catena-Poly[[[aqua­[3-(2-pyridyl­sulfanyl)propionato N-oxide-[kappa]O¹]copper(II)]-[mu]-[3-(2-pyridylsulfanyl)­propionato N-oxide-[kappa]³O³:O¹,O^1'] dihydrate]

In the title complex, {[Cu(C₈H₈NO₃S)₂(H₂O)]·2H₂O}_n, the Cu^II cation has a distorted square-pyramidal coordination environment consisting of five O atoms, one from a water mol­ecule, one from an N-O group and the other three from the carboxylate groups of two 3-(2-pyridylsulfanyl)propionate N-oxide anions. The aqua­[3-(2-pyridylsulfanyl)propionato N-oxide]copper(II) moieties are bridged by 3-(2-pyridyl­sulfanyl)­propionate N-oxide anions to form an infinite three-dimensional coordination polymer with a zigzag chain structure. The crystal structure is stabilized by hydrogen bonds.

S1. Comment

In recent years, intense research activity has been directed towards the design and construction of novel coordination polymers based on covalent interactions (Fujita et al., 1994) or supramolecular contacts, such as hydrogen bonds and π–π stacking interactions (Desiraju, 1995). They are of interest not only due to their fascinating structures, but also because of their unexpected properties for potential application in areas such as gas adsorption, catalysis and optoelectronic devices (Matsumoto et al., 1999; Chui et al., 1999). The key step in the design of coordination polymers is to select suitable multidentate bridging ligands and spacers. Many pyridine-based carboxylate ligands (Kumaresan et al., 2006; Hussain, 1996; Fariati et al., 1998) have been used to obtain coordination polymers but, to the best of our knowledge, very little is known about the coordination chemistry of 1-oxopyridinium-2-thiopropionic acid, HOPTP (Ramasubramanian et al., 2007). The HOPTP ligand possesses several features. It is a polydentate ligand with up to four donor atoms. The N-oxide group has proved to be more versatile in its coordination mode than the pyridine, because the lone pairs of the O atom of the N-oxide provide more coordination flexibility than the N atom of the pyridine, which affords only a straight coordination geometry. Steric hindrance is much smaller for N-oxide and, in addition, it has the capability of forming hydrogen bonds. Finally, some N-oxides possess important antimicrobial activity (Danish & Rajendraprasad, 2003) and they are also recognized as potential DNA-cleaving agents (Ganley et al., 2001). In view of the above facts and our interest in the synthesis and characterization of coordination complexes, we report here the synthesis and single-crystal characterization of the title complex, (I).

Complex (I) is a one-dimensional polymer, the dimeric units [Cu(C₈H₈O₃NS)(H₂O)]⁺ and [C₈H₈O₃NS]^- being the elemental links that define the chain structure. The Cu^II metal centre is strongly bonded to four O atoms and weakly bonded to a fifth O atom, displaying a distorted square-pyramidal geometry, as evidenced by the bond angles around atom Cu1 (Fig. 1, Table 1): the dihedral angle between the planes of O1/Cu1/O2(-x + 2, y + 1/2, -z + 1/2) and O5/Cu1/O7 is 49.66 (8)°. The O atoms involved in the coordination of the Cu^II ion belong to the [C₈H₈O₃NS]^- anions (O2, O3 and O5), the pyridine N-oxide (O1) and the water molcule (O7) (Fig. 1). Two water molecules (O8 and O9) are left uncoordinated in the crystal structure.

An infinite three-dimensional coordination polymer with a zigzag chain structure is formed by the Cu^II cations, µ₃-bridging and terminal OPTP^- anions, and one terminal water molecule (Fig. 2). The Cu—O carboxylate bond lengths are in the range 1.914 (2)–2.755 (1) Å (Table 1), within which the semi-coordinating Cu1—O3 distance [2.755 (1) Å] is considerably longer than the Cu—O distance reported earlier (2.010 Å; Zou et al., 1998), while the Cu1—O5 distance of 1.914 (2) Å is shorter than the normal literature value (1.927 Å; Hu et al., 2003). The pyridine N-oxide rings are non-planar. The puckering parameters (ϕ₂, θ₂ and Q; Cremer & Pople, 1975) for the rings N1/C1–C5 and N2/C9–C13 indicate that these rings are in envelope (⁵E) and half-chair (⁵H₄) conformations, respectively.

Overall, the structure of (I) does not depart from what might be expected, but its most interesting feature is its self-assembly into a three-dimensional structure. This process is achieved through a dense network of C—H···O hydrogen bonds involving most of the available H atoms of the [Cu(C₈H₈O₃NS)(H₂O)]⁺ units and only one H atom of the [C₈H₈O₃NS]^- units (Table 2). The two solvent water molecules interlink neighbouring [Cu(C₈H₈O₃NS)(H₂O)]⁺ units through O—H···O hydrogen-bond interactions (Table 2). The O atom of the coordinated water molecule (O7) is involved in intermolecular hydrogen-bond interactions with the N—O group of the OPTP^- ion and with solvent water molecule O9. These interactions stabilize the crystal packing (Fig. 2). On the whole, the network of C—H···O and O—H···O hydrogen bonds can be described by Etter's hydrogen-bond notation (Etter, 1990) as R₂²(22), R₆⁸(30), R₃³(28), R₃²(11), R₂²(19) and R₂²(18). Among these, the two adjacent hydrogen-bonded rings R₂²(22) and R₆⁸(30) form an infinite ladder in the crystal structure via O—H···O interactions.

Related literature

For related literature, see: Chui et al. (1999); Cremer & Pople (1975); Danish & Rajendraprasad (2003); Desiraju (1995); Etter (1990); Fariati, Craig & Phillips (1998); Fujita et al. (1994); Ganley et al. (2001); Hu et al. (2003); Hussain (1996); Kumaresan et al. (2006); Matsumoto et al. (1999); Ramasubramanian et al. (2007); Zou et al. (1998).

S2. Experimental

A mixture of CuSO₄·5H₂O (0.0624 g, 0.25 mmol), HOPTP (0.0995 g, 0.50 mmol) and NaOH (0.040 g, 0.50 mmol) in ethanol (20 ml) was stirred for 10 h at room temperature. The stirred solution was filtered and kept for slow evaporation. After a week, peacock-blue coloured [Red in CIF - please clarify] crystalline blocks of [Cu(C₈H₈O₃NS)₂(H₂O)]_n.2nH₂O appeared. The crystals were collected by filtration, washed with deionized water followed by diethyl ether, and then dried (yield 0.090 g, 70%).

S3. Refinement

Water H atoms were located and refined subject to O—H distance restraints of 0.82 (1) Å. The remaining H atoms were refined using a riding model, with C—H = 0.97 Å and U_iso(H) = 1.5U_eq(C) for idealized secondary CH₂, and with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C) for aromatic C—H.

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2004); software used to prepare material for publication: SHELXTL (Bruker, 2004).

Figures

	Fig. 1. A view of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level and H atoms are shown as small spheres of arbitrary radii. [Symmetry codes: (i) -x + 2, y - 1/2, -z - 1/2; (ii)-x + 2, y + 1/2, -z + 1/2.]
	Fig. 2. A perspective view of the hydrogen bonding in (I). Dashed lines indicate O—H···O and C—H···O interactions.

catena-Poly[[[aqua[3-(2-pyridylsulfanyl)propionato N-oxide-κO¹]copper(II)]-µ-[3-(2-pyridylsulfanyl)propionato N-oxide-κ³O³:O¹,O^1'] dihydrate]

Crystal data

[Cu(C8H8NO3S)2(H2O)]·2H2O	F(000) = 1060
Mr = 514.02	Dx = 1.632 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5123 reflections
a = 6.9091 (5) Å	θ = 2.3–25.0°
b = 8.6855 (7) Å	µ = 1.30 mm^−1
c = 34.899 (3) Å	T = 298 K
β = 92.974 (1)°	Block, blue
V = 2091.4 (3) Å^3	0.36 × 0.22 × 0.14 mm
Z = 4

Data collection

Bruker APEX CCD area-detector diffractometer	3769 independent reflections
Radiation source: fine-focus sealed tube	3567 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
ϕ and ω scans	θmax = 25.2°, θmin = 1.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −8→7
Tmin = 0.653, Tmax = 0.839	k = −10→9
10850 measured reflections	l = −41→41

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.19	w = 1/[σ^2(Fo^2) + (0.0548P)^2 + 2.1602P] where P = (Fo^2 + 2Fc^2)/3
3769 reflections	(Δ/σ)max = 0.001
289 parameters	Δρmax = 0.78 e Å^−3
9 restraints	Δρmin = −0.28 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
Cu1	0.95692 (6)	0.87437 (5)	0.147830 (11)	0.02869 (15)
S1	0.98543 (13)	0.81422 (11)	0.25851 (2)	0.0345 (2)
S2	0.76836 (14)	0.34348 (12)	0.01097 (3)	0.0420 (2)
O1	0.8147 (4)	0.7737 (3)	0.18764 (7)	0.0375 (6)
O2	1.0496 (3)	0.5728 (3)	0.32722 (7)	0.0324 (5)
O3	1.2928 (4)	0.6147 (3)	0.36954 (8)	0.0489 (7)
O4	0.7569 (4)	0.1764 (4)	−0.05276 (9)	0.0627 (9)
O5	0.9776 (3)	0.6844 (3)	0.12055 (7)	0.0366 (6)
O6	0.6608 (4)	0.6647 (3)	0.10854 (8)	0.0448 (6)
O7	1.1583 (5)	0.9511 (3)	0.11680 (9)	0.0617 (9)
O8	0.6717 (4)	0.0348 (4)	0.36558 (11)	0.0641 (9)
O9	0.6673 (5)	0.7248 (4)	0.38212 (12)	0.0692 (10)
N1	0.7013 (4)	0.8632 (3)	0.20840 (8)	0.0319 (6)
N2	0.5847 (4)	0.1671 (4)	−0.03813 (9)	0.0377 (7)
C1	0.7630 (5)	0.8959 (4)	0.24509 (9)	0.0294 (7)
C2	0.6413 (5)	0.9823 (4)	0.26747 (10)	0.0359 (8)
H2	0.6795	1.0070	0.2927	0.043*
C3	0.4645 (6)	1.0307 (4)	0.25203 (12)	0.0428 (9)
H3	0.3823	1.0870	0.2670	0.051*
C4	0.4081 (5)	0.9958 (5)	0.21415 (12)	0.0456 (9)
H4	0.2898	1.0304	0.2035	0.055*
C5	0.5277 (6)	0.9106 (4)	0.19292 (11)	0.0413 (9)
H5	0.4905	0.8848	0.1677	0.050*
C6	1.0202 (5)	0.8859 (4)	0.30723 (10)	0.0348 (8)
H6A	1.0299	0.9973	0.3070	0.042*
H6B	0.9102	0.8577	0.3219	0.042*
C7	1.2059 (5)	0.8166 (4)	0.32586 (11)	0.0368 (8)
H7A	1.3028	0.8117	0.3068	0.044*
H7B	1.2546	0.8852	0.3461	0.044*
C8	1.1821 (5)	0.6575 (4)	0.34270 (10)	0.0318 (7)
C9	0.5595 (5)	0.2460 (4)	−0.00514 (10)	0.0330 (8)
C10	0.3816 (5)	0.2391 (4)	0.01102 (11)	0.0424 (9)
H10	0.3618	0.2925	0.0336	0.051*
C11	0.2331 (6)	0.1534 (5)	−0.00615 (13)	0.0481 (10)
H11	0.1131	0.1489	0.0047	0.058*
C12	0.2640 (6)	0.0752 (5)	−0.03926 (13)	0.0484 (10)
H12	0.1653	0.0161	−0.0509	0.058*
C13	0.4397 (6)	0.0839 (5)	−0.05510 (11)	0.0450 (9)
H13	0.4597	0.0320	−0.0779	0.054*
C14	0.6951 (5)	0.4274 (4)	0.05541 (10)	0.0383 (8)
H14A	0.5920	0.5017	0.0504	0.046*
H14B	0.6489	0.3482	0.0723	0.046*
C15	0.8727 (5)	0.5056 (4)	0.07359 (11)	0.0395 (8)
H15A	0.9434	0.5546	0.0536	0.047*
H15B	0.9566	0.4280	0.0856	0.047*
C16	0.8265 (5)	0.6255 (4)	0.10336 (9)	0.0310 (7)
H7C	1.192 (5)	1.042 (2)	0.1184 (9)	0.037*
H7D	1.184 (5)	0.911 (3)	0.0958 (7)	0.037*
H9C	0.556 (3)	0.696 (4)	0.3784 (11)	0.037*
H9D	0.691 (5)	0.814 (2)	0.3799 (12)	0.037*
H8C	0.567 (3)	0.071 (4)	0.3727 (10)	0.037*
H8D	0.767 (3)	0.079 (4)	0.3772 (10)	0.037*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0300 (2)	0.0272 (2)	0.0287 (2)	0.00117 (15)	0.00023 (17)	−0.00681 (16)
S1	0.0336 (5)	0.0378 (5)	0.0319 (5)	0.0097 (4)	0.0008 (4)	−0.0004 (4)
S2	0.0402 (5)	0.0477 (6)	0.0386 (5)	−0.0093 (4)	0.0063 (4)	−0.0179 (4)
O1	0.0514 (15)	0.0292 (12)	0.0325 (12)	0.0044 (11)	0.0086 (11)	−0.0012 (10)
O2	0.0381 (13)	0.0258 (12)	0.0332 (12)	−0.0046 (10)	−0.0001 (10)	0.0067 (10)
O3	0.0509 (17)	0.0465 (16)	0.0475 (16)	−0.0011 (13)	−0.0144 (13)	0.0155 (13)
O4	0.0521 (18)	0.085 (2)	0.0533 (18)	−0.0226 (16)	0.0200 (14)	−0.0373 (17)
O5	0.0335 (13)	0.0324 (13)	0.0443 (14)	−0.0013 (10)	0.0050 (11)	−0.0165 (11)
O6	0.0346 (15)	0.0496 (16)	0.0504 (16)	0.0034 (12)	0.0037 (12)	−0.0125 (13)
O7	0.077 (2)	0.0455 (17)	0.067 (2)	−0.0287 (16)	0.0422 (17)	−0.0309 (16)
O8	0.0381 (17)	0.0564 (19)	0.098 (3)	−0.0045 (14)	0.0092 (17)	−0.0187 (18)
O9	0.0418 (17)	0.0453 (18)	0.120 (3)	0.0050 (14)	0.0011 (19)	0.010 (2)
N1	0.0378 (16)	0.0302 (15)	0.0279 (14)	−0.0017 (12)	0.0042 (12)	−0.0003 (12)
N2	0.0394 (17)	0.0399 (17)	0.0339 (16)	−0.0025 (13)	0.0020 (13)	−0.0073 (14)
C1	0.0316 (18)	0.0247 (16)	0.0321 (17)	0.0002 (13)	0.0024 (14)	0.0038 (14)
C2	0.039 (2)	0.0338 (19)	0.0348 (18)	0.0041 (15)	0.0048 (15)	0.0012 (15)
C3	0.040 (2)	0.039 (2)	0.051 (2)	0.0049 (16)	0.0131 (18)	0.0031 (18)
C4	0.031 (2)	0.052 (2)	0.054 (2)	0.0031 (17)	−0.0032 (18)	0.011 (2)
C5	0.041 (2)	0.044 (2)	0.038 (2)	−0.0051 (17)	−0.0052 (16)	0.0084 (17)
C6	0.044 (2)	0.0258 (17)	0.0339 (18)	0.0040 (15)	−0.0025 (16)	−0.0006 (14)
C7	0.041 (2)	0.0296 (18)	0.0388 (19)	−0.0052 (15)	−0.0087 (16)	0.0028 (15)
C8	0.0345 (19)	0.0313 (17)	0.0300 (17)	0.0036 (14)	0.0042 (15)	0.0016 (14)
C9	0.037 (2)	0.0308 (18)	0.0310 (17)	0.0021 (14)	−0.0008 (15)	−0.0020 (15)
C10	0.042 (2)	0.041 (2)	0.044 (2)	0.0055 (17)	0.0030 (17)	−0.0054 (18)
C11	0.030 (2)	0.048 (2)	0.066 (3)	0.0027 (17)	−0.0002 (19)	0.004 (2)
C12	0.046 (2)	0.037 (2)	0.060 (3)	−0.0063 (17)	−0.016 (2)	0.0033 (19)
C13	0.053 (2)	0.043 (2)	0.038 (2)	−0.0046 (18)	−0.0070 (18)	−0.0068 (17)
C14	0.045 (2)	0.039 (2)	0.0319 (18)	−0.0029 (16)	0.0041 (16)	−0.0109 (16)
C15	0.040 (2)	0.040 (2)	0.0387 (19)	−0.0019 (16)	0.0046 (16)	−0.0108 (17)
C16	0.039 (2)	0.0252 (16)	0.0291 (17)	−0.0047 (14)	0.0011 (15)	−0.0011 (14)

Geometric parameters (Å, º)

Cu1—O5	1.914 (2)	C2—C3	1.375 (5)
Cu1—O7	1.926 (3)	C2—H2	0.9300
Cu1—O2^i	1.933 (2)	C3—C4	1.392 (6)
Cu1—O3^i	2.755 (1)	C3—H3	0.9300
Cu1—O1	1.950 (2)	C4—C5	1.358 (6)
S1—C1	1.735 (3)	C4—H4	0.9300
S1—C6	1.815 (3)	C5—H5	0.9300
S2—C9	1.741 (4)	C6—C7	1.531 (5)
S2—C14	1.810 (3)	C6—H6A	0.9700
O1—N1	1.342 (4)	C6—H6B	0.9700
O2—C8	1.273 (4)	C7—C8	1.514 (5)
O2—Cu1^ii	1.933 (2)	C7—H7A	0.9700
O3—C8	1.235 (4)	C7—H7B	0.9700
O4—N2	1.321 (4)	C9—C10	1.380 (5)
O5—C16	1.283 (4)	C10—C11	1.379 (6)
O6—C16	1.217 (4)	C10—H10	0.9300
O7—H7C	0.822 (17)	C11—C12	1.367 (6)
O7—H7D	0.839 (17)	C11—H11	0.9300
O8—H8C	0.837 (17)	C12—C13	1.362 (6)
O8—H8D	0.847 (18)	C12—H12	0.9300
O9—H9C	0.811 (17)	C13—H13	0.9300
O9—H9D	0.798 (17)	C14—C15	1.513 (5)
N1—C5	1.353 (5)	C14—H14A	0.9700
N1—C1	1.358 (4)	C14—H14B	0.9700
N2—C13	1.347 (5)	C15—C16	1.517 (5)
N2—C9	1.359 (4)	C15—H15A	0.9700
C1—C2	1.396 (5)	C15—H15B	0.9700
O5—Cu1—O7	86.80 (11)	C7—C6—H6B	109.8
O5—Cu1—O2^i	175.57 (11)	S1—C6—H6B	109.8
O7—Cu1—O2^i	88.78 (11)	H6A—C6—H6B	108.3
O5—Cu1—O1	91.22 (10)	C8—C7—C6	114.7 (3)
O7—Cu1—O1	164.02 (14)	C8—C7—H7A	108.6
O1—Cu1—O2^i	93.12 (10)	C6—C7—H7A	108.6
O7—Cu1—O3^i	94.38 (1)	C8—C7—H7B	108.6
O1—Cu1—O3^i	99.40 (1)	C6—C7—H7B	108.6
C1—S1—C6	100.66 (16)	H7A—C7—H7B	107.6
C9—S2—C14	102.04 (17)	O3—C8—O2	123.4 (3)
N1—O1—Cu1	117.08 (19)	O3—C8—C7	119.6 (3)
C8—O2—Cu1^ii	110.9 (2)	O2—C8—C7	116.9 (3)
C16—O5—Cu1	119.8 (2)	N2—C9—C10	118.7 (3)
Cu1—O7—H7C	120 (2)	N2—C9—S2	112.2 (3)
Cu1—O7—H7D	123 (2)	C10—C9—S2	129.0 (3)
H7C—O7—H7D	113 (2)	C11—C10—C9	120.3 (4)
H8C—O8—H8D	110 (2)	C11—C10—H10	119.9
H9C—O9—H9D	119 (3)	C9—C10—H10	119.9
O1—N1—C5	119.4 (3)	C12—C11—C10	119.4 (4)
O1—N1—C1	117.8 (3)	C12—C11—H11	120.3
C5—N1—C1	122.7 (3)	C10—C11—H11	120.3
O4—N2—C13	121.8 (3)	C13—C12—C11	119.8 (4)
O4—N2—C9	117.0 (3)	C13—C12—H12	120.1
C13—N2—C9	121.2 (3)	C11—C12—H12	120.1
N1—C1—C2	118.1 (3)	N2—C13—C12	120.7 (4)
N1—C1—S1	113.5 (2)	N2—C13—H13	119.7
C2—C1—S1	128.3 (3)	C12—C13—H13	119.7
C3—C2—C1	119.6 (3)	C15—C14—S2	106.5 (2)
C3—C2—H2	120.2	C15—C14—H14A	110.4
C1—C2—H2	120.2	S2—C14—H14A	110.4
C2—C3—C4	120.3 (4)	C15—C14—H14B	110.4
C2—C3—H3	119.8	S2—C14—H14B	110.4
C4—C3—H3	119.8	H14A—C14—H14B	108.6
C5—C4—C3	119.2 (4)	C14—C15—C16	113.6 (3)
C5—C4—H4	120.4	C14—C15—H15A	108.8
C3—C4—H4	120.4	C16—C15—H15A	108.8
N1—C5—C4	120.0 (3)	C14—C15—H15B	108.8
N1—C5—H5	120.0	C16—C15—H15B	108.8
C4—C5—H5	120.0	H15A—C15—H15B	107.7
C7—C6—S1	109.3 (2)	O6—C16—O5	124.6 (3)
C7—C6—H6A	109.8	O6—C16—C15	121.8 (3)
S1—C6—H6A	109.8	O5—C16—C15	113.5 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7C···O9^i	0.82 (2)	1.86 (2)	2.664 (4)	164 (4)
O7—H7D···O4^iii	0.84 (2)	1.75 (2)	2.589 (4)	178 (4)
O9—H9C···O3^iv	0.81 (2)	1.96 (2)	2.772 (4)	177 (4)
O9—H9D···O8^v	0.80 (2)	1.98 (2)	2.754 (5)	162 (3)
O8—H8C···O6^vi	0.84 (2)	1.92 (2)	2.754 (4)	176 (3)
O8—H8D···O5^ii	0.85 (2)	1.99 (2)	2.770 (4)	154 (3)

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