Solvatomorphism in (E)-2-(2,6-di­chloro-4-hy­droxy­benzyl­idene)hydrazinecarboximidamide

The structures of ortho­rhom­bic (E)-4-(2-{[amino­(iminio)meth­yl]amino}­vin­yl)-3,5-dichloro­phenolate dihydrate, C₈H₈Cl₂N₄O·2H₂O, (I), triclinic (E)-4-(2-{[amino­(iminio)meth­yl]amino}­vin­yl)-3,5-dichloro­phenolate methanol disolvate, C₈H₈Cl₂N₄O·2CH₄O, (II), and ortho­rhom­bic (E)-amino­[(2,6-di­chloro-4-hy­droxy­styr­yl)amino]­methaniminium acetate, C₈H₉Cl₂N₄O⁺·C₂H₃O₂^-, (III), all crystallize with one formula unit in the asymmetric unit, with the mol­ecule in an E configuration and the phenol H atom transferred to the guanidine N atom. Although the mol­ecules of the title compounds form extended chains via hydrogen bonding in all three forms, owing to the presence of different solvent mol­ecules, those chains are connected differently in the individual forms. In (II), the mol­ecules are all coplanar, while in (I) and (III), adjacent mol­ecules are tilted relative to one another to varying degrees. Also, because of the variation in hydrogen-bond-formation ability of the solvents, the hydrogen-bonding arrangements vary in the three forms.

S1. Comment

Solvatomorphism, the counterpart of polymorphism and sometimes called pseudopolymorphism, deals with systems with different crystal structures of the same substance associated with various amounts or types of solvent molecules (Brittain, 2010; Seddon, 2004; Desiraju, 2004; Bernstein, 2005; Nangia, 2006). Unlike polymorphs, solvatomorphs not only have different molecular arrangements but also possess diverse molecular compositions due to the presence of solvent molecules. Like polymorphism, solvatomorphism is also commonly observed in organics and is of great significance in pharmaceuticals and materials. The title compound (1) is a metabolite of gaunabenz, an antiprion drug for the treatment of neurodegenerative disorders in mammals and also a potent tranquilizer used to sedate horses (Fluck et al. 1983). In this report, we describe three crystal structures of (1) which include two solvates, (I) and (II), and one acetate salt, (III) (Fig. 1).

Our analysis establishes that (I) is orthorhombic (space group Pbca) (Fig. 2), (II) is triclinic (space group P1) (Fig. 3) and (III) is again orthorhombic (space group Pbca) (Fig. 4), with one formula unit in the asymmetric unit in each case. In the water, (I), and methanol, (II), solvates, the title compound exists as a zwitterion with the phenol proton transferred to the guanidine N atom. In the acetate salt, (III), the title compound is protonated by the acetic acid and is thus positively charged. The molecules in the three forms are all in the E configuration and are nearly flat.

Without considering the participation of the solvent molecules, all three forms show the same C11 hydrogen-bonding pattern in the graph-set concept (Bernstein et al., 1995), i.e. one-dimensional chains based on the hydrogen bond between the phenol O and a guanidine NH [for example N12—H12B···O1ⁱ in (I); symmetry code: (i) x, -y + 1/2, z + 1/2] (Tables 1–3). The relative positions of the molecules in the chains differ, however, with molecules in the chain of (II) in the same plane, and molecules in the chains of (I) and (III) tilted toward each other to different degrees as indicated by the dihedral angles between the arene rings on adjacent molecules in the three forms: ca 22° for (I), 0° for (II) and 55° for (III) (Fig. 5).

Since compound (1) is associated with different guest molecules in the three forms, the packing is distinct in each case because of different hydrogen-bonding patterns. In (I), there are two equivalents of water, and water is both a hydrogen-bond donor and acceptor (Fig. 6). When acting as a hydrogen-bond donor, one H₂O (O1W) forms hydrogen bonds with both O1 of the host molecule and O2W of the other water molecule [O1W—H2W1···O2Wⁱⁱⁱ; symmetry code: (iii) x - 1/2, -y + 1/2, -z + 1] (Table 1); while serving as a hydrogen-bond acceptor, O1W accepts H atoms from both N11 and N12 from the guanine group of the host molecule [N11—H11A···O1Wⁱⁱ and N12—H12A···O1Wⁱⁱ; symmetry code: (ii) -x + 1, y - 1/2, -z + 3/2]. When the second H₂O (O2W) acts as a hydrogen-bond donor, it links two adjacent host molecule chains through hydrogen bonds with O1; when it works as a hydrogen-bond acceptor, it forms hydrogen bonds with the other water molecule and N9—H9 of the host molecule (N9—H9···O2Wⁱ).

Form (II) also contains two equivalents of another solvent molecule, methanol. The O—H of methanol similarly participates in hydrogen bonds as both a donor and acceptor (Fig. 7). The first methanol molecule connects two adjacent chains by using the O15—H15 group as a hydrogen-bond donor to O1 of the host molecule from one chain and meanwhile utilizing O15 as a hydrogen-bond acceptor to accept H atoms from both N9 and N12 of the host molecule from another chain [N9—H9..O15ⁱ and N12—H12B···O15ⁱ; symmetry code: (i) -x + 2, -y + 2, -z + 1] (Table 2). The second methanol molecule forms hydrogen bonds with O1 as a donor and N11 as an acceptor N11—H11A···O16ⁱⁱ; symmetry code: (ii) x, y + 1, z + 1].

As a 1:1 organic acetate salt in (III), compound (1) is protonated. Both O atoms of the acetate act as hydrogen-bond acceptors (Fig. 8). O15 accepts hydrogen bonds from O1 and N11 from different cations [O1—H1···O15ⁱ and N11—H11A···O15ⁱⁱ; symmetry codes: (i) -x + 3/2, -y, z - 1/2; (ii) -x + 2, y + 1/2, -z + 3/2] and O16 also accepts hydrogen bonds from N9 and N12 of two different cations (N9—H9···O16 and N12—H12A···O16ⁱⁱ). Thus, one acetate anion bridges three chains through hydrogen bonding with one cation in each chain.

Attempts were made to obtain good-quality crystals of an unsolvated and/or a neutral form of the title compound without success. A Cambridge Structural Database (CSD; version 5.32; Allen, 2002) search resulted in six structurally related hits. None was found to form multiple solvates though. Among them, the complex chloro-(β-resorcylidene aminoguanidine)-copper(II) tetrahydrate [refcode RIYMIV (Onuska et al., 1996)] is similar to (III) with the O protonated and a hydrogen bond existing between the O and the guanine N leading to one-dimensional chains. In N-(2,4-dimethoxybenzylideneamino)guanidinium dihydrogenphosphate [refcode DAYHOB (Dinçer et al., 2005)], 7-amino-5-(p-tolyl)-4-phenyl-2- (p-methoxyphenyl)-3,4-dihydroimidazo(1,5-b)pyridazine [refcode LORRAL (Kolos et al., 1999)], 2,4,6-trimethoxybenzylidene-aminoguanidinium chloride [refcode MELBIO (Bats & Hoffmann, 2000)] and (4-methoxy-3-nitrobenzylideneamino)guanidinium chloride [refcode RIGKOI (Ring et al., 2007)], the corresponding O is methylated. The chain structure is replaced by a dimer based on two hydrogen bonds between methoxyl O and guanine N [R²₂(22)] in DAYHOB, and no hydrogen bonds form between the corresponding atoms in the other three compounds. In 2-methyl-4-hydroxybenzaldehyde 2-imidazolin-2-yl-hydrazone hydrochloride monohydrate [refcode FAJHED (Atfani et al., 1986)], the O atom is protonated as in (III), and the two N atoms in the guanine group are integrated into a five-membered ring. Still, a one-dimensional chain similar to that in (III) is observed. Thus, it seems this hydrogen-bonding motif is a common observation in (E)-2-(4-hydroxybenzylidene)hydrazinecarboximidamides likely due to the relatively high strength of the N—H···O interaction.

Our work has thus shown that compound (1) can form at least two solvated crystalline forms and salt formation with acids should be expected as indicated by the existence of an acetate salt. Owing to the presence of different solvents or acids, the crystals have diverse packing and hydrogen-bond arrangements.

Related literature

For related literature, see: Brittain (2010); Desiraju (2004); Fluck et al. (1983); Gug et al. (2010); Holzer & Györgydeák (1992); Li et al. (2010); Nangia (2006); Seddon (2004).

S2. Experimental

Compound (1) was synthesized according to a modified literature procedure (Li et al., 2010; Holzer et al., 1992; Gug et al., 2010). To a solution of HCl (20%, 1 ml) in ethanol (17 ml) was added 2,6-dichloro-4-hydroxybenzaldehyde (0.5g, 2.62 mmol), followed by a solution of aminoguanidin bicarbonate in H₂O (3 ml) slowly. After liberation of CO₂, the solution was heated to reflux and then cooled to room temperature. Then, an aqueous solution of 40% KOH (8.5 ml) was added and the solution was refluxed for 10 min. Afterward, the solution was left stirring overnight at room temperature. To quench the reaction, the pH was adjusted to 7 using 5N NaOH. NaHCO₃ (15 ml) and dichloromethane (15 ml) were added and the mixture was stirred for 30 min. The product precipitated as an orange powder. The crystals were grown from acetone, (I), methanol, (II), and acetic acid, (III).

S3. Refinement

For (II) and (III), H atoms were found in difference Fourier maps and were subsequently placed in idealized positions, with O—H = 0.84 Å, N—H = 0.88 Å, Csp²—H = 0.93 Å and Csp³—H = 0.96 Å for methyl H atoms. For (I), H atoms were all found in difference Fourier maps and were subsequently placed in idealized positions, except for those on the water molecules, with N—H = 0.88 Å, Csp²—H = 0.93 Å and Csp³—H = 0.96 Å for methyl H atoms. The water H atoms were refined with restraints of O—H = 0.82 (2) Å and H···H = 1.30 (3) Å. Isotropic displacement parameters for all H atoms were fixed at U_iso(H) = 1.5U_eq(parent atoms) for hydroxy and methyl H atoms and 1.2Ueq(parent atoms) for all others.

Computing details

For all compounds, data collection: COLLECT (Nonius, 1998); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO-SMN (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008). Software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and local procedures for (I), (II); SHELX97 (Sheldrick, 2008) and local procedures for (III).

Figures

	Fig. 1. Representative crystals of (I), (II) and (III).
	Fig. 2. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 3. The molecular structure of (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 4. The molecular structure of (III), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 5. Crystal packing of (I) (top), (II) (middle) and (III) (bottom) without considering the solvent molecules and acetate.
	Fig. 6. Crystal packing of (I); for details of symmetry codes see Table 1. Additionally: (iv) x, -y+0.5, z-0.5; (v) x+0.5, -y+0.5, -z+1.
	Fig. 7. Crystal packing of (II); for details of symmetry codes see Table 2. Additionally: (iv) x, y-1, z-1; (v) x+1, y+1, z+1.
	Fig. 8. Crystal packing of (III); for details of symmetry codes see Table 3. Additionally: (iv) x, -y+0.5, z-0.5; (v) -x+2, y-0.5, -z+1.5; (vi) -x+1.5, -y, z+0.5.

(I) (E)-4-(2-{[amino(iminio)methyl]amino}vinyl)-3,5-dichlorophenolate dihydrate

Crystal data

C8H8Cl2N4O·2H2O	Dx = 1.485 Mg m^−3
Mr = 283.12	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 3301 reflections
a = 6.8802 (1) Å	θ = 1.0–27.5°
b = 16.7892 (4) Å	µ = 0.52 mm^−1
c = 21.9240 (5) Å	T = 90 K
V = 2532.51 (9) Å^3	Needle, colorless
Z = 8	0.40 × 0.10 × 0.03 mm
F(000) = 1168

Data collection

Nonius KappaCCD diffractometer	2898 independent reflections
Radiation source: fine-focus sealed tube	1692 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.061
Detector resolution: 18 pixels mm^-1	θmax = 27.5°, θmin = 1.9°
ω scans at fixed χ = 55°	h = −8→8
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997)	k = −21→21
Tmin = 0.820, Tmax = 0.985	l = −28→28
5390 measured reflections

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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.142	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.071P)^2] where P = (Fo^2 + 2Fc^2)/3
2898 reflections	(Δ/σ)max = 0.001
167 parameters	Δρmax = 0.66 e Å^−3
6 restraints	Δρmin = −0.41 e Å^−3

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.

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 > 2sigma(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
Cl1	0.53741 (12)	0.40341 (4)	0.77631 (3)	0.0226 (2)
O1	0.5751 (3)	0.31245 (11)	0.55752 (8)	0.0228 (5)
C4	0.6041 (4)	0.24863 (16)	0.74267 (13)	0.0183 (7)
Cl2	0.67992 (12)	0.09293 (4)	0.70898 (3)	0.0240 (2)
C3	0.5685 (5)	0.32651 (16)	0.72278 (13)	0.0193 (7)
C2	0.5581 (4)	0.34924 (17)	0.66244 (13)	0.0195 (7)
H2	0.5337	0.4033	0.6522	0.023*
C1	0.5836 (5)	0.29268 (18)	0.61650 (13)	0.0212 (7)
C6	0.6226 (5)	0.21380 (18)	0.63426 (13)	0.0205 (7)
H6	0.6429	0.1742	0.6040	0.025*
C5	0.6316 (5)	0.19333 (16)	0.69504 (14)	0.0198 (7)
C7	0.6033 (5)	0.23057 (16)	0.80773 (13)	0.0185 (7)
H7	0.5600	0.2705	0.8353	0.022*
N8	0.6579 (4)	0.16375 (14)	0.82941 (11)	0.0215 (6)
N9	0.6422 (4)	0.15480 (14)	0.89184 (11)	0.0226 (6)
H9	0.6046	0.1938	0.9159	0.027*
C10	0.6885 (5)	0.08229 (17)	0.91313 (14)	0.0210 (7)
N11	0.7468 (4)	0.02731 (14)	0.87434 (11)	0.0297 (7)
H11A	0.7800	−0.0202	0.8877	0.036*
H11B	0.7527	0.0381	0.8351	0.036*
N12	0.6793 (4)	0.06648 (15)	0.97222 (11)	0.0246 (7)
H12A	0.7123	0.0190	0.9858	0.030*
H12B	0.6403	0.1034	0.9979	0.030*
O1W	0.2315 (4)	0.39940 (12)	0.54192 (12)	0.0307 (6)
H1W1	0.333 (4)	0.3727 (19)	0.5475 (17)	0.046*
H2W1	0.141 (4)	0.3696 (19)	0.5391 (17)	0.046*
O2W	0.4685 (3)	0.22363 (12)	0.46540 (9)	0.0229 (5)
H1W2	0.485 (4)	0.243 (2)	0.4996 (11)	0.034*
H2W2	0.350 (3)	0.217 (2)	0.4613 (14)	0.034*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0293 (5)	0.0189 (4)	0.0195 (4)	0.0008 (3)	−0.0006 (3)	−0.0038 (3)
O1	0.0327 (14)	0.0232 (11)	0.0125 (11)	−0.0010 (10)	−0.0021 (10)	0.0008 (9)
C4	0.0172 (16)	0.0196 (15)	0.0183 (17)	−0.0025 (14)	−0.0004 (14)	0.0003 (12)
Cl2	0.0350 (5)	0.0159 (4)	0.0211 (4)	0.0013 (4)	−0.0003 (4)	0.0003 (3)
C3	0.0212 (19)	0.0167 (15)	0.0200 (17)	−0.0004 (13)	0.0006 (14)	−0.0029 (13)
C2	0.0215 (19)	0.0138 (15)	0.0232 (17)	−0.0003 (13)	−0.0022 (14)	0.0016 (12)
C1	0.0246 (19)	0.0252 (17)	0.0138 (16)	−0.0019 (15)	0.0010 (14)	0.0019 (13)
C6	0.0241 (19)	0.0216 (16)	0.0160 (17)	−0.0020 (15)	0.0009 (14)	−0.0017 (13)
C5	0.0200 (19)	0.0166 (15)	0.0230 (17)	−0.0013 (13)	−0.0006 (14)	0.0006 (13)
C7	0.0207 (18)	0.0181 (15)	0.0167 (16)	−0.0048 (14)	0.0013 (14)	−0.0005 (12)
N8	0.0235 (16)	0.0262 (14)	0.0146 (14)	−0.0003 (12)	0.0018 (12)	0.0019 (11)
N9	0.0337 (18)	0.0208 (14)	0.0133 (14)	0.0017 (12)	0.0032 (12)	0.0005 (11)
C10	0.0229 (19)	0.0205 (16)	0.0197 (17)	0.0012 (14)	0.0003 (14)	0.0007 (13)
N11	0.051 (2)	0.0195 (14)	0.0183 (15)	0.0071 (14)	0.0067 (14)	0.0006 (11)
N12	0.0428 (19)	0.0172 (13)	0.0139 (14)	0.0052 (13)	0.0033 (13)	0.0017 (10)
O1W	0.0339 (16)	0.0203 (12)	0.0379 (15)	−0.0037 (11)	−0.0032 (13)	0.0009 (11)
O2W	0.0276 (14)	0.0241 (12)	0.0170 (12)	−0.0020 (11)	−0.0026 (11)	−0.0014 (9)

Geometric parameters (Å, º)

Cl1—C3	1.758 (3)	N8—N9	1.381 (3)
O1—C1	1.336 (3)	N9—C10	1.342 (3)
C4—C3	1.400 (4)	N9—H9	0.8800
C4—C5	1.410 (4)	C10—N11	1.318 (4)
C4—C7	1.458 (4)	C10—N12	1.324 (4)
Cl2—C5	1.745 (3)	N11—H11A	0.8800
C3—C2	1.379 (4)	N11—H11B	0.8800
C2—C1	1.395 (4)	N12—H12A	0.8800
C2—H2	0.9500	N12—H12B	0.8800
C1—C6	1.406 (4)	O1W—H1W1	0.84 (2)
C6—C5	1.377 (4)	O1W—H2W1	0.80 (2)
C6—H6	0.9500	O2W—H1W2	0.82 (2)
C7—N8	1.275 (3)	O2W—H2W2	0.82 (2)
C7—H7	0.9500
C3—C4—C5	114.1 (3)	N8—C7—C4	123.1 (3)
C3—C4—C7	119.9 (3)	N8—C7—H7	118.4
C5—C4—C7	126.0 (3)	C4—C7—H7	118.4
C2—C3—C4	124.5 (3)	C7—N8—N9	116.2 (2)
C2—C3—Cl1	115.5 (2)	C10—N9—N8	115.1 (2)
C4—C3—Cl1	120.0 (2)	C10—N9—H9	122.4
C3—C2—C1	119.8 (3)	N8—N9—H9	122.4
C3—C2—H2	120.1	N11—C10—N12	120.4 (3)
C1—C2—H2	120.1	N11—C10—N9	118.9 (3)
O1—C1—C2	121.6 (3)	N12—C10—N9	120.7 (3)
O1—C1—C6	120.7 (3)	C10—N11—H11A	120.0
C2—C1—C6	117.7 (3)	C10—N11—H11B	120.0
C5—C6—C1	120.8 (3)	H11A—N11—H11B	120.0
C5—C6—H6	119.6	C10—N12—H12A	120.0
C1—C6—H6	119.6	C10—N12—H12B	120.0
C6—C5—C4	123.1 (3)	H12A—N12—H12B	120.0
C6—C5—Cl2	114.8 (2)	H1W1—O1W—H2W1	109 (3)
C4—C5—Cl2	122.1 (2)	H1W2—O2W—H2W2	107 (3)
C5—C4—C3—C2	0.7 (4)	C1—C6—C5—Cl2	179.7 (3)
C7—C4—C3—C2	−177.2 (3)	C3—C4—C5—C6	−0.5 (4)
C5—C4—C3—Cl1	−178.3 (2)	C7—C4—C5—C6	177.2 (3)
C7—C4—C3—Cl1	3.8 (4)	C3—C4—C5—Cl2	179.5 (2)
C4—C3—C2—C1	0.1 (5)	C7—C4—C5—Cl2	−2.8 (4)
Cl1—C3—C2—C1	179.1 (2)	C3—C4—C7—N8	−171.0 (3)
C3—C2—C1—O1	−179.8 (3)	C5—C4—C7—N8	11.4 (5)
C3—C2—C1—C6	−1.0 (5)	C4—C7—N8—N9	−177.8 (3)
O1—C1—C6—C5	179.9 (3)	C7—N8—N9—C10	175.9 (3)
C2—C1—C6—C5	1.1 (5)	N8—N9—C10—N11	1.2 (4)
C1—C6—C5—C4	−0.3 (5)	N8—N9—C10—N12	179.9 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N9—H9···O2W^i	0.88	1.99	2.863 (3)	169
N11—H11A···O1W^ii	0.88	2.05	2.829 (3)	147
N11—H11B···Cl2	0.88	2.96	3.817 (3)	166
N12—H12A···O1W^ii	0.88	2.13	2.888 (3)	143
N12—H12B···O1^i	0.88	1.98	2.854 (3)	175
O1W—H1W1···O1	0.84 (2)	1.96 (2)	2.800 (3)	178 (4)
O1W—H2W1···O2W^iii	0.80 (2)	1.97 (2)	2.751 (3)	166 (3)
O2W—H1W2···O1	0.82 (2)	1.83 (2)	2.616 (3)	158 (3)
O2W—H2W2···O1^iii	0.82 (2)	2.00 (2)	2.819 (3)	171 (3)

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

(II) (E)-4-(2-{[amino(iminio)methyl]amino}vinyl)-3,5-dichlorophenolate methanol disolvate

Crystal data

C8H8Cl2N4O·2CH4O	Z = 2
Mr = 311.17	F(000) = 324
Triclinic, P1	Dx = 1.439 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.0255 (1) Å	Cell parameters from 3251 reflections
b = 10.0683 (2) Å	θ = 1.0–27.5°
c = 11.7580 (2) Å	µ = 0.46 mm^−1
α = 112.3416 (8)°	T = 90 K
β = 93.9597 (9)°	Block, colourless
γ = 107.4271 (9)°	0.40 × 0.30 × 0.20 mm
V = 718.02 (2) Å^3

Data collection

Nonius KappaCCD diffractometer	3269 independent reflections
Radiation source: fine-focus sealed tube	2673 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
Detector resolution: 9.1 pixels mm^-1	θmax = 27.5°, θmin = 1.9°
ω scans at fixed χ = 55°	h = −9→9
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997)	k = −13→12
Tmin = 0.837, Tmax = 0.913	l = −15→15
6495 measured reflections

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.095	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0453P)^2 + 0.3166P] where P = (Fo^2 + 2Fc^2)/3
3269 reflections	(Δ/σ)max = 0.001
176 parameters	Δρmax = 0.34 e Å^−3
0 restraints	Δρmin = −0.33 e Å^−3

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.

Refinement. Refinement of F² against all reflections. The weighted R-value wR and goodness of fit S are based on F². Conventional R-values R are based on F, with F set to zero for negative F². The threshold expression of F² > 2σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-values based on F² are statistically about twice as large as those based on F, and R-values based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.87919 (6)	1.04881 (4)	0.31259 (4)	0.02157 (12)
Cl2	0.53514 (7)	0.75447 (5)	0.59664 (4)	0.02501 (13)
O1	0.68224 (19)	0.47871 (13)	0.17692 (11)	0.0246 (3)
C4	0.7178 (2)	0.90206 (17)	0.45646 (14)	0.0154 (3)
C3	0.7800 (2)	0.88676 (19)	0.34198 (15)	0.0175 (3)
C2	0.7675 (2)	0.74826 (19)	0.24789 (15)	0.0188 (3)
H2	0.8128	0.7458	0.1731	0.023*
C1	0.6886 (2)	0.61173 (19)	0.26242 (15)	0.0191 (3)
C6	0.6182 (3)	0.62176 (19)	0.37365 (16)	0.0203 (3)
H6	0.5597	0.5310	0.3854	0.024*
C5	0.6331 (2)	0.76164 (19)	0.46573 (15)	0.0175 (3)
C7	0.7447 (2)	1.05409 (19)	0.55230 (15)	0.0176 (3)
H7	0.7964	1.1402	0.5334	0.021*
N8	0.7017 (2)	1.07651 (15)	0.66070 (13)	0.0184 (3)
N9	0.7384 (2)	1.22675 (15)	0.74020 (12)	0.0185 (3)
H9	0.7884	1.3012	0.7167	0.022*
C10	0.6954 (2)	1.25627 (19)	0.85477 (15)	0.0187 (3)
N12	0.7304 (2)	1.40192 (16)	0.93120 (13)	0.0230 (3)
H12A	0.7051	1.4255	1.0073	0.028*
H12B	0.7790	1.4746	0.9057	0.028*
N11	0.6228 (2)	1.14271 (16)	0.88806 (13)	0.0233 (3)
H11A	0.5957	1.1619	0.9634	0.028*
H11B	0.6016	1.0477	0.8349	0.028*
C13	1.0498 (4)	0.4265 (3)	0.3339 (3)	0.0527 (7)
H13A	1.1524	0.3783	0.3330	0.079*
H13B	0.9145	0.3522	0.3222	0.079*
H13C	1.0804	0.5154	0.4147	0.079*
O15	1.0532 (2)	0.47495 (15)	0.23545 (13)	0.0292 (3)
H15	0.9352	0.4687	0.2089	0.044*
C14	0.2570 (3)	0.1542 (3)	0.0776 (2)	0.0382 (5)
H14A	0.1854	0.1259	0.1383	0.057*
H14B	0.2032	0.0692	−0.0062	0.057*
H14C	0.2362	0.2456	0.0761	0.057*
O16	0.46957 (19)	0.18621 (14)	0.11360 (12)	0.0264 (3)
H16	0.5313	0.2816	0.1485	0.040*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0273 (2)	0.0184 (2)	0.0195 (2)	0.00569 (17)	0.00861 (16)	0.00966 (17)
Cl2	0.0392 (3)	0.0182 (2)	0.0200 (2)	0.00961 (18)	0.01616 (18)	0.00922 (17)
O1	0.0344 (7)	0.0157 (6)	0.0177 (6)	0.0078 (5)	0.0089 (5)	0.0011 (5)
C4	0.0154 (8)	0.0147 (8)	0.0144 (8)	0.0044 (6)	0.0034 (6)	0.0049 (6)
C3	0.0165 (8)	0.0170 (8)	0.0182 (8)	0.0045 (6)	0.0042 (6)	0.0077 (6)
C2	0.0204 (8)	0.0205 (8)	0.0140 (8)	0.0068 (7)	0.0065 (6)	0.0055 (7)
C1	0.0196 (8)	0.0180 (8)	0.0161 (8)	0.0059 (6)	0.0042 (6)	0.0040 (7)
C6	0.0240 (9)	0.0156 (8)	0.0196 (8)	0.0058 (7)	0.0062 (7)	0.0063 (7)
C5	0.0193 (8)	0.0199 (8)	0.0140 (7)	0.0074 (7)	0.0065 (6)	0.0070 (6)
C7	0.0205 (8)	0.0155 (8)	0.0170 (8)	0.0066 (6)	0.0048 (6)	0.0065 (6)
N8	0.0205 (7)	0.0156 (7)	0.0166 (7)	0.0071 (6)	0.0046 (5)	0.0037 (6)
N9	0.0242 (7)	0.0133 (7)	0.0160 (7)	0.0053 (6)	0.0072 (6)	0.0047 (5)
C10	0.0186 (8)	0.0197 (8)	0.0161 (8)	0.0073 (7)	0.0044 (6)	0.0051 (7)
N12	0.0313 (8)	0.0164 (7)	0.0156 (7)	0.0059 (6)	0.0065 (6)	0.0027 (6)
N11	0.0338 (8)	0.0175 (7)	0.0151 (7)	0.0074 (6)	0.0099 (6)	0.0037 (6)
C13	0.0514 (15)	0.0628 (17)	0.0685 (17)	0.0225 (13)	0.0216 (13)	0.0496 (15)
O15	0.0307 (7)	0.0261 (7)	0.0357 (8)	0.0105 (6)	0.0131 (6)	0.0168 (6)
C14	0.0339 (11)	0.0430 (12)	0.0349 (11)	0.0091 (9)	0.0074 (9)	0.0168 (10)
O16	0.0309 (7)	0.0208 (6)	0.0226 (6)	0.0048 (5)	0.0086 (5)	0.0069 (5)

Geometric parameters (Å, º)

Cl1—C3	1.7459 (17)	C10—N11	1.319 (2)
Cl2—C5	1.7460 (16)	C10—N12	1.330 (2)
O1—C1	1.3194 (19)	N12—H12A	0.8800
C4—C5	1.410 (2)	N12—H12B	0.8800
C4—C3	1.411 (2)	N11—H11A	0.8800
C4—C7	1.461 (2)	N11—H11B	0.8800
C3—C2	1.384 (2)	C13—O15	1.416 (3)
C2—C1	1.401 (2)	C13—H13A	0.9800
C2—H2	0.9500	C13—H13B	0.9800
C1—C6	1.408 (2)	C13—H13C	0.9800
C6—C5	1.380 (2)	O15—H15	0.8400
C6—H6	0.9500	C14—O16	1.426 (2)
C7—N8	1.282 (2)	C14—H14A	0.9800
C7—H7	0.9500	C14—H14B	0.9800
N8—N9	1.3735 (19)	C14—H14C	0.9800
N9—C10	1.342 (2)	O16—H16	0.8400
N9—H9	0.8800
C5—C4—C3	113.95 (14)	N8—N9—H9	121.1
C5—C4—C7	126.11 (14)	N11—C10—N12	122.59 (15)
C3—C4—C7	119.94 (14)	N11—C10—N9	119.84 (15)
C2—C3—C4	123.96 (15)	N12—C10—N9	117.57 (15)
C2—C3—Cl1	116.17 (13)	C10—N12—H12A	120.0
C4—C3—Cl1	119.88 (12)	C10—N12—H12B	120.0
C3—C2—C1	120.36 (15)	H12A—N12—H12B	120.0
C3—C2—H2	119.8	C10—N11—H11A	120.0
C1—C2—H2	119.8	C10—N11—H11B	120.0
O1—C1—C2	121.91 (14)	H11A—N11—H11B	120.0
O1—C1—C6	120.78 (15)	O15—C13—H13A	109.5
C2—C1—C6	117.30 (14)	O15—C13—H13B	109.5
C5—C6—C1	120.90 (16)	H13A—C13—H13B	109.5
C5—C6—H6	119.6	O15—C13—H13C	109.5
C1—C6—H6	119.6	H13A—C13—H13C	109.5
C6—C5—C4	123.47 (15)	H13B—C13—H13C	109.5
C6—C5—Cl2	115.35 (13)	C13—O15—H15	109.5
C4—C5—Cl2	121.17 (12)	O16—C14—H14A	109.5
N8—C7—C4	122.97 (15)	O16—C14—H14B	109.5
N8—C7—H7	118.5	H14A—C14—H14B	109.5
C4—C7—H7	118.5	O16—C14—H14C	109.5
C7—N8—N9	115.51 (14)	H14A—C14—H14C	109.5
C10—N9—N8	117.82 (14)	H14B—C14—H14C	109.5
C10—N9—H9	121.1	C14—O16—H16	109.5
C5—C4—C3—C2	−2.3 (2)	C1—C6—C5—Cl2	178.97 (13)
C7—C4—C3—C2	177.49 (15)	C3—C4—C5—C6	2.2 (2)
C5—C4—C3—Cl1	177.54 (12)	C7—C4—C5—C6	−177.61 (15)
C7—C4—C3—Cl1	−2.6 (2)	C3—C4—C5—Cl2	−176.82 (12)
C4—C3—C2—C1	0.4 (3)	C7—C4—C5—Cl2	3.4 (2)
Cl1—C3—C2—C1	−179.53 (12)	C5—C4—C7—N8	3.7 (3)
C3—C2—C1—O1	−177.18 (15)	C3—C4—C7—N8	−176.12 (15)
C3—C2—C1—C6	1.9 (2)	C4—C7—N8—N9	179.24 (14)
O1—C1—C6—C5	177.06 (15)	C7—N8—N9—C10	179.85 (14)
C2—C1—C6—C5	−2.0 (2)	N8—N9—C10—N11	0.8 (2)
C1—C6—C5—C4	−0.1 (3)	N8—N9—C10—N12	−179.74 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O15—H15···O1	0.84	1.83	2.6640 (18)	171
O16—H16···O1	0.84	1.83	2.6464 (17)	163
N9—H9···O15^i	0.88	2.02	2.8109 (18)	149
N12—H12A···O1^ii	0.88	1.89	2.7665 (19)	173
N12—H12B···O15^i	0.88	2.23	2.969 (2)	142
N11—H11A···O16^ii	0.88	1.99	2.8596 (19)	167
N11—H11B···O16^iii	0.88	2.57	3.1702 (19)	127

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

(III) (E)-amino[(2,6-dichloro-4-hydroxystyryl)amino]methaniminium acetate

Crystal data

C8H9Cl2N4O^+·C2H3O2^−	Dx = 1.584 Mg m^−3
Mr = 307.14	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 3373 reflections
a = 15.9630 (1) Å	θ = 1.0–27.5°
b = 7.4060 (2) Å	µ = 0.51 mm^−1
c = 21.7930 (3) Å	T = 90 K
V = 2576.41 (8) Å^3	Plate, yellow
Z = 8	0.40 × 0.20 × 0.10 mm
F(000) = 1264

Data collection

Nonius KappaCCD diffractometer	2952 independent reflections
Radiation source: fine-focus sealed tube	2375 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
Detector resolution: 18 pixels mm^-1	θmax = 27.5°, θmin = 1.9°
ω scans at fixed χ = 55°	h = −20→20
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997)	k = −9→9
Tmin = 0.821, Tmax = 0.950	l = −28→28
5505 measured reflections

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.100	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.045P)^2 + 2.1571P] where P = (Fo^2 + 2Fc^2)/3
2952 reflections	(Δ/σ)max = 0.001
174 parameters	Δρmax = 0.38 e Å^−3
0 restraints	Δρmin = −0.34 e Å^−3

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.

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 > 2sigma(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
Cl2	1.07155 (3)	0.28736 (7)	0.45954 (2)	0.01973 (13)
O1	0.88677 (8)	−0.0078 (2)	0.30487 (6)	0.0233 (3)
H1	0.8373	−0.0403	0.2977	0.035*
C4	0.91343 (11)	0.1639 (3)	0.48732 (8)	0.0164 (4)
Cl1	0.75724 (3)	0.03255 (7)	0.51572 (2)	0.02042 (13)
C3	0.84077 (11)	0.0771 (3)	0.46581 (8)	0.0173 (4)
C2	0.82964 (11)	0.0180 (3)	0.40625 (8)	0.0182 (4)
H2	0.7794	−0.0416	0.3946	0.022*
C1	0.89309 (11)	0.0468 (3)	0.36348 (8)	0.0178 (4)
C6	0.96676 (11)	0.1323 (3)	0.38199 (8)	0.0187 (4)
H6	1.0106	0.1523	0.3533	0.022*
C5	0.97596 (11)	0.1879 (3)	0.44206 (9)	0.0168 (4)
C7	0.91835 (11)	0.2184 (3)	0.55131 (8)	0.0167 (4)
H7	0.8701	0.2008	0.5762	0.020*
N8	0.98321 (10)	0.2886 (2)	0.57661 (7)	0.0185 (3)
N9	0.97274 (10)	0.3331 (2)	0.63747 (7)	0.0195 (4)
H9	0.9253	0.3109	0.6566	0.023*
C10	1.03725 (11)	0.4115 (3)	0.66666 (8)	0.0180 (4)
N11	1.10909 (10)	0.4393 (2)	0.63789 (7)	0.0213 (4)
H11A	1.1510	0.4916	0.6572	0.026*
H11B	1.1150	0.4055	0.5994	0.026*
N12	1.02762 (10)	0.4618 (2)	0.72464 (7)	0.0233 (4)
H12A	1.0692	0.5142	0.7443	0.028*
H12B	0.9796	0.4429	0.7435	0.028*
C13	0.70888 (13)	0.2009 (3)	0.68690 (9)	0.0249 (4)
H13A	0.6850	0.0907	0.6692	0.037*
H13B	0.7292	0.2795	0.6539	0.037*
H13C	0.6657	0.2644	0.7105	0.037*
C14	0.78090 (12)	0.1520 (3)	0.72871 (9)	0.0204 (4)
O15	0.76421 (8)	0.0862 (2)	0.78087 (6)	0.0250 (3)
O16	0.85473 (9)	0.1725 (2)	0.70986 (6)	0.0266 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl2	0.0144 (2)	0.0244 (3)	0.0203 (2)	−0.00447 (18)	−0.00047 (16)	0.00180 (18)
O1	0.0145 (6)	0.0389 (9)	0.0165 (6)	−0.0032 (6)	−0.0008 (5)	−0.0033 (6)
C4	0.0150 (8)	0.0169 (9)	0.0174 (9)	0.0025 (7)	−0.0008 (7)	0.0025 (7)
Cl1	0.0143 (2)	0.0251 (3)	0.0219 (2)	−0.00211 (18)	0.00351 (16)	−0.00007 (18)
C3	0.0135 (8)	0.0172 (9)	0.0212 (9)	0.0025 (7)	0.0035 (7)	0.0042 (7)
C2	0.0108 (8)	0.0219 (10)	0.0218 (9)	0.0000 (7)	−0.0025 (7)	0.0003 (8)
C1	0.0150 (9)	0.0216 (10)	0.0168 (8)	0.0036 (8)	−0.0018 (7)	0.0005 (7)
C6	0.0130 (8)	0.0244 (10)	0.0186 (9)	0.0017 (8)	0.0000 (7)	0.0034 (8)
C5	0.0122 (8)	0.0164 (9)	0.0216 (9)	0.0014 (7)	−0.0030 (7)	0.0029 (7)
C7	0.0158 (8)	0.0145 (9)	0.0198 (9)	0.0018 (7)	0.0008 (7)	0.0026 (7)
N8	0.0200 (8)	0.0201 (8)	0.0154 (7)	0.0000 (7)	0.0003 (6)	0.0002 (6)
N9	0.0143 (7)	0.0294 (9)	0.0147 (7)	−0.0029 (7)	0.0013 (6)	0.0005 (7)
C10	0.0162 (9)	0.0196 (10)	0.0182 (9)	0.0022 (8)	−0.0005 (7)	0.0024 (8)
N11	0.0160 (8)	0.0304 (10)	0.0175 (8)	−0.0029 (7)	0.0018 (6)	−0.0036 (7)
N12	0.0159 (8)	0.0371 (10)	0.0169 (8)	−0.0007 (7)	0.0018 (6)	−0.0025 (7)
C13	0.0222 (10)	0.0325 (12)	0.0200 (9)	0.0011 (9)	−0.0018 (8)	0.0044 (8)
C14	0.0202 (9)	0.0205 (10)	0.0205 (9)	−0.0013 (8)	0.0010 (7)	0.0015 (8)
O15	0.0168 (7)	0.0383 (9)	0.0200 (6)	−0.0006 (6)	0.0019 (5)	0.0088 (6)
O16	0.0186 (7)	0.0374 (9)	0.0239 (7)	−0.0030 (6)	0.0039 (6)	0.0086 (6)

Geometric parameters (Å, º)

Cl2—C5	1.7367 (18)	N8—N9	1.377 (2)
O1—C1	1.344 (2)	N9—C10	1.342 (2)
O1—H1	0.8400	N9—H9	0.8800
C4—C3	1.406 (3)	C10—N11	1.323 (2)
C4—C5	1.414 (3)	C10—N12	1.326 (2)
C4—C7	1.454 (3)	N11—H11A	0.8800
Cl1—C3	1.7520 (18)	N11—H11B	0.8800
C3—C2	1.381 (3)	N12—H12A	0.8800
C2—C1	1.393 (3)	N12—H12B	0.8800
C2—H2	0.9500	C13—C14	1.511 (3)
C1—C6	1.395 (3)	C13—H13A	0.9800
C6—C5	1.380 (3)	C13—H13B	0.9800
C6—H6	0.9500	C13—H13C	0.9800
C7—N8	1.283 (2)	C14—O16	1.257 (2)
C7—H7	0.9500	C14—O15	1.265 (2)
C1—O1—H1	109.5	C7—N8—N9	114.39 (15)
C3—C4—C5	114.02 (16)	C10—N9—N8	117.83 (15)
C3—C4—C7	119.42 (16)	C10—N9—H9	121.1
C5—C4—C7	126.56 (17)	N8—N9—H9	121.1
C2—C3—C4	124.34 (17)	N11—C10—N12	120.55 (17)
C2—C3—Cl1	115.21 (14)	N11—C10—N9	120.50 (17)
C4—C3—Cl1	120.44 (14)	N12—C10—N9	118.95 (17)
C3—C2—C1	119.13 (17)	C10—N11—H11A	120.0
C3—C2—H2	120.4	C10—N11—H11B	120.0
C1—C2—H2	120.4	H11A—N11—H11B	120.0
O1—C1—C2	122.38 (17)	C10—N12—H12A	120.0
O1—C1—C6	118.34 (17)	C10—N12—H12B	120.0
C2—C1—C6	119.26 (17)	H12A—N12—H12B	120.0
C5—C6—C1	119.96 (17)	C14—C13—H13A	109.5
C5—C6—H6	120.0	C14—C13—H13B	109.5
C1—C6—H6	120.0	H13A—C13—H13B	109.5
C6—C5—C4	123.28 (17)	C14—C13—H13C	109.5
C6—C5—Cl2	115.34 (14)	H13A—C13—H13C	109.5
C4—C5—Cl2	121.37 (14)	H13B—C13—H13C	109.5
N8—C7—C4	124.63 (17)	O16—C14—O15	122.53 (18)
N8—C7—H7	117.7	O16—C14—C13	119.14 (17)
C4—C7—H7	117.7	O15—C14—C13	118.29 (17)
C5—C4—C3—C2	0.4 (3)	C1—C6—C5—Cl2	178.44 (15)
C7—C4—C3—C2	−179.33 (18)	C3—C4—C5—C6	0.3 (3)
C5—C4—C3—Cl1	179.00 (14)	C7—C4—C5—C6	179.97 (19)
C7—C4—C3—Cl1	−0.7 (3)	C3—C4—C5—Cl2	−178.42 (14)
C4—C3—C2—C1	−1.0 (3)	C7—C4—C5—Cl2	1.2 (3)
Cl1—C3—C2—C1	−179.66 (15)	C3—C4—C7—N8	175.70 (19)
C3—C2—C1—O1	179.66 (18)	C5—C4—C7—N8	−3.9 (3)
C3—C2—C1—C6	0.9 (3)	C4—C7—N8—N9	178.65 (17)
O1—C1—C6—C5	−179.08 (17)	C7—N8—N9—C10	−178.35 (17)
C2—C1—C6—C5	−0.2 (3)	N8—N9—C10—N11	−2.0 (3)
C1—C6—C5—C4	−0.4 (3)	N8—N9—C10—N12	177.47 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O15^i	0.84	1.70	2.5336 (19)	175
N9—H9···O16	0.88	1.91	2.730 (2)	153
N11—H11A···O15^ii	0.88	2.04	2.900 (2)	167
N12—H12A···O16^ii	0.88	1.96	2.828 (2)	168
N12—H12B···O1^iii	0.88	2.05	2.868 (2)	153

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