The inner-salt zwitterion, the dihydro­chloride dihydrate and the dimethyl sulfoxide disolvate of 3,6-bis­(pyridin-2-yl)pyrazine-2,5-dicarb­oxy­lic acid

In the inner-salt zwitterion of 3,6-bis­(pyridin-2-yl)pyrazine-2,5-dicarb­oxy­lic acid, (I), namely 5-carb­oxy-3-(pyridin-1-ium-2-yl)-6-(pyridin-2-yl)pyrazine-2-carboxyl­ate, [C₁₆H₁₀N₄O₄, (Ia)], the pyrazine ring has a twist–boat conformation. The opposing pyridine and pyridinium rings are almost perpendicular to one another, with a dihedral angle of 80.24 (18)°, and are inclined to the pyrazine mean plane by 36.83 (17) and 43.74 (17)°, respectively. The carb­oxy and carboxyl­ate groups are inclined to the mean plane of the pyrazine ring by 43.60 (17) and 45.46 (17)°, respectively. In the crystal structure, the mol­ecules are linked via N—H...O and O—H...O hydrogen bonds, leading to the formation of double-stranded chains propagating in the [010] direction. On treating (Ia) with aqueous 1 M HCl, the diprotonated dihydrate form 2,2′-(3,6-dicar­boxy­pyrazine-2,5-di­yl)bis­(pyridin-1-ium) dichloride dihydrate [C₁₆H₁₂N₄O₄²⁺·2Cl⁻·2H₂O, (Ib)] was obtained. The cation lies about an inversion centre. The pyridinium rings and carb­oxy groups are inclined to the planar pyrazine ring by 55.53 (9) and 19.8 (2)°, respectively. In the crystal structure, the mol­ecules are involved in N—H...Cl, O—H...O_water and O_water—H...Cl hydrogen bonds, leading to the formation of chains propagating in the [010] direction. When (Ia) was recrystallized from dimethyl sulfoxide (DMSO), the DMSO disolvate 3,6-bis­(pyridin-2-yl)pyrazine-2,5-dicarb­oxy­lic acid dimethyl sulfoxide disolvate [C₁₆H₁₀N₄O₄·2C₂H₆OS, (Ic)] of (I) was obtained. Here, the mol­ecule of (I) lies about an inversion centre and the pyridine rings are inclined to the planar pyrazine ring by only 23.59 (12)°. However, the carb­oxy groups are inclined to the pyrazine ring by 69.0 (3)°. In the crystal structure, the carb­oxy groups are linked to the DMSO mol­ecules by O—H...O hydrogen bonds. In all three crystal structures, the presence of nonclassical hydrogen bonds gives rise to the formation of three-dimensional supra­molecular architectures.

S1. Comment

Various pyrazine carboxylic acids have been used for many years as ligands in coordination chemistry. A search of the Cambridge Structural Database (CSD, Version 5.33, Update 4, August 2012; Allen, 2002), for pyrazine-2,5-dicarboxylic acid yielded 63 hits, including more than 50 coordination complexes. A search for 2,5-bis(pyridin-2-yl)pyrazine yielded 27 hits, including 26 coordination complexes. Among the pyridyl and carboxylic acid derivatives of pyrazine, 2,3,5,6-tetrakis(pyridin-2-yl)pyrazine (TPPZ) and pyrazine-2,3,5,6-tetracarboxylic acid (H4pztca) also feature. Both ligands are relatively old; TPPZ was first synthesized in 1959 by Goodwin & Lions (1959), while the first mention of the synthesis of H4pztca dates back to 1887 (Wolf, 1887, 1893). These compounds have also been studied extensively in the domain of coordination chemistry. A search of the CSD revealed 173 hits for TPPZ, including more than 150 mono-, bi-, tri- or polynuclear coordination complexes. There were 56 hits for H4pztca, including more than 40 mono-, bi- or polynuclear coordination complexes. For example, it was shown for the first time that a binuclear copper(II) complex of TPPZ could be formed, namely bis[diaqua[µ₂-2,3,5,6-tetrakis(2-pyridyl)pyrazine-κ⁶N,N',N'',N''',N'''',N''''']copper(II)] tetraperchlorate dihydrate (Graf et al., 1993). It possesses an inversion centre and the pyridine rings rotate out of the plane of the planar pyrazine ring to accommodate the Cu^II atoms. The first crystal structure analysis of a metal complex of H4pztca involved iron(II) and resulted in the formation of a one-dimensional coordination polymer, namely catena-poly[[trans-diaqua(µ₂-2,5-dicarboxypyrazine-3,6-dicarboxylato-κ²N,O)diiron(II)] dihydrate] (Marioni et al., 1986).

3,6-Bis(pyridin-2-yl)pyrazine-2,5-dicarboxylic acid, (I), and the isostructural compound 5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylic acid, (II) (Alfonso et al., 2001), with a combination of pyridine and carboxylic acid substituents, were synthesized to study their coordination behaviour with first-row transition metals. They do indeed exhibit a highly diverse coordination geometry (Wang, 1996; Alfonso, 1999). A prominent characteristic of these compounds is their amphoteric character, as they can exist as inner-salt zwitterions and as doubly charged species.

The inner-salt zwitterion of (I), 5-carboxy-3-(pyridin-1-ium-2-yl)-6-(pyridin-2-yl)pyrazine-2-carboxylate, (Ia) (Fig. 1), was obtained on treating the diethyl ester of (I) with KOH (see Experimental). The pyrazine ring (atoms N1/N2/C1–C4) is not planar [maximum deviation = 0.052 (3) Å for atom C2] but has a twist–boat conformation [puckering parameters (Cremer & Pople, 1975): pucking amplitude = 0.091 (3) Å, θ = 94.1 (19)° and ϕ = 280.4 (19)°]. The opposing pyridine and pyridinium rings are almost perpendicular to one another, with a dihedral angle of 80.24 (18)°, and they are inclined to the pyrazine ring mean plane by 36.83 (17) and 43.74 (17)°, respectively. The carboxy (–COOH) and carboxylate (COO–) groups are inclined to the mean plane of the pyrazine ring by 43.60 (17) and 45.46 (17)°, respectively.

In the crystal structure of (Ia), the pyridinium H atoms and the carboxy and carboxylate groups are involved in N—H···O and O—H···O hydrogen bonds (Table 1 and Fig. 2), leading to the formation of double-stranded chains propagating in the [010] direction. These chains incorporate R₃³(19) ring motifs (Bernstein et al., 1995) involving three molecules. The presence of C—H···O interactions leads to the formation of two-dimensional networks lying parallel to the bc plane (Table 1). These networks are in turn linked via C—H···N interactions to form a three-dimensional structure (Fig. 3).

On treating (Ia) with aqueous 1M HCl, the diprotonated dihydrate form 2,2'-(3,6-dicarboxypyrazine-2,5-diyl)bis(pyridin-1-ium) dichloride dihydrate, (Ib), was obtained (Fig. 4). The cation lies about an inversion centre and the pyrazine ring is planar. The pyridinium rings and the carboxy groups (–COOH) are inclined to the pyrazine ring by 55.53 (9) and 19.8 (2)°, respectively.

In the crystal structure of (Ib), the molecules are involved in N—H···Cl and O—H···O_water hydrogen bonds (Table 2 and Fig. 5). The Cl^- anions are in turn bridged by O_water—H..Cl hydrogen bonds, forming R₄²(8) ring motifs. This leads to the formation of chains propagating in the [010] direction. The presence of C—H···Cl and C—H···O interactions leads to the formation of a three-dimensional framework-like structure (Table 2 and Fig. 6)

When (Ia) was recrystallized from dimethyl sulfoxide (DMSO), the DMSO disolvate of (I) was obtained, viz. 3,6-bis(pyridin-2-yl)pyrazine-2,5-dicarboxylic acid dimethyl sulfoxide disolvate, (Ic) (Fig. 7). Here, the molecule of (I) lies about an inversion centre and the pyrazine ring is planar. The pyridine rings are inclined to the pyrazine ring by 23.59 (12)°, while the carboxy (–COOH) groups are inclined to the pyrazine ring by 69.0 (3)°.

In the crystal structure of (Ic), the carboxy groups are linked to the DMSO molecules by O—H···O hydrogen bonds (Table 3 and Fig. 8). A series of C—H···O interactions involving both components of the crystal structure leads to the formation of a three-dimensional supramolecular structure (Table 3 and Fig. 9).

The dimethyl ester, (III), and the diethyl ester, (IV), of (I) both crystallize in the triclinic space group P1 (Wang & Stoeckli-Evans, 2012a,b). In both cases, the whole molecules are generated by crystallographic inversion symmetry. The pyridine rings lie almost in the plane of the pyrazine ring, with dihedral angles of 7.89 (13)° for (III) and 1.7 (2)° for (IV). In (III), the methyl carboxylate mean plane [maximum deviation for non-H atoms = 0.041 (3) Å [For which atom?]] makes a dihedral angle of 74.09 (19)° with the pyrazine ring. In (IV), the ethyl carboxylate mean plane [maximum deviation for non-H atoms = 0.042 (5) Å [For which atom?]] makes a dihedral angle of 79.5 (3)°. In the crystal structures of both esters, the molecules are linked by pairs of C—H···O hydrogen bonds to form chains propagating along [101] and incorporating R₂²(10) ring motifs.

Related literature

For related literature, see: Alfonso (1999); Alfonso et al. (2001); Allen (2002); Altaf et al. (2012); Bernstein et al. (1995); Cremer & Pople (1975); Goodwin & Lions (1959); Graf et al. (1993); Marioni et al. (1986); Wang (1996); Wang & Stoeckli-Evans (2012a, 2012b); Wolf (1887, 1893).

S2. Experimental

Ethyl 2-amino-3-oxo-3-(pyridin-2-yl)propanoate, (V), was first prepared by hydrogenation of ethyl 2-hydroxyimino-3-oxo-3-(pyridin-2-yl)propanoate (Altaf et al., 2012) in dry ethyl acetate using 5% Rh/Al₂O₃ catalyst (0.3 g) in an autoclave for 24 h at room temperature. The initial pressure of hydrogen was 3.5 bar (1 bar = 100 000 Pa). After stopping the reaction, the solution was filtered to remove the catalyst, then the filtrate was concentrated under reduced pressure as quickly as possible to afford (V) as a white solid (yield 2.02 g, 97%; m.p. 401–404 K). This compound is not stable in solution and was used directly to be transformed into diethyl 3,6-bis(pyridin-2-yl)pyrazine-2,5-dicarboxylate, (IV), by dissolving (V) (4.16 g, 20 mmol) in chloroform (200 ml). The solution was stirred under a condenser at room temperature until the starting material had been consumed, then the solvent was removed under reduced pressure to yield the crude product. Recrystallization from ethanol gave (IV) as colourless crystals (Wang & Stoeckli-Evans, 2012b) (yield 1.40 g, 37%; m.p. 187–189 K ???).

Compound (IV) (775 mg, 2.05 mmol) was then added to an aqueous solution of KOH (5 g, 13 ml H₂O). The mixture was refluxed at 375 K for 3 h and then allowed to cool to room temperature. It was then acidified with 4 N HCl until a white solid formed (ca pH = 2). This was filtered off, washed with water and chloroform and dried under vacuum to yield (Ia) as a white solid (yield 640 mg, 92%; m.p. 515–516 K). Colourless crystals of (Ia) were obtained by slow evaporation of a solution in water. Compound (Ib) was obtained by dissolving (Ia) in aqueous 1M HCl. On slow evaporation of the solvent at room temperature, colourless crystals were obtained (m.p. 537 K). Compound (Ic) was obtained by dissolving (Ia) in DMSO. On slow evaporation of the solvent at room temperature, colourless crystals were obtained (m.p. 499–501 K).

S3. Refinement

In all three compounds, the O-bound, N-bound and water H atoms were located in difference electron-density maps and refined with distance restraints of O—H = 0.84 (2) Å and N—H = 0.88 (2) Å. C-bound H atoms were included in calculated positions and treated as riding, with C—H = 0.94 and 0.97 Å for CH and CH₃ H atoms, respectively, and with U_iso(H) = kU_eq(C), where k = 1.5 for methyl H atoms and 1.2 otherwise.

Computing details

For all compounds, data collection: STADI-4 Software (Stoe & Cie, 1997); cell refinement: STADI-4 Software (Stoe & Cie, 1997); data reduction: X-RED (Stoe & Cie, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures

	Fig. 1. The molecular structure of (Ia), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A partial view of the crystal packing of (Ia), viewed along the a axis. N—H···O and O—H···O hydrogen bonds are shown as dashed lines (see Table 1 for details).
	Fig. 3. The crystal packing of (Ia), viewed along the b axis. N—H···O, O—H···O, C—H···O and C—H···N hydrogen bonds are shown as dashed lines (see Table 1 for details).
	Fig. 4. The molecular structure of (Ib), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Only one of the inversion-related Cl^- anions and solvent water molecules are shown. [Symmetry code: (a) -x + 1, -y + 1, -z + 1.]
	Fig. 5. The crystal packing of (Ib), viewed along the a axis. O—H···Cl, N—H···Cl and O—H···O hydrogen bonds are shown as dashed lines (see Table 2 for details).
	Fig. 6. The crystal packing of (Ib), viewed along the b axis. O—H···Cl, N—H···Cl, O—H···O, C—H···Cl and C—H···O hydrogen bonds are shown as dashed lines (see Table 2 for details; Cl^- anions are shown as large balls).
	Fig. 7. The molecular structure of (Ic), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Only one of the inversion-related DMSO molecules, hydrogen-bonded (dashed lines) to the molecule of (I), is shown. [Symmetry code: (a) -x + 1, -y + 1, -z + 1.]
	Fig. 8. The crystal packing of (Ic), viewed along the b axis. O—H···O hydrogen bonds are shown as dashed lines (see Table 3 for details). [Where's the origin?]
	Fig. 9. The crystal packing of (Ic), viewed along the b axis. O—H···O and C—H···O hydrogen bonds are shown as dashed lines (see Table 3 for details).

(Ia) 5-Carboxy-3-(pyridin-1-ium-2-yl)-6-(pyridin-2-yl)pyrazine-2-carboxylate

Crystal data

C16H10N4O4	F(000) = 664
Mr = 322.28	Dx = 1.499 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 17 reflections
a = 8.304 (3) Å	θ = 14.0–19.0°
b = 9.684 (1) Å	µ = 0.11 mm^−1
c = 17.802 (2) Å	T = 213 K
β = 93.89 (1)°	Rod, colourless
V = 1428.3 (6) Å^3	0.49 × 0.27 × 0.10 mm
Z = 4

Data collection

Stoe AED-2 four-circle diffractometer	Rint = 0.087
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.3°
Graphite monochromator	h = −9→9
2θ/ω scans	k = 0→11
2502 measured reflections	l = 0→21
2371 independent reflections	2 standard reflections every 60 min
1731 reflections with I > 2σ(I)	intensity decay: 2%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.061	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.165	w = 1/[σ^2(Fo^2) + (0.0837P)^2 + 0.1644P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max < 0.001
2371 reflections	Δρmax = 0.24 e Å^−3
226 parameters	Δρmin = −0.33 e Å^−3
2 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.007 (2)

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O1	0.6004 (3)	−0.3146 (2)	0.05568 (12)	0.0370 (8)
O2	0.7772 (3)	−0.3595 (2)	0.15328 (13)	0.0359 (9)
O3	0.5723 (3)	0.3148 (2)	0.21142 (12)	0.0344 (8)
O4	0.7608 (3)	0.3811 (2)	0.13479 (13)	0.0409 (9)
N1	0.7303 (3)	0.1069 (3)	0.08187 (13)	0.0242 (8)
N2	0.7305 (3)	−0.0916 (3)	0.19477 (13)	0.0234 (8)
N3	0.8607 (3)	−0.1718 (3)	−0.02336 (13)	0.0266 (9)
N4	0.6567 (4)	−0.0069 (3)	0.33651 (13)	0.0262 (9)
C1	0.7395 (4)	−0.0271 (3)	0.06572 (15)	0.0220 (9)
C2	0.7278 (4)	−0.1275 (3)	0.12231 (15)	0.0234 (10)
C3	0.7287 (4)	0.0440 (3)	0.21090 (15)	0.0222 (9)
C4	0.7188 (4)	0.1433 (3)	0.15377 (15)	0.0218 (9)
C5	0.7623 (4)	−0.0648 (3)	−0.01387 (15)	0.0222 (9)
C6	0.6891 (4)	0.0109 (3)	−0.07274 (16)	0.0304 (10)
C7	0.7123 (5)	−0.0301 (4)	−0.14580 (17)	0.0377 (11)
C8	0.8116 (5)	−0.1408 (4)	−0.15661 (17)	0.0382 (13)
C9	0.8836 (4)	−0.2080 (4)	−0.09475 (17)	0.0325 (11)
C10	0.6967 (4)	−0.2791 (3)	0.10605 (16)	0.0261 (10)
C11	0.7422 (4)	0.0757 (3)	0.29247 (16)	0.0243 (9)
C12	0.8446 (4)	0.1715 (3)	0.32588 (17)	0.0300 (11)
C13	0.8587 (4)	0.1823 (4)	0.40439 (18)	0.0358 (11)
C14	0.7696 (4)	0.0969 (4)	0.44688 (18)	0.0366 (11)
C15	0.6672 (4)	0.0026 (4)	0.41177 (16)	0.0325 (11)
C16	0.6829 (4)	0.2937 (3)	0.16834 (15)	0.0261 (10)
H2O	0.750 (5)	−0.447 (2)	0.145 (2)	0.073 (15)*
H4N	0.584 (4)	−0.065 (3)	0.3160 (19)	0.044 (11)*
H6	0.62520	0.08840	−0.06340	0.0360*
H7	0.66110	0.01670	−0.18710	0.0450*
H8	0.83020	−0.17040	−0.20550	0.0460*
H9	0.95220	−0.28290	−0.10300	0.0390*
H12	0.90510	0.22970	0.29630	0.0360*
H13	0.92900	0.24770	0.42790	0.0430*
H14	0.77860	0.10310	0.49970	0.0440*
H15	0.60440	−0.05550	0.44040	0.0390*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0560 (17)	0.0270 (13)	0.0277 (12)	−0.0042 (12)	0.0016 (12)	−0.0033 (10)
O2	0.0595 (18)	0.0190 (13)	0.0287 (13)	0.0020 (12)	−0.0005 (11)	0.0016 (10)
O3	0.0496 (15)	0.0288 (13)	0.0256 (12)	0.0069 (11)	0.0091 (11)	0.0001 (10)
O4	0.0731 (19)	0.0175 (13)	0.0348 (13)	−0.0024 (12)	0.0229 (13)	0.0022 (10)
N1	0.0398 (17)	0.0157 (14)	0.0174 (12)	−0.0018 (12)	0.0050 (11)	0.0005 (10)
N2	0.0378 (16)	0.0165 (13)	0.0161 (12)	−0.0020 (11)	0.0034 (11)	0.0004 (10)
N3	0.0392 (17)	0.0251 (15)	0.0162 (12)	0.0010 (12)	0.0074 (11)	−0.0029 (11)
N4	0.0411 (18)	0.0197 (14)	0.0183 (13)	−0.0011 (13)	0.0047 (12)	0.0004 (11)
C1	0.0299 (18)	0.0178 (16)	0.0181 (15)	0.0010 (13)	0.0006 (13)	−0.0008 (12)
C2	0.0362 (19)	0.0183 (16)	0.0159 (14)	0.0008 (14)	0.0033 (13)	−0.0009 (12)
C3	0.0308 (18)	0.0181 (16)	0.0183 (14)	−0.0033 (13)	0.0064 (12)	−0.0024 (13)
C4	0.0312 (18)	0.0189 (16)	0.0159 (14)	−0.0023 (13)	0.0055 (12)	−0.0008 (12)
C5	0.0324 (18)	0.0194 (17)	0.0149 (14)	−0.0040 (14)	0.0026 (12)	−0.0008 (12)
C6	0.046 (2)	0.0227 (18)	0.0223 (16)	−0.0008 (15)	0.0012 (15)	0.0029 (13)
C7	0.053 (2)	0.043 (2)	0.0167 (15)	−0.0049 (18)	−0.0008 (15)	0.0053 (15)
C8	0.058 (3)	0.041 (2)	0.0165 (16)	−0.0079 (19)	0.0093 (16)	−0.0021 (15)
C9	0.046 (2)	0.0299 (19)	0.0228 (16)	−0.0011 (16)	0.0104 (15)	−0.0066 (14)
C10	0.040 (2)	0.0236 (17)	0.0153 (15)	−0.0020 (14)	0.0074 (14)	−0.0030 (13)
C11	0.0381 (19)	0.0167 (15)	0.0184 (14)	0.0044 (14)	0.0047 (13)	0.0011 (13)
C12	0.038 (2)	0.0265 (19)	0.0256 (16)	−0.0018 (15)	0.0024 (14)	−0.0031 (14)
C13	0.039 (2)	0.039 (2)	0.0284 (18)	0.0042 (17)	−0.0052 (15)	−0.0129 (16)
C14	0.051 (2)	0.043 (2)	0.0158 (15)	0.0066 (18)	0.0024 (15)	−0.0038 (15)
C15	0.049 (2)	0.033 (2)	0.0163 (15)	0.0069 (17)	0.0081 (15)	0.0000 (14)
C16	0.042 (2)	0.0238 (18)	0.0123 (14)	0.0032 (15)	0.0011 (14)	−0.0002 (13)

Geometric parameters (Å, º)

O1—C10	1.210 (4)	C3—C11	1.481 (4)
O2—C10	1.298 (4)	C4—C16	1.513 (4)
O3—C16	1.253 (4)	C5—C6	1.385 (4)
O4—C16	1.243 (4)	C6—C7	1.386 (4)
O2—H2O	0.89 (2)	C7—C8	1.374 (6)
N1—C4	1.337 (4)	C8—C9	1.380 (5)
N1—C1	1.332 (4)	C11—C12	1.367 (4)
N2—C2	1.335 (4)	C12—C13	1.399 (4)
N2—C3	1.345 (4)	C13—C14	1.371 (5)
N3—C9	1.344 (4)	C14—C15	1.370 (5)
N3—C5	1.337 (4)	C6—H6	0.9400
N4—C11	1.354 (4)	C7—H7	0.9400
N4—C15	1.340 (4)	C8—H8	0.9400
N4—H4N	0.89 (3)	C9—H9	0.9400
C1—C2	1.408 (4)	C12—H12	0.9400
C1—C5	1.488 (4)	C13—H13	0.9400
C2—C10	1.515 (4)	C14—H14	0.9400
C3—C4	1.398 (4)	C15—H15	0.9400
C10—O2—H2O	111 (2)	O1—C10—O2	126.5 (3)
C1—N1—C4	118.2 (3)	N4—C11—C3	115.9 (3)
C2—N2—C3	117.5 (3)	N4—C11—C12	119.0 (3)
C5—N3—C9	116.6 (3)	C3—C11—C12	124.8 (3)
C11—N4—C15	122.5 (3)	C11—C12—C13	119.5 (3)
C15—N4—H4N	117 (2)	C12—C13—C14	119.6 (3)
C11—N4—H4N	120 (2)	C13—C14—C15	119.5 (3)
N1—C1—C2	120.7 (2)	N4—C15—C14	119.9 (3)
C2—C1—C5	122.1 (3)	O3—C16—O4	127.6 (3)
N1—C1—C5	117.2 (2)	O3—C16—C4	115.0 (3)
C1—C2—C10	123.5 (2)	O4—C16—C4	117.3 (3)
N2—C2—C1	120.9 (3)	C5—C6—H6	121.00
N2—C2—C10	115.4 (3)	C7—C6—H6	121.00
N2—C3—C4	121.2 (2)	C6—C7—H7	121.00
N2—C3—C11	114.3 (2)	C8—C7—H7	121.00
C4—C3—C11	124.6 (3)	C7—C8—H8	120.00
N1—C4—C3	120.7 (3)	C9—C8—H8	120.00
N1—C4—C16	116.5 (2)	N3—C9—H9	118.00
C3—C4—C16	122.7 (2)	C8—C9—H9	118.00
N3—C5—C6	123.7 (3)	C11—C12—H12	120.00
N3—C5—C1	115.4 (2)	C13—C12—H12	120.00
C1—C5—C6	120.9 (3)	C12—C13—H13	120.00
C5—C6—C7	118.5 (3)	C14—C13—H13	120.00
C6—C7—C8	118.6 (3)	C13—C14—H14	120.00
C7—C8—C9	119.2 (3)	C15—C14—H14	120.00
N3—C9—C8	123.4 (3)	N4—C15—H15	120.00
O2—C10—C2	112.6 (3)	C14—C15—H15	120.00
O1—C10—C2	120.8 (3)
C4—N1—C1—C2	3.7 (5)	C1—C2—C10—O1	−40.8 (5)
C4—N1—C1—C5	−176.4 (3)	C1—C2—C10—O2	142.2 (3)
C1—N1—C4—C3	4.8 (5)	N2—C3—C4—N1	−8.1 (5)
C1—N1—C4—C16	−170.9 (3)	N2—C3—C4—C16	167.4 (3)
C3—N2—C2—C1	6.4 (5)	C11—C3—C4—N1	170.3 (3)
C3—N2—C2—C10	−168.4 (3)	C11—C3—C4—C16	−14.3 (5)
C2—N2—C3—C4	2.1 (5)	N2—C3—C11—N4	−41.0 (4)
C2—N2—C3—C11	−176.4 (3)	N2—C3—C11—C12	132.5 (3)
C9—N3—C5—C1	−179.9 (3)	C4—C3—C11—N4	140.6 (3)
C9—N3—C5—C6	−2.1 (5)	C4—C3—C11—C12	−46.0 (5)
C5—N3—C9—C8	0.1 (5)	N1—C4—C16—O3	132.1 (3)
C15—N4—C11—C3	174.6 (3)	N1—C4—C16—O4	−45.5 (4)
C15—N4—C11—C12	0.8 (5)	C3—C4—C16—O3	−43.6 (4)
C11—N4—C15—C14	−1.2 (5)	C3—C4—C16—O4	138.9 (3)
N1—C1—C2—N2	−9.7 (5)	N3—C5—C6—C7	3.3 (5)
N1—C1—C2—C10	164.7 (3)	C1—C5—C6—C7	−179.0 (3)
C5—C1—C2—N2	170.4 (3)	C5—C6—C7—C8	−2.4 (5)
C5—C1—C2—C10	−15.3 (5)	C6—C7—C8—C9	0.5 (6)
N1—C1—C5—N3	141.7 (3)	C7—C8—C9—N3	0.7 (6)
N1—C1—C5—C6	−36.3 (5)	N4—C11—C12—C13	−0.1 (5)
C2—C1—C5—N3	−38.4 (4)	C3—C11—C12—C13	−173.4 (3)
C2—C1—C5—C6	143.7 (3)	C11—C12—C13—C14	−0.1 (5)
N2—C2—C10—O1	133.9 (3)	C12—C13—C14—C15	−0.4 (5)
N2—C2—C10—O2	−43.2 (4)	C13—C14—C15—N4	1.0 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2O···O4^i	0.89 (2)	1.68 (2)	2.536 (3)	162 (4)
N4—H4N···O3^ii	0.89 (3)	1.79 (3)	2.666 (4)	171 (3)
C7—H7···O3^iii	0.94	2.51	3.429 (4)	166
C8—H8···O2^iv	0.94	2.54	3.377 (4)	149
C13—H13···N3^v	0.94	2.48	3.353 (4)	155
C14—H14···O4^vi	0.94	2.42	3.358 (4)	172
C15—H15···O1^vii	0.94	2.41	3.222 (4)	145

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

(Ib) 2,2'-(3,6-Dicarboxypyrazine-2,5-diyl)bis(pyridin-1-ium) dichloride dihydrate

Crystal data

C16H12N4O4^2+·2Cl^−·2H2O	Z = 1
Mr = 431.23	F(000) = 222
Triclinic, P1	Dx = 1.497 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.857 (1) Å	Cell parameters from 21 reflections
b = 8.576 (1) Å	θ = 14.0–20.0°
c = 9.187 (2) Å	µ = 0.38 mm^−1
α = 63.40 (1)°	T = 213 K
β = 81.94 (1)°	Rod, colourless
γ = 87.47 (1)°	0.49 × 0.34 × 0.27 mm
V = 478.19 (14) Å^3

Data collection

Stoe AED-2 four-circle diffractometer	Rint = 0.035
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.5°
Graphite monochromator	h = −8→8
2θ/ω scans	k = −10→10
3504 measured reflections	l = −10→10
1681 independent reflections	3 standard reflections every 60 min
1463 reflections with I > 2˘I)	intensity decay: 7%

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.093	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0596P)^2 + 0.0431P] where P = (Fo^2 + 2Fc^2)/3
1681 reflections	(Δ/σ)max < 0.001
143 parameters	Δρmax = 0.27 e Å^−3
2 restraints	Δρmin = −0.32 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O1	1.00015 (17)	0.49490 (17)	0.31111 (14)	0.0275 (4)
O2	0.92722 (19)	0.23783 (17)	0.53000 (16)	0.0339 (4)
N1	0.5886 (2)	0.35779 (19)	0.61518 (16)	0.0213 (4)
N2	0.2702 (2)	0.38465 (19)	0.92225 (16)	0.0224 (4)
C1	0.4106 (2)	0.4098 (2)	0.65399 (19)	0.0209 (5)
C2	0.6788 (2)	0.4478 (2)	0.46210 (19)	0.0201 (5)
C5	0.3229 (2)	0.3023 (2)	0.82833 (19)	0.0203 (5)
C6	0.3015 (3)	0.1241 (2)	0.8968 (2)	0.0258 (5)
C7	0.2197 (3)	0.0334 (2)	1.0613 (2)	0.0304 (5)
C8	0.1635 (3)	0.1233 (3)	1.1525 (2)	0.0317 (6)
C9	0.1921 (3)	0.3007 (2)	1.0801 (2)	0.0286 (5)
C10	0.8865 (2)	0.3959 (2)	0.42515 (19)	0.0222 (5)
Cl1	0.35647 (7)	0.77154 (6)	0.77915 (6)	0.0328 (2)
O1W	0.2839 (2)	0.1436 (2)	0.5001 (2)	0.0400 (5)
H2N	0.288 (3)	0.500 (2)	0.880 (2)	0.037 (6)*
H2O	1.044 (3)	0.211 (4)	0.511 (3)	0.065 (8)*
H6	0.34130	0.06410	0.83390	0.0310*
H7	0.20300	−0.08850	1.10970	0.0360*
H8	0.10640	0.06370	1.26270	0.0380*
H9	0.15690	0.36330	1.14140	0.0340*
H1WA	0.305 (5)	0.044 (4)	0.565 (4)	0.071 (10)*
H2WB	0.370 (4)	0.164 (3)	0.423 (3)	0.050 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0230 (6)	0.0307 (7)	0.0216 (6)	0.0003 (5)	0.0030 (5)	−0.0070 (5)
O2	0.0259 (7)	0.0293 (8)	0.0311 (7)	0.0092 (6)	0.0035 (6)	−0.0027 (6)
N1	0.0225 (7)	0.0224 (7)	0.0181 (7)	0.0013 (6)	−0.0007 (6)	−0.0089 (6)
N2	0.0256 (7)	0.0216 (8)	0.0180 (7)	0.0016 (6)	−0.0003 (6)	−0.0080 (6)
C1	0.0229 (8)	0.0216 (9)	0.0180 (8)	0.0000 (7)	0.0007 (7)	−0.0096 (7)
C2	0.0217 (8)	0.0210 (9)	0.0178 (8)	−0.0006 (7)	0.0000 (6)	−0.0096 (7)
C5	0.0189 (8)	0.0232 (9)	0.0158 (8)	0.0027 (7)	−0.0014 (6)	−0.0064 (7)
C6	0.0272 (9)	0.0245 (9)	0.0243 (9)	0.0020 (7)	−0.0020 (7)	−0.0102 (8)
C7	0.0297 (10)	0.0224 (9)	0.0286 (9)	−0.0017 (8)	−0.0049 (8)	−0.0017 (8)
C8	0.0312 (10)	0.0364 (11)	0.0167 (8)	−0.0025 (8)	0.0017 (7)	−0.0034 (8)
C9	0.0305 (9)	0.0353 (11)	0.0172 (8)	0.0012 (8)	0.0006 (7)	−0.0105 (8)
C10	0.0230 (9)	0.0250 (9)	0.0196 (8)	0.0036 (7)	−0.0026 (7)	−0.0112 (7)
Cl1	0.0360 (3)	0.0244 (3)	0.0353 (3)	−0.0007 (2)	−0.0004 (2)	−0.0121 (2)
O1W	0.0319 (8)	0.0415 (10)	0.0335 (8)	0.0145 (7)	−0.0002 (7)	−0.0076 (7)

Geometric parameters (Å, º)

O1—C10	1.208 (2)	C1—C5	1.495 (2)
O2—C10	1.310 (2)	C2—C10	1.512 (2)
O2—H2O	0.84 (2)	C5—C6	1.373 (3)
O1W—H2WB	0.81 (3)	C6—C7	1.397 (2)
O1W—H1WA	0.81 (4)	C7—C8	1.381 (3)
N1—C1	1.337 (2)	C8—C9	1.371 (3)
N1—C2	1.335 (2)	C6—H6	0.9400
N2—C9	1.338 (2)	C7—H7	0.9400
N2—C5	1.345 (2)	C8—H8	0.9400
N2—H2N	0.893 (19)	C9—H9	0.9400
C1—C2^i	1.398 (2)
C10—O2—H2O	113 (2)	C5—C6—C7	119.02 (17)
H1WA—O1W—H2WB	104 (3)	C6—C7—C8	119.82 (18)
C1—N1—C2	117.62 (14)	C7—C8—C9	119.12 (16)
C5—N2—C9	122.74 (17)	N2—C9—C8	119.93 (17)
C9—N2—H2N	117.2 (11)	O1—C10—C2	121.69 (16)
C5—N2—H2N	120.0 (11)	O2—C10—C2	113.08 (13)
N1—C1—C5	113.61 (14)	O1—C10—O2	125.22 (15)
C2^i—C1—C5	125.20 (14)	C5—C6—H6	120.00
N1—C1—C2^i	121.20 (14)	C7—C6—H6	121.00
N1—C2—C1^i	121.18 (14)	C8—C7—H7	120.00
N1—C2—C10	116.60 (14)	C6—C7—H7	120.00
C1^i—C2—C10	122.08 (14)	C7—C8—H8	120.00
N2—C5—C6	119.33 (15)	C9—C8—H8	120.00
C1—C5—C6	122.73 (16)	N2—C9—H9	120.00
N2—C5—C1	117.90 (16)	C8—C9—H9	120.00
C2—N1—C1—C5	−179.32 (16)	N1—C1—C2^i—C10^i	174.85 (16)
C2—N1—C1—C2^i	0.7 (3)	C5—C1—C2^i—N1^i	179.30 (17)
C1—N1—C2—C10	175.11 (16)	C5—C1—C2^i—C10^i	−5.2 (3)
C1—N1—C2—C1^i	−0.7 (3)	N1—C2—C10—O1	−158.32 (17)
C9—N2—C5—C1	−179.39 (15)	N1—C2—C10—O2	20.5 (2)
C9—N2—C5—C6	−1.8 (2)	C1^i—C2—C10—O1	17.4 (3)
C5—N2—C9—C8	0.2 (3)	C1^i—C2—C10—O2	−163.80 (16)
N1—C1—C5—N2	123.35 (17)	N2—C5—C6—C7	2.0 (3)
N1—C1—C5—C6	−54.1 (2)	C1—C5—C6—C7	179.39 (16)
C2^i—C1—C5—N2	−56.7 (2)	C5—C6—C7—C8	−0.6 (3)
C2^i—C1—C5—C6	125.9 (2)	C6—C7—C8—C9	−1.0 (3)
N1—C1—C2^i—N1^i	−0.7 (3)	C7—C8—C9—N2	1.2 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···Cl1^ii	0.81 (4)	2.34 (3)	3.1453 (19)	172 (3)
O1W—H2WB···Cl1^i	0.81 (3)	2.34 (3)	3.1472 (17)	173 (2)
N2—H2N···Cl1	0.89 (2)	2.13 (2)	3.0226 (19)	175 (2)
O2—H2O···O1W^iii	0.84 (2)	1.72 (2)	2.559 (2)	172 (3)
C6—H6···Cl1^ii	0.94	2.77	3.628 (2)	153
C8—H8···O2^iv	0.94	2.43	3.172 (3)	136
C9—H9···O1^v	0.94	2.42	3.346 (2)	168

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

(Ic) 3,6-Bis(pyridin-2-yl)pyrazine-2,5-dicarboxylic acid dimethyl sulfoxide disolvate

Crystal data

C16H10N4O4·2C2H6OS	F(000) = 500
Mr = 478.54	Dx = 1.410 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 20 reflections
a = 13.067 (1) Å	θ = 14.0–18.5°
b = 6.138 (1) Å	µ = 0.28 mm^−1
c = 14.453 (1) Å	T = 213 K
β = 103.59 (1)°	Rod, colourless
V = 1126.8 (2) Å^3	0.53 × 0.38 × 0.30 mm
Z = 2

Data collection

Stoe AED-2 four-circle diffractometer	Rint = 0.000
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.9°
Graphite monochromator	h = −15→15
2θ/ω scans	k = 0→7
1979 measured reflections	l = 0→17
1979 independent reflections	2 standard reflections every 60 min
1296 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.093	H atoms treated by a mixture of independent and constrained refinement
S = 0.96	w = 1/[σ^2(Fo^2) + (0.0401P)^2] where P = (Fo^2 + 2Fc^2)/3
1979 reflections	(Δ/σ)max < 0.001
151 parameters	Δρmax = 0.20 e Å^−3
1 restraint	Δρmin = −0.27 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O1	0.38051 (15)	0.3095 (3)	0.68347 (12)	0.0393 (7)
O2	0.54242 (14)	0.1658 (4)	0.70910 (14)	0.0422 (7)
N1	0.55440 (16)	0.5453 (3)	0.59271 (14)	0.0291 (7)
N2	0.36463 (16)	−0.0091 (3)	0.52033 (15)	0.0317 (8)
C1	0.42877 (19)	0.3352 (4)	0.47999 (18)	0.0284 (8)
C2	0.4843 (2)	0.3838 (4)	0.57293 (17)	0.0275 (8)
C5	0.35261 (19)	0.1527 (4)	0.45630 (17)	0.0286 (8)
C6	0.2742 (2)	0.1535 (5)	0.37278 (18)	0.0369 (9)
C7	0.2060 (2)	−0.0222 (5)	0.3539 (2)	0.0417 (10)
C8	0.2182 (2)	−0.1897 (5)	0.4179 (2)	0.0387 (10)
C9	0.2977 (2)	−0.1765 (4)	0.49948 (19)	0.0341 (9)
C10	0.4624 (2)	0.2776 (4)	0.66021 (17)	0.0310 (9)
S1	0.38909 (6)	−0.05423 (12)	0.86118 (5)	0.0385 (2)
O3	0.50225 (14)	0.0048 (3)	0.86415 (13)	0.0528 (8)
C11	0.3409 (2)	−0.1835 (5)	0.75067 (19)	0.0463 (11)
C12	0.3951 (3)	−0.2859 (6)	0.9351 (2)	0.0669 (14)
H2O	0.526 (3)	0.119 (5)	0.7597 (17)	0.074 (12)*
H6	0.26750	0.27080	0.33000	0.0440*
H7	0.15220	−0.02620	0.29790	0.0500*
H8	0.17330	−0.31140	0.40640	0.0460*
H9	0.30540	−0.29230	0.54310	0.0410*
H11A	0.38370	−0.31020	0.74610	0.0690*
H11B	0.34370	−0.08280	0.69960	0.0690*
H11C	0.26860	−0.22860	0.74540	0.0690*
H12A	0.42300	−0.24430	1.00090	0.1010*
H12B	0.44060	−0.39470	0.91690	0.1010*
H12C	0.32500	−0.34580	0.92780	0.1010*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0445 (12)	0.0356 (12)	0.0429 (11)	0.0053 (10)	0.0208 (9)	0.0025 (9)
O2	0.0323 (11)	0.0548 (14)	0.0382 (12)	−0.0004 (10)	0.0059 (9)	0.0177 (11)
N1	0.0296 (12)	0.0280 (12)	0.0290 (12)	−0.0014 (11)	0.0053 (9)	−0.0016 (11)
N2	0.0338 (13)	0.0274 (13)	0.0343 (13)	−0.0015 (11)	0.0088 (10)	−0.0017 (10)
C1	0.0277 (14)	0.0267 (14)	0.0312 (14)	0.0036 (12)	0.0076 (12)	0.0016 (13)
C2	0.0287 (14)	0.0266 (15)	0.0268 (14)	0.0034 (12)	0.0059 (11)	−0.0004 (12)
C5	0.0300 (15)	0.0297 (15)	0.0278 (14)	0.0002 (13)	0.0101 (12)	−0.0028 (13)
C6	0.0404 (17)	0.0397 (17)	0.0312 (15)	−0.0005 (15)	0.0097 (13)	0.0028 (14)
C7	0.0347 (16)	0.0476 (19)	0.0388 (16)	−0.0053 (15)	0.0007 (13)	−0.0112 (15)
C8	0.0355 (17)	0.0324 (17)	0.0476 (18)	−0.0072 (14)	0.0084 (14)	−0.0122 (15)
C9	0.0398 (17)	0.0243 (15)	0.0401 (16)	−0.0006 (13)	0.0130 (13)	−0.0025 (13)
C10	0.0371 (17)	0.0256 (15)	0.0292 (15)	−0.0056 (14)	0.0058 (13)	−0.0052 (12)
S1	0.0362 (4)	0.0395 (4)	0.0393 (4)	−0.0020 (4)	0.0080 (3)	0.0012 (4)
O3	0.0339 (11)	0.0723 (16)	0.0464 (12)	−0.0144 (11)	−0.0019 (9)	0.0258 (11)
C11	0.054 (2)	0.0406 (18)	0.0460 (18)	−0.0133 (16)	0.0149 (15)	−0.0061 (15)
C12	0.068 (2)	0.079 (3)	0.052 (2)	−0.023 (2)	0.0106 (18)	0.020 (2)

Geometric parameters (Å, º)

S1—O3	1.513 (2)	C6—C7	1.385 (4)
S1—C11	1.762 (3)	C7—C8	1.367 (4)
S1—C12	1.769 (3)	C8—C9	1.379 (4)
O1—C10	1.211 (3)	C6—H6	0.9400
O2—C10	1.310 (3)	C7—H7	0.9400
O2—H2O	0.86 (3)	C8—H8	0.9400
N1—C2	1.334 (3)	C9—H9	0.9400
N1—C1^i	1.341 (3)	C11—H11A	0.9700
N2—C9	1.337 (3)	C11—H11B	0.9700
N2—C5	1.341 (3)	C11—H11C	0.9700
C1—C5	1.484 (4)	C12—H12A	0.9700
C1—C2	1.401 (4)	C12—H12B	0.9700
C2—C10	1.506 (3)	C12—H12C	0.9700
C5—C6	1.388 (4)
C11—S1—C12	98.11 (15)	O2—C10—C2	113.2 (2)
O3—S1—C11	105.80 (12)	C5—C6—H6	121.00
O3—S1—C12	105.72 (15)	C7—C6—H6	121.00
C10—O2—H2O	108 (3)	C8—C7—H7	121.00
C1^i—N1—C2	118.0 (2)	C6—C7—H7	120.00
C5—N2—C9	116.7 (2)	C7—C8—H8	121.00
C2—C1—C5	123.4 (2)	C9—C8—H8	121.00
N1^i—C1—C5	117.2 (2)	N2—C9—H9	118.00
N1^i—C1—C2	119.4 (2)	C8—C9—H9	118.00
N1—C2—C1	122.6 (2)	S1—C11—H11A	110.00
N1—C2—C10	113.5 (2)	S1—C11—H11B	109.00
C1—C2—C10	123.6 (2)	S1—C11—H11C	109.00
N2—C5—C6	123.1 (2)	H11A—C11—H11B	110.00
C1—C5—C6	121.1 (2)	H11A—C11—H11C	109.00
N2—C5—C1	115.9 (2)	H11B—C11—H11C	109.00
C5—C6—C7	118.6 (3)	S1—C12—H12A	110.00
C6—C7—C8	119.0 (3)	S1—C12—H12B	109.00
C7—C8—C9	118.6 (3)	S1—C12—H12C	109.00
N2—C9—C8	124.0 (2)	H12A—C12—H12B	110.00
O1—C10—C2	121.1 (2)	H12A—C12—H12C	110.00
O1—C10—O2	125.5 (2)	H12B—C12—H12C	109.00
C1^i—N1—C2—C1	0.2 (4)	C2—C1—C5—C6	157.3 (3)
C1^i—N1—C2—C10	−173.3 (2)	N1^i—C1—C5—N2	156.1 (2)
C2—N1—C1^i—C2^i	−0.2 (4)	N1^i—C1—C5—C6	−24.1 (4)
C2—N1—C1^i—C5^i	178.4 (2)	N1—C2—C10—O1	106.4 (3)
C9—N2—C5—C1	−179.0 (2)	N1—C2—C10—O2	−68.9 (3)
C9—N2—C5—C6	1.2 (4)	C1—C2—C10—O1	−67.1 (3)
C5—N2—C9—C8	−0.7 (4)	C1—C2—C10—O2	117.7 (3)
C5—C1—C2—N1	178.3 (2)	N2—C5—C6—C7	−0.9 (4)
C5—C1—C2—C10	−8.8 (4)	C1—C5—C6—C7	179.4 (2)
N1^i—C1—C2—N1	−0.2 (4)	C5—C6—C7—C8	0.0 (4)
N1^i—C1—C2—C10	172.6 (2)	C6—C7—C8—C9	0.5 (4)
C2—C1—C5—N2	−22.5 (4)	C7—C8—C9—N2	−0.2 (4)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2O···O3	0.86 (3)	1.76 (3)	2.613 (3)	175 (3)
C8—H8···O3^ii	0.94	2.48	3.358 (3)	156
C11—H11A···O1^iii	0.97	2.50	3.336 (4)	144
C11—H11C···O1^iv	0.97	2.42	3.252 (3)	144
C12—H12A···O3^v	0.97	2.45	3.371 (4)	158

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