4,4′-(1,2-Di­aza­niumyl­ethane-1,2-di­yl)dibenzoate trihydrate

Numata, T.; Ikenomoto, S.; Akitsu, T.

doi:10.1107/S2414314616002522

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 1| Part 2| February 2016| x160252

https://doi.org/10.1107/S2414314616002522

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4,4′-(1,2-Diazaniumylethane-1,2-diyl)dibenzoate trihydrate

Takashi Numata,^a Shun Ikenomoto ^a and Takashiro Akitsu ^a ^*

^aDepartment of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
^*Correspondence e-mail: akitsu@rs.kagu.tus.ac.jp

Edited by C. Rizzoli, Universita degli Studi di Parma, Italy (Received 22 January 2016; accepted 10 February 2016; online 24 February 2016)

The title compound, C₁₆H₁₆N₂O₄·3H₂O, was synthesized from (1R,2R)-1,2-bis(2-hydroxyphenyl)ethylenediamine and terephthalaldehydic acid. The compound crystallizes from water as a double zwitterion with protonated amine groups and deprotonated carboxylate groups. The dihedral angle formed by the aromatic rings is 3.86 (11)°. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link molecules into a three-dimensional network.

Keywords: crystal structure; double zwitterion; hydrogen bonds.

CCDC reference: 1452936

Structure description

In recent years, dyes that led to an improvement in efficiency of the current generation of dye-sensitized solar cells (DSSC) have been devised (Nazeeruddin et al., 1993 ; Hagfeldt et al., 2010 ; Brewster et al., 2013 ; Komatsu et al., 2013 ; Brown et al., 2013 ; Sinn et al., 2014 ). In our laboratory, we have been engaged in the study of chiral salen-type complexes as dyes containing carboxyl groups which can be adsorbed on the surface of TiO₂, and with extended π-conjugated system in order to improve the power generation efficiency. During the course of this study, the title diamine compound as precursor of chiral salen-type ligands was synthesized, and its structure is reported herein. The molecule of the title compound crystallizes as a zwitterion with protonated amine groups NH₃⁺ and deprotonated carboxylate groups COO⁻ (Fig. 1). The C—O bonds lengths within the carboxylate groups range from 1.252 (4) to 1.262 (3) Å, indicating delocalization of the negative charge, and are in good agreement with those observed in the organic zwitterion 4-(ammoniomethyl)benzoate (Atria et al., 2014 ). The torsion angle C7—C8—C9—C10 is 178.8 (2)°. In the crystal, intermolecular N—H⋯O and O—H⋯O involving all ammonium groups, carboxylate groups and water molecules are observed, linking molecules into a three-dimensional network (Table 1).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O5	0.91	2.01	2.911 (3)	173
N1—H1B⋯O3ⁱ	0.91	1.80	2.686 (3)	165
N1—H1C⋯O2ⁱⁱ	0.91	1.90	2.807 (3)	176
N2—H2A⋯O5	0.91	1.89	2.798 (3)	177
N2—H2B⋯O1ⁱⁱⁱ	0.91	1.93	2.787 (3)	156
N2—H2C⋯O6^iv	0.91	1.83	2.744 (4)	178
O7—H19⋯O1ⁱⁱ	0.87 (5)	1.92 (5)	2.768 (4)	162 (5)
O7—H18⋯O2^v	0.89 (4)	1.81 (4)	2.688 (3)	166 (4)
O6—H20⋯O4^vi	0.87 (6)	1.85 (6)	2.720 (4)	172 (5)
O5—H17⋯O7	0.85 (7)	1.77 (7)	2.619 (4)	172 (6)
O6—H21⋯O3ⁱ	0.81 (6)	1.93 (5)	2.696 (3)	157 (5)
O5—H16⋯O4^vi	0.84 (4)	1.83 (4)	2.654 (2)	166 (4)
Symmetry codes: (i) x, y+1, z+1; (ii) x, y, z-1; (iii) x, y-1, z-1; (iv) x, y-1, z; (v) x+1, y, z-1; (vi) x+1, y+1, z+1.

Figure 1
The molecular structure of the title compound, with displacement ellipsoids drawn at the 50% probability level.

Synthesis and crystallization

To a solution of (1R,2R)-bis(2-hydroxyphenyl)ethylendiamine (1.222 g, 5 mmol) dissolved in ethanol (17 ml) was added 4-formylbenzoic acid (1.801 g, 12 mmol). The resulting mixture was stirred at 298 K for 3 h to give a yellow precipitate of (I), which was washed with water (5 ml), filtered off and dried in a vacuum. To a clear solution of (I) in tetrahydrofuran (THF, 50 ml) was added acidified water (HCl, 3.0 ml, 37%), and the mixture was stirred at 300 K for 3 h. The white precipitate afforded was filtered and washed with THF to give analytically pure 4,4′-(1,2-diazaniumylethane-1,2-diyl)dibenzoate (yield: 1.046 g, 69.7%). The compound was recrystallized by slow evaporation from a water solution to give colourless prismatic single crystals. IR (KBr, cm⁻¹): 421 (w), 505 (w), 540 (w), 606 (w), 667 (w), 743 (w), 777 (w), 863 (w), 977 (w), 1018 (w), 1078 (w), 1121 (m), 1181 (m), 1220 (m), 1384 (m), 1427 (w), 1469 (m), 1517 (m), 1572 (m), 1614 (m), 1697 (s, C=O), 2610 (m), 2976 (s), 3060 (s). MS (TOF–MASS) [M⁻] calculated for C₁₆H₁₅N₂O₄⁻ = 299.10; found = 299.13.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The absolute configuration could not be determined unambigously as there was no significant anomalous dispersion using data collected with Mo radiation.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₆H₁₆N₂O₄·3H₂O
M_r	354.35
Crystal system, space group	Triclinic, P1
Temperature (K)	173
a, b, c (Å)	6.778 (3), 6.953 (3), 9.458 (4)
α, β, γ (°)	109.182 (6), 93.369 (6), 98.437 (6)
V (Å³)	413.7 (3)
Z	1
Radiation type	Mo Kα
μ (mm⁻¹)	0.11
Crystal size (mm)	0.49 × 0.34 × 0.07

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2013 )
T_min, T_max	0.946, 0.990
No. of measured, independent and observed [I > 2σ(I)] reflections	2325, 2030, 1969
R_int	0.019
(sin θ/λ)_max (Å⁻¹)	0.651

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.038, 0.103, 1.03
No. of reflections	2030
No. of parameters	253
No. of restraints	3
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.37, −0.21
Absolute structure	Flack x determined using 217 quotients [(I⁺) − (I⁻)]/[(I⁺) + (I⁻)] (Parsons et al., 2013 )
Absolute structure parameter	−0.2 (10)
Computer programs: APEX2 (Bruker, 2013), SAINT (Bruker, 2013), SHELXS2013 (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ), SHELXTL (Sheldrick, 2008).

Structural data

CCDC reference: 1452936

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S2414314616002522/rz4001sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314616002522/rz4001Isup2.hkl

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2013); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

4,4'-(1,2-Diazaniumylethane-1,2-diyl)dibenzoate trihydrate top

Crystal data top

C₁₆H₁₆N₂O₄·3H₂O	Z = 1
M_r = 354.35	F(000) = 188
Triclinic, P1	D_x = 1.422 Mg m⁻³
a = 6.778 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 6.953 (3) Å	Cell parameters from 2325 reflections
c = 9.458 (4) Å	θ = 2.3–27.5°
α = 109.182 (6)°	µ = 0.11 mm⁻¹
β = 93.369 (6)°	T = 173 K
γ = 98.437 (6)°	Prism, colourless
V = 413.7 (3) Å³	0.49 × 0.34 × 0.07 mm

Data collection top

Bruker APEXII CCD diffractometer	2030 independent reflections
Radiation source: fine-forcus sealed tube	1969 reflections with I > 2σ(I)
Detector resolution: 8.333 pixels mm^-1	R_int = 0.019
φ and ω scans	θ_max = 27.5°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2013)	h = −8→8
T_min = 0.946, T_max = 0.990	k = −8→9
2325 measured reflections	l = −12→6

Refinement top

Refinement on F²	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F² > 2σ(F²)] = 0.038	w = 1/[σ²(F_o²) + (0.0632P)² + 0.1469P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.103	(Δ/σ)_max = 0.001
S = 1.03	Δρ_max = 0.37 e Å⁻³
2030 reflections	Δρ_min = −0.21 e Å⁻³
253 parameters	Extinction correction: SHELXL2014 (Sheldrick 2015)
3 restraints	Extinction coefficient: 0.061 (11)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack x determined using 217 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
Secondary atom site location: difference Fourier map	Absolute structure parameter: −0.2 (10)

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C2	0.2668 (4)	−0.0431 (4)	0.0660 (3)	0.0148 (5)
C14	0.6379 (4)	0.5409 (4)	1.0399 (3)	0.0186 (6)
H14	0.7642	0.6159	1.0928	0.022*
C10	0.4424 (4)	0.3099 (4)	0.8089 (3)	0.0150 (5)
C13	0.4672 (4)	0.5516 (4)	1.1153 (3)	0.0154 (5)
C4	0.4811 (4)	0.1770 (4)	0.2925 (3)	0.0165 (5)
H4	0.6097	0.2517	0.3405	0.02*
C15	0.6259 (4)	0.4219 (4)	0.8886 (3)	0.0180 (5)
H15	0.7439	0.4169	0.8389	0.022*
C9	0.4215 (4)	0.1817 (4)	0.6422 (3)	0.0155 (5)
H9	0.3206	0.054	0.6262	0.019*
C1	0.2389 (4)	−0.1709 (4)	−0.1001 (3)	0.0177 (5)
C12	0.2827 (4)	0.4406 (4)	1.0366 (3)	0.0166 (5)
H12	0.1651	0.4459	1.0866	0.02*
C8	0.3387 (4)	0.2978 (4)	0.5438 (3)	0.0145 (5)
H8	0.2001	0.3148	0.5703	0.017*
C6	0.1036 (4)	−0.0325 (4)	0.1485 (3)	0.0189 (6)
H6	−0.0263	−0.1009	0.0992	0.023*
C5	0.1280 (4)	0.0772 (4)	0.3027 (3)	0.0188 (6)
H5	0.0154	0.0814	0.3582	0.023*
C3	0.4556 (4)	0.0630 (4)	0.1388 (3)	0.0156 (5)
H3	0.5681	0.0577	0.0831	0.019*
C16	0.4895 (4)	0.6773 (4)	1.2817 (3)	0.0167 (5)
C11	0.2706 (4)	0.3217 (4)	0.8846 (3)	0.0170 (5)
H11	0.1441	0.2476	0.8315	0.02*
C7	0.3178 (4)	0.1811 (4)	0.3758 (3)	0.0151 (5)
O4	0.0625 (3)	−0.2489 (3)	−0.1609 (2)	0.0281 (5)
O1	0.6571 (3)	0.7863 (3)	1.3418 (2)	0.0245 (5)
O3	0.3929 (3)	−0.1941 (3)	−0.1665 (2)	0.0240 (5)
O2	0.3413 (3)	0.6659 (3)	1.3551 (2)	0.0223 (4)
O6	0.7705 (4)	0.9702 (4)	0.8108 (3)	0.0346 (6)
O5	0.8755 (3)	0.4606 (3)	0.5889 (2)	0.0230 (4)
O7	0.9441 (4)	0.5415 (4)	0.3428 (3)	0.0338 (5)
N1	0.4571 (3)	0.5128 (3)	0.5815 (2)	0.0161 (4)
H1A	0.5904	0.5072	0.5822	0.024*
H1B	0.4329	0.5936	0.674	0.024*
H1C	0.4195	0.5676	0.5112	0.024*
N2	0.6159 (3)	0.1137 (3)	0.5979 (2)	0.0162 (4)
H2A	0.7043	0.2233	0.5941	0.024*
H2B	0.5935	0.0126	0.5057	0.024*
H2C	0.6677	0.064	0.6671	0.024*
H19	0.875 (7)	0.639 (7)	0.346 (5)	0.050 (13)*
H18	1.071 (6)	0.586 (5)	0.333 (4)	0.026 (9)*
H20	0.867 (8)	0.900 (8)	0.812 (6)	0.057 (14)*
H17	0.903 (8)	0.478 (8)	0.507 (7)	0.068 (16)*
H21	0.667 (8)	0.937 (8)	0.842 (6)	0.057 (15)*
H16	0.951 (6)	0.543 (7)	0.664 (5)	0.042 (11)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C2	0.0215 (12)	0.0117 (12)	0.0079 (11)	0.0007 (10)	−0.0062 (9)	0.0012 (9)
C14	0.0207 (13)	0.0203 (13)	0.0111 (12)	−0.0028 (10)	−0.0045 (9)	0.0044 (10)
C10	0.0225 (13)	0.0138 (12)	0.0079 (12)	0.0023 (10)	−0.0030 (9)	0.0036 (9)
C13	0.0209 (13)	0.0143 (12)	0.0112 (12)	0.0017 (10)	−0.0029 (9)	0.0058 (9)
C4	0.0168 (12)	0.0181 (13)	0.0102 (12)	−0.0016 (10)	−0.0060 (9)	0.0025 (9)
C15	0.0186 (13)	0.0217 (12)	0.0121 (12)	0.0000 (10)	−0.0009 (9)	0.0056 (10)
C9	0.0218 (12)	0.0165 (12)	0.0068 (11)	0.0016 (10)	−0.0028 (9)	0.0036 (9)
C1	0.0261 (14)	0.0130 (11)	0.0107 (12)	0.0028 (10)	−0.0067 (10)	0.0014 (9)
C12	0.0191 (13)	0.0184 (12)	0.0118 (12)	0.0012 (10)	−0.0018 (9)	0.0058 (10)
C8	0.0141 (11)	0.0162 (11)	0.0085 (11)	−0.0018 (9)	−0.0051 (8)	0.0012 (9)
C6	0.0157 (12)	0.0208 (13)	0.0146 (13)	−0.0025 (10)	−0.0078 (10)	0.0025 (10)
C5	0.0181 (13)	0.0213 (13)	0.0122 (12)	−0.0016 (10)	−0.0026 (10)	0.0023 (10)
C3	0.0176 (12)	0.0176 (12)	0.0102 (12)	0.0023 (10)	−0.0025 (9)	0.0040 (9)
C16	0.0226 (13)	0.0163 (12)	0.0116 (12)	0.0049 (10)	−0.0041 (9)	0.0056 (9)
C11	0.0189 (12)	0.0173 (12)	0.0119 (12)	−0.0012 (10)	−0.0053 (10)	0.0043 (10)
C7	0.0183 (12)	0.0156 (11)	0.0098 (12)	0.0019 (9)	−0.0049 (9)	0.0039 (9)
O4	0.0273 (10)	0.0318 (11)	0.0135 (10)	0.0040 (8)	−0.0128 (8)	−0.0049 (8)
O1	0.0239 (10)	0.0266 (10)	0.0143 (9)	0.0012 (8)	−0.0055 (7)	−0.0017 (8)
O3	0.0285 (10)	0.0241 (10)	0.0122 (9)	0.0006 (8)	−0.0014 (8)	−0.0010 (7)
O2	0.0245 (10)	0.0304 (10)	0.0128 (9)	0.0078 (8)	0.0013 (7)	0.0072 (7)
O6	0.0288 (12)	0.0487 (15)	0.0387 (13)	0.0121 (11)	0.0036 (10)	0.0291 (11)
O5	0.0235 (10)	0.0246 (10)	0.0129 (9)	−0.0058 (8)	−0.0052 (8)	0.0012 (8)
O7	0.0253 (12)	0.0523 (14)	0.0305 (12)	0.0073 (11)	0.0019 (9)	0.0229 (10)
N1	0.0210 (10)	0.0164 (10)	0.0089 (9)	0.0013 (8)	−0.0033 (8)	0.0034 (7)
N2	0.0227 (10)	0.0157 (9)	0.0086 (9)	0.0036 (8)	−0.0041 (7)	0.0030 (8)

Geometric parameters (Å, º) top

C2—C6	1.387 (4)	C8—C7	1.516 (3)
C2—C3	1.393 (3)	C8—H8	1.0
C2—C1	1.514 (3)	C6—C5	1.393 (4)
C14—C13	1.393 (4)	C6—H6	0.95
C14—C15	1.389 (4)	C5—C7	1.396 (3)
C14—H14	0.95	C5—H5	0.95
C10—C15	1.394 (4)	C3—H3	0.95
C10—C11	1.401 (4)	C16—O1	1.255 (3)
C10—C9	1.521 (3)	C16—O2	1.262 (3)
C13—C12	1.394 (3)	C11—H11	0.95
C13—C16	1.514 (3)	O6—H20	0.88 (6)
C4—C7	1.394 (4)	O6—H21	0.81 (6)
C4—C3	1.395 (3)	O5—H17	0.85 (6)
C4—H4	0.95	O5—H16	0.83 (5)
C15—H15	0.95	O7—H19	0.87 (5)
C9—N2	1.501 (4)	O7—H18	0.89 (4)
C9—C8	1.549 (3)	N1—H1A	0.91
C9—H9	1.0	N1—H1B	0.91
C1—O4	1.256 (3)	N1—H1C	0.91
C1—O3	1.252 (4)	N2—H2A	0.91
C12—C11	1.394 (4)	N2—H2B	0.91
C12—H12	0.95	N2—H2C	0.91
C8—N1	1.507 (3)

C6—C2—C3	119.0 (2)	C9—C8—H8	106.4
C6—C2—C1	120.1 (2)	C2—C6—C5	120.8 (2)
C3—C2—C1	120.9 (2)	C2—C6—H6	119.6
C13—C14—C15	120.9 (2)	C5—C6—H6	119.6
C13—C14—H14	119.5	C6—C5—C7	120.1 (2)
C15—C14—H14	119.5	C6—C5—H5	120.0
C15—C10—C11	118.5 (2)	C7—C5—H5	120.0
C15—C10—C9	122.3 (2)	C2—C3—C4	120.7 (2)
C11—C10—C9	119.1 (2)	C2—C3—H3	119.7
C14—C13—C12	119.0 (2)	C4—C3—H3	119.7
C14—C13—C16	118.8 (2)	O1—C16—O2	122.6 (2)
C12—C13—C16	122.1 (2)	O1—C16—C13	118.3 (2)
C7—C4—C3	120.0 (2)	O2—C16—C13	119.1 (2)
C7—C4—H4	120.0	C12—C11—C10	120.9 (2)
C3—C4—H4	120.0	C12—C11—H11	119.5
C14—C15—C10	120.6 (2)	C10—C11—H11	119.5
C14—C15—H15	119.7	C4—C7—C5	119.4 (2)
C10—C15—H15	119.7	C4—C7—C8	122.0 (2)
N2—C9—C10	110.8 (2)	C5—C7—C8	118.6 (2)
N2—C9—C8	112.81 (19)	H20—O6—H21	118 (5)
C10—C9—C8	111.31 (19)	H17—O5—H16	113 (4)
N2—C9—H9	107.2	H19—O7—H18	109 (4)
C10—C9—H9	107.2	C8—N1—H1A	109.5
C8—C9—H9	107.2	C8—N1—H1B	109.5
O4—C1—O3	124.7 (2)	H1A—N1—H1B	109.5
O4—C1—C2	117.4 (2)	C8—N1—H1C	109.5
O3—C1—C2	117.9 (2)	H1A—N1—H1C	109.5
C11—C12—C13	120.1 (2)	H1B—N1—H1C	109.5
C11—C12—H12	119.9	C9—N2—H2A	109.5
C13—C12—H12	119.9	C9—N2—H2B	109.5
N1—C8—C7	110.9 (2)	H2A—N2—H2B	109.5
N1—C8—C9	111.91 (18)	C9—N2—H2C	109.5
C7—C8—C9	114.34 (19)	H2A—N2—H2C	109.5
N1—C8—H8	106.4	H2B—N2—H2C	109.5
C7—C8—H8	106.4

C15—C14—C13—C12	0.1 (4)	C1—C2—C6—C5	177.3 (2)
C15—C14—C13—C16	177.8 (2)	C2—C6—C5—C7	1.1 (4)
C13—C14—C15—C10	−0.2 (4)	C6—C2—C3—C4	0.5 (4)
C11—C10—C15—C14	0.6 (4)	C1—C2—C3—C4	−178.6 (2)
C9—C10—C15—C14	178.5 (2)	C7—C4—C3—C2	1.7 (4)
C15—C10—C9—N2	26.1 (3)	C14—C13—C16—O1	8.0 (4)
C11—C10—C9—N2	−155.9 (2)	C12—C13—C16—O1	−174.4 (2)
C15—C10—C9—C8	−100.3 (3)	C14—C13—C16—O2	−170.7 (2)
C11—C10—C9—C8	77.7 (3)	C12—C13—C16—O2	7.0 (4)
C6—C2—C1—O4	6.4 (4)	C13—C12—C11—C10	0.6 (4)
C3—C2—C1—O4	−174.5 (2)	C15—C10—C11—C12	−0.8 (4)
C6—C2—C1—O3	−172.6 (3)	C9—C10—C11—C12	−178.8 (2)
C3—C2—C1—O3	6.6 (4)	C3—C4—C7—C5	−2.5 (4)
C14—C13—C12—C11	−0.3 (4)	C3—C4—C7—C8	178.3 (2)
C16—C13—C12—C11	−177.9 (2)	C6—C5—C7—C4	1.2 (4)
N2—C9—C8—N1	−73.5 (2)	C6—C5—C7—C8	−179.6 (2)
C10—C9—C8—N1	51.7 (3)	N1—C8—C7—C4	47.4 (3)
N2—C9—C8—C7	53.6 (3)	C9—C8—C7—C4	−80.3 (3)
C10—C9—C8—C7	178.8 (2)	N1—C8—C7—C5	−131.8 (2)
C3—C2—C6—C5	−1.9 (4)	C9—C8—C7—C5	100.6 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O5	0.91	2.01	2.911 (3)	173
N1—H1B···O3ⁱ	0.91	1.80	2.686 (3)	165
N1—H1C···O2ⁱⁱ	0.91	1.90	2.807 (3)	176
N2—H2A···O5	0.91	1.89	2.798 (3)	177
N2—H2B···O1ⁱⁱⁱ	0.91	1.93	2.787 (3)	156
N2—H2C···O6^iv	0.91	1.83	2.744 (4)	178
O7—H19···O1ⁱⁱ	0.87 (5)	1.92 (5)	2.768 (4)	162 (5)
O7—H18···O2^v	0.89 (4)	1.81 (4)	2.688 (3)	166 (4)
O6—H20···O4^vi	0.87 (6)	1.85 (6)	2.720 (4)	172 (5)
O5—H17···O7	0.85 (7)	1.77 (7)	2.619 (4)	172 (6)
O6—H21···O3ⁱ	0.81 (6)	1.93 (5)	2.696 (3)	157 (5)
O5—H16···O4^vi	0.84 (4)	1.83 (4)	2.654 (2)	166 (4)

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

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