments.

The tetrachloromanganese(II) ion has a crystallographically imposed C3 symmetry, with the Mn and Cl2 atoms lying on the threefold axis. However, it features almost perfect Td symmetry. The maximum deviation of the Cl–Mn–Cl bond angle from the ideal tetrahedral value is 1.08 (4)° and the two symmetry independent Mn–Cl bond lengths are equal within esu and compare well with typical values for this anion.

In addition to the chelating water molecules, the unit cell contains a total of 36 solvent water molecules, corresponding to six solvent molecules per formula unit. Such a high solvent content is not uncommon in this type of compounds which often have water contents as high as ten molecules per formula unit and for which zeolitic behaviour was reported (Cannon & White, 1988). The two symmetry-independent water molecules exhaust their full potential as hydrogen donors, carving a two-dimensional hydrogen-bond network. One of them (O3) lies on a binary axis and donates the hydrogen atoms to two symmetry-related water molecules occupying a general crystallographic position (O5). These water molecules, on their turn, establish hydrogen bonds as donors to the isolated chlorine ions and also to one of the chlorine atoms of the tetrachloromanganate ion (Fig. 2). The resulting hydrogen-bond network extends in planes parallel to (001). It is remarkable that one of the isolated chlorine ions accepts three protons from neighbour water molecules while the other ion does not establish any classical hydrogen bond.

Related literature

For related literature, see: Allen & Kennard (1993); Allen et al. (1998); Anso et al. (1997); Cannon & White (1988); Cannon et al. (1991, 1994); Chen & Mak (1991); Chen et al. (1995); Holt et al. (1974); Oh et al. (1984); Sato et al. (1996); Spek (1995); Thundathil et al. (1977); Viertorinne et al. (1999); Woehler, Richard, Oh, Kambara, Hendrickson, Innisss & Strouse (1987); Woehler, Wittebort, Oh, Kambara, Hendrickson, Inniss & Strouse (1987).

S2. Experimental

Iron chloride hydrated (5 mmol), manganese chloride hydrated (5 mmol) and betaine (20 mmol) were dissolved in an water/ethanol (50:50) solution. Metallic iron (2 mmol) and a few drops of HCl were added to the solution that was further dissolved in warm methanol. After a few months good quality single crystals could be found from the inhomogeneous precipitate.

S3. Refinement

The hydrogen atoms of the water molecules were located in a difference Fourier map and refined with the O—H distances restrained to be equal with an effective e.s.u. of 0.03 Å and with an isotropic displacement parameter constrained to be 1.5 times larger than that of the parent oxygen atom. The remaining hydrogen atoms were placed at calculated positions and refined as riding using the SHELXL97 defaults.

Examination of the crystal structure with PLATON (Spek, 1995) showed that 2% of the unit cell volume (194 ų) is available as additional potential solvent volume, but each of the voids (11 ų) is too small to acoomodate an extra water molecule. All calculations were performed on a Pentium 330 MHz PC running LINUX.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: HELENA (Spek, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. ORTEPII (Johnson, 1976) plot of the title compound. Displacement ellipsoids are drawn at the 50% level.
	Fig. 2. Hydrogen-bond pattern viewed along a.

Triaqua-hexakis-(µ-betaine)-µ₃-oxo- triiron(III) trichloride bis(tetrachloromanganate) hexahydrate

Crystal data

[Fe3(C5H11NO2)6O(H2O)3]Cl3(MnCl4)2·6H2O	Dx = 1.524 Mg m^−3
Mr = 1548.41	Mo Kα radiation, λ = 0.71073 Å
Hexagonal, R3c	Cell parameters from 25 reflections
Hall symbol: -R 3 2"c	θ = 9.9–15.1°
a = 12.5921 (15) Å	µ = 1.49 mm^−1
c = 73.721 (7) Å	T = 293 K
V = 10123 (2) Å^3	Prism, translucent light orange
Z = 6	0.29 × 0.25 × 0.20 mm
F(000) = 4782

Data collection

Enraf-Nonius CAD-4 diffractometer	1499 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.044
Graphite monochromator	θmax = 27.5°, θmin = 1.7°
profile data from ω scans	h = −15→0
Absorption correction: ψ scan (North et al., 1968)	k = −12→16
Tmin = 0.835, Tmax = 0.912	l = −90→94
3330 measured reflections	3 standard reflections every 180 min
2570 independent reflections	intensity decay: 2.5%

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.112	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0573P)^2 + 8.7323P] where P = (Fo^2 + 2Fc^2)/3
2570 reflections	(Δ/σ)max < 0.001
126 parameters	Δρmax = 0.53 e Å^−3
3 restraints	Δρmin = −0.57 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
Fe	0.51454 (5)	0.18120 (5)	0.0833	0.02327 (17)
O1	0.4355 (2)	0.2421 (2)	0.06481 (3)	0.0332 (6)
O2	0.5519 (2)	0.4452 (2)	0.06255 (3)	0.0353 (6)
O3	0.3537 (3)	0.0204 (3)	0.0833	0.0395 (9)
H31	0.326 (4)	−0.042 (3)	0.0760 (5)	0.059*
O4	0.6667	0.3333	0.0833	0.0229 (11)
N1	0.2951 (2)	0.2376 (3)	0.03382 (4)	0.0338 (7)
C1	0.4677 (3)	0.3427 (3)	0.05748 (4)	0.0269 (7)
C2	0.4031 (3)	0.3522 (3)	0.04079 (5)	0.0365 (8)
H2A	0.3762	0.4106	0.0434	0.044*
H2B	0.4629	0.3865	0.0311	0.044*
C3	0.1951 (4)	0.1840 (4)	0.04775 (6)	0.0520 (11)
H3A	0.1236	0.1156	0.0426	0.078*
H3B	0.1754	0.2452	0.0515	0.078*
H3C	0.2221	0.1571	0.0580	0.078*
C4	0.2501 (4)	0.2757 (4)	0.01764 (5)	0.0577 (13)
H4A	0.3158	0.3165	0.0091	0.087*
H4B	0.2221	0.3305	0.0214	0.087*
H4C	0.1837	0.2045	0.0121	0.087*
C5	0.3276 (4)	0.1440 (4)	0.02809 (5)	0.0497 (11)
H5A	0.3901	0.1781	0.0189	0.074*
H5B	0.2562	0.0737	0.0233	0.074*
H5C	0.3575	0.1199	0.0384	0.074*
Mn	0.6667	0.3333	−0.007746 (14)	0.0449 (3)
Cl1	0.50375 (11)	0.36092 (11)	−0.018028 (17)	0.0636 (3)
Cl2	0.6667	0.3333	0.02437 (2)	0.0524 (5)
O5	0.1699 (3)	0.4403 (3)	0.06019 (5)	0.0694 (10)
H51	0.206 (5)	0.509 (4)	0.0668 (8)	0.104*
H52	0.161 (5)	0.470 (5)	0.0500 (6)	0.104*
Cl3	0.0000	0.0000	0.08253 (3)	0.0789 (7)
Cl4	0.0000	0.0000	0.0000	0.0492 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe	0.0256 (3)	0.0256 (3)	0.0193 (3)	0.0134 (3)	0.00114 (13)	−0.00114 (13)
O1	0.0325 (13)	0.0322 (13)	0.0326 (12)	0.0144 (11)	−0.0094 (10)	0.0021 (10)
O2	0.0388 (14)	0.0319 (14)	0.0316 (12)	0.0151 (11)	−0.0142 (11)	−0.0038 (11)
O3	0.0334 (14)	0.0334 (14)	0.040 (2)	0.0074 (18)	0.0070 (9)	−0.0070 (9)
O4	0.0202 (16)	0.0202 (16)	0.028 (3)	0.0101 (8)	0.000	0.000
N1	0.0311 (15)	0.0333 (16)	0.0291 (15)	0.0102 (13)	−0.0111 (12)	−0.0037 (12)
C1	0.0288 (18)	0.0325 (19)	0.0233 (16)	0.0183 (17)	−0.0052 (13)	−0.0016 (14)
C2	0.038 (2)	0.0270 (18)	0.0351 (19)	0.0089 (16)	−0.0152 (15)	−0.0011 (15)
C3	0.032 (2)	0.054 (3)	0.057 (3)	0.012 (2)	0.0051 (18)	0.003 (2)
C4	0.059 (3)	0.056 (3)	0.046 (2)	0.019 (2)	−0.030 (2)	0.000 (2)
C5	0.057 (3)	0.050 (3)	0.043 (2)	0.029 (2)	−0.014 (2)	−0.0172 (19)
Mn	0.0460 (4)	0.0460 (4)	0.0425 (6)	0.0230 (2)	0.000	0.000
Cl1	0.0591 (7)	0.0674 (8)	0.0707 (8)	0.0364 (6)	−0.0031 (6)	0.0132 (6)
Cl2	0.0583 (7)	0.0583 (7)	0.0407 (9)	0.0291 (4)	0.000	0.000
O5	0.064 (2)	0.070 (2)	0.068 (2)	0.029 (2)	0.0169 (18)	0.0101 (19)
Cl3	0.0910 (11)	0.0910 (11)	0.0546 (12)	0.0455 (5)	0.000	0.000
Cl4	0.0351 (8)	0.0351 (8)	0.0774 (18)	0.0175 (4)	0.000	0.000

Geometric parameters (Å, º)

Fe—O4	1.9156 (7)	C2—H2A	0.9700
Fe—O2^i	1.990 (2)	C2—H2B	0.9700
Fe—O2^ii	1.990 (2)	C3—H3A	0.9600
Fe—O3	2.025 (4)	C3—H3B	0.9600
Fe—O1	2.051 (2)	C3—H3C	0.9600
Fe—O1^iii	2.051 (2)	C4—H4A	0.9600
O1—C1	1.245 (4)	C4—H4B	0.9600
O2—C1	1.249 (4)	C4—H4C	0.9600
O2—Fe^iv	1.990 (2)	C5—H5A	0.9600
O3—H31	0.86 (3)	C5—H5B	0.9600
O4—Fe^ii	1.9156 (7)	C5—H5C	0.9600
O4—Fe^iv	1.9157 (7)	Mn—Cl2	2.368 (2)
N1—C5	1.489 (5)	Mn—Cl1	2.3699 (12)
N1—C2	1.494 (4)	Mn—Cl1^ii	2.3699 (12)
N1—C4	1.498 (4)	Mn—Cl1^iv	2.3699 (12)
N1—C3	1.499 (5)	O5—H51	0.89 (3)
C1—C2	1.512 (4)	O5—H52	0.87 (3)
O4—Fe—O2^i	96.22 (7)	N1—C2—H2A	107.8
O4—Fe—O2^ii	96.22 (7)	C1—C2—H2A	107.8
O2^i—Fe—O2^ii	167.57 (14)	N1—C2—H2B	107.8
O4—Fe—O3	180.00 (18)	C1—C2—H2B	107.8
O2^i—Fe—O3	83.78 (7)	H2A—C2—H2B	107.1
O2^ii—Fe—O3	83.78 (7)	N1—C3—H3A	109.5
O4—Fe—O1	93.21 (7)	N1—C3—H3B	109.5
O2^i—Fe—O1	92.22 (10)	H3A—C3—H3B	109.5
O2^ii—Fe—O1	87.09 (10)	N1—C3—H3C	109.5
O3—Fe—O1	86.79 (7)	H3A—C3—H3C	109.5
O4—Fe—O1^iii	93.21 (7)	H3B—C3—H3C	109.5
O2^i—Fe—O1^iii	87.09 (10)	N1—C4—H4A	109.5
O2^ii—Fe—O1^iii	92.22 (10)	N1—C4—H4B	109.5
O3—Fe—O1^iii	86.79 (7)	H4A—C4—H4B	109.5
O1—Fe—O1^iii	173.59 (13)	N1—C4—H4C	109.5
C1—O1—Fe	134.2 (2)	H4A—C4—H4C	109.5
C1—O2—Fe^iv	128.8 (2)	H4B—C4—H4C	109.5
Fe—O3—H31	131 (3)	N1—C5—H5A	109.5
Fe^ii—O4—Fe	120.0	N1—C5—H5B	109.5
Fe^ii—O4—Fe^iv	120.0	H5A—C5—H5B	109.5
Fe—O4—Fe^iv	120.0	N1—C5—H5C	109.5
C5—N1—C2	112.6 (3)	H5A—C5—H5C	109.5
C5—N1—C4	109.0 (3)	H5B—C5—H5C	109.5
C2—N1—C4	105.8 (3)	Cl2—Mn—Cl1	108.65 (4)
C5—N1—C3	109.9 (3)	Cl2—Mn—Cl1^ii	108.65 (4)
C2—N1—C3	110.7 (3)	Cl1—Mn—Cl1^ii	110.28 (4)
C4—N1—C3	108.8 (3)	Cl2—Mn—Cl1^iv	108.65 (4)
O1—C1—O2	126.8 (3)	Cl1—Mn—Cl1^iv	110.28 (4)
O1—C1—C2	121.2 (3)	Cl1^ii—Mn—Cl1^iv	110.28 (4)
O2—C1—C2	112.0 (3)	H51—O5—H52	100 (6)
N1—C2—C1	118.0 (3)
O4—Fe—O1—C1	−6.1 (3)	O3—Fe—O4—Fe^iv	0 (37)
O2^i—Fe—O1—C1	90.2 (3)	O1—Fe—O4—Fe^iv	41.84 (7)
O2^ii—Fe—O1—C1	−102.2 (3)	O1^iii—Fe—O4—Fe^iv	−138.16 (7)
O3—Fe—O1—C1	173.9 (3)	Fe—O1—C1—O2	−16.5 (5)
O1^iii—Fe—O1—C1	173.9 (3)	Fe—O1—C1—C2	164.4 (3)
O2^i—Fe—O4—Fe^ii	129.24 (7)	Fe^iv—O2—C1—O1	1.7 (5)
O2^ii—Fe—O4—Fe^ii	−50.77 (7)	Fe^iv—O2—C1—C2	−179.1 (2)
O3—Fe—O4—Fe^ii	180 (37)	C5—N1—C2—C1	−61.9 (4)
O1—Fe—O4—Fe^ii	−138.18 (7)	C4—N1—C2—C1	179.2 (3)
O1^iii—Fe—O4—Fe^ii	41.82 (7)	C3—N1—C2—C1	61.5 (4)
O2^i—Fe—O4—Fe^iv	−50.75 (7)	O1—C1—C2—N1	2.9 (5)
O2^ii—Fe—O4—Fe^iv	129.25 (7)	O2—C1—C2—N1	−176.3 (3)

Symmetry codes: (i) x−y+1/3, −y+2/3, −z+1/6; (ii) −y+1, x−y, z; (iii) y+1/3, x−1/3, −z+1/6; (iv) −x+y+1, −x+1, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H31···O5^v	0.86 (3)	1.83 (3)	2.690 (4)	178 (4)
O5—H51···Cl3^vi	0.89 (3)	2.23 (4)	3.100 (4)	166 (6)
O5—H52···Cl1^vii	0.87 (3)	2.43 (4)	3.269 (4)	163 (6)

Symmetry codes: (v) −x+y, −x, z; (vi) y+1/3, x+2/3, −z+1/6; (vii) x−y, x, −z.