4-(5-Amino-1H-1,2,4-triazol-3-yl)pyridinium chloride monohydrate

Chernyshev, V.M.; Tarasova, E.V.; Chernysheva, A.V.; Rybakov, V.B.

doi:10.1107/S1600536811002406

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 2| February 2011| Pages o466-o467

doi:10.1107/S1600536811002406

Open

access

4-(5-Amino-1H-1,2,4-triazol-3-yl)pyridinium chloride monohydrate

Victor M. Chernyshev,^a Elena V. Tarasova,^a Anna V. Chernysheva ^a and Victor B. Rybakov ^b ^*

^aSouth-Russia State Technical University, 346428 Novocherkassk, Russian Federation, and ^bDepartment of Chemistry, Moscow State University, 119992 Moscow, Russian Federation
^*Correspondence e-mail: rybakov20021@yandex.ru

(Received 8 January 2011; accepted 17 January 2011; online 22 January 2011)

In the cation of the title compound, C₇H₈N₅⁺·Cl⁻·H₂O, the mean planes of the pyridine and 1,2,4-triazole rings form a dihedral angle of 2.3 (1)°. The N atom of the amino group adopts a trigonal–pyramidal configuration. The N atom of the pyridine ring is protonated, forming a chloride salt. In the crystal, intermolecular N—H⋯O, N—H⋯N, N—H⋯Cl and O—H⋯Cl hydrogen bonds link the cations, anions and water molecules into layers parallel to the (1, 0, $[{\script{1\over 2}}]$ ) plane.

Related literature

For the use of 3-pyridyl-substituted 5-amino-1,2,4-triazoles in the synthesis of biologically active compounds, see: Lipinski (1983 ); Ram (1988 ); Akahoshi et al. (1998 ); Young et al. (2001 ); Ouyang et al. (2005 ); Dolzhenko et al. (2007 ). For metal complexes of 3-pyridyl-substituted 5-amino-1,2,4-triazoles, see: Mishra et al. (1989 ); Ferrer et al. (2004 ); Castineiras & Garcia-Santos (2008 ). For a theoretical investigation of the protonation of C-amino-1,2,4-triazoles, see: Anders et al. (1997 ). For the crystal structures of protonated C-amino-1,2,4-triazoles, see: Lynch et al. (1999 ); Baouab et al. (2000 ); Bichay et al. (2006 ); Guerfel et al. (2007 ); Matulková et al. (2007 ). For the ionization constants (pK_α) of 3-substituted 5-amino-1H-1,2,4-triazoles, see: Voronkov et al. (1976 ). For the ¹H and ¹³C NMR spectra of 3-pyridyl-substituted 5-amino-1,2,4-triazoles, see: Dolzhenko et al. (2009a ). For typical NMR chemical shifts of 3-substituted 5-amino-1,2,4-triazoles and their salts, see: Chernyshev et al. (2010 ). For the crystal structures of 3-substituted 5-amino-1H-1,2,4-triazoles, see: Rusinov et al. (1991 ); Daro et al. (2000 ); Boechat et al. (2004 ); Dolzhenko et al. (2009b ,c ). For the crystal structures of 3(5)-pyridyl-substituted 1,2,4-triazoles protonated at the pyridine ring, see: Ren & Jian (2008 ); Xie et al. (2009 ); Du et al. (2009 ). For values of bond lengths in organic compounds, see: Allen et al. (1987 ). For the correlation of bond lengths with bond orders between sp²-hybridized C and N atoms, see: Burke-Laing & Laing (1976 ).

Experimental

Crystal data

C₇H₈N₅⁺·Cl⁻·H₂O
M_r = 215.65
Monoclinic, P 2₁ /c
a = 5.3411 (5) Å
b = 24.656 (3) Å
c = 7.3488 (7) Å
β = 97.62 (2)°
V = 959.22 (18) Å³
Z = 4
Ag Kα radiation
λ = 0.56085 Å
μ = 0.20 mm⁻¹
T = 295 K
0.20 × 0.20 × 0.20 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: refined from ΔF (Walker & Stuart, 1983 ) T_min = 0.314, T_max = 0.961
2389 measured reflections
2389 independent reflections
1518 reflections with I > 2σ(I)
R_int = 0.000
1 standard reflections every 60 min intensity decay: 2%

Refinement

R[F² > 2σ(F²)] = 0.042
wR(F²) = 0.109
S = 0.93
2389 reflections
151 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1ⁱ	0.876 (19)	1.97 (2)	2.842 (2)	175.0 (18)
N16—H16⋯Cl1	0.85 (2)	2.22 (2)	3.0574 (18)	169 (2)
N51—H51A⋯Cl1ⁱⁱ	0.82 (2)	2.52 (2)	3.3092 (18)	160.5 (19)
N51—H51B⋯N4ⁱⁱⁱ	0.82 (2)	2.15 (2)	2.963 (2)	174 (2)
O1—H1A⋯Cl1^iv	0.89 (3)	2.29 (3)	3.159 (2)	167 (3)
O1—H1B⋯Cl1^v	0.88 (3)	2.32 (3)	3.187 (2)	168 (2)
Symmetry codes: (i) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (ii) $[-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (iii) -x+2, -y, -z+2; (iv) -x, -y+1, -z+1; (v) -x+1, -y+1, -z+1.

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811002406/aa2001sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811002406/aa2001Isup2.hkl

checkCIF report

Comment top

3-Pyridyl-substituted 5-amino-1,2,4-triazoles are used as reagents and ligands for the synthesis of biologically active compounds (Lipinski, 1983; Ram, 1988; Akahoshi et al., 1998; Young et al., 2001; Ouyang et al., 2005; Dolzhenko et al., 2007) and metal complexes (Mishra et al., 1989; Ferrer et al., 2004; Castineiras & Garcia-Santos, 2008). These substances are weak bases and form salts with acids. However, the positions of protonation centres of their molecules are open to question. For example, one would assume the existence of the tautomers A–E for the hydrochloride of 5-amino-3-(pyridin-4-yl)-1,2,4-triazole (Fig. 1). The tautomers A and D can be expected to be the most probable on the basis of the theoretical investigation of the protonation of C-amino-1,2,4-triazoles (Anders et al., 1997) and X-ray studies of C-amino-1,2,4-triazolium salts (Lynch et al., 1999; Baouab et al., 2000; Bichay et al., 2006; Guerfel et al., 2007; Matulková et al., 2007). Since knowledge of specific features of protonation of 3-pyridyl-substituted 5-amino-1,2,4-triazoles is essential for understanding their reactivity and biological properties, we investigated the structure of the hydrochloride of 5-amino-3-(pyridin-4-yl)-1,2,4-triazole in the solution and solid state. This compound was obtained by one-pot synthesis starting from aminoguanidine hydrogen carbonate, isonicotinic acid and hydrochloric acid (see Fig. 2 and Experimental).

By potentiometric titration with 0.1 M hydrochloric acid we established that the pK_α of the 5-amino-3-(pyridin-4-yl)-1,2,4-triazole in water is 4.68 (5) at 293 K. A model compound, 5-amino-3-phenyl-1H-1,2,4-triazole, which is protonated at the N⁴ of triazole cycle in acid solutions (Voronkov et al., 1976), has the pK_α = 3.80 (3) at 293 K. Since the basicity of the 5-amino-3-(pyridin-4-yl)-1,2,4-triazole is almost eight times higher than the model compound, it is possible to assume that in water solution the pyridine rather than triazole cycle is protonated. In the ¹³C NMR spectrum of the hydrochloride of 5-amino-3-(pyridin-4-yl)-1,2,4-triazole in dimethyl sulfoxide (DMSO-d₆), the signals of the triazole carbons C^3' and C^5' are observed at 153.71 and 157.83 ppm, correspondingly (for the chemical numbering scheme, see Fig. 1). These values are very close to the same signals of the unprotonated 5-amino-3-(pyridin-4-yl)-1H-1,2,4-triazole (Dolzhenko et al., 2009a) and are typical for 5-amino-1H-1,2,4-triazoles (Chernyshev et al., 2010). The chemical shift of the carbon connected to amino group is most representative. Thus, in the 5-amino- and 3-amino-4H-1,2,4-triazolium salts the signals of the same atoms are high field shifted to 149.3–154.7 ppm (Chernyshev et al., 2010). Therefore, it could be concluded that the triazole cycle is unprotonated in DMSO solution of the studied salt. However, the signals of the carbons of the pyridine cycle of the hydrochloride (especially the carbons, connected with nitrogen atom) differ sufficiently from the ones of unprotonated 5-amino-3-(pyridin-4-yl)-1,2,4-triazole. In the unprotonated compound the signals of C² and C⁶ are detected at 149.9 ppm (Dolzhenko et al., 2009a), while in the hydrochloride they are observed at 142.9 ppm. Therefore, we can conclude that the pyridine cycle is protonated and the tautomeric form A is predominant in DMSO (Fig. 1). For unambiguous confirmation of the proposed structure, we performed an X-ray investigation of the title compound. In the ensuing discussion of the structure, the crystallographic numbering system will be used (Fig. 3). In accordance with the X-ray diffraction data, the studied compound in the crystal exists as the tautomer A (Fig. 3). The pyridine and triazole rings are almost coplanar, the dihedral angle between the planes of the rings is 2.3 (1)°. Bond lengths and angles in the triazole cycle are within the normal ranges and are comparable with those found in the other 3-substituted 5-amino-1H-1,2,4-triazoles (Rusinov et al., 1991; Daro et al., 2000; Boechat et al., 2004; Dolzhenko et al., 2009b,c). The nitrogen atom of the amino group is in a trigonal pyramidal configuration (sum of valence angles is 356.0° and deviates from the triazole plane by only 0.020 (3)Å. Conjugation between the unshared electron pair of N21 and the π-system of the triazole fragment leads to a shortening of the N21—C2 bond (1.330 (2)Å) relative to the standard length of a purely single Nsp²—Csp² bond (1.43–1.45Å) (Burke-Laing & Laing, 1976; Allen et al., 1987). Bond lengths and angles in the pyridine cycle are analogous to the ones in the pyridyl-substituted 1,2,4-triazoles, protonated at the pyridine cycle (Ren & Jian, 2008; Xie et al., 2009; Du et al., 2009).

The wide system of hydrogen bonds are found in crystal structure of title compound. Firstly, atom Cl1 form contact 2.22 (2)Å (Table 1) with atom H16 of pyridyl moiety; secondly, atom H3 of triazole moiety, forms contact with O1ⁱ atom from water molecule (symmetry code: (i) x, -y+1/2, z+1/2; thirdly, atom H1Bⁱ from water molecule forms contact with Cl1ⁱⁱ (symmetry code: (ii) -x+1, y-1/2, -z+3/2). Thus, we can see chain of hydrogen bonds along [0 1 0]. These chains form layers parallel (1, 0, 1/2) plane (Fig. 4). These layers connected by hydrogen bonds with involving H1A atoms of water molecule (Fig. 5).

In the future, it would be interesting to investigate the structure of isomers of the studied compound, i.e. salts of the 5-amino-3-(pyridin-2-yl)-1,2,4-triazole and 5-amino-3-(pyridin-3-yl)-1,2,4-triazole in order to estimate the influence of structural peculiarities on protonation.

Related literature top

For the use of 3-pyridyl-substituted 5-amino-1,2,4-triazoles in the synthesis of biologically active compounds, see: Lipinski (1983); Ram (1988); Akahoshi et al. (1998); Young et al. (2001); Ouyang et al. (2005); Dolzhenko et al. (2007). For metal complexes of 3-pyridyl-substituted 5-amino-1,2,4-triazoles, see: Mishra et al. (1989); Ferrer et al. (2004); Castineiras & Garcia-Santos (2008). For a theoretical investigation of the protonation of C-amino-1,2,4-triazoles, see: Anders et al. (1997). For the crystal structures of protonated C-amino-1,2,4-triazoles, see: Lynch et al. (1999); Baouab et al. (2000); Bichay et al. (2006); Guerfel et al. (2007); Matulková et al. (2007). For the ionization constants (pK_α) of 3-substituted 5-amino-1H-1,2,4-triazoles, see: Voronkov et al. (1976). For the ¹H and ¹³C NMR spectra of 3-pyridyl-substituted 5-amino-1,2,4-triazoles, see: Dolzhenko et al. (2009a). For typical NMR chemical shifts of 3-substituted 5-amino-1,2,4-triazoles and their salts, see: Chernyshev et al. (2010). For the crystal structures of 3-substituted 5-amino-1H-1,2,4-triazoles, see: Rusinov et al. (1991); Daro et al. (2000); Boechat et al. (2004); Dolzhenko et al. (2009b,c). For the crystal structures of 3(5)-pyridyl-substituted 1,2,4-triazoles protonated at the pyridine ring, see: Ren & Jian (2008); Xie et al. (2009); Du et al. (2009). For values of bond lengths in organic compounds, see: Allen et al. (1987). For the correlation of bond lengths with bond orders between sp^2-hybridized C and N atoms, see: Burke-Laing & Laing (1976).

Experimental top

The title compound was prepared by the following procedure. A mixture of aminoguanidine hydrogen carbonate (5.53 g, 40.6 mmol), isonicotinic acid (5.01 g, 40.7 mmol) and 33.5% hydrochloric acid (5.0 ml) was heated to reflux for 15 min, then water was distilled off until the temperature of the reaction mixture raised to 448–453 K. The reaction mixture was heated at the same temperature for 6 h, cooled to ~373 K and dissolved in water (5 ml). The resulted solution was cooled to 276–278 K, the precipitate formed was isolated by filtration, recrystallized from 50% ethanol and dried at 403 K to give 6.82 g (85% yield) of yellowish powder, m. p. 579–581 K. Spectrum ¹H NMR (600 MHz), δ: 6.61 (br s, 2H, NH₂), 8.26 (d, J = 6.7 Hz, 2H, Ar), 8.85 (d, J = 6.7 Hz, 2H, Ar). Spectrum ¹³C NMR (150 MHz), δ: 121.78 (C³ and C⁵ of pyridine), 142.92 (C² and C⁶ of pyridine), 145.51 (C⁴ of pyridine), 153.71 (C^3' of triazole), 157.83 (C^5' of triazole). MS (EI, 70 eV), m/z (%): 162 (10) [C₇H₈N₅⁺], 161 (100) [C₇H₇N₅⁺], 119 (26), 105 (45), 78 (46), 57 (68), 51 (71), 50 (38), 43 (38). Anal. Calcd for C₇H₈ClN₅: C, 42.54; H, 4.08; N, 35.44. Found: C 42.35; H 4.19; N 35.18. The crystals of title compound suitable for X-ray analysis were grown by slow evaporation from water at room temperature.

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. Possible tautomeric forms for hydrochloride of 5-amino-3-(pyridin-4-yl)-1,2,4-triazole.
	Fig. 2. Synthesis of the title compound.
	Fig. 3. ORTEP-3 (Farrugia, 1997) plot of molecular structure of the title compound showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as a small spheres of arbitrary radius.
	Fig. 4. The molecular packing of the title compound along the b-axis showing molecular layers parallel to the plane (1, 0, 1/2). Hydrogen bonds are shown as dashed lines.
	Fig. 5. The molecular packing of the title compound along the c axis. Hydrogen bonds are shown as dashed lines.

4-(5-Amino-1H-1,2,4-triazol-3-yl)pyridinium chloride monohydrate top

Crystal data top

C₇H₈N₅⁺·Cl⁻·H₂O	F(000) = 448
M_r = 215.65	D_x = 1.493 Mg m⁻³
Monoclinic, P2₁/c	Melting point = 579–581 K
Hall symbol: -P 2ybc	Ag Kα radiation, λ = 0.56085 Å
a = 5.3411 (5) Å	Cell parameters from 25 reflections
b = 24.656 (3) Å	θ = 12.1–14.0°
c = 7.3488 (7) Å	µ = 0.20 mm⁻¹
β = 97.62 (2)°	T = 295 K
V = 959.22 (18) Å³	Prism, yellow
Z = 4	0.20 × 0.20 × 0.20 mm

Data collection top

Enraf–Nonius CAD-4 diffractometer	1518 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.000
Graphite monochromator	θ_max = 22.0°, θ_min = 1.3°
Non–profiled ω scans	h = −7→7
Absorption correction: part of the refinement model (ΔF) (Walker & Stuart, 1983)	k = 0→32
T_min = 0.314, T_max = 0.961	l = 0→9
2389 measured reflections	1 standard reflections every 60 min
2389 independent reflections	intensity decay: 2%

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.109	H atoms treated by a mixture of independent and constrained refinement
S = 0.93	w = 1/[σ²(F_o²) + (0.0642P)²] where P = (F_o² + 2F_c²)/3
2389 reflections	(Δ/σ)_max = 0.001
151 parameters	Δρ_max = 0.26 e Å⁻³
0 restraints	Δρ_min = −0.24 e Å⁻³

Crystal data top

C₇H₈N₅⁺·Cl⁻·H₂O	V = 959.22 (18) Å³
M_r = 215.65	Z = 4
Monoclinic, P2₁/c	Ag Kα radiation, λ = 0.56085 Å
a = 5.3411 (5) Å	µ = 0.20 mm⁻¹
b = 24.656 (3) Å	T = 295 K
c = 7.3488 (7) Å	0.20 × 0.20 × 0.20 mm
β = 97.62 (2)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1518 reflections with I > 2σ(I)
Absorption correction: part of the refinement model (ΔF) (Walker & Stuart, 1983)	R_int = 0.000
T_min = 0.314, T_max = 0.961	1 standard reflections every 60 min
2389 measured reflections	intensity decay: 2%
2389 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.042	0 restraints
wR(F²) = 0.109	H atoms treated by a mixture of independent and constrained refinement
S = 0.93	Δρ_max = 0.26 e Å⁻³
2389 reflections	Δρ_min = −0.24 e Å⁻³
151 parameters

Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 (Å²) top

	x	y	z	U_iso*/U_eq
Cl1	0.03502 (9)	0.29662 (2)	0.52890 (9)	0.0585 (2)
N1	0.4858 (3)	−0.06015 (6)	0.7559 (2)	0.0421 (4)
H1	0.458 (3)	−0.0952 (8)	0.751 (3)	0.038 (5)*
N2	0.3363 (3)	−0.01915 (6)	0.6821 (2)	0.0438 (4)
C3	0.4713 (3)	0.02346 (7)	0.7339 (3)	0.0380 (4)
N4	0.7008 (3)	0.01345 (6)	0.8344 (2)	0.0401 (4)
C5	0.7035 (3)	−0.03999 (7)	0.8458 (3)	0.0391 (4)
C13	0.3868 (3)	0.07839 (7)	0.6860 (3)	0.0376 (4)
C14	0.1558 (3)	0.08732 (8)	0.5770 (3)	0.0477 (5)
H14	0.0536	0.0583	0.5337	0.057*
C15	0.0833 (4)	0.13903 (8)	0.5355 (3)	0.0512 (5)
H15	−0.0694	0.1455	0.4620	0.061*
N16	0.2275 (3)	0.18070 (7)	0.5984 (3)	0.0514 (5)
H16	0.197 (4)	0.2140 (9)	0.580 (3)	0.053 (6)*
C17	0.4501 (4)	0.17327 (8)	0.7024 (3)	0.0535 (6)
H17	0.5484	0.2031	0.7435	0.064*
C18	0.5325 (3)	0.12272 (8)	0.7479 (3)	0.0468 (5)
H18	0.6869	0.1177	0.8207	0.056*
N51	0.8895 (3)	−0.07055 (7)	0.9294 (3)	0.0514 (5)
H51A	0.869 (4)	−0.1036 (9)	0.934 (3)	0.048 (6)*
H51B	0.994 (4)	−0.0532 (9)	0.998 (3)	0.063 (7)*
O1	0.4229 (4)	0.67460 (7)	0.2570 (3)	0.0635 (5)
H1A	0.309 (6)	0.6799 (12)	0.333 (4)	0.092 (11)*
H1B	0.562 (6)	0.6872 (11)	0.319 (4)	0.092 (10)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0424 (3)	0.0401 (3)	0.0893 (5)	0.0049 (2)	−0.0051 (3)	0.0026 (3)
N1	0.0292 (7)	0.0325 (8)	0.0603 (11)	−0.0045 (6)	−0.0100 (7)	0.0005 (8)
N2	0.0291 (7)	0.0428 (8)	0.0560 (10)	−0.0051 (6)	−0.0078 (7)	−0.0022 (8)
C3	0.0237 (8)	0.0429 (10)	0.0452 (11)	−0.0004 (7)	−0.0041 (7)	−0.0041 (8)
N4	0.0289 (7)	0.0330 (7)	0.0545 (10)	−0.0017 (6)	−0.0082 (7)	−0.0009 (7)
C5	0.0283 (8)	0.0359 (8)	0.0501 (11)	−0.0031 (7)	−0.0063 (7)	−0.0005 (8)
C13	0.0273 (8)	0.0392 (9)	0.0450 (10)	0.0019 (7)	−0.0002 (7)	−0.0004 (8)
C14	0.0320 (9)	0.0486 (11)	0.0584 (13)	−0.0007 (8)	−0.0092 (9)	−0.0014 (9)
C15	0.0312 (9)	0.0532 (12)	0.0650 (14)	0.0094 (8)	−0.0090 (9)	0.0057 (10)
N16	0.0413 (9)	0.0419 (9)	0.0686 (13)	0.0117 (7)	−0.0012 (8)	0.0048 (9)
C17	0.0393 (10)	0.0464 (11)	0.0706 (16)	0.0013 (9)	−0.0078 (10)	−0.0023 (10)
C18	0.0285 (9)	0.0426 (10)	0.0657 (13)	0.0029 (8)	−0.0076 (9)	0.0008 (10)
N51	0.0361 (8)	0.0326 (9)	0.0784 (14)	−0.0011 (7)	−0.0187 (8)	0.0002 (9)
O1	0.0426 (9)	0.0564 (10)	0.0867 (13)	0.0052 (7)	−0.0094 (10)	−0.0090 (9)

Geometric parameters (Å, º) top

N4—C5	1.320 (2)	C15—N16	1.330 (3)
N4—C3	1.367 (2)	C15—H15	0.9300
C5—N51	1.330 (2)	N16—C17	1.338 (3)
C5—N1	1.353 (2)	N16—H16	0.85 (2)
N1—N2	1.356 (2)	C17—C18	1.349 (3)
N1—H1	0.876 (19)	C17—H17	0.9300
N2—C3	1.302 (2)	C18—H18	0.9300
C3—C13	1.456 (2)	N51—H51A	0.82 (2)
C13—C18	1.383 (2)	N51—H51B	0.82 (2)
C13—C14	1.396 (2)	O1—H1A	0.89 (3)
C14—C15	1.355 (3)	O1—H1B	0.88 (3)
C14—H14	0.9300

C5—N4—C3	102.47 (14)	N16—C15—C14	120.89 (17)
N4—C5—N51	126.56 (17)	N16—C15—H15	119.6
N4—C5—N1	109.53 (15)	C14—C15—H15	119.6
N51—C5—N1	123.90 (18)	C15—N16—C17	121.52 (18)
C5—N1—N2	110.08 (15)	C15—N16—H16	127.1 (16)
C5—N1—H1	120.6 (12)	C17—N16—H16	111.3 (16)
N2—N1—H1	129.3 (12)	N16—C17—C18	120.25 (18)
C3—N2—N1	102.18 (14)	N16—C17—H17	119.9
N2—C3—N4	115.73 (16)	C18—C17—H17	119.9
N2—C3—C13	122.53 (15)	C17—C18—C13	119.87 (17)
N4—C3—C13	121.73 (15)	C17—C18—H18	120.1
C18—C13—C14	118.66 (17)	C13—C18—H18	120.1
C18—C13—C3	120.84 (15)	C5—N51—H51A	118.8 (15)
C14—C13—C3	120.50 (16)	C5—N51—H51B	113.2 (17)
C15—C14—C13	118.80 (17)	H51A—N51—H51B	125 (2)
C15—C14—H14	120.6	H1A—O1—H1B	103 (3)
C13—C14—H14	120.6

C3—N4—C5—N51	179.2 (2)	N2—C3—C13—C14	−1.6 (3)
C3—N4—C5—N1	0.1 (2)	N4—C3—C13—C14	177.42 (19)
N4—C5—N1—N2	0.4 (2)	C18—C13—C14—C15	0.2 (3)
N51—C5—N1—N2	−178.75 (19)	C3—C13—C14—C15	179.92 (19)
C5—N1—N2—C3	−0.8 (2)	C13—C14—C15—N16	−0.6 (3)
N1—N2—C3—N4	0.9 (2)	C14—C15—N16—C17	0.9 (3)
N1—N2—C3—C13	179.91 (17)	C15—N16—C17—C18	−0.7 (3)
C5—N4—C3—N2	−0.6 (2)	N16—C17—C18—C13	0.3 (3)
C5—N4—C3—C13	−179.68 (18)	C14—C13—C18—C17	0.0 (3)
N2—C3—C13—C18	178.20 (19)	C3—C13—C18—C17	−179.8 (2)
N4—C3—C13—C18	−2.8 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱ	0.876 (19)	1.97 (2)	2.842 (2)	175.0 (18)
N16—H16···Cl1	0.85 (2)	2.22 (2)	3.0574 (18)	169 (2)
N51—H51A···Cl1ⁱⁱ	0.82 (2)	2.52 (2)	3.3092 (18)	160.5 (19)
N51—H51B···N4ⁱⁱⁱ	0.82 (2)	2.15 (2)	2.963 (2)	174 (2)
O1—H1A···Cl1^iv	0.89 (3)	2.29 (3)	3.159 (2)	167 (3)
O1—H1B···Cl1^v	0.88 (3)	2.32 (3)	3.187 (2)	168 (2)

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

Experimental details

Crystal data
Chemical formula	C₇H₈N₅⁺·Cl⁻·H₂O
M_r	215.65
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	295
a, b, c (Å)	5.3411 (5), 24.656 (3), 7.3488 (7)
β (°)	97.62 (2)
V (Å³)	959.22 (18)
Z	4
Radiation type	Ag Kα, λ = 0.56085 Å
µ (mm⁻¹)	0.20
Crystal size (mm)	0.20 × 0.20 × 0.20

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	Part of the refinement model (ΔF) (Walker & Stuart, 1983)
T_min, T_max	0.314, 0.961
No. of measured, independent and observed [I > 2σ(I)] reflections	2389, 2389, 1518
R_int	0.000
(sin θ/λ)_max (Å⁻¹)	0.668

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.042, 0.109, 0.93
No. of reflections	2389
No. of parameters	151
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.26, −0.24

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱ	0.876 (19)	1.97 (2)	2.842 (2)	175.0 (18)
N16—H16···Cl1	0.85 (2)	2.22 (2)	3.0574 (18)	169 (2)
N51—H51A···Cl1ⁱⁱ	0.82 (2)	2.52 (2)	3.3092 (18)	160.5 (19)
N51—H51B···N4ⁱⁱⁱ	0.82 (2)	2.15 (2)	2.963 (2)	174 (2)
O1—H1A···Cl1^iv	0.89 (3)	2.29 (3)	3.159 (2)	167 (3)
O1—H1B···Cl1^v	0.88 (3)	2.32 (3)	3.187 (2)	168 (2)

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

Acknowledgements

This work was supported by the Ministry of Education and Science of the Russian Federation through the Federal Target Program `Research and Educational Personnel of Innovative Russia at 2009–2013 Years', State contract P1472, project NK-186P/3. The authors are indebted to the Russian Foundation for Basic Research for covering the licence fee for use of the Cambridge Structural Database (Allen, 2002 ).

References

Akahoshi, F., Takeda, S., Okada, T., Kajii, M., Nishimura, H., Sugiura, M., Inoue, Y., Fukaya, C., Naito, Y., Imagawa, T. & Nakamura, N. (1998). J. Med. Chem. 41, 2985–2993. Web of Science CrossRef CAS PubMed Google Scholar
Allen, F. H. (2002). Acta Cryst. B58, 380–388. Web of Science CrossRef CAS IUCr Journals Google Scholar
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. 1–19. CrossRef Web of Science Google Scholar
Anders, E., Wermann, K., Wiedel, B. & Vanden Eynde, J.-J. (1997). Liebigs Ann. Chem. Rec. pp. 745–752. CrossRef Google Scholar
Baouab, L., Guerfel, T., Soussi, M. & Jouini, A. (2000). J. Chem. Crystallogr. 30, 805–809. Web of Science CSD CrossRef CAS Google Scholar
Bichay, M., Fronabarger, J. W., Gilardi, R., Butcher, R. J., Sanborn, W. B., Sitzmann, M. E. & Williams, M. D. (2006). Tetrahedron Lett. 47, 6663–6666. Web of Science CSD CrossRef CAS Google Scholar
Boechat, N., Dutra, K. D. B., Valverde, A. L., Wardell, S. M. S. V., Low, J. N. & Glidewell, C. (2004). Acta Cryst. C60, o733–o736. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Burke-Laing, M. & Laing, M. (1976). Acta Cryst. B32, 3216–3224. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Castineiras, A. & Garcia-Santos, I. (2008). Z. Anorg. Allg. Chem. 634, 2907–2916. CAS Google Scholar
Chernyshev, V. M., Chernysheva, A. V. & Starikova, Z. A. (2010). Heterocycles, 81, 229–2311. Google Scholar
Daro, N., Sutter, J.-P., Pink, M. & Kahn, O. (2000). J. Chem. Soc. Perkin Trans. 2, pp. 1087–1089. CrossRef Google Scholar
Dolzhenko, A. V., Dolzhenko, A. V. & Chui, W.-K. (2007). Heterocycles, 71, 429–436. CAS Google Scholar
Dolzhenko, A. V., Pastorin, G., Dolzhenko, A. V. & Chui, W.-K. (2009a). Tetrahedron Lett. 50, 2124–2128. Web of Science CrossRef CAS Google Scholar
Dolzhenko, A. V., Tan, G. K., Koh, L. L., Dolzhenko, A. V. & Chui, W. K. (2009b). Acta Cryst. E65, o125. Web of Science CSD CrossRef IUCr Journals Google Scholar
Dolzhenko, A. V., Tan, G. K., Koh, L. L., Dolzhenko, A. V. & Chui, W. K. (2009c). Acta Cryst. E65, o126. Web of Science CSD CrossRef IUCr Journals Google Scholar
Du, M., Jiang, X.-J., Tan, X., Zhang, Zh.-H. & Cai, H. (2009). CrystEngComm, 11, 454–462. Web of Science CSD CrossRef CAS Google Scholar
Enraf–Nonius (1994). CAD-4 EXPRESS. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Ferrer, S., Ballesteros, R., Sambartolome, A., Gonzales, M., Alzuet, G., Borras, J. & Liu, M. (2004). J. Inorg. Biochem. 98, 1436–1446. Web of Science CSD CrossRef PubMed CAS Google Scholar
Guerfel, T., Guelmami, L. & Jouini, A. (2007). J. Soc. Alger. Chim. 17, 27–35. CAS Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
Lipinski, Ch. A. (1983). J. Med. Chem. 26, 1–6. CrossRef CAS PubMed Web of Science Google Scholar
Lynch, D. E., Dougall, T., Smith, G., Byriel, K. A. & Kennard, C. H. L. (1999). J. Chem. Crystallogr. 29, 67–73. Web of Science CSD CrossRef CAS Google Scholar
Matulková, I., Němec, I., Císařová, I., Němec, P. & Mička, Z. (2007). J. Mol. Struct. 834, 328–335. Google Scholar
Mishra, L., Ram, V. J. & Kushwaha, D. S. (1989). Transition Met. Chem. 14, 384–386. CrossRef CAS Web of Science Google Scholar
Ouyang, X., Chen, X., Piatnitski, E. L., Kiselyov, A. S., He, H.-Y., Mao, Y., Pattaropong, V., Yu, Y., Kim, K. H., Kincaid, J., Smith, L., Wong, W. C., Lee, S. P., Milligan, D. L., Malikzay, A., Fleming, J., Gerlak, J., Deevi, D., Doody, J. F., Chiang, H.-H., Patel, Sh. N., Wang, Y., Rolser, R. L., Kussie, P., Labelle, M. & Tuma, M. C. (2005). Bioorg. Med. Chem. Lett. 15, 5154–5159. Web of Science CrossRef PubMed CAS Google Scholar
Ram, V. J. (1988). Indian J. Chem. Sect. B, 27, 825–829. Google Scholar
Ren, X.-Y. & Jian, F.-F. (2008). Acta Cryst. E64, o1792. Web of Science CSD CrossRef IUCr Journals Google Scholar
Rusinov, V. L., Myasnikov, A. V., Chupakhin, O. N. & Aleksandrov, G. G. (1991). Chem. Heterocycl. Compd, 27, 530–533. CrossRef Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Voronkov, M. G., Kashik, T. V., Makarskii, V. V., Lopyrev, V. A., Ponomareva, S. M. & Shibanova, E. F. (1976). Dokl. Akad. Nauk SSSR, 227, 1116–1119. CAS Google Scholar
Walker, N. & Stuart, D. (1983). Acta Cryst. A39, 158–166. CrossRef CAS Web of Science IUCr Journals Google Scholar
Xie, X.-F., Chen, S.-P., Xia, Zh.-Q. & Gao, Sh.-L. (2009). Polyhedron, 28, 679–688. Web of Science CSD CrossRef CAS Google Scholar
Young, C. K., Ho, K. S., Ghilsoo, N., Hong, S. J., Hoon, K. S., Il, Ch K., Hyup, K. J. & Deok-Chan, H. (2001). J. Antibiot. 54, 460–462. Google Scholar