Hydrazinium 2-amino-4-nitro­benzoate dihydrate: crystal structure and Hirshfeld surface analysis

In the anion of the title salt hydrate, H₅N₂⁺·C₇H₅N₂O₄⁻·2H₂O, the carboxyl­ate and nitro groups lie out of the plane of the benzene ring to which they are bound [dihedral angles = 18.80 (10) and 8.04 (9)°, respectively], and as these groups are conrotatory, the dihedral angle between them is 26.73 (15)°. An intra­molecular amino-N—H⋯O(carboxyl­ate) hydrogen bond is noted. The main feature of the crystal packing is the formation of a supra­molecular chain along the b axis, with a zigzag topology, sustained by charge-assisted water-O—H⋯O(carboxyl­ate) hydrogen bonds and comprising alternating twelve-membered {⋯OCO⋯HOH}₂ and eight-membered {⋯O⋯HOH}₂ synthons. Each ammonium-N—H atom forms a charge-assisted hydrogen bond to a water mol­ecule and, in addition, one of these forms a hydrogen bond with a nitro-O atom. The amine-N—H atoms form hydrogen bonds to carboxyl­ate-O and water-O atoms, and the amine N atom accepts a hydrogen bond from an amino-H atom. The hydrogen bonds lead to a three-dimensional architecture. An analysis of the Hirshfeld surface highlights the major contribution of O⋯H/H⋯O hydrogen bonding to the overall surface, i.e. 46.8%, compared with H⋯H contacts (32.4%).

1. Chemical context

The present structure determination of the title salt dihydrate, [NH₂NH₃][O₂C₆H₄NO₂-4]·2H₂O (I), is a continuation of on-going structural studies of the relatively unexplored chemistry of 2-amino-4-nitro­benzoic acid. This acid carries several groups capable of hydrogen bonding, viz. carb­oxy­lic/carboxyl­ate, amino and even nitro, and is anti­cipated to form crystals with significant hydrogen-bonding inter­actions, in both its neutral and deprotonated forms. Beyond the structure determination of several polymorphs of the parent structure (Wardell & Tiekink, 2011; Wardell & Wardell, 2016) and its 1:1 co-crystal with bis­(pyridin-2-yl)methanone and 2:1 co-crystal with 2-amino-4-nitro­benzoic acid (Wardell & Tiekink, 2011), all other investigations have been of deprotonated forms of the acid. Thus, the anion has been found coordinating in the carboxyl­ate-O, amino-N mode towards Pb^II in the coordination polymer catena-[bis­(μ₂-2-amino-4-nitro­benzoato)lead(II)] (Chen & Huang, 2009), with the remaining literature structures being salts. These are either alkali metal salts, i.e. Na⁺, K⁺ (Smith, 2013), Rb⁺ (Smith, 2014a) and Cs⁺ (Smith & Wermuth, 2011), or are ammonium salts, as discussed below. Herein, the crystal and mol­ecular structures of (I) are described along with an evaluation of its Hirshfeld surface.

2. Structural commentary

The mol­ecular structures of the constituents of (I) are shown in Fig. 1; the asymmetric unit comprises one hydrazinium cation, one 2-amino-4-nitro­benzoate anion and two water mol­ecules of crystallization. In all-organic structures, when protonated in crystals, hydrazine is ten times more likely to be present as a mono-protonated hydrazinium cation rather than in its the diprotonated form, i.e. hydrazine-1,2-diium di-cation (Groom et al., 2016); when non-organic structures are also considered, this ratio increases to 20:1. The confirmation of the mono-protonation in (I) is found in the pattern of inter­molecular inter­actions, in particular in the observation that the amine-N4 atom accepts a hydrogen bond (see below). The N3—N4 bond length in (I) is 1.4492 (15) Å. The assignment of deprotonation of 2-amino-4-nitro­benzoic acid during co-crystallization is readily adduced in the near equivalence of the carboxyl­ate C—O bond lengths, i.e. C7—O1 = 1.2579 (15) and C7—O2 = 1.2746 (15) Å. While there is an intra­molecular amino-N—H⋯O(carboxyl­ate) hydrogen bond, Table 1, a significant twist of the carboxyl­ate group with respect to the benzene ring to which it is connected is noted, as evidenced in the value of the C2—C1—C7—O1 torsion angle of 18.83 (17)°. With respect to the nitro group, this is also twisted but, to a lesser extent: the O3—N2—C4—C3 torsion angle is 7.53 (16)°. The terminal groups are conrotatory, forming a dihedral angle of 26.73 (15)°.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1	0.88 (1)	2.07 (1)	2.7098 (15)	129 (1)
N1—H2N⋯N4	0.88 (1)	2.29 (1)	3.1403 (16)	165 (1)
N3—H3N⋯O1W^i	0.86 (1)	1.97 (1)	2.8136 (15)	167 (1)
N3—H4N⋯O2W^i	0.87 (2)	2.25 (2)	2.8969 (16)	132 (1)
N3—H4N⋯O4^ii	0.87 (2)	2.34 (1)	3.0739 (15)	143 (1)
N3—H5N⋯O2W^iii	0.87 (1)	1.93 (2)	2.7862 (15)	167 (1)
N4—H6N⋯O1^iii	0.87 (1)	2.20 (1)	3.0623 (15)	178 (1)
N4—H7N⋯O1W^iv	0.87 (1)	2.20 (1)	3.0106 (15)	155 (1)
O1W—H1W⋯O2	0.86 (2)	1.97 (2)	2.8071 (14)	166 (2)
O1W—H2W⋯O2^v	0.83 (2)	1.90 (2)	2.7208 (13)	171 (2)
O2W—H3W⋯O2	0.85 (2)	1.92 (2)	2.7479 (13)	165 (2)
O2W—H4W⋯O1^vi	0.85 (2)	1.91 (2)	2.7627 (14)	175 (2)
Symmetry codes: (i) x, y, z+1; (ii) x, y+1, z; (iii) -x, -y+1, -z+1; (iv) -x, -y, -z+1; (v) -x+1, -y, -z; (vi) -x+1, -y+1, -z.

Figure 1 The mol­ecular structures of the asymmetric unit of (I), showing displacement ellipsoids at the 70% probability level.

3. Supra­molecular features

As expected from the chemical composition of (I), there are a number of conventional hydrogen-bonding inter­actions in the crystal, involving all possible hydrogen-bond donors and acceptors, Table 1. These sustain a three-dimensional architecture. A view of the inter­actions involving the hydrazinium cation is shown in Fig. 2a. Each of the ammonium-N3—H atoms forms a charge-assisted hydrogen bond to a water mol­ecule, with the HN4 atom also forming a hydrogen bond to a nitro-O4 atom indicating that the HN4 atom is bifurcated [i.e.: N—H⋯(O,O)]. The amine-N4—H atoms form a hydrogen bond to a carboxyl­ate-O1 atom and to a water mol­ecule and at the same time accept a hydrogen bond from an amino-H atom, this being the only N—H⋯N hydrogen bond in the structure; the second amino-H atom forms an intra­molecular hydrogen bond with the carboxyl­ate-O1 atom, as mentioned above. Each of the water-H atoms forms a charge-assisted hydrogen bond with a carboxyl­ate-O atom, leading to a zigzag supra­molecular chain aligned along the b axis, as shown in Fig. 2b. The chain comprises alternating twelve-membered {⋯OCO⋯HOH}₂ and eight-membered {⋯O⋯HOH}₂ synthons. As shown in Fig. 2c, two of the ammonium-N3—H atoms bridge water mol­ecules in the chain shown in Fig. 2b to form a non-symmetric, eight-membered {⋯HNH⋯OH⋯O⋯HO} synthon while the amine-H atoms provide a second bridge between water- and carboxyl­ate-O atoms to form a ten-membered {⋯HNH⋯OH⋯O⋯HOH⋯O} synthon. Further hydrogen bonds to water mol­ecules leads to the formation of additional synthons, i.e. ten-membered {⋯HNNH⋯O}₂ and eight-membered {⋯HNH⋯O}₂. A view of the unit-cell contents is shown in Fig. 2d. In addition to the above, π(phen­yl)–π(phen­yl) inter­actions are noted between inversion-related rings with the inter-centroid separation being 3.6190 (8) Å [symmetry operation 1 − x, −y, 1 − z].

Figure 2 The mol­ecular packing in (I): (a) immediate environment about the [H2NNH3] cation, (b) supra­molecular chain comprising anions and water mol­ecules only, orientated along the b axis and sustained by water-O—H⋯O(carboxyl­ate) hydrogen bonding, (c) decoration of the chain of (b) with cations and additional water mol­ecules to highlight the formation of various supra­molecular synthons (see text) and (d) a view of the unit-cell contents in projection down the b axis. The O—H⋯O, N—H⋯O, N—H⋯N and intra­molecular N—H⋯O hydrogen bonds are shown as orange, blue, brown and pink dashed lines, respectively. In (b) and (c), all but the CO2 groups of the two central benzoate residues have been removed for clarity.

4. Hirshfeld surface analysis

The Hirshfeld surface analysis of (I) provides additional insight into its mol­ecular packing and was performed in accord with a recent study of related ammonium salts (Wardell et al., 2016). The Hirshfeld surface mapped over electrostatic potential in Fig. 3 highlights the positive potential (blue region) around the hydrazinium cation and the negative potential (red) about the carboxyl­ate-oxygen atoms of the nitro­benzoate anion. The numerous bright-, diminutive- and faint-red spots appearing on the Hirshfeld surface mapped over d_norm in Fig. 4 are indicative of the variety of inter­molecular inter­actions in the crystal. The pair of charge-assisted water-O—H⋯O(carboxyl­ate) hydrogen bonds between the water-O—H2W and —H4W atoms and carboxyl­ate-O1 and -O2 atoms are evident through the bright-red spots appearing near the respective donor and acceptor atoms, Fig. 4a. The donors of these inter­actions appear as light-blue spots near the water O—H atoms and the acceptors as red regions surrounding carboxyl­ate-O1 and -O2 atoms on the Hirshfeld surface mapped over electrostatic potential in Fig. 3.

Figure 3 Two views of the Hirshfeld surface for (I) mapped over the electrostatic potential over the range −0.214 to +0.341 au; the red and blue regions represent negative and positive electrostatic potentials, respectively.

Figure 4 Two views of the Hirshfeld surface for (I) mapped over dnorm over the range −0.352 to 1.156 au.

The two pairs of bright-red spots near each water-O1W and -O2W atoms, and near the hydrazinium-H3N, H4N, H5N and H7N atoms in Fig. 4b are indicative of the hydrazinium-N—H⋯O(water) hydrogen bonds. In the same way, the amine-N4—H6N⋯O1 hydrogen bond is also viewed as a pair of bright-red spots near these atoms in Fig. 4b. The bifurcated ammonium-HN4 atom, forming comparatively weaker N—H⋯O hydrogen bonds compared to those just described, is viewed as the diminutive red spot in Fig. 4a. The presence of faint-red spots near the phenyl-C2–C4 atoms in Fig. 4b indicate their participation in edge-to-edge overlap with a symmetry-related phenyl ring, as seen in the short inter­atomic C⋯C contacts listed in Table 2. In addition to above inter­molecular inter­actions, the crystal also features short inter­atomic C⋯O/O⋯C and N⋯O/O⋯N contacts, Table 2, which are viewed as very faint-red spots in Fig. 4. In Fig. 4b, two spots are noted in the vicinity of the O4 atom, one corresponding to the conventional hydrogen bond and the other (to the left) to the weak H2N⋯O4 inter­action, Table 2. The immediate environments about a reference ion-pair within the d_norm- and shape-index mapped Hirshfeld surfaces highlighting the O—H⋯O and O—H⋯N hydrogen bonds, and short inter­atomic C⋯C, C⋯O/O⋯C and N⋯O/O⋯N contacts are illustrated in Fig. 5a and 5b, respectively.

Table 2
Summary of short inter­atomic contacts (Å) in (I)

Contact	Distance	Symmetry operation
H5N⋯H3W	2.38 (2)	-x, 1 − y, 1 − z
H7N⋯H2W	2.34 (2)	-x, −y, 1 − z
H4N⋯O3	2.626 (15)	x, 1 + y, z
H5⋯O4	2.61	1 − x, −1 − y, 1 − z
H2N⋯O4	2.652 (15)	x, 1 + y, z
N1⋯O4	3.0205 (15)	x, 1 + y, z
C7⋯O3	3.1231 (17)	-x, −y, 1 − z
C2⋯C4	3.2936 (19)	-x, −y, 1 − z
C3⋯C3	3.3235 (19)	-x, −y, 1 − z

Figure 5 View of Hirshfeld surface for (I) mapped (a) over dnorm about a reference mol­ecule showing hydrogen bonds as white dashed lines and (b) mapped with the shape-index property about a reference ion-pair. The short inter­atomic C⋯C, N⋯O and C⋯O contacts are indicated with red, blue and white dotted lines, respectively

The overall two-dimensional fingerprint plot for (I) and those delineated (McKinnon et al., 2007) into O⋯H/H⋯O, H⋯H, C⋯C, C⋯H/H⋯C, C⋯O/O⋯C and N⋯O/O⋯N contacts are illustrated in Fig. 6a–g, respectively; their relative contributions to the Hirshfeld surfaces are summarized in Table 3. It is important to note that the most significant contribution to the Hirshfeld surface in (I) comes from O⋯H/H⋯O contacts, i.e. 46.8%, due to the involvement of all the acidic hydrogen atoms in hydrogen bonds, mainly to oxygen, many of which are charge-assisted. Reflecting this dominance, sharp spikes are evident in the fingerprint plot delineated into O⋯H/H⋯O contacts shown in Fig. 6b. The pair of green spikes have their tips at d_e + d_i ∼1.9 Å and extend linearly up to d_e + d_i ∼2.3 Å. The points merged within the plot up to d_e + d_i ∼2.7 Å indicate the presence of short inter­atomic O⋯H/H⋯O contacts, Table 2. The extensive hydrogen bonding is the cause of the relatively small percentage contribution to the Hirshfeld surface from H⋯H contacts, i.e. 32.4%, Fig. 6c, as relatively few hydrogen atoms are available to form inter­atomic contacts. The pair of tips at d_e + d_i ∼2.3 Å in the mirror-reflected saw-tooth distribution are due to short inter­atomic H⋯H contacts involving water- and hydrazinium-hydrogen atoms, Table 2. The distributions of points in the fingerprint plot delineated into C⋯C contacts, shown in Fig. 6d, represents two π–π stacking inter­actions. In the first of these, the symmetry-related phenyl rings have a face-to-face overlap to give the arrow-like distribution in lower (d_e, d_i) region at around d_e = d_i = 1.6 Å. This inter­action is also seen as the flat region appearing about the phenyl ring on the Hirshfeld surface mapped over curvedness, shown in Fig. 7. The other π–π stacking inter­action involves edge-to-edge overlap through short inter­atomic C⋯C contacts involving the C2–C4 atoms, Fig. 4b and Table 2, and is viewed as the arrow-like distribution of points around d_e = d_i = 1.8 Å, i.e. adjacent to first arrow-like distribution. Even though C⋯H/H⋯C contacts have a significant contribution to the Hirshfeld surface, i.e. 5.9%, as seen from the fingerprint plot in Fig. 6e, the inter­atomic separations are much greater than sum of their van der Waals radii and hence do not appear to have influence on the mol­ecular packing. The presence of short inter­atomic C⋯O/O⋯C and N⋯O/O⋯N contacts in the crystal, Table 2, is also evident from the small but significant contributions of 3.3 and 1.3%, respectively, to the Hirshfeld surfaces and appear as pairs of forceps-like tips, Fig. 6f, and conical tips, Fig. 6g, at d_e + d_i ∼3.1 Å in their respective fingerprint plots. The small contributions from the other inter­atomic O⋯O, C⋯N/N⋯C, N⋯N and N⋯H/H⋯N contacts listed in Table 2 have a negligible effect on the packing in the crystal.

Table 3
Percentage contribution to inter­atomic contacts from the Hirshfeld surface for (I)

Contact	Percentage contribution
O⋯H/H⋯O	46.8
H⋯H	32.4
C⋯H/H⋯C	5.9
C⋯C	5.7
C⋯O/O⋯C	3.3
O⋯O	1.6
N⋯O/O⋯N	1.3
C⋯N / N⋯C	1.2
N⋯N	1.0
N⋯H/H⋯N	0.8

Figure 6 (a)The full two-dimensional fingerprint plot for (I) and fingerprint plots delineated into (b) O⋯H/H⋯O, (c) H⋯H, (d) C⋯C, (e) C⋯H/H⋯C, (f) C⋯O/O⋯C and (g) N⋯O/O⋯N contacts.

Figure 7 A view of Hirshfeld surfaces mapped over curvedness showing the flat region about the phenyl ring engaged in face-to-face π–π inter­actions.

5. Database survey

In the Chemical context section above, it was indicated that in the crystallographic literature there are several ammonium salts of 2-amino-4-nitro­benzoate anions. The ammonium cations range from the simple ammonium cation (Smith, 2014b) to R₂NH₂, i.e. R = Me, n-Bu (Wardell et al., 2016), Cy (Smith et al., 2004) and R₂ = (CH₂CH₂)₂O (Smith & Lynch, 2016). More exotic examples of ammonium cations are found with [(H₂N)₂C=NH₂]⁺, i.e. guanidinium (Smith et al., 2007) and the dication, [H₃NCH₂CH₂NH₃]²⁺ (Smith et al., 2002). Key geometric data for these are collated in Table 4. From these data it is apparent that the dihedral angle formed between the the carboxyl­ate group and benzene ring in (I) is at the upper end of structures included in Table 4, and in the same way, the angle between the nitro group and benzene ring is in the upper range of comparable angles. Given that the relationship between the carboxyl­ate and nitro groups in (I) is conrotatory, the dihedral angle between these groups in (I), at 26.73 (14)°, is the greatest among the series.

Table 4
Geometric data (°) for ammonium salts of 2-amino-4-nitro­benzoate. Extreme values for each parameter are bolded

cation	Z′	C6/CO2	C6/NO2	CO2/NO2	Ref.
[NH4]^+ ^a	1	26.4 (3)	2.9 (3)	24.1 (4)	Smith (2014b)
[Me2NH2]^+	1	11.45 (13)	3.71 (15)	7.9 (2)	Wardell et al. (2016)
[n-Bu2NH2]^+	2	12.73 (6)	4.30 (10)	17.02 (8)	Wardell et al. (2016)
		8.1 (4)	12.6 (3)	19.0 (5)
[Cy2NH2]^+	2	9.87 (10)	7.58 (15)	3.42 (19)	Smith et al. (2004)
		9.52 (9)	7.86 (11)	3.92 (2)
[O(CH2CH2)2NH2]^+	1	17.92 (9)	1.28 (11)	19.19 (13)	Smith & Lynch (2016)
[(H2N)2C=NH2]^+ ^a	1	5.88 (11)	5.64 (12)		Smith et al. (2007)
[H3NCH2CH2NH3]^2+ ^b	1	3.44 (14)	0.69 (11)	3.2 (2)	Smith et al. (2002)
[H2NNH3]^2+ ^b	1	18.80 (10)	8.04 (9)	26.73 (14)	this work
Notes: (a) crystallized as a monohydrate; (b) crystallized as a dihydrate.

6. Synthesis and crystallization

Solutions of 2-amino-4-nitrobenzoic acid (1 mmol) in MeOH (10 ml) and hydrazine (1 mmol) in MeOH (15 ml) were mixed and heated under reflux for 30 min. The reaction mixture was left at room temperatures for three days and the red blocks that formed were collected. M.p. 375–377 K (dec.). IR (KBr: cm⁻¹): 3514(s), 3399(s), 3400–2500(br,s), 1680, 1553, 1526, 1425, 1359, 1276, 830, 733.

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 5. Carbon-bound H-atoms were placed in calculated positions (C—H = 0.95–0.99 Å) and were included in the refinement in the riding-model approximation, with U_iso(H) set to 1.2U_eq(C). The O- and N-bound H atoms were located from difference maps, but refined with O—H = 0.84±0.01 Å and U_iso(H) = 1.5U_eq(O), and with N—H = 0.86–0.88±0.01 Å and U_iso(H) = 1.2U_eq(N), respectively. Owing to poor agreement, two reflections, i.e. (202) and (212), were omitted from the final cycles of refinement.

Table 5
Experimental details

Crystal data
Chemical formula	H5N2^+·C7H5N2O4^−·2H2O
Mr	250.22
Crystal system, space group	Triclinic, P
Temperature (K)	120
a, b, c (Å)	6.9695 (2), 8.0960 (3), 10.5316 (3)
α, β, γ (°)	76.468 (2), 73.251 (2), 75.390 (2)
V (Å^3)	542.23 (3)
Z	2
Radiation type	Mo Kα
μ (mm^−1)	0.13
Crystal size (mm)	0.41 × 0.22 × 0.13
Data collection
Diffractometer	Bruker–Nonius Roper CCD camera on κ-goniostat
Absorption correction	Multi-scan (SADABS; Sheldrick, 2007)
Tmin, Tmax	0.644, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	11539, 2497, 2147
Rint	0.034
Refinement
R[F^2 > 2σ(F^2)], wR(F^2), S	0.039, 0.110, 1.05
No. of reflections	2497
No. of parameters	187
No. of restraints	13
Δρmax, Δρmin (e Å^−3)	0.29, −0.30
Computer programs: DENZO (Otwinowski & Minor, 1997), COLLECT (Hooft, 1998), SHELXS97 (Sheldrick, 2008), SHELXL2014 (Sheldrick, 2015), ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2006) and publCIF (Westrip, 2010).

Supporting information

Computing details

Data collection: COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); data reduction: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Hydrazinium 2-amino-4-nitrobenzoate dihydrate

Crystal data

H5N2^+·C7H5N2O4^−·2H2O	Z = 2
Mr = 250.22	F(000) = 264
Triclinic, P1	Dx = 1.533 Mg m^−3
a = 6.9695 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.0960 (3) Å	Cell parameters from 7476 reflections
c = 10.5316 (3) Å	θ = 2.9–27.5°
α = 76.468 (2)°	µ = 0.13 mm^−1
β = 73.251 (2)°	T = 120 K
γ = 75.390 (2)°	Block, red
V = 542.23 (3) Å^3	0.41 × 0.22 × 0.13 mm

Data collection

Bruker–Nonius Roper CCD camera on κ-goniostat diffractometer	2497 independent reflections
Radiation source: Bruker–Nonius FR591 rotating anode	2147 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
Detector resolution: 9.091 pixels mm^-1	θmax = 27.6°, θmin = 3.1°
φ & ω scans	h = −9→8
Absorption correction: multi-scan (SADABS; Sheldrick, 2007)	k = −10→10
Tmin = 0.644, Tmax = 0.746	l = −13→13
11539 measured reflections

Refinement

Refinement on F^2	13 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.039	w = 1/[σ^2(Fo^2) + (0.0646P)^2 + 0.1366P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.110	(Δ/σ)max < 0.001
S = 1.05	Δρmax = 0.29 e Å^−3
2497 reflections	Δρmin = −0.30 e Å^−3
187 parameters

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.40595 (14)	0.36669 (11)	0.25616 (9)	0.0168 (2)
O2	0.46220 (13)	0.18017 (11)	0.11781 (9)	0.0164 (2)
O3	0.04781 (14)	−0.28112 (12)	0.77375 (9)	0.0224 (2)
O4	0.24000 (15)	−0.47250 (11)	0.65475 (9)	0.0195 (2)
N1	0.15996 (17)	0.28747 (14)	0.50370 (11)	0.0163 (2)
H1N	0.218 (2)	0.3697 (17)	0.4483 (14)	0.020*
H2N	0.107 (2)	0.301 (2)	0.5877 (10)	0.020*
N2	0.17056 (16)	−0.32135 (13)	0.67034 (10)	0.0150 (2)
C1	0.34738 (18)	0.08075 (15)	0.35268 (12)	0.0128 (3)
C2	0.23062 (17)	0.12171 (15)	0.47960 (12)	0.0123 (3)
C3	0.17447 (18)	−0.01538 (16)	0.58371 (12)	0.0133 (3)
H3	0.0949	0.0079	0.6698	0.016*
C4	0.23572 (18)	−0.18300 (15)	0.55975 (12)	0.0132 (3)
C5	0.35262 (19)	−0.22781 (16)	0.43707 (13)	0.0152 (3)
H5	0.3943	−0.3450	0.4241	0.018*
C6	0.40531 (19)	−0.09256 (16)	0.33461 (12)	0.0148 (3)
H6	0.4836	−0.1183	0.2489	0.018*
C7	0.40929 (18)	0.21917 (15)	0.23517 (12)	0.0130 (3)
N3	−0.00982 (17)	0.32666 (14)	0.90634 (11)	0.0161 (2)
H3N	0.045 (2)	0.2268 (14)	0.9450 (14)	0.019*
H4N	0.086 (2)	0.3844 (19)	0.8652 (14)	0.019*
H5N	−0.102 (2)	0.3825 (19)	0.9655 (13)	0.019*
N4	−0.09239 (17)	0.30241 (15)	0.80197 (11)	0.0180 (3)
H6N	−0.179 (2)	0.3973 (15)	0.7857 (16)	0.022*
H7N	−0.159 (2)	0.2192 (17)	0.8375 (15)	0.022*
O1W	0.21973 (14)	0.02486 (12)	0.02803 (10)	0.0184 (2)
H1W	0.279 (3)	0.070 (2)	0.0681 (16)	0.028*
H2W	0.312 (2)	−0.033 (2)	−0.0235 (15)	0.028*
O2W	0.31998 (14)	0.45790 (12)	−0.06089 (9)	0.0170 (2)
H3W	0.381 (2)	0.382 (2)	−0.0080 (15)	0.025*
H4W	0.409 (2)	0.506 (2)	−0.1221 (15)	0.025*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0211 (5)	0.0127 (5)	0.0162 (4)	−0.0063 (3)	−0.0025 (3)	−0.0008 (3)
O2	0.0197 (5)	0.0145 (5)	0.0126 (4)	−0.0027 (3)	−0.0020 (3)	−0.0008 (3)
O3	0.0216 (5)	0.0207 (5)	0.0165 (5)	−0.0019 (4)	0.0023 (4)	0.0019 (4)
O4	0.0268 (5)	0.0115 (5)	0.0204 (5)	−0.0057 (4)	−0.0067 (4)	0.0005 (3)
N1	0.0209 (6)	0.0119 (5)	0.0145 (5)	−0.0046 (4)	−0.0005 (4)	−0.0026 (4)
N2	0.0151 (5)	0.0145 (5)	0.0158 (5)	−0.0045 (4)	−0.0059 (4)	0.0009 (4)
C1	0.0127 (6)	0.0121 (6)	0.0139 (6)	−0.0033 (4)	−0.0043 (4)	−0.0004 (4)
C2	0.0113 (6)	0.0120 (6)	0.0147 (6)	−0.0027 (4)	−0.0058 (4)	−0.0009 (4)
C3	0.0122 (6)	0.0148 (6)	0.0126 (6)	−0.0031 (4)	−0.0033 (4)	−0.0012 (4)
C4	0.0129 (6)	0.0127 (6)	0.0140 (6)	−0.0046 (4)	−0.0052 (4)	0.0021 (5)
C5	0.0162 (6)	0.0102 (6)	0.0187 (6)	−0.0014 (4)	−0.0055 (5)	−0.0014 (5)
C6	0.0146 (6)	0.0148 (6)	0.0140 (6)	−0.0025 (4)	−0.0024 (4)	−0.0027 (5)
C7	0.0109 (6)	0.0129 (6)	0.0142 (6)	−0.0016 (4)	−0.0035 (4)	−0.0005 (4)
N3	0.0162 (5)	0.0139 (5)	0.0173 (6)	−0.0033 (4)	−0.0034 (4)	−0.0017 (4)
N4	0.0207 (6)	0.0166 (6)	0.0173 (6)	−0.0050 (4)	−0.0047 (4)	−0.0025 (4)
O1W	0.0177 (5)	0.0171 (5)	0.0203 (5)	−0.0020 (4)	−0.0038 (4)	−0.0056 (4)
O2W	0.0154 (4)	0.0169 (5)	0.0161 (5)	−0.0045 (3)	−0.0037 (3)	0.0029 (4)

Geometric parameters (Å, º)

O1—C7	1.2579 (15)	C4—C5	1.3886 (18)
O2—C7	1.2746 (15)	C5—C6	1.3855 (18)
O3—N2	1.2299 (14)	C5—H5	0.9500
O4—N2	1.2280 (14)	C6—H6	0.9500
N1—C2	1.3644 (16)	N3—N4	1.4492 (15)
N1—H1N	0.873 (9)	N3—H3N	0.864 (9)
N1—H2N	0.877 (9)	N3—H4N	0.865 (9)
N2—C4	1.4692 (15)	N3—H5N	0.872 (9)
C1—C6	1.4010 (17)	N4—H6N	0.864 (9)
C1—C2	1.4153 (17)	N4—H7N	0.865 (9)
C1—C7	1.5035 (16)	O1W—H1W	0.856 (14)
C2—C3	1.4106 (17)	O1W—H2W	0.834 (13)
C3—C4	1.3760 (18)	O2W—H3W	0.847 (13)
C3—H3	0.9500	O2W—H4W	0.852 (13)
C2—N1—H1N	118.5 (11)	C6—C5—H5	121.8
C2—N1—H2N	117.4 (10)	C4—C5—H5	121.8
H1N—N1—H2N	117.3 (15)	C5—C6—C1	122.44 (12)
O4—N2—O3	122.87 (10)	C5—C6—H6	118.8
O4—N2—C4	118.34 (10)	C1—C6—H6	118.8
O3—N2—C4	118.79 (10)	O1—C7—O2	123.11 (11)
C6—C1—C2	119.62 (11)	O1—C7—C1	119.32 (11)
C6—C1—C7	118.73 (11)	O2—C7—C1	117.57 (11)
C2—C1—C7	121.65 (11)	N4—N3—H3N	109.2 (10)
N1—C2—C3	118.52 (11)	N4—N3—H4N	105.8 (10)
N1—C2—C1	123.24 (11)	H3N—N3—H4N	108.1 (15)
C3—C2—C1	118.13 (11)	N4—N3—H5N	112.3 (10)
C4—C3—C2	119.56 (11)	H3N—N3—H5N	110.6 (15)
C4—C3—H3	120.2	H4N—N3—H5N	110.6 (15)
C2—C3—H3	120.2	N3—N4—H6N	105.4 (11)
C3—C4—C5	123.75 (11)	N3—N4—H7N	106.2 (11)
C3—C4—N2	117.70 (11)	H6N—N4—H7N	108.5 (16)
C5—C4—N2	118.54 (11)	H1W—O1W—H2W	106.4 (15)
C6—C5—C4	116.48 (11)	H3W—O2W—H4W	108.3 (15)
C6—C1—C2—N1	−176.80 (11)	O3—N2—C4—C5	−171.63 (11)
C7—C1—C2—N1	2.39 (18)	C3—C4—C5—C6	−0.98 (18)
C6—C1—C2—C3	−0.76 (17)	N2—C4—C5—C6	178.13 (10)
C7—C1—C2—C3	178.43 (10)	C4—C5—C6—C1	0.86 (18)
N1—C2—C3—C4	176.90 (11)	C2—C1—C6—C5	−0.02 (18)
C1—C2—C3—C4	0.67 (17)	C7—C1—C6—C5	−179.23 (11)
C2—C3—C4—C5	0.22 (18)	C6—C1—C7—O1	−161.98 (11)
C2—C3—C4—N2	−178.90 (10)	C2—C1—C7—O1	18.83 (17)
O4—N2—C4—C3	−173.12 (10)	C6—C1—C7—O2	18.36 (16)
O3—N2—C4—C3	7.53 (16)	C2—C1—C7—O2	−160.84 (11)
O4—N2—C4—C5	7.72 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1	0.88 (1)	2.07 (1)	2.7098 (15)	129 (1)
N1—H2N···N4	0.88 (1)	2.29 (1)	3.1403 (16)	165 (1)
N3—H3N···O1W^i	0.86 (1)	1.97 (1)	2.8136 (15)	167 (1)
N3—H4N···O2W^i	0.87 (2)	2.25 (2)	2.8969 (16)	132 (1)
N3—H4N···O4^ii	0.87 (2)	2.34 (1)	3.0739 (15)	143 (1)
N3—H5N···O2W^iii	0.87 (1)	1.93 (2)	2.7862 (15)	167 (1)
N4—H6N···O1^iii	0.87 (1)	2.20 (1)	3.0623 (15)	178 (1)
N4—H7N···O1W^iv	0.87 (1)	2.20 (1)	3.0106 (15)	155 (1)
O1W—H1W···O2	0.86 (2)	1.97 (2)	2.8071 (14)	166 (2)
O1W—H2W···O2^v	0.83 (2)	1.90 (2)	2.7208 (13)	171 (2)
O2W—H3W···O2	0.85 (2)	1.92 (2)	2.7479 (13)	165 (2)
O2W—H4W···O1^vi	0.85 (2)	1.91 (2)	2.7627 (14)	175 (2)

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

 

Footnotes

‡Additional correspondence author, e-mail: [e-mail].