Two N,N-dimethylbiguanidium salts displaying double hydrogen bonds to the counter-ions

The crystal structures of N,N-di­methyl­biguanidium oxalate monohydrate, C₄H₁₃N₅²⁺·C₂O₄²⁻·H₂O, (I), and N,N-di­methyl­biguanidium sulfate monohydrate, C₄H₁₃N₅²⁺·SO₄²⁻·H₂O, (II), show that both compounds contain the same N,N-di­methyl­biguanidium dication. In (I), two independent oxalate ions lie about inversion centres. Strong double hydrogen bonds, with D...A distances of 2.658 (2) and 2.830 (3) Å in (I), and 2.722 (3) and 2.815 (3) Å in (II), are present between N atoms of the N,N-di­methyl­biguanidium moieties and either the carboxyl­ate group of the oxalate anion or the sulfate anion.

S1. Comment

An N-substituted derivative of biguanide, metformin (N,N-dimethylbiguanide), is a powerful oral antihyperglycaemic drug that has been used in many countries for over 40 years for treating diabetic patients with non-insulin-dependent diabetes mellitus. However, the mechanism of action of this drug is still unknown. Because this compound contains a biguanidinium group, it can form complexes with many metal ions (Ray, 1961; Zhu et al., 2002a,2002b,2002c; Lu et al., 2004b). Recently, we found that N,N-dimethybiguanidium loses its ability to lower blood glucose levels when forming a monodentate [mononuclear?] complex with Zn²⁺, but retains this ability when forming bidentate [binuclear?] complexes with Cu²⁺ and Ni²⁺ (Zhu et al. 2004). On the other hand, guanidinium may play an important role in recognizing anions, such as carboxylates, phosphates, sulfates and nitrates, in biological systems (Baggio et al., 1997; Liu et al., 2001; Lu et al., 2001; Best et al., 2003). It has been proven that a strong interaction between the guanidinium groups and anions through charge pairing and hydrogen bonding facilitates the recognition of small target anions by receptors containing guanidinium groups in competitive solvent systems (Best et al., 2003). We elucidate here the possible mechanism of N,N-dimethybiguanide interacting with target molecules by reporting the crystal structures of N,N-dimethybiguanidinium oxalate(I) and N,N-dimethybiguanidinium sulfate(II).

Some features of the molecular geometries of (I) and (II) are listed in Table 1. The molecular conformation is illustrated in Figs.1 and 2. Compound (I) contains one N,N-dimethybiguanidinium dication, one oxalate anion and one water molecule. Compound (II) consists of one N,N-dimethybiguanidinium dication, one sulfate anion and one water molecule. Both compounds thus contain the same N,N-dimethybiguanidinium dication. The C—N bonds of the biguanidinium moiety in both compounds range from 1.302 (3) to 1.374 (3) Å in (I) and 1.308 (4) to 1.383 (4) Å in (II); this situation differs from that in N,N-dimethybiguanidinium nitrate, in which the C—N bonds are more uniform [1.324 (3)–1.343 (3) Å; Zhu et al., 2003). The dihedral angles between the two guanidine group planes are 52.8 (1) and 56.1 (1)° in (I) and (II)?, respectively. Therefore, the anions slightly influence the structure of N,N-dimethybiguanide.

The hydrogen-bonding geometries in (I) and (II) are listed in Table 2 and illustrated in Figs. 3 and 4. A number of intra- and intermolecular hydrogen bonds stabilize crystal structure of each compound. These hydrogen bonds are formed mainly between the biguanidinium groups and the oxalate or sulfate anion, between the biguanidinium groups and the water molecules, and between? the carboxylate or sulfate and water molecules. Strong double hydrogen bonds are formed between either the carboxylate groups of the oxalate anion or the sulfate groups and atoms N3 and N5 of the biguanidinium groups of the cation. The D···A distances are 2.658 (2) and 2.830 (3) Å in (I), and 2.722 (3) and 2.815 (3) Å in (II), giving rise to an elongated hexagon. Double hydrogen bonds are also found in N,N-dimethybiguanidium nitrate at the corresponding N3- and N5-atom sites, but these bonds are formed between a pair of N,N-dimethybiguanidium cations, not between the N,N-dimethybiguanidium cations and the nitrate anions (Zhu et al., 2003). Therefore, the N,N-dimethybiguanidium cation exhibits a common characteristic that the N3- and N5-atom sites take part in the formation of double hydrogen bonds, in contrast to the double hydrogen bonds formed in biguanidinium nitrate, in which double hydrogen bonds are formed between nitrate anions and atoms N1 and N2 or N4 and N5 of the biguanidinium cation (Lu et al., 2004a). Because N,N-dimethybiguanidium loses its ability to lower blood glucose levels when complexing with the Zn²⁺ ion at the N3-atom site (perhaps interfering the formation of double hydrogen bonds), and yet retains this ability when forming bidentate [binuclear?] complexes with Cu²⁺ and Ni²⁺ ions at the N2 and N4 sites, we speculate that this double hydrogen bond between N,N-dimethybiguanide and its target molecules plays an important role in the interaction with target molecules in biological systems.

S2. Experimental

All chemicals were commercially available from the Beijing Chemical Reagents Company, People's Republic of China, were of reagent grade and were used without further purification. N,N-Dimethylbiguanide was obtained from a 1:1 molar ratio of N,N-dimethylbiguanide hydrochloride and NaOH in 2-propanol. The suspension was stirred for an hour at 313 K and then filtered. The filtrate was evaporated and a white solid, without Cl⁻ (checked by 0.1 M AgNO³ solution), was collected. Compounds (I) and (II) were prepared by dissolving N,N-dimethylbiguanide (10.0 mmol) in water (5 ml) and adding either oxalic or sulfuric acid, adjusting the pH to 4. Crystals of both compounds were obtained from their respective solutions after several weeks, by slow evaporation of the aqueous solvent at room temperature.

S3. Refinement

In both (I) and (II), H atoms attached to C and N atoms were placed in idealized positions [Csp³—H = 0.96 Å and Nsp²—H = 0.86 Å] and constrained to ride on their parent atoms, with U_iso(H) values of 1.5U_eq(C) or 1.2U_eq(N). H atoms attached to O atoms were located from difference Fourier maps and their parameters were refined, assuming a common U_iso(H) value. The O—H distances are in the range 0.819–0.821 Å.

Computing details

For both compounds, data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2000); program(s) used to refine structure: SHELXL97 (Sheldrick, 2000); molecular graphics: SHELXTL/PC (Sheldrick, 1999); software used to prepare material for publication: SHELXTL/PC.

Figures

	Fig. 1. The structure of (I), with displacement ellipsoids drawn at the 40% probability level for non-H atoms. [Symmetry codes: (A) 2 − x, 2 − y, 2 − z; (B) −x, 1 − y, −z.]
	Fig. 2. The structure of (II), with displacement ellipsoids drawn at the 40% probability level.
	Fig. 3. The double hydrogen bonds between atoms N3 and N5 of the biguanidium groups and the carboxylate groups of the oxalate anion in (I). [Symmetry codes: (A) x, 1.5 − y, −0.5 + z; (B) 2 − x, y − 0.5 1.5 − z; (C) x, 1.5 − y, −0.5 + z; (E) 2 − x, 1 − y, 1 − z; (G) −1 + x, y, z; (H) −1 + x,1.5 − y, −0.5 + z; (I) 1 − x,-0.5 + y, 1.5 − z; (J) 1 − x, 1 − y, 1 − z; (K) 1 − x, −0.5 + y, 0.5 − z; (L) 1 + x, 0.5 − y, 0.5 + z.]
	Fig. 4. The double hydrogen bonds between atoms N3 and N5 of the biguanidinium groups and the sulfate anions in (II). [Symmetry codes: (A) x − 1, y − 1, z; (B) 1 − x, 1 − y, 1 − z; (C) 2 − x, 2 − y, 1 − z.]

(I) N,N-dimethylbiguanidium oxalate hydrate

Crystal data

C4H13N5^2+·C2O4^2^−·H2O	F(000) = 504
Mr = 237.23	Dx = 1.468 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1102 reflections
a = 6.775 (2) Å	θ = 2.3–22.0°
b = 10.762 (3) Å	µ = 0.13 mm^−1
c = 14.731 (4) Å	T = 298 K
β = 92.561 (4)°	Block, colorless
V = 1073.1 (5) Å^3	0.40 × 0.18 × 0.12 mm
Z = 4

Data collection

Brker SMART 1K CCD area-detector diffractometer	1885 independent reflections
Radiation source: fine-focus sealed tube	1295 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.059
ω scan	θmax = 25.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −8→7
Tmin = 0.614, Tmax = 0.974	k = −12→6
4303 measured reflections	l = −17→17

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) = 0.102	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0368P)^2] where P = (Fo^2 + 2Fc^2)/3
1885 reflections	(Δ/σ)max < 0.001
155 parameters	Δρmax = 0.24 e Å^−3
0 restraints	Δρmin = −0.23 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
C1	0.4687 (4)	1.0035 (2)	0.86910 (16)	0.0431 (7)
H4A	0.5299	0.9571	0.9184	0.065*
H4B	0.3413	1.0322	0.8860	0.065*
H4C	0.5501	1.0735	0.8555	0.065*
C2	0.2794 (4)	0.8373 (2)	0.78772 (17)	0.0429 (7)
H3A	0.1598	0.8807	0.7704	0.064*
H3B	0.2680	0.8021	0.8471	0.064*
H3C	0.3012	0.7722	0.7448	0.064*
C3	0.5704 (3)	0.9300 (2)	0.72262 (14)	0.0255 (5)
C4	0.6255 (3)	0.8159 (2)	0.58361 (15)	0.0273 (5)
N1	0.4456 (3)	0.92407 (19)	0.78902 (12)	0.0299 (5)
N2	0.7407 (3)	0.98811 (17)	0.72951 (12)	0.0300 (5)
H21	0.7765	1.0251	0.7793	0.036*
H22	0.8165	0.9892	0.6842	0.036*
N3	0.5085 (3)	0.87860 (18)	0.64082 (12)	0.0285 (5)
H3	0.3858	0.8867	0.6244	0.034*
N4	0.7931 (3)	0.76763 (18)	0.61228 (13)	0.0337 (5)
H41	0.8628	0.7259	0.5756	0.040*
H42	0.8342	0.7775	0.6679	0.040*
N5	0.5575 (3)	0.8030 (2)	0.49935 (12)	0.0376 (6)
H51	0.6241	0.7618	0.4612	0.045*
H52	0.4462	0.8359	0.4822	0.045*
C5	0.9501 (3)	0.9780 (2)	0.95391 (15)	0.0281 (6)
O1	0.8822 (3)	0.86957 (16)	0.95187 (10)	0.0422 (5)
O2	0.9466 (2)	1.05278 (16)	0.88959 (10)	0.0419 (5)
C6	0.1005 (3)	0.5310 (2)	0.01310 (15)	0.0268 (5)
O3	0.1527 (2)	0.53023 (16)	0.09624 (10)	0.0365 (4)
O4	0.1963 (2)	0.57688 (16)	−0.04908 (10)	0.0373 (4)
O1W	0.1800 (3)	0.20718 (18)	0.69388 (12)	0.0563 (6)
H11	0.1521	0.2556	0.6522	0.071 (8)*
H12	0.1575	0.1395	0.6702	0.071 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0453 (15)	0.0503 (18)	0.0344 (14)	0.0026 (14)	0.0092 (12)	−0.0109 (13)
C2	0.0375 (15)	0.0486 (18)	0.0431 (16)	−0.0060 (14)	0.0091 (12)	0.0012 (14)
C3	0.0279 (12)	0.0240 (13)	0.0244 (12)	0.0072 (11)	−0.0005 (10)	0.0008 (10)
C4	0.0262 (12)	0.0243 (13)	0.0318 (13)	−0.0022 (11)	0.0040 (11)	−0.0020 (11)
N1	0.0277 (10)	0.0355 (12)	0.0268 (11)	0.0015 (10)	0.0052 (8)	−0.0029 (9)
N2	0.0306 (11)	0.0351 (13)	0.0246 (10)	−0.0040 (10)	0.0035 (8)	−0.0086 (9)
N3	0.0192 (9)	0.0384 (12)	0.0277 (10)	0.0037 (9)	−0.0006 (8)	−0.0086 (10)
N4	0.0258 (11)	0.0365 (13)	0.0387 (12)	0.0063 (10)	−0.0003 (9)	−0.0118 (10)
N5	0.0364 (12)	0.0456 (14)	0.0307 (11)	0.0093 (11)	0.0008 (9)	−0.0151 (10)
C5	0.0254 (12)	0.0328 (15)	0.0266 (13)	−0.0060 (11)	0.0068 (10)	−0.0019 (12)
O1	0.0589 (12)	0.0358 (11)	0.0318 (10)	−0.0172 (10)	0.0008 (8)	−0.0013 (9)
O2	0.0514 (11)	0.0453 (12)	0.0284 (9)	−0.0186 (9)	−0.0064 (8)	0.0094 (9)
C6	0.0250 (12)	0.0276 (14)	0.0278 (13)	0.0028 (11)	0.0014 (10)	−0.0028 (11)
O3	0.0345 (9)	0.0481 (11)	0.0265 (9)	−0.0051 (8)	−0.0034 (7)	0.0005 (8)
O4	0.0345 (9)	0.0478 (12)	0.0298 (9)	−0.0109 (9)	0.0037 (8)	−0.0002 (8)
O1W	0.0872 (16)	0.0414 (12)	0.0395 (11)	0.0030 (11)	−0.0079 (10)	0.0005 (9)

Geometric parameters (Å, º)

C1—N1	1.460 (3)	N2—H22	0.8600
C1—H4A	0.9600	N3—H3	0.8600
C1—H4B	0.9600	N4—H41	0.8600
C1—H4C	0.9600	N4—H42	0.8600
C2—N1	1.463 (3)	N5—H51	0.8600
C2—H3A	0.9600	N5—H52	0.8600
C2—H3B	0.9600	C5—O2	1.243 (3)
C2—H3C	0.9600	C5—O1	1.254 (3)
C3—N2	1.312 (3)	C5—C5^i	1.563 (4)
C3—N1	1.323 (3)	C6—O4	1.248 (2)
C3—N3	1.374 (3)	C6—O3	1.260 (3)
C4—N4	1.302 (3)	C6—C6^ii	1.549 (4)
C4—N5	1.312 (3)	O1W—H11	0.8209
C4—N3	1.361 (3)	O1W—H12	0.8191
N2—H21	0.8600
N1—C1—H4A	109.5	C1—N1—C2	116.05 (18)
N1—C1—H4B	109.5	C3—N2—H21	120.0
H4A—C1—H4B	109.5	C3—N2—H22	120.0
N1—C1—H4C	109.5	H21—N2—H22	120.0
H4A—C1—H4C	109.5	C4—N3—C3	125.4 (2)
H4B—C1—H4C	109.5	C4—N3—H3	117.3
N1—C2—H3A	109.5	C3—N3—H3	117.3
N1—C2—H3B	109.5	C4—N4—H41	120.0
H3A—C2—H3B	109.5	C4—N4—H42	120.0
N1—C2—H3C	109.5	H41—N4—H42	120.0
H3A—C2—H3C	109.5	C4—N5—H51	120.0
H3B—C2—H3C	109.5	C4—N5—H52	120.0
N2—C3—N1	123.7 (2)	H51—N5—H52	120.0
N2—C3—N3	119.5 (2)	O2—C5—O1	126.1 (2)
N1—C3—N3	116.7 (2)	O2—C5—C5^i	117.3 (3)
N4—C4—N5	122.0 (2)	O1—C5—C5^i	116.5 (3)
N4—C4—N3	121.4 (2)	O4—C6—O3	125.7 (2)
N5—C4—N3	116.6 (2)	O4—C6—C6^ii	117.9 (2)
C3—N1—C1	121.4 (2)	O3—C6—C6^ii	116.5 (2)
C3—N1—C2	122.6 (2)	H11—O1W—H11	102.3
N2—C3—N1—C1	13.0 (3)	N4—C4—N3—C3	20.3 (3)
N3—C3—N1—C1	−162.6 (2)	N5—C4—N3—C3	−161.9 (2)
N2—C3—N1—C2	−166.1 (2)	N2—C3—N3—C4	41.0 (3)
N3—C3—N1—C2	18.3 (3)	N1—C3—N3—C4	−143.1 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H21···O2	0.86	1.97	2.774 (2)	155
N3—H3···O3^iii	0.86	1.85	2.658 (2)	157
N4—H41···O1^iv	0.86	2.10	2.873 (2)	149
N4—H42···O1W^v	0.86	2.18	2.926 (3)	145
N5—H51···O1^iv	0.86	2.26	2.986 (3)	143
N5—H52···O4^iii	0.86	1.97	2.830 (3)	175
O1W—H12···O3^vi	0.82	2.13	2.934 (3)	169
O1W—H11···O1^vii	0.82	1.97	2.786 (2)	173
N2—H22···O4^viii	0.86	2.20	2.874 (2)	135

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

(II) N,N-dimethylbiguanidium sulfate hydrate

Crystal data

C4H13N5^2+·O4S^2^−·H2O	Z = 2
Mr = 245.27	F(000) = 260
Triclinic, P1	Dx = 1.512 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.056 (3) Å	Cell parameters from 1531 reflections
b = 8.862 (4) Å	θ = 2.5–26.9°
c = 9.462 (4) Å	µ = 0.32 mm^−1
α = 99.830 (6)°	T = 293 K
β = 96.020 (7)°	Block, colorless
γ = 110.099 (7)°	0.32 × 0.15 × 0.15 mm
V = 538.8 (4) Å^3

Data collection

Bruker SMART 1K CCD area-detector diffractometer	1741 independent reflections
Radiation source: fine-focus sealed tube	1508 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
ω scan	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −8→6
Tmin = 0.094, Tmax = 0.966	k = −10→10
2516 measured reflections	l = −11→10

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.162	H atoms treated by a mixture of independent and constrained refinement
S = 1.18	w = 1/[σ^2(Fo^2) + (0.0993P)^2 + 0.1217P] where P = (Fo^2 + 2Fc^2)/3
1739 reflections	(Δ/σ)max < 0.001
139 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.36 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
C1	1.0935 (6)	0.5395 (4)	0.3032 (5)	0.0492 (10)
H1A	0.9725	0.4717	0.3327	0.074*
H1B	1.2128	0.5445	0.3657	0.074*
H1C	1.0961	0.4932	0.2044	0.074*
C2	1.2107 (6)	0.8309 (4)	0.4479 (4)	0.0474 (9)
H2A	1.3532	0.8719	0.4404	0.071*
H2B	1.1936	0.7815	0.5308	0.071*
H2C	1.1621	0.9203	0.4595	0.071*
C3	0.9666 (4)	0.7343 (3)	0.2191 (3)	0.0271 (7)
C4	0.8455 (5)	0.9577 (4)	0.1907 (3)	0.0274 (7)
N1	1.0919 (4)	0.7060 (3)	0.3139 (3)	0.0314 (6)
N2	0.8228 (4)	0.6166 (3)	0.1207 (3)	0.0315 (6)
H22	0.8079	0.5154	0.1165	0.038*
H21	0.7437	0.6409	0.0605	0.038*
N3	0.9962 (4)	0.8966 (3)	0.2180 (3)	0.0297 (6)
H3	1.1208	0.9656	0.2361	0.036*
N4	0.6618 (4)	0.8843 (3)	0.2172 (3)	0.0319 (6)
H41	0.5697	0.9263	0.2046	0.038*
H42	0.6331	0.7941	0.2472	0.038*
N5	0.8969 (4)	1.0953 (3)	0.1448 (3)	0.0340 (7)
H51	0.8085	1.1406	0.1311	0.041*
H52	1.0191	1.1404	0.1284	0.041*
S1	0.47039 (11)	0.24350 (8)	0.19611 (7)	0.0258 (3)
O1	0.3021 (3)	0.2777 (3)	0.1209 (2)	0.0368 (6)
O2	0.6393 (3)	0.2732 (3)	0.1132 (2)	0.0362 (6)
O3	0.3956 (3)	0.0702 (3)	0.2107 (3)	0.0405 (6)
O4	0.5446 (4)	0.3507 (3)	0.3411 (3)	0.0487 (7)
O1W	0.6623 (4)	0.6879 (3)	0.4229 (3)	0.0565 (8)
H11	0.6325	0.7086	0.5035	0.066 (10)*
H12	0.6286	0.5895	0.3867	0.066 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.050 (2)	0.0320 (17)	0.063 (2)	0.0180 (16)	−0.0140 (18)	0.0121 (16)
C2	0.052 (2)	0.0405 (19)	0.040 (2)	0.0134 (17)	−0.0123 (17)	0.0043 (15)
C3	0.0298 (17)	0.0273 (15)	0.0301 (15)	0.0132 (13)	0.0103 (13)	0.0131 (12)
C4	0.0340 (17)	0.0261 (15)	0.0242 (15)	0.0150 (13)	0.0026 (12)	0.0046 (11)
N1	0.0327 (14)	0.0281 (13)	0.0339 (14)	0.0119 (11)	0.0007 (11)	0.0098 (11)
N2	0.0407 (16)	0.0242 (12)	0.0309 (14)	0.0145 (11)	−0.0003 (11)	0.0078 (11)
N3	0.0189 (13)	0.0213 (12)	0.0452 (15)	0.0024 (10)	0.0031 (11)	0.0103 (11)
N4	0.0280 (14)	0.0291 (13)	0.0429 (15)	0.0128 (11)	0.0081 (11)	0.0130 (11)
N5	0.0286 (14)	0.0304 (14)	0.0500 (17)	0.0141 (11)	0.0096 (12)	0.0185 (12)
S1	0.0274 (5)	0.0227 (4)	0.0288 (5)	0.0098 (3)	0.0042 (3)	0.0092 (3)
O1	0.0327 (12)	0.0432 (13)	0.0408 (13)	0.0171 (10)	0.0045 (10)	0.0204 (10)
O2	0.0367 (13)	0.0305 (11)	0.0484 (14)	0.0162 (10)	0.0140 (11)	0.0149 (10)
O3	0.0325 (13)	0.0286 (12)	0.0658 (16)	0.0119 (10)	0.0104 (11)	0.0216 (11)
O4	0.0619 (17)	0.0455 (14)	0.0299 (13)	0.0130 (12)	0.0011 (11)	0.0043 (11)
O1W	0.083 (2)	0.0428 (15)	0.0516 (16)	0.0231 (14)	0.0326 (14)	0.0193 (12)

Geometric parameters (Å, º)

C1—N1	1.466 (4)	N2—H22	0.8600
C1—H1A	0.9600	N2—H21	0.8600
C1—H1B	0.9600	N3—H3	0.8600
C1—H1C	0.9600	N4—H41	0.8600
C2—N1	1.482 (4)	N4—H42	0.8600
C2—H2A	0.9600	N5—H51	0.8600
C2—H2B	0.9600	N5—H52	0.8600
C2—H2C	0.9600	S1—O4	1.457 (2)
C3—N1	1.308 (4)	S1—O1	1.467 (2)
C3—N2	1.314 (4)	S1—O2	1.468 (2)
C3—N3	1.383 (4)	S1—O3	1.479 (2)
C4—N4	1.308 (4)	O1W—H11	0.8195
C4—N5	1.310 (4)	O1W—H12	0.8202
C4—N3	1.370 (4)
N1—C1—H1A	109.5	C1—N1—C2	117.0 (3)
N1—C1—H1B	109.5	C3—N2—H22	120.0
H1A—C1—H1B	109.5	C3—N2—H21	120.0
N1—C1—H1C	109.5	H22—N2—H21	120.0
H1A—C1—H1C	109.5	C4—N3—C3	126.1 (2)
H1B—C1—H1C	109.5	C4—N3—H3	117.0
N1—C2—H2A	109.5	C3—N3—H3	117.0
N1—C2—H2B	109.5	C4—N4—H41	120.0
H2A—C2—H2B	109.5	C4—N4—H42	120.0
N1—C2—H2C	109.5	H41—N4—H42	120.0
H2A—C2—H2C	109.5	C4—N5—H51	120.0
H2B—C2—H2C	109.5	C4—N5—H52	120.0
N1—C3—N2	123.1 (3)	H51—N5—H52	120.0
N1—C3—N3	117.8 (3)	O4—S1—O1	109.78 (15)
N2—C3—N3	118.9 (3)	O4—S1—O2	109.13 (15)
N4—C4—N5	122.4 (3)	O1—S1—O2	109.81 (13)
N4—C4—N3	120.4 (3)	O4—S1—O3	108.73 (14)
N5—C4—N3	117.2 (3)	O1—S1—O3	109.52 (13)
C3—N1—C1	120.4 (3)	O2—S1—O3	109.85 (13)
C3—N1—C2	121.9 (3)	H11—O1W—H12	115.0
N2—C3—N1—C1	7.4 (5)	N4—C4—N3—C3	26.4 (4)
N3—C3—N1—C1	−168.6 (3)	N5—C4—N3—C3	−157.0 (3)
N2—C3—N1—C2	−162.2 (3)	N1—C3—N3—C4	−144.4 (3)
N3—C3—N1—C2	21.8 (4)	N2—C3—N3—C4	39.4 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H22···O2	0.86	2.06	2.854 (3)	153
N2—H21···O1^i	0.86	2.01	2.784 (3)	150
N3—H3···O3^ii	0.86	1.90	2.722 (3)	159
N4—H41···O3^iii	0.86	2.05	2.895 (3)	167
N4—H42···O1W	0.86	2.07	2.825 (4)	146
N5—H51···O2^iii	0.86	1.96	2.810 (3)	172
N5—H52···O1^ii	0.86	1.97	2.815 (3)	169
O1W—H11···O4^iv	0.82	2.05	2.799 (4)	152
O1W—H12···O4	0.82	1.95	2.755 (4)	168

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