Tizanidine and tizanidine hydro­chloride: on the correct tautomeric form of tizanidine

A crystallization series of tizanidine hydro­chloride, used as a muscle relaxant for spasticity acting centrally as an [alpha]₂-adrenergic agonist, yielded single crystals of the free base and the hydro­chloride salt. The crystal structures of tizanidine [systematic name: 5-chloro-N-(imidazolidin-2-yl­idene)-2,1,3-benzothia­diazol-4-amine], C₉H₈ClN₅S, (I), and tizanidine hydro­chloride {systematic name: 2-[(5-chloro-2,1,3-benzothia­diazol-4-yl)amino]­imidazolidinium chloride}, C₉H₉ClN₅S⁺·Cl^-, (II), have been determined. Tizanidine crystallizes with two almost identical mol­ecules in the asymmetric unit (r.m.s. deviation = 0.179 Å for all non-H atoms). The mol­ecules are connected by N-H...N hydrogen bonds forming chains running along [21]. The present structure determination corrects the structure determination of tizanidine by John et al. [Acta Cryst. (2011), E67, o838-o839], which shows an incorrect tautomeric form. Tizanidine does not crystallize as the usually drawn 2-amino-imidazoline tautomer, but as the 2-imino-imidazolidine tautomer. This tautomer is present in solution as well, as shown by ¹H NMR analysis. In tizanidine hydro­chloride, cations and anions are connected by N-H...Cl hydrogen bonds to form layers parallel to (100).

S1. Comment

Diseases like brain or spinal cord injury (BCI and SCI), multiple sclerosis (MS), stroke and traumatic brain injuries are often associated with spasticity and involuntary muscle tension, stiffening, or contraction resulting in abnormal movement of extremities. These movements are caused by excessive motor activity resulting from injured upper motor neurons in the spinal cord sending no longer normal information from the brain to the nerve cells in the muscles. Over 12 million people are affected by spasticity worldwide (Kamen et al., 2008). A huge number of active pharmaceutical ingrediants (APIs) (e.g. tetracepam, flupirtin, baclofen, pridinol, tolperison, eperison, or methocarbamol) for the management of spasticity have been developed over the past few decades, each with its own receptor specificity giving it a unique pharmacological effect. One of these is tizanidine and its currently applied hydrochloride salt.

The free base of tizanidine, (I), was first synthesized by Neumann (1974) in the laboratories of Sandoz–Wander Inc., currently known as Novartis AG. It was patented as an antitremor and antirigor agent together with other 2,1,3-benzothiadiazole derivatives. It can exist in two possible tautomers (Scheme 2 shows the imidazolin-2-amine tautomer on the left and the imidazolidin-2-imine tautomer on the right), but only in the patent a capability of tautomerism from the amino–imidazoline (Ia) to the imino–imidazolidine (Ib) tautomer is mentioned. In the common literature for chemistry and pharmacology (e.g. Falbe & Regitz, 1992; O'Neil, 2006; Mutschler et al., 2008; Bruchhausen et al., 1994; Aktories et al., 2009) and in all related publications only the amino–imidazoline tautomer is mentioned. Also the latest structure determination from single-crystal diffraction data by John et al. (2011) claimed that this tautomer would exist in the solid state. In this context, a recent paper (Cruz-Cabeza & Groom, 2011) reporting on wrong tautomeric assignments in published structures is relevant.

To date the most common and orally administered salt form of tizanidine is its hydrochloride salt, (II), marketed by Novartis AG under the registered trade name Sirdalud^TM or Zanaflex^TM and approved by the US Food and Drug Administration (FDA) in November 1996 for use in adults for spasticity. Tizanidine hydrochloride has been shown to act as an α₂-adrenergic agonist (Turski et al., 1986; Kameyama et al., 1986). Its mechanism of action is currently under investigation and has not been fully clarified, but it is believed that the pharmacodynamic effects of tizanidine are linked to its α₂-adrenergic agonist properties, albeit its imidazolidine receptor binding may play a role (Bes et al., 1988; Eyssette et al., 1988; Muramatsu & Kigoshi, 1992; Coward, 1994; Milanov & Georgiev, 1994; Landau, 1995; Wagstaff & Bryson, 1997; Mirbagheri et al., 2010; Kaddar et al., 2011).

Polymorph screening on the hydrochloride salt of tizanidine was performed by crystallizing the compound from a variety of different solvents and using various methods. The crystallization experiments resulted in single crystals suitable for X-ray diffraction of the solvent-free compounds (I) and (II). New polymorphs or pseudopolymorphs were not obtained.

Although the free base has already been published, a redetermination was necessary to clarify its tautomeric form in the solid state. Additionally ¹H NMR studies were performed to investigate the tautomeric form in the liquid state to give additional impulse to the investigation of the mode of action of tizanidine as a muscle relaxant and the body's response to them during therapy of e.g. multiple sclerosis (MS).

Tizanidine (Fig. 1) crystallizes in P1 with two almost identical molecules in the asymmetric unit (r.m.s. deviation = 0.179 Å for all non-H atoms). Bond lengths in the two molecules show only insignificant differences (see Table 5). Just the acyclic torsion angles differ slightly in both molecules [C4—C3—N3—C11 = -55.7 (2)°, C4A—C3A—N3A—C11A = -67.4 (2)°, C3—N3—C11—N15 = -14.0 (2)° and C3A—N3A—C11A—N15A = -12.9 (3)°]. The molecules are connected by N—H···N hydrogen bonds forming chains running along [211] (Fig. 2). The structure of tizanidine has already been published (John et al., 2011). However, these authors have misplaced the H atoms at two N atoms. Instead of two protonated N atoms in the imidazolidine ring, they have placed only one H atom at one of the imidazolidine N atoms and the other one on the bridging N atom. However, their data show unequivocally that: (i) the bond from the imidazolidine C atom to the bridging N atom is a double bond [1.290 (2) and 1.296 (2) Å]; (ii) in the difference map (Fig. 3) there is no peak indicating an H atom at the bridging N atom; (iii) there are peaks in the difference map indicating that both imidazolidine N atoms are protonated. Additionally a comparison with another ten up-to-date known solvent-free derivatives of (I) in the CSD [Cambridge Structural Database (CSD; Allen, 2002)] revealed that all of them show the imino–imidazolidine tautomer (Ib) [CSD refcode ALALEF (Saczewski et al., 2011), GOLNIE (Elssfah et al., 1999a), HIGGOU (Begum & Vasundhara, 2007), HODQOG (Elssfah et al., 1999b), KIBRAO (Koch et al., 1990), LUVPOH (Varga et al., 2003), QIBBOS (Isobe et al., 2000, VOVCUE01 (Schröder et al., 2003) XERHOS (Kornicka et al., 2006) and ZAYQOF: Dupont et al., 1995)]. Finally, ¹H NMR measurements show that (for the –CH₂ group), instead of two different signals, as would be expected for the asymmetrical 2-amino–imidazoline tautomer (Ia), only one signal appeared, indicating the symmetrical 2-imino–imidazolidine tautomer (Ib). This proves that the 2-imino–imidazolidine tautomer exists also in the liquid state. As a result, the structure of John et al. (2011) has to be revised.

Tizanidine hydrochloride (Fig. 4) crystallizes with a tizanidium cation (which is protonated at the bridging N atom) and a chloride anion in the asymmetric unit. The only significant structural difference between tizanidine and the protonated molecule are the N—C bond lengths to the bridging N atom (Table 5) which are elongated in the protonated molecule. A least-squares fit of the molecular structures of the two molecules in the asymmetric unit of tizanidine and the tizanidium anion is shown in Fig. 5. The cation and neutral molecule differ in the dihedral angle between the imidazolidine and benzothiadiazole moieties [dihedral angles: 53.89 (4)/67.33 (5) versus. 89.68 (6)°]. Whereas the mean value of the dihedral angle is approximately 60° in the neutral molecule, the ring systems are almost perpendicular in the protonated molecule. Whereas the neutral tizanidine molecules in the crystal are only connected by N—H···N hydrogen bonds, the cations in the structure of tizanidine hydrochloride are not directly connected to each other, but via N—H···Cl hydrogen bonds (Fig. 6). Each Cl anion acts as an acceptor for four N—H hydrogen-bond donors, two of which are from the same cation and the remaining two from two further cations. One of the imidazolidine N—H donors forms a bifurcated hydrogen bond to two different chloride anions, whereas the other two N—H groups are bonded to only one chloride ion each. The hydrogen-bond network leads to a layer parallel to (100).

Although no further polymorph or pseudopolymorph could be obtained from the initial polymorph screening, but the tautomerism of the free base of tizanidine in solid and liquid state could be revealed. The results presented here may give further guiding principles for further examinations on derivatives of tizanidine for developments in this field of study. More to the point, it could support studies dealing with the mechanism of action of tizanidine.

Related literature

For related literature, see: Aktories et al. (2009); Allen (2002); Begum & Vasundhara (2007); Bes et al. (1988); Bruchhausen et al. (1994); Coward (1994); Dupont et al. (1995); Elssfah et al. (1999a, 1999b); Eyssette et al. (1988); Falbe & Regitz (1992); Isobe et al. (2000); John et al. (2011); Kaddar et al. (2011); Kamen et al. (2008); Kameyama et al. (1986); Koch et al. (1990); Kornicka et al. (2006); Landau (1995); Milanov & Georgiev (1994); Mirbagheri et al. (2010); Muramatsu & Kigoshi (1992); Mutschler et al. (2008); Neumann (1974); O'Neil (2006); Saczewski et al. (2011); Schröder et al. (2003); Turski et al. (1986); Varga et al. (2003); Wagstaff & Bryson (1997).

S2. Experimental

Tizanidine hydrochloride was purchased from TCI EUROPE NV Belgium (>98%, purity), used as received and was found to be soluble at room temperature in methanol, ethanol, water, quinoline, morpholine, 2-picoline, N,N'-dimethylformamide, N,N'-dimethylacetamide and dimethyl sulfoxide. Subsequently, different methods of crystallization were employed including: (i) slurry experiments by suspending (II) in different solvents at room temperature; (ii) solvent-assisted grinding experiments by addition of several drops of solvent to the solid of (II) and grinding by hand using a mortar and pestle for several minutes at room temperature; (iii) evaporation crystallization at room temperature and at 353 K; (iv) slow or rapid antisolvent crystallization by overlaying a solution of (II) with an antisolvent (as antisolvents for crystallization experiments a multitude of different organic solvents, e.g. ketones, ethers, esters, alcohols, benzene derivatives and alkanes were used); (v) recrystallization under reflux by subsequent slow or fast cooling; (vi) treatment of a solution or suspension of (II) in an ultrasonic bath at room temperature; (vii) slow or rapid vapour diffusion experiments by diffusion of an antisolvent into a solution of (II) via the gas phase; (viii) thermal treatment using differential scanning calorimetry (DSC) performed on a DSC 131 (SETARAM) device. For the DSC about 25–30 mg of the sample was filled into an aluminium crucible and measured from room temperature to 500 K at a rate of 3 K min^-1 under a nitrogen atmosphere to observe phase transitions. All solids thus obtained were analysed by using X-ray powder diffraction data recorded under ambient conditions in transmission mode on a Stoe Stadi-P diffractometer with a Ge(111) monochromator and a linear position-sensitive detector using Cu Kα₁ radiation (λ = 1.5406 Å).

The ¹H NMR spectra for (I) and (II) were measured on a Bruker Avance 400 device with 400 MHz in tubes filled with d₆-DMSO and about 5 mg substance. The elemental analyses (CHNS) were carried out on an Elementar (vario MICRO cube) elemental analyzer. About 1–4 mg of the samples were filled into a tin vessel and measured at 1423 K under a helium atmosphere with addition of oxygen during the measurement.

In order to obtain single crystals of (I), the commercially available compound (II) (60 mg) was dissolved in morpholine (3 ml) in an ultrasonic bath at room temperature. Subsequently, the solution was filtered and diisopropyl ether (7 ml) was added. After 8 d, orange single crystals precipitated. ¹H NMR (400 MHz, d₆-DMSO): δ 7.64 (d, ³J_HH = 9.2 Hz, 1H, H6), 7.52 (d, ³J_HH = 9.2 Hz, 1H, H5), 6.33 (s, 2H, H12 and H15), 3.38 (s, 4H, H13A, H13B, H14A and H14B); Elemental analysis calculated for C₉H₈ClN₅S (%): C 42.61, H 3.18, N 27.60, S 12.64; found (%): C 42.48, H 3.07, N 27.43, S 12.92.

For growing crystals of (II), the commercially available compound (II) (340 mg) was dissolved in water (17 ml) in an ultrasonic bath at room temperature. Subsequently, the solution was filtered and the filtrate was allowed to evaporate at room temperature. After 10 d, pale-yellow single crystals precipitated. ¹H NMR (400 MHz, d₆-DMSO): δ 11.14 (s, 1H, H3), 8.48 (s, 2H, H12 and H15), 8.21 (d, ³J_HH = 9.2 Hz, 1H, H6), 7.94 (d, ³J_HH = 9.2 Hz, 1H, H5), 3.71 (s, 4H, H13A, H13B, H14A and H14B); Elemental analysis calculated for C₉H₉Cl₂N₅S (%): C 37.25, H 3.13, N 24.14, S 11.05; found (%): C 37.31, H 3.23, N 23.92, S 10.88.

S3. Refinement

All H atoms were located in Fourier difference maps. Nevertheless, H atoms bonded to C atoms were geometrically positioned and refined using a riding model with fixed individual displacement parameters [U_iso(H) = 1.2U_eq(C)] using a riding model with aromatic C—H = 0.95 Å or methylene C—H = 0.99 Å. H atoms bonded to N atoms were refined freely. Only the N15—H15 distance in tizanidine was restrained to 0.88 (1) Å.

Computing details

For both compounds, data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA (Stoe & Cie, 2001); data reduction: X-AREA (Stoe & Cie, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures

	Fig. 1. Perspective view of the two molecules in the asymmetric unit of tizanidine, (I), with the atom-numbering scheme. Displacement ellipsoids are at the 50% probability level and H atoms are drawn as small spheres of arbitrary radii.
	Fig. 2. Packing diagram of tizanidine, (I). H atoms not involved in hydrogen bonds have been omitted for clarity and hydrogen bonds are drawn as dashed lines. [Symmetry codes: (B) -x+1, -y+2, -z+1; (C) x, y-1, z; (D) -x+1, -y+1, -z+1; (E) -x+1, -y+1, -z+1.]
	Fig. 3. Difference electron-density map calculated on the basis of the data by John et al. (2011). H atoms bonded to N atoms have been omitted for calculating the Fourier map, but the positions of all H atoms as set by John et al. (2011) are shown in the figure.
	Fig. 4. Perspective view of tizanidine hydrochloride, (II), with the atom-numbering scheme. Displacement ellipsoids are at the 50% probability level and H atoms are drawn as small spheres of arbitrary radii.
	Fig. 5. Least-squares fit of the two molecules of tizanidine, (I), in the asymmetric unit [full bonds for molecule (Ia) and dashed bonds for molecule (Ib)] with the cation of tizanidine hydrochloride, (II) (open bonds). The nine atoms of the benzothiadiazole moiety had been fitted.
	Fig. 6. Packing diagram of tizanidine hydrochloride, (II). H atoms not involved in hydrogen bonds have been omitted for clarity and hydrogen bonds are drawn as dashed lines. [Symmetry codes: (A) x, -y+3/2, z-1/2; (B) -x+1, y-1/2, -z+1/2; (C) -x+1, -y+1, -z; (D) -x+1, -y+1, -z+1; (E) -x+1, y-1/2, -z+3/2; (F) x, -y+3/2, z+1/2; (G) x, y, z+1; (H) -x+1, y+1/2, -z+1/2; (I) -x+1, y-1/2, -z-1/2; (J) x, -y+3/2, z+1/2; (K) -x+1, y+1/2, -z+3/2; (L) x, -y+1/2, z-1/2; (M) x, -y+1/2, z+1/2.]

(I) 5-chloro-N-(imidazolidin-2-ylidene)-2,1,3-benzothiadiazol-4-amine

Crystal data

C9H8ClN5S	Z = 4
Mr = 253.71	F(000) = 520
Triclinic, P1	Dx = 1.621 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.5935 (6) Å	Cell parameters from 8083 reflections
b = 10.8712 (9) Å	θ = 3.4–26.0°
c = 12.8862 (12) Å	µ = 0.55 mm^−1
α = 95.794 (7)°	T = 173 K
β = 100.349 (7)°	Block, orange
γ = 92.125 (7)°	0.47 × 0.47 × 0.45 mm
V = 1039.45 (15) Å^3

Data collection

Stoe IPDS II two-circle diffractometer	3872 independent reflections
Radiation source: fine-focus sealed tube	3537 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.033
ω scans	θmax = 25.6°, θmin = 3.4°
Absorption correction: multi-scan (MULABS; Spek, 2009; Blessing, 1995)	h = −9→9
Tmin = 0.784, Tmax = 0.792	k = −13→12
9426 measured reflections	l = −15→15

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)] = 0.029	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.076	w = 1/[σ^2(Fo^2) + (0.0395P)^2 + 0.3667P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.001
3872 reflections	Δρmax = 0.29 e Å^−3
306 parameters	Δρmin = −0.27 e Å^−3
1 restraint	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: 0.0305 (18)

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
Cl1	0.87633 (5)	0.81691 (4)	0.35774 (3)	0.02998 (12)
S1	0.64157 (6)	1.12938 (4)	0.75043 (3)	0.03014 (13)
N1	0.61354 (18)	1.19340 (12)	0.64090 (11)	0.0285 (3)
N2	0.72209 (17)	0.99966 (12)	0.71384 (10)	0.0228 (3)
N3	0.85938 (16)	0.80253 (11)	0.59751 (10)	0.0196 (3)
C1	0.6682 (2)	1.11225 (14)	0.56883 (13)	0.0232 (3)
C2	0.72960 (19)	1.00099 (13)	0.61074 (12)	0.0195 (3)
C3	0.79219 (18)	0.90114 (13)	0.54686 (12)	0.0184 (3)
C4	0.79366 (19)	0.92490 (15)	0.44363 (12)	0.0225 (3)
C5	0.7348 (2)	1.03598 (16)	0.40233 (13)	0.0281 (4)
H5	0.7399	1.0457	0.3305	0.034*
C6	0.6716 (2)	1.12861 (15)	0.46169 (14)	0.0278 (4)
H6	0.6312	1.2016	0.4324	0.033*
C11	0.81239 (19)	0.68749 (14)	0.56164 (11)	0.0184 (3)
N12	0.89949 (18)	0.59355 (12)	0.60423 (11)	0.0230 (3)
H12	0.977 (3)	0.6061 (18)	0.6588 (17)	0.030 (5)*
C13	0.8035 (2)	0.47479 (14)	0.56282 (13)	0.0252 (3)
H13A	0.7233	0.4487	0.6102	0.030*
H13B	0.8870	0.4090	0.5516	0.030*
C14	0.6974 (2)	0.50735 (14)	0.45782 (13)	0.0240 (3)
H14A	0.7666	0.4946	0.3998	0.029*
H14B	0.5814	0.4587	0.4375	0.029*
N15	0.67228 (17)	0.63892 (12)	0.48498 (10)	0.0211 (3)
H15	0.620 (2)	0.6844 (16)	0.4391 (13)	0.028 (5)*
Cl1A	1.59135 (6)	0.73702 (4)	0.77597 (3)	0.03394 (13)
S1A	1.14534 (6)	0.30136 (4)	0.92207 (4)	0.03389 (13)
N1A	1.3580 (2)	0.28329 (12)	0.93078 (11)	0.0296 (3)
N2A	1.12605 (19)	0.43135 (13)	0.87212 (12)	0.0294 (3)
N3A	1.20243 (19)	0.65918 (12)	0.78831 (11)	0.0266 (3)
C1A	1.4254 (2)	0.38312 (14)	0.89417 (12)	0.0241 (3)
C2A	1.2917 (2)	0.46815 (14)	0.86089 (12)	0.0228 (3)
C3A	1.3382 (2)	0.58288 (14)	0.82357 (12)	0.0230 (3)
C4A	1.5168 (2)	0.60176 (15)	0.81929 (12)	0.0251 (3)
C5A	1.6497 (2)	0.51658 (15)	0.85015 (12)	0.0264 (3)
H5A	1.7704	0.5350	0.8440	0.032*
C6A	1.6067 (2)	0.40925 (15)	0.88834 (12)	0.0262 (3)
H6A	1.6960	0.3536	0.9104	0.031*
C11A	1.1998 (2)	0.76958 (14)	0.83723 (12)	0.0204 (3)
N12A	1.08719 (18)	0.85375 (12)	0.79985 (11)	0.0225 (3)
H12A	1.013 (3)	0.8373 (18)	0.7452 (17)	0.030 (5)*
C13A	1.0908 (2)	0.95967 (16)	0.87703 (14)	0.0311 (4)
H13C	0.9937	0.9522	0.9184	0.037*
H13D	1.0815	1.0376	0.8433	0.037*
C14A	1.2758 (2)	0.95219 (16)	0.94604 (14)	0.0320 (4)
H14C	1.3701	0.9979	0.9189	0.038*
H14D	1.2772	0.9843	1.0209	0.038*
N15A	1.29726 (19)	0.81865 (13)	0.93449 (10)	0.0238 (3)
H15A	1.396 (3)	0.7939 (18)	0.9540 (16)	0.027 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0270 (2)	0.0404 (2)	0.0234 (2)	−0.00064 (16)	0.00831 (15)	0.00188 (16)
S1	0.0374 (2)	0.0235 (2)	0.0268 (2)	0.00911 (17)	−0.00057 (17)	−0.00144 (16)
N1	0.0286 (7)	0.0195 (7)	0.0340 (8)	0.0034 (5)	−0.0038 (6)	0.0033 (6)
N2	0.0258 (7)	0.0191 (6)	0.0215 (6)	0.0032 (5)	−0.0009 (5)	0.0008 (5)
N3	0.0197 (6)	0.0190 (6)	0.0189 (6)	0.0017 (5)	−0.0002 (5)	0.0024 (5)
C1	0.0181 (7)	0.0182 (7)	0.0306 (8)	−0.0031 (5)	−0.0035 (6)	0.0063 (6)
C2	0.0160 (7)	0.0185 (7)	0.0221 (7)	−0.0026 (5)	−0.0024 (6)	0.0042 (6)
C3	0.0145 (6)	0.0192 (7)	0.0197 (7)	−0.0028 (5)	−0.0019 (5)	0.0032 (6)
C4	0.0170 (7)	0.0286 (8)	0.0215 (7)	−0.0032 (6)	0.0020 (6)	0.0049 (6)
C5	0.0227 (8)	0.0364 (9)	0.0253 (8)	−0.0053 (7)	0.0009 (6)	0.0140 (7)
C6	0.0241 (8)	0.0257 (8)	0.0325 (9)	−0.0028 (6)	−0.0033 (7)	0.0148 (7)
C11	0.0166 (7)	0.0205 (7)	0.0188 (7)	0.0025 (5)	0.0047 (5)	0.0024 (6)
N12	0.0218 (6)	0.0183 (6)	0.0259 (7)	0.0039 (5)	−0.0029 (6)	−0.0003 (5)
C13	0.0242 (8)	0.0186 (8)	0.0320 (9)	0.0029 (6)	0.0043 (6)	0.0002 (6)
C14	0.0209 (7)	0.0207 (8)	0.0287 (8)	0.0002 (6)	0.0036 (6)	−0.0039 (6)
N15	0.0187 (6)	0.0191 (6)	0.0234 (7)	0.0011 (5)	−0.0011 (5)	0.0016 (5)
Cl1A	0.0408 (2)	0.0314 (2)	0.0329 (2)	0.00316 (17)	0.01010 (18)	0.01310 (17)
S1A	0.0350 (2)	0.0222 (2)	0.0420 (3)	−0.00166 (17)	0.00052 (19)	0.00486 (18)
N1A	0.0370 (8)	0.0194 (7)	0.0298 (7)	0.0039 (6)	−0.0016 (6)	0.0022 (6)
N2A	0.0300 (7)	0.0206 (7)	0.0335 (8)	0.0018 (5)	−0.0031 (6)	0.0002 (6)
N3A	0.0306 (7)	0.0196 (7)	0.0254 (7)	0.0064 (5)	−0.0069 (6)	0.0020 (5)
C1A	0.0329 (8)	0.0178 (7)	0.0182 (7)	0.0055 (6)	−0.0030 (6)	−0.0019 (6)
C2A	0.0287 (8)	0.0176 (7)	0.0185 (7)	0.0041 (6)	−0.0038 (6)	−0.0026 (6)
C3A	0.0300 (8)	0.0188 (7)	0.0170 (7)	0.0055 (6)	−0.0038 (6)	−0.0002 (6)
C4A	0.0340 (9)	0.0224 (8)	0.0182 (7)	0.0044 (6)	0.0024 (6)	0.0024 (6)
C5A	0.0283 (8)	0.0289 (8)	0.0211 (7)	0.0073 (6)	0.0035 (6)	−0.0016 (6)
C6A	0.0309 (8)	0.0230 (8)	0.0222 (8)	0.0115 (6)	−0.0014 (6)	−0.0014 (6)
C11A	0.0215 (7)	0.0212 (7)	0.0185 (7)	0.0018 (6)	0.0012 (6)	0.0058 (6)
N12A	0.0251 (7)	0.0203 (7)	0.0191 (6)	0.0063 (5)	−0.0047 (5)	0.0010 (5)
C13A	0.0293 (8)	0.0303 (9)	0.0278 (8)	0.0109 (7)	−0.0061 (7)	−0.0077 (7)
C14A	0.0317 (9)	0.0273 (9)	0.0301 (9)	0.0090 (7)	−0.0089 (7)	−0.0064 (7)
N15A	0.0237 (7)	0.0260 (7)	0.0193 (6)	0.0070 (6)	−0.0033 (5)	0.0020 (5)

Geometric parameters (Å, º)

Cl1—C4	1.7434 (16)	Cl1A—C4A	1.7356 (17)
S1—N2	1.6181 (13)	S1A—N2A	1.6117 (15)
S1—N1	1.6196 (15)	S1A—N1A	1.6190 (15)
N1—C1	1.347 (2)	N1A—C1A	1.346 (2)
N2—C2	1.342 (2)	N2A—C2A	1.343 (2)
N3—C11	1.302 (2)	N3A—C11A	1.301 (2)
N3—C3	1.3776 (19)	N3A—C3A	1.388 (2)
C1—C6	1.414 (2)	C1A—C6A	1.412 (2)
C1—C2	1.434 (2)	C1A—C2A	1.436 (2)
C2—C3	1.442 (2)	C2A—C3A	1.435 (2)
C3—C4	1.382 (2)	C3A—C4A	1.376 (2)
C4—C5	1.423 (2)	C4A—C5A	1.426 (2)
C5—C6	1.357 (3)	C5A—C6A	1.362 (2)
C5—H5	0.9500	C5A—H5A	0.9500
C6—H6	0.9500	C6A—H6A	0.9500
C11—N12	1.347 (2)	C11A—N12A	1.3415 (19)
C11—N15	1.3645 (19)	C11A—N15A	1.380 (2)
N12—C13	1.461 (2)	N12A—C13A	1.440 (2)
N12—H12	0.83 (2)	N12A—H12A	0.82 (2)
C13—C14	1.527 (2)	C13A—C14A	1.531 (2)
C13—H13A	0.9900	C13A—H13C	0.9900
C13—H13B	0.9900	C13A—H13D	0.9900
C14—N15	1.4656 (19)	C14A—N15A	1.462 (2)
C14—H14A	0.9900	C14A—H14C	0.9900
C14—H14B	0.9900	C14A—H14D	0.9900
N15—H15	0.861 (9)	N15A—H15A	0.81 (2)
N2—S1—N1	101.09 (7)	N2A—S1A—N1A	101.29 (8)
C1—N1—S1	105.97 (11)	C1A—N1A—S1A	106.08 (11)
C2—N2—S1	106.21 (10)	C2A—N2A—S1A	106.06 (11)
C11—N3—C3	123.23 (12)	C11A—N3A—C3A	119.65 (13)
N1—C1—C6	126.59 (15)	N1A—C1A—C6A	126.58 (14)
N1—C1—C2	113.35 (14)	N1A—C1A—C2A	112.98 (15)
C6—C1—C2	120.06 (15)	C6A—C1A—C2A	120.43 (15)
N2—C2—C1	113.38 (14)	N2A—C2A—C3A	124.94 (14)
N2—C2—C3	124.10 (13)	N2A—C2A—C1A	113.58 (15)
C1—C2—C3	122.52 (14)	C3A—C2A—C1A	121.44 (15)
N3—C3—C4	128.45 (14)	C4A—C3A—N3A	125.96 (15)
N3—C3—C2	117.27 (13)	C4A—C3A—C2A	114.93 (14)
C4—C3—C2	113.87 (13)	N3A—C3A—C2A	118.92 (15)
C3—C4—C5	123.61 (15)	C3A—C4A—C5A	123.95 (15)
C3—C4—Cl1	119.70 (12)	C3A—C4A—Cl1A	119.72 (12)
C5—C4—Cl1	116.67 (12)	C5A—C4A—Cl1A	116.33 (13)
C6—C5—C4	122.51 (15)	C6A—C5A—C4A	121.17 (16)
C6—C5—H5	118.7	C6A—C5A—H5A	119.4
C4—C5—H5	118.7	C4A—C5A—H5A	119.4
C5—C6—C1	117.39 (15)	C5A—C6A—C1A	118.04 (14)
C5—C6—H6	121.3	C5A—C6A—H6A	121.0
C1—C6—H6	121.3	C1A—C6A—H6A	121.0
N3—C11—N12	121.49 (13)	N3A—C11A—N12A	122.80 (14)
N3—C11—N15	129.87 (13)	N3A—C11A—N15A	128.51 (14)
N12—C11—N15	108.54 (13)	N12A—C11A—N15A	108.58 (13)
C11—N12—C13	110.81 (13)	C11A—N12A—C13A	111.44 (13)
C11—N12—H12	121.2 (14)	C11A—N12A—H12A	121.2 (14)
C13—N12—H12	125.4 (14)	C13A—N12A—H12A	126.2 (14)
N12—C13—C14	100.63 (12)	N12A—C13A—C14A	100.95 (13)
N12—C13—H13A	111.6	N12A—C13A—H13C	111.6
C14—C13—H13A	111.6	C14A—C13A—H13C	111.6
N12—C13—H13B	111.6	N12A—C13A—H13D	111.6
C14—C13—H13B	111.6	C14A—C13A—H13D	111.6
H13A—C13—H13B	109.4	H13C—C13A—H13D	109.4
N15—C14—C13	100.79 (12)	N15A—C14A—C13A	101.10 (13)
N15—C14—H14A	111.6	N15A—C14A—H14C	111.6
C13—C14—H14A	111.6	C13A—C14A—H14C	111.6
N15—C14—H14B	111.6	N15A—C14A—H14D	111.6
C13—C14—H14B	111.6	C13A—C14A—H14D	111.6
H14A—C14—H14B	109.4	H14C—C14A—H14D	109.4
C11—N15—C14	108.98 (12)	C11A—N15A—C14A	108.15 (12)
C11—N15—H15	120.3 (13)	C11A—N15A—H15A	118.6 (14)
C14—N15—H15	122.2 (13)	C14A—N15A—H15A	118.3 (14)
N2—S1—N1—C1	0.07 (12)	N2A—S1A—N1A—C1A	0.52 (12)
N1—S1—N2—C2	−0.34 (12)	N1A—S1A—N2A—C2A	−0.73 (12)
S1—N1—C1—C6	−178.86 (13)	S1A—N1A—C1A—C6A	178.74 (13)
S1—N1—C1—C2	0.22 (15)	S1A—N1A—C1A—C2A	−0.16 (16)
S1—N2—C2—C1	0.51 (15)	S1A—N2A—C2A—C3A	−176.93 (12)
S1—N2—C2—C3	−179.27 (11)	S1A—N2A—C2A—C1A	0.71 (16)
N1—C1—C2—N2	−0.50 (18)	N1A—C1A—C2A—N2A	−0.38 (19)
C6—C1—C2—N2	178.65 (13)	C6A—C1A—C2A—N2A	−179.35 (14)
N1—C1—C2—C3	179.28 (13)	N1A—C1A—C2A—C3A	177.35 (14)
C6—C1—C2—C3	−1.6 (2)	C6A—C1A—C2A—C3A	−1.6 (2)
C11—N3—C3—C4	−55.7 (2)	C11A—N3A—C3A—C4A	−67.4 (2)
C11—N3—C3—C2	132.12 (15)	C11A—N3A—C3A—C2A	117.81 (17)
N2—C2—C3—N3	−4.6 (2)	N2A—C2A—C3A—C4A	179.47 (15)
C1—C2—C3—N3	175.66 (13)	C1A—C2A—C3A—C4A	2.0 (2)
N2—C2—C3—C4	−177.91 (14)	N2A—C2A—C3A—N3A	−5.2 (2)
C1—C2—C3—C4	2.33 (19)	C1A—C2A—C3A—N3A	177.38 (13)
N3—C3—C4—C5	−173.98 (14)	N3A—C3A—C4A—C5A	−175.72 (15)
C2—C3—C4—C5	−1.6 (2)	C2A—C3A—C4A—C5A	−0.7 (2)
N3—C3—C4—Cl1	4.3 (2)	N3A—C3A—C4A—Cl1A	5.2 (2)
C2—C3—C4—Cl1	176.77 (10)	C2A—C3A—C4A—Cl1A	−179.80 (11)
C3—C4—C5—C6	−0.1 (2)	C3A—C4A—C5A—C6A	−1.1 (2)
Cl1—C4—C5—C6	−178.42 (13)	Cl1A—C4A—C5A—C6A	178.04 (12)
C4—C5—C6—C1	1.0 (2)	C4A—C5A—C6A—C1A	1.5 (2)
N1—C1—C6—C5	178.87 (15)	N1A—C1A—C6A—C5A	−179.02 (15)
C2—C1—C6—C5	−0.2 (2)	C2A—C1A—C6A—C5A	−0.2 (2)
C3—N3—C11—N12	170.07 (14)	C3A—N3A—C11A—N12A	171.20 (15)
C3—N3—C11—N15	−14.0 (2)	C3A—N3A—C11A—N15A	−12.9 (3)
N3—C11—N12—C13	170.34 (14)	N3A—C11A—N12A—C13A	170.28 (16)
N15—C11—N12—C13	−6.37 (17)	N15A—C11A—N12A—C13A	−6.31 (19)
C11—N12—C13—C14	23.74 (16)	C11A—N12A—C13A—C14A	23.24 (19)
N12—C13—C14—N15	−30.12 (14)	N12A—C13A—C14A—N15A	−29.64 (18)
N3—C11—N15—C14	168.37 (15)	N3A—C11A—N15A—C14A	168.77 (17)
N12—C11—N15—C14	−15.28 (17)	N12A—C11A—N15A—C14A	−14.89 (18)
C13—C14—N15—C11	28.97 (16)	C13A—C14A—N15A—C11A	28.04 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N12—H12···N3A	0.83 (2)	2.18 (2)	3.0006 (19)	171 (2)
N15—H15···N1^i	0.86 (1)	2.40 (1)	3.2078 (18)	156 (2)
N12A—H12A···N3	0.82 (2)	2.04 (2)	2.8489 (19)	172 (2)
N15A—H15A···N1A^ii	0.81 (2)	2.40 (2)	3.173 (2)	158.7 (18)

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

(II) 2-[(5-chloro-2,1,3-benzothiadiazol-4-yl)amino]imidazolidinium chloride

Crystal data

C9H9ClN5S^+·Cl^−	F(000) = 592
Mr = 290.17	Dx = 1.648 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 8524 reflections
a = 8.5321 (7) Å	θ = 3.6–26.7°
b = 14.0679 (9) Å	µ = 0.72 mm^−1
c = 10.1266 (8) Å	T = 173 K
β = 105.856 (6)°	Block, colourless
V = 1169.24 (15) Å^3	0.34 × 0.31 × 0.25 mm
Z = 4

Data collection

Stoe IPDS II two-circle diffractometer	2383 independent reflections
Radiation source: fine-focus sealed tube	1907 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.076
ω scans	θmax = 26.4°, θmin = 3.6°
Absorption correction: multi-scan (MULABS; Spek, 2009; Blessing, 1995)	h = −10→10
Tmin = 0.793, Tmax = 0.841	k = −17→17
9834 measured reflections	l = −12→11

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)] = 0.032	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.080	w = 1/[σ^2(Fo^2) + (0.0451P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.98	(Δ/σ)max < 0.001
2383 reflections	Δρmax = 0.32 e Å^−3
167 parameters	Δρmin = −0.24 e Å^−3
0 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: 0.0090 (16)

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
Cl1	0.02346 (7)	0.76066 (4)	0.10240 (6)	0.03510 (16)
Cl2	0.31350 (6)	0.55662 (3)	0.04050 (5)	0.02433 (14)
S1	0.35864 (7)	0.50130 (4)	0.61467 (6)	0.03430 (16)
N1	0.2089 (2)	0.45298 (12)	0.50161 (19)	0.0306 (4)
N2	0.3675 (2)	0.60402 (13)	0.54601 (18)	0.0289 (4)
N3	0.3045 (2)	0.76637 (12)	0.35886 (19)	0.0245 (4)
H3	0.288 (3)	0.806 (2)	0.405 (3)	0.031 (7)*
C1	0.1570 (2)	0.51819 (14)	0.4013 (2)	0.0242 (4)
C2	0.2488 (2)	0.60462 (13)	0.4276 (2)	0.0220 (4)
C3	0.2105 (2)	0.68171 (13)	0.3333 (2)	0.0218 (4)
C4	0.0821 (2)	0.66948 (13)	0.2200 (2)	0.0229 (4)
C5	−0.0093 (2)	0.58291 (14)	0.1926 (2)	0.0258 (4)
H5	−0.0966	0.5775	0.1113	0.031*
C6	0.0266 (2)	0.50853 (14)	0.2808 (2)	0.0253 (4)
H6	−0.0343	0.4512	0.2621	0.030*
C11	0.4458 (2)	0.77332 (13)	0.32691 (19)	0.0215 (4)
N12	0.5017 (2)	0.70962 (12)	0.25494 (18)	0.0248 (4)
H12	0.444 (3)	0.669 (2)	0.212 (3)	0.036 (7)*
C13	0.6536 (3)	0.74216 (16)	0.2301 (2)	0.0328 (5)
H13A	0.6410	0.7511	0.1308	0.039*
H13B	0.7430	0.6964	0.2672	0.039*
C14	0.6863 (2)	0.83720 (15)	0.3069 (2)	0.0284 (4)
H14A	0.7913	0.8359	0.3792	0.034*
H14B	0.6874	0.8904	0.2432	0.034*
N15	0.5488 (2)	0.84520 (13)	0.36646 (19)	0.0267 (4)
H15	0.530 (3)	0.8892 (18)	0.404 (3)	0.027 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0424 (3)	0.0251 (3)	0.0331 (3)	−0.0026 (2)	0.0024 (2)	0.0062 (2)
Cl2	0.0299 (2)	0.0167 (2)	0.0272 (2)	−0.00025 (17)	0.00912 (19)	0.00016 (18)
S1	0.0411 (3)	0.0291 (3)	0.0284 (3)	−0.0006 (2)	0.0024 (2)	0.0035 (2)
N1	0.0377 (10)	0.0236 (9)	0.0299 (9)	−0.0021 (7)	0.0080 (8)	0.0021 (7)
N2	0.0314 (9)	0.0270 (9)	0.0267 (9)	−0.0011 (7)	0.0054 (7)	−0.0032 (7)
N3	0.0294 (9)	0.0176 (8)	0.0288 (9)	−0.0042 (6)	0.0117 (7)	−0.0073 (7)
C1	0.0281 (10)	0.0193 (9)	0.0285 (10)	−0.0004 (7)	0.0136 (8)	−0.0023 (8)
C2	0.0233 (9)	0.0220 (9)	0.0220 (9)	−0.0006 (7)	0.0086 (8)	−0.0032 (8)
C3	0.0248 (9)	0.0175 (9)	0.0261 (10)	−0.0023 (7)	0.0122 (8)	−0.0047 (7)
C4	0.0271 (9)	0.0192 (9)	0.0240 (9)	0.0006 (7)	0.0095 (8)	0.0011 (8)
C5	0.0248 (10)	0.0259 (10)	0.0272 (10)	−0.0034 (8)	0.0079 (8)	−0.0048 (8)
C6	0.0256 (10)	0.0214 (9)	0.0303 (11)	−0.0067 (7)	0.0100 (8)	−0.0057 (8)
C11	0.0274 (10)	0.0172 (9)	0.0187 (8)	−0.0019 (7)	0.0042 (7)	0.0010 (7)
N12	0.0258 (8)	0.0200 (8)	0.0289 (9)	−0.0046 (7)	0.0079 (7)	−0.0053 (7)
C13	0.0330 (11)	0.0310 (11)	0.0388 (12)	−0.0069 (9)	0.0170 (10)	−0.0063 (10)
C14	0.0253 (10)	0.0274 (10)	0.0313 (11)	−0.0056 (8)	0.0057 (8)	0.0006 (9)
N15	0.0329 (9)	0.0194 (8)	0.0302 (9)	−0.0091 (7)	0.0129 (8)	−0.0073 (7)

Geometric parameters (Å, º)

Cl1—C4	1.728 (2)	C5—H5	0.9500
S1—N1	1.614 (2)	C6—H6	0.9500
S1—N2	1.6143 (19)	C11—N12	1.324 (2)
N1—C1	1.351 (3)	C11—N15	1.328 (2)
N2—C2	1.342 (3)	N12—C13	1.460 (3)
N3—C11	1.334 (3)	N12—H12	0.80 (3)
N3—C3	1.420 (2)	C13—C14	1.534 (3)
N3—H3	0.76 (3)	C13—H13A	0.9900
C1—C6	1.415 (3)	C13—H13B	0.9900
C1—C2	1.431 (3)	C14—N15	1.463 (3)
C2—C3	1.423 (3)	C14—H14A	0.9900
C3—C4	1.363 (3)	C14—H14B	0.9900
C4—C5	1.432 (3)	N15—H15	0.77 (3)
C5—C6	1.355 (3)
N1—S1—N2	101.10 (10)	C1—C6—H6	120.8
C1—N1—S1	106.32 (14)	N12—C11—N15	111.91 (17)
C2—N2—S1	106.12 (14)	N12—C11—N3	124.71 (17)
C11—N3—C3	121.34 (16)	N15—C11—N3	123.37 (18)
C11—N3—H3	114.9 (19)	C11—N12—C13	110.69 (17)
C3—N3—H3	122.4 (19)	C11—N12—H12	121.4 (19)
N1—C1—C6	127.05 (18)	C13—N12—H12	125.1 (19)
N1—C1—C2	112.71 (19)	N12—C13—C14	103.46 (16)
C6—C1—C2	120.24 (18)	N12—C13—H13A	111.1
N2—C2—C3	125.70 (17)	C14—C13—H13A	111.1
N2—C2—C1	113.74 (17)	N12—C13—H13B	111.1
C3—C2—C1	120.56 (18)	C14—C13—H13B	111.1
C4—C3—N3	122.92 (18)	H13A—C13—H13B	109.0
C4—C3—C2	116.95 (17)	N15—C14—C13	102.77 (15)
N3—C3—C2	120.13 (17)	N15—C14—H14A	111.2
C3—C4—C5	122.69 (18)	C13—C14—H14A	111.2
C3—C4—Cl1	120.05 (15)	N15—C14—H14B	111.2
C5—C4—Cl1	117.26 (16)	C13—C14—H14B	111.2
C6—C5—C4	121.06 (19)	H14A—C14—H14B	109.1
C6—C5—H5	119.5	C11—N15—C14	110.89 (17)
C4—C5—H5	119.5	C11—N15—H15	123.7 (18)
C5—C6—C1	118.49 (17)	C14—N15—H15	124.6 (18)
C5—C6—H6	120.8
N2—S1—N1—C1	−0.22 (15)	C2—C3—C4—C5	−1.7 (3)
N1—S1—N2—C2	0.20 (14)	N3—C3—C4—Cl1	−2.0 (3)
S1—N1—C1—C6	−179.25 (16)	C2—C3—C4—Cl1	178.17 (13)
S1—N1—C1—C2	0.17 (19)	C3—C4—C5—C6	1.1 (3)
S1—N2—C2—C3	179.38 (15)	Cl1—C4—C5—C6	−178.76 (15)
S1—N2—C2—C1	−0.12 (19)	C4—C5—C6—C1	0.1 (3)
N1—C1—C2—N2	0.0 (2)	N1—C1—C6—C5	178.86 (18)
C6—C1—C2—N2	179.43 (16)	C2—C1—C6—C5	−0.5 (3)
N1—C1—C2—C3	−179.57 (16)	C3—N3—C11—N12	8.8 (3)
C6—C1—C2—C3	−0.1 (3)	C3—N3—C11—N15	−169.93 (19)
C11—N3—C3—C4	−97.5 (2)	N15—C11—N12—C13	−5.2 (2)
C11—N3—C3—C2	82.3 (2)	N3—C11—N12—C13	175.9 (2)
N2—C2—C3—C4	−178.29 (17)	C11—N12—C13—C14	2.6 (2)
C1—C2—C3—C4	1.2 (2)	N12—C13—C14—N15	0.6 (2)
N2—C2—C3—N3	1.9 (3)	N12—C11—N15—C14	5.7 (2)
C1—C2—C3—N3	−178.62 (16)	N3—C11—N15—C14	−175.45 (19)
N3—C3—C4—C5	178.10 (17)	C13—C14—N15—C11	−3.6 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···Cl2^i	0.76 (3)	2.35 (3)	3.0843 (18)	163 (2)
N12—H12···Cl2	0.80 (3)	2.39 (3)	3.1656 (18)	164 (2)
N15—H15···Cl2^i	0.77 (3)	2.70 (2)	3.3131 (19)	138 (2)
N15—H15···Cl2^ii	0.77 (3)	2.69 (3)	3.2419 (18)	131 (2)

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