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In the crystal structure of the title salt, C5H6ClN2+·C7H5O3, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl­ate O atoms via a pair of N—H...O hydrogen bonds, forming R22(8) ring motifs. These motifs are centrosymmetrically paired via N—H...O hydrogen bonds, forming a complementary donor–donor–acceptor–acceptor (DDAA) array. A typical intra­molecular O—H...O hydrogen bond is also observed in the salicylate anion. The crystal structure is further stabilized by weak C—H...π inter­actions.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536810018210/sj5004sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536810018210/sj5004Isup2.hkl
Contains datablock I

CCDC reference: 781392

Key indicators

  • Single-crystal X-ray study
  • T = 100 K
  • Mean [sigma](C-C) = 0.001 Å
  • R factor = 0.035
  • wR factor = 0.124
  • Data-to-parameter ratio = 31.4

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L= 0.600 33 PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF .... 4 PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings Differ ? PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L= 0.600 22
Alert level G PLAT432_ALERT_2_G Short Inter X...Y Contact C3 .. C12 .. 3.20 Ang.
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 1 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

2-Aminopyridine is one of the most frequently used synthons in supramolecular chemistry based on hydrogen bonds (Gellert & Hsu, 1988; Banerjee & Murugavel, 2004; Bis & Zaworotko, 2005; Bis et al., 2006). A series of similar complexes formed from 2-amino-5-chloropyridine and carboxylates has been reported previously (Hemamalini & Fun, 2010a,b,c). Salicylic acid (Cochran, 1953) and its derivatives are widely used as analgesic. They are also used for various gastric tympany and externally as antiseptic and antifungal agents for various skin conditions. The crystal structure of salicylic acid and its complexes, for example, antipyrine-salicylic acid (salipyrine) (Singh & Vijayan, 1974) and piperazinedione-salicylic acid (1:2) (Varughese & Kartha, 1982), have been reported in literature. In a continuation of our studies of pyridinium derivatives, the crystal structure determination of the title compound has been undertaken.

The asymmetric unit (Fig. 1) contains one 2-amino-5-chloropyridinium cation and one salicylate anion. The proton transfer from the carboxyl group to atom N1 of 2-amino-5-chloropyridine resulted in the widening of C1—N1—C5 angle of the pyridinium ring to 122.87 (8)°, compared to the corresponding angle of 118.11 (12)° in neutral 2-amino-5-chloropyridine (Pourayoubi et al., 2007). The 2-amino-5-chloropyridinium cation is essentially planar, with a maximum deviation of 0.020 (1) Å for atom Cl. The bond lengths (Allen et al., 1987) and angles are normal.

In the crystal packing (Fig. 2), the protonated N1 atom and the 2-amino group (N2) are hydrogen-bonded to the carboxylate oxygen atoms (O2 and O3) via a pair of intermolecular N1—H1···O2 and N2—H2A···O3 hydrogen bonds forming an R22(8) ring motif (Bernstein et al., 1995). These motifs are centrosymmetrically paired via N—H···O hydrogen bonds, forming a complementary DDAA array (Baskar Raj et al. 2003). There is an intramolecular O1—H1B···O2 hydrogen bond in the salicylate anion, which generates an S(6) ring motif. This motif is also observed in the crystal structure of 2-aminopyridinium salicylate (Gellert & Hsu, 1988). The crystal structure is further stabilized by weak C—H···π interactions (Table 1) involving the C7–C12 (centroid Cg1) ring.

Related literature top

For 2-aminopyridines, see: Gellert & Hsu (1988); Banerjee & Murugavel (2004); Bis & Zaworotko (2005); Bis et al. (2006) and for salicylic acid, see: Cochran (1953); Singh & Vijayan (1974); Varughese & Kartha (1982). For related structures, see: Hemamalini & Fun (2010a,b,c). Pourayoubi et al. (2007). For hydrogen-bond motifs, see: Bernstein et al. (1995) and for hydrogen-bonding patterns in organic salts, see: Baskar Raj et al. (2003). For bond-length data, see: Allen et al. (1987). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

Experimental top

A hot methanol solution (20 ml) of 2-amino-5-chloropyridine (64 mg, Aldrich) and salicylic acid (69 mg, Merck) were mixed and warmed over a magnetic stirrer hotplate for a few minutes. The resulting solution was allowed to cool slowly at room temperature and crystals of the title compound appeared after a few days.

Refinement top

All hydrogen atoms were positioned geometrically [C–H = 0.93 Å, N–H = 0.86 Å and O–H = 0.82 Å] and were refined using a riding model, with Uiso(H) = 1.2 Ueq(C, N) or 1.5 Ueq(O).

Structure description top

2-Aminopyridine is one of the most frequently used synthons in supramolecular chemistry based on hydrogen bonds (Gellert & Hsu, 1988; Banerjee & Murugavel, 2004; Bis & Zaworotko, 2005; Bis et al., 2006). A series of similar complexes formed from 2-amino-5-chloropyridine and carboxylates has been reported previously (Hemamalini & Fun, 2010a,b,c). Salicylic acid (Cochran, 1953) and its derivatives are widely used as analgesic. They are also used for various gastric tympany and externally as antiseptic and antifungal agents for various skin conditions. The crystal structure of salicylic acid and its complexes, for example, antipyrine-salicylic acid (salipyrine) (Singh & Vijayan, 1974) and piperazinedione-salicylic acid (1:2) (Varughese & Kartha, 1982), have been reported in literature. In a continuation of our studies of pyridinium derivatives, the crystal structure determination of the title compound has been undertaken.

The asymmetric unit (Fig. 1) contains one 2-amino-5-chloropyridinium cation and one salicylate anion. The proton transfer from the carboxyl group to atom N1 of 2-amino-5-chloropyridine resulted in the widening of C1—N1—C5 angle of the pyridinium ring to 122.87 (8)°, compared to the corresponding angle of 118.11 (12)° in neutral 2-amino-5-chloropyridine (Pourayoubi et al., 2007). The 2-amino-5-chloropyridinium cation is essentially planar, with a maximum deviation of 0.020 (1) Å for atom Cl. The bond lengths (Allen et al., 1987) and angles are normal.

In the crystal packing (Fig. 2), the protonated N1 atom and the 2-amino group (N2) are hydrogen-bonded to the carboxylate oxygen atoms (O2 and O3) via a pair of intermolecular N1—H1···O2 and N2—H2A···O3 hydrogen bonds forming an R22(8) ring motif (Bernstein et al., 1995). These motifs are centrosymmetrically paired via N—H···O hydrogen bonds, forming a complementary DDAA array (Baskar Raj et al. 2003). There is an intramolecular O1—H1B···O2 hydrogen bond in the salicylate anion, which generates an S(6) ring motif. This motif is also observed in the crystal structure of 2-aminopyridinium salicylate (Gellert & Hsu, 1988). The crystal structure is further stabilized by weak C—H···π interactions (Table 1) involving the C7–C12 (centroid Cg1) ring.

For 2-aminopyridines, see: Gellert & Hsu (1988); Banerjee & Murugavel (2004); Bis & Zaworotko (2005); Bis et al. (2006) and for salicylic acid, see: Cochran (1953); Singh & Vijayan (1974); Varughese & Kartha (1982). For related structures, see: Hemamalini & Fun (2010a,b,c). Pourayoubi et al. (2007). For hydrogen-bond motifs, see: Bernstein et al. (1995) and for hydrogen-bonding patterns in organic salts, see: Baskar Raj et al. (2003). For bond-length data, see: Allen et al. (1987). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 50% probability level. A dashed line indicates the intramolecular hydrogen bond.
[Figure 2] Fig. 2. The crystal packing of the title compound, showing hydrogen-bonded (dashed lines) networks. H atoms not involved in hydrogen bond interactions are omitted for clarity.
2-amino-5-chloropyridinium 2-hydroxybenzoate top
Crystal data top
C5H6ClN2+·C7H5O3F(000) = 552
Mr = 266.68Dx = 1.506 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 8071 reflections
a = 6.7403 (6) Åθ = 2.8–35.0°
b = 14.5574 (12) ŵ = 0.33 mm1
c = 13.2857 (9) ÅT = 100 K
β = 115.550 (4)°Block, colourless
V = 1176.13 (16) Å30.38 × 0.34 × 0.23 mm
Z = 4
Data collection top
Bruker APEXII DUO CCD area-detector
diffractometer
5144 independent reflections
Radiation source: fine-focus sealed tube4405 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
φ and ω scansθmax = 35.1°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 109
Tmin = 0.887, Tmax = 0.929k = 2323
19132 measured reflectionsl = 2121
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.035Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.124H-atom parameters constrained
S = 1.17 w = 1/[σ2(Fo2) + (0.0671P)2 + 0.2275P]
where P = (Fo2 + 2Fc2)/3
5144 reflections(Δ/σ)max = 0.001
164 parametersΔρmax = 0.66 e Å3
0 restraintsΔρmin = 0.43 e Å3
Crystal data top
C5H6ClN2+·C7H5O3V = 1176.13 (16) Å3
Mr = 266.68Z = 4
Monoclinic, P21/cMo Kα radiation
a = 6.7403 (6) ŵ = 0.33 mm1
b = 14.5574 (12) ÅT = 100 K
c = 13.2857 (9) Å0.38 × 0.34 × 0.23 mm
β = 115.550 (4)°
Data collection top
Bruker APEXII DUO CCD area-detector
diffractometer
5144 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
4405 reflections with I > 2σ(I)
Tmin = 0.887, Tmax = 0.929Rint = 0.026
19132 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0350 restraints
wR(F2) = 0.124H-atom parameters constrained
S = 1.17Δρmax = 0.66 e Å3
5144 reflectionsΔρmin = 0.43 e Å3
164 parameters
Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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
xyzUiso*/Ueq
Cl10.19050 (4)0.904645 (18)0.14133 (2)0.02103 (8)
N10.41620 (13)0.90963 (5)0.37992 (7)0.01402 (14)
H10.48270.88880.44690.017*
N20.74627 (14)0.97248 (6)0.40024 (7)0.01929 (16)
H2A0.80720.95140.46720.023*
H2B0.82291.00300.37410.023*
C10.19743 (15)0.89260 (6)0.32167 (8)0.01479 (15)
H1A0.12250.85950.35440.018*
C20.08837 (15)0.92433 (7)0.21489 (7)0.01471 (15)
C30.20331 (15)0.97455 (7)0.16657 (7)0.01588 (15)
H30.12980.99650.09400.019*
C40.42261 (15)0.99101 (7)0.22608 (7)0.01550 (15)
H40.49921.02380.19410.019*
C50.53371 (15)0.95784 (6)0.33713 (7)0.01379 (15)
O10.56169 (12)0.72179 (6)0.25181 (6)0.01955 (15)
H1B0.52990.70700.18710.029*
O20.62190 (11)0.65244 (5)0.09104 (6)0.01729 (14)
O30.95143 (13)0.59845 (5)0.11872 (6)0.01772 (14)
C70.77978 (15)0.70954 (6)0.31440 (7)0.01377 (15)
C80.86682 (17)0.73401 (7)0.42726 (8)0.01670 (16)
H80.77540.75830.45670.020*
C91.08961 (17)0.72202 (7)0.49541 (8)0.01810 (17)
H91.14640.73800.57040.022*
C101.22897 (16)0.68615 (7)0.45190 (8)0.01796 (17)
H101.37820.67870.49750.022*
C111.14261 (15)0.66179 (6)0.34034 (8)0.01524 (15)
H111.23530.63820.31130.018*
C120.91805 (14)0.67199 (6)0.27039 (7)0.01249 (14)
C130.82718 (15)0.63875 (6)0.15205 (7)0.01318 (15)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.01164 (11)0.02568 (13)0.02128 (12)0.00140 (7)0.00287 (8)0.00279 (8)
N10.0125 (3)0.0153 (3)0.0128 (3)0.0010 (2)0.0041 (2)0.0018 (2)
N20.0127 (3)0.0256 (4)0.0160 (3)0.0046 (3)0.0029 (3)0.0045 (3)
C10.0129 (3)0.0144 (4)0.0164 (4)0.0011 (3)0.0057 (3)0.0001 (3)
C20.0116 (3)0.0160 (4)0.0147 (3)0.0002 (3)0.0039 (3)0.0016 (3)
C30.0148 (4)0.0178 (4)0.0127 (3)0.0013 (3)0.0038 (3)0.0009 (3)
C40.0150 (4)0.0173 (4)0.0136 (3)0.0003 (3)0.0056 (3)0.0025 (3)
C50.0122 (3)0.0149 (4)0.0131 (3)0.0006 (3)0.0044 (3)0.0007 (3)
O10.0123 (3)0.0292 (4)0.0164 (3)0.0026 (2)0.0054 (2)0.0033 (3)
O20.0128 (3)0.0237 (3)0.0128 (3)0.0018 (2)0.0031 (2)0.0024 (2)
O30.0176 (3)0.0215 (3)0.0145 (3)0.0046 (2)0.0074 (3)0.0015 (2)
C70.0133 (3)0.0146 (3)0.0134 (3)0.0001 (3)0.0057 (3)0.0004 (3)
C80.0184 (4)0.0189 (4)0.0139 (3)0.0001 (3)0.0079 (3)0.0016 (3)
C90.0209 (4)0.0187 (4)0.0117 (3)0.0012 (3)0.0042 (3)0.0008 (3)
C100.0158 (4)0.0181 (4)0.0150 (4)0.0010 (3)0.0019 (3)0.0000 (3)
C110.0133 (3)0.0153 (4)0.0155 (3)0.0012 (3)0.0047 (3)0.0005 (3)
C120.0123 (3)0.0130 (3)0.0116 (3)0.0004 (3)0.0047 (3)0.0001 (3)
C130.0138 (3)0.0135 (3)0.0118 (3)0.0004 (3)0.0052 (3)0.0004 (3)
Geometric parameters (Å, º) top
Cl1—C21.7280 (9)O1—H1B0.8200
N1—C51.3534 (12)O2—C131.2821 (11)
N1—C11.3603 (12)O3—C131.2496 (11)
N1—H10.8600C7—C81.4002 (13)
N2—C51.3285 (12)C7—C121.4069 (12)
N2—H2A0.8600C8—C91.3901 (14)
N2—H2B0.8600C8—H80.9300
C1—C21.3662 (13)C9—C101.3992 (14)
C1—H1A0.9300C9—H90.9300
C2—C31.4057 (13)C10—C111.3846 (13)
C3—C41.3635 (13)C10—H100.9300
C3—H30.9300C11—C121.4012 (13)
C4—C51.4204 (12)C11—H110.9300
C4—H40.9300C12—C131.5001 (12)
O1—C71.3527 (11)
C5—N1—C1122.87 (8)O1—C7—C8117.84 (8)
C5—N1—H1118.6O1—C7—C12122.33 (8)
C1—N1—H1118.6C8—C7—C12119.81 (8)
C5—N2—H2A120.0C9—C8—C7120.10 (8)
C5—N2—H2B120.0C9—C8—H8119.9
H2A—N2—H2B120.0C7—C8—H8119.9
N1—C1—C2119.66 (8)C8—C9—C10120.45 (8)
N1—C1—H1A120.2C8—C9—H9119.8
C2—C1—H1A120.2C10—C9—H9119.8
C1—C2—C3119.63 (8)C11—C10—C9119.39 (9)
C1—C2—Cl1119.87 (7)C11—C10—H10120.3
C3—C2—Cl1120.48 (7)C9—C10—H10120.3
C4—C3—C2119.98 (8)C10—C11—C12121.20 (8)
C4—C3—H3120.0C10—C11—H11119.4
C2—C3—H3120.0C12—C11—H11119.4
C3—C4—C5119.78 (8)C11—C12—C7119.03 (8)
C3—C4—H4120.1C11—C12—C13119.80 (8)
C5—C4—H4120.1C7—C12—C13121.11 (8)
N2—C5—N1119.03 (8)O3—C13—O2123.67 (8)
N2—C5—C4122.89 (8)O3—C13—C12119.32 (8)
N1—C5—C4118.08 (8)O2—C13—C12117.00 (7)
C7—O1—H1B109.5
C5—N1—C1—C20.46 (14)C8—C9—C10—C110.61 (15)
N1—C1—C2—C30.25 (14)C9—C10—C11—C120.31 (15)
N1—C1—C2—Cl1178.88 (7)C10—C11—C12—C71.35 (14)
C1—C2—C3—C40.27 (14)C10—C11—C12—C13175.67 (9)
Cl1—C2—C3—C4178.89 (7)O1—C7—C12—C11179.72 (8)
C2—C3—C4—C50.47 (14)C8—C7—C12—C111.48 (13)
C1—N1—C5—N2179.07 (9)O1—C7—C12—C133.30 (14)
C1—N1—C5—C40.64 (13)C8—C7—C12—C13175.51 (8)
C3—C4—C5—N2179.05 (9)C11—C12—C13—O33.25 (13)
C3—C4—C5—N10.64 (13)C7—C12—C13—O3173.71 (8)
O1—C7—C8—C9179.44 (9)C11—C12—C13—O2177.95 (8)
C12—C7—C8—C90.58 (14)C7—C12—C13—O25.09 (13)
C7—C8—C9—C100.47 (15)
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C7–C12 ring.
D—H···AD—HH···AD···AD—H···A
N1—H1···O2i0.861.832.6928 (10)178
O1—H1B···O20.821.822.5483 (11)147
N2—H2A···O3i0.861.962.8181 (11)178
N2—H2B···O3ii0.862.032.8321 (13)154
C1—H1A···Cg1iii0.932.573.3680 (11)144
Symmetry codes: (i) x, y+3/2, z+1/2; (ii) x+2, y+1/2, z+1/2; (iii) x1, y, z.

Experimental details

Crystal data
Chemical formulaC5H6ClN2+·C7H5O3
Mr266.68
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)6.7403 (6), 14.5574 (12), 13.2857 (9)
β (°) 115.550 (4)
V3)1176.13 (16)
Z4
Radiation typeMo Kα
µ (mm1)0.33
Crystal size (mm)0.38 × 0.34 × 0.23
Data collection
DiffractometerBruker APEXII DUO CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.887, 0.929
No. of measured, independent and
observed [I > 2σ(I)] reflections
19132, 5144, 4405
Rint0.026
(sin θ/λ)max1)0.808
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.124, 1.17
No. of reflections5144
No. of parameters164
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.66, 0.43

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C7–C12 ring.
D—H···AD—HH···AD···AD—H···A
N1—H1···O2i0.86001.83002.6928 (10)178.30
O1—H1B···O20.82001.82002.5483 (11)147.00
N2—H2A···O3i0.86001.96002.8181 (11)178.00
N2—H2B···O3ii0.86002.03002.8321 (13)154.00
C1—H1A···Cg1iii0.93002.57003.3680 (11)144.00
Symmetry codes: (i) x, y+3/2, z+1/2; (ii) x+2, y+1/2, z+1/2; (iii) x1, y, z.
 

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