





Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536810018210/sj5004sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S1600536810018210/sj5004Isup2.hkl |
CCDC reference: 781392
Key indicators
- Single-crystal X-ray study
- T = 100 K
- Mean
(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
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.
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).
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).
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).
C5H6ClN2+·C7H5O3− | F(000) = 552 |
Mr = 266.68 | Dx = 1.506 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 8071 reflections |
a = 6.7403 (6) Å | θ = 2.8–35.0° |
b = 14.5574 (12) Å | µ = 0.33 mm−1 |
c = 13.2857 (9) Å | T = 100 K |
β = 115.550 (4)° | Block, colourless |
V = 1176.13 (16) Å3 | 0.38 × 0.34 × 0.23 mm |
Z = 4 |
Bruker APEXII DUO CCD area-detector diffractometer | 5144 independent reflections |
Radiation source: fine-focus sealed tube | 4405 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.026 |
φ and ω scans | θmax = 35.1°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | h = −10→9 |
Tmin = 0.887, Tmax = 0.929 | k = −23→23 |
19132 measured reflections | l = −21→21 |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.124 | H-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 parameters | Δρmax = 0.66 e Å−3 |
0 restraints | Δρmin = −0.43 e Å−3 |
C5H6ClN2+·C7H5O3− | V = 1176.13 (16) Å3 |
Mr = 266.68 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 6.7403 (6) Å | µ = 0.33 mm−1 |
b = 14.5574 (12) Å | T = 100 K |
c = 13.2857 (9) Å | 0.38 × 0.34 × 0.23 mm |
β = 115.550 (4)° |
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 = 0.929 | Rint = 0.026 |
19132 measured reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.124 | H-atom parameters constrained |
S = 1.17 | Δρmax = 0.66 e Å−3 |
5144 reflections | Δρmin = −0.43 e Å−3 |
164 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Cl1 | −0.19050 (4) | 0.904645 (18) | 0.14133 (2) | 0.02103 (8) | |
N1 | 0.41620 (13) | 0.90963 (5) | 0.37992 (7) | 0.01402 (14) | |
H1 | 0.4827 | 0.8888 | 0.4469 | 0.017* | |
N2 | 0.74627 (14) | 0.97248 (6) | 0.40024 (7) | 0.01929 (16) | |
H2A | 0.8072 | 0.9514 | 0.4672 | 0.023* | |
H2B | 0.8229 | 1.0030 | 0.3741 | 0.023* | |
C1 | 0.19743 (15) | 0.89260 (6) | 0.32167 (8) | 0.01479 (15) | |
H1A | 0.1225 | 0.8595 | 0.3544 | 0.018* | |
C2 | 0.08837 (15) | 0.92433 (7) | 0.21489 (7) | 0.01471 (15) | |
C3 | 0.20331 (15) | 0.97455 (7) | 0.16657 (7) | 0.01588 (15) | |
H3 | 0.1298 | 0.9965 | 0.0940 | 0.019* | |
C4 | 0.42261 (15) | 0.99101 (7) | 0.22608 (7) | 0.01550 (15) | |
H4 | 0.4992 | 1.0238 | 0.1941 | 0.019* | |
C5 | 0.53371 (15) | 0.95784 (6) | 0.33713 (7) | 0.01379 (15) | |
O1 | 0.56169 (12) | 0.72179 (6) | 0.25181 (6) | 0.01955 (15) | |
H1B | 0.5299 | 0.7070 | 0.1871 | 0.029* | |
O2 | 0.62190 (11) | 0.65244 (5) | 0.09104 (6) | 0.01729 (14) | |
O3 | 0.95143 (13) | 0.59845 (5) | 0.11872 (6) | 0.01772 (14) | |
C7 | 0.77978 (15) | 0.70954 (6) | 0.31440 (7) | 0.01377 (15) | |
C8 | 0.86682 (17) | 0.73401 (7) | 0.42726 (8) | 0.01670 (16) | |
H8 | 0.7754 | 0.7583 | 0.4567 | 0.020* | |
C9 | 1.08961 (17) | 0.72202 (7) | 0.49541 (8) | 0.01810 (17) | |
H9 | 1.1464 | 0.7380 | 0.5704 | 0.022* | |
C10 | 1.22897 (16) | 0.68615 (7) | 0.45190 (8) | 0.01796 (17) | |
H10 | 1.3782 | 0.6787 | 0.4975 | 0.022* | |
C11 | 1.14261 (15) | 0.66179 (6) | 0.34034 (8) | 0.01524 (15) | |
H11 | 1.2353 | 0.6382 | 0.3113 | 0.018* | |
C12 | 0.91805 (14) | 0.67199 (6) | 0.27039 (7) | 0.01249 (14) | |
C13 | 0.82718 (15) | 0.63875 (6) | 0.15205 (7) | 0.01318 (15) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.01164 (11) | 0.02568 (13) | 0.02128 (12) | −0.00140 (7) | 0.00287 (8) | −0.00279 (8) |
N1 | 0.0125 (3) | 0.0153 (3) | 0.0128 (3) | −0.0010 (2) | 0.0041 (2) | 0.0018 (2) |
N2 | 0.0127 (3) | 0.0256 (4) | 0.0160 (3) | −0.0046 (3) | 0.0029 (3) | 0.0045 (3) |
C1 | 0.0129 (3) | 0.0144 (4) | 0.0164 (4) | −0.0011 (3) | 0.0057 (3) | −0.0001 (3) |
C2 | 0.0116 (3) | 0.0160 (4) | 0.0147 (3) | −0.0002 (3) | 0.0039 (3) | −0.0016 (3) |
C3 | 0.0148 (4) | 0.0178 (4) | 0.0127 (3) | 0.0013 (3) | 0.0038 (3) | 0.0009 (3) |
C4 | 0.0150 (4) | 0.0173 (4) | 0.0136 (3) | −0.0003 (3) | 0.0056 (3) | 0.0025 (3) |
C5 | 0.0122 (3) | 0.0149 (4) | 0.0131 (3) | −0.0006 (3) | 0.0044 (3) | 0.0007 (3) |
O1 | 0.0123 (3) | 0.0292 (4) | 0.0164 (3) | 0.0026 (2) | 0.0054 (2) | −0.0033 (3) |
O2 | 0.0128 (3) | 0.0237 (3) | 0.0128 (3) | 0.0018 (2) | 0.0031 (2) | −0.0024 (2) |
O3 | 0.0176 (3) | 0.0215 (3) | 0.0145 (3) | 0.0046 (2) | 0.0074 (3) | −0.0015 (2) |
C7 | 0.0133 (3) | 0.0146 (3) | 0.0134 (3) | −0.0001 (3) | 0.0057 (3) | −0.0004 (3) |
C8 | 0.0184 (4) | 0.0189 (4) | 0.0139 (3) | 0.0001 (3) | 0.0079 (3) | −0.0016 (3) |
C9 | 0.0209 (4) | 0.0187 (4) | 0.0117 (3) | −0.0012 (3) | 0.0042 (3) | −0.0008 (3) |
C10 | 0.0158 (4) | 0.0181 (4) | 0.0150 (4) | 0.0010 (3) | 0.0019 (3) | 0.0000 (3) |
C11 | 0.0133 (3) | 0.0153 (4) | 0.0155 (3) | 0.0012 (3) | 0.0047 (3) | −0.0005 (3) |
C12 | 0.0123 (3) | 0.0130 (3) | 0.0116 (3) | 0.0004 (3) | 0.0047 (3) | −0.0001 (3) |
C13 | 0.0138 (3) | 0.0135 (3) | 0.0118 (3) | 0.0004 (3) | 0.0052 (3) | 0.0004 (3) |
Cl1—C2 | 1.7280 (9) | O1—H1B | 0.8200 |
N1—C5 | 1.3534 (12) | O2—C13 | 1.2821 (11) |
N1—C1 | 1.3603 (12) | O3—C13 | 1.2496 (11) |
N1—H1 | 0.8600 | C7—C8 | 1.4002 (13) |
N2—C5 | 1.3285 (12) | C7—C12 | 1.4069 (12) |
N2—H2A | 0.8600 | C8—C9 | 1.3901 (14) |
N2—H2B | 0.8600 | C8—H8 | 0.9300 |
C1—C2 | 1.3662 (13) | C9—C10 | 1.3992 (14) |
C1—H1A | 0.9300 | C9—H9 | 0.9300 |
C2—C3 | 1.4057 (13) | C10—C11 | 1.3846 (13) |
C3—C4 | 1.3635 (13) | C10—H10 | 0.9300 |
C3—H3 | 0.9300 | C11—C12 | 1.4012 (13) |
C4—C5 | 1.4204 (12) | C11—H11 | 0.9300 |
C4—H4 | 0.9300 | C12—C13 | 1.5001 (12) |
O1—C7 | 1.3527 (11) | ||
C5—N1—C1 | 122.87 (8) | O1—C7—C8 | 117.84 (8) |
C5—N1—H1 | 118.6 | O1—C7—C12 | 122.33 (8) |
C1—N1—H1 | 118.6 | C8—C7—C12 | 119.81 (8) |
C5—N2—H2A | 120.0 | C9—C8—C7 | 120.10 (8) |
C5—N2—H2B | 120.0 | C9—C8—H8 | 119.9 |
H2A—N2—H2B | 120.0 | C7—C8—H8 | 119.9 |
N1—C1—C2 | 119.66 (8) | C8—C9—C10 | 120.45 (8) |
N1—C1—H1A | 120.2 | C8—C9—H9 | 119.8 |
C2—C1—H1A | 120.2 | C10—C9—H9 | 119.8 |
C1—C2—C3 | 119.63 (8) | C11—C10—C9 | 119.39 (9) |
C1—C2—Cl1 | 119.87 (7) | C11—C10—H10 | 120.3 |
C3—C2—Cl1 | 120.48 (7) | C9—C10—H10 | 120.3 |
C4—C3—C2 | 119.98 (8) | C10—C11—C12 | 121.20 (8) |
C4—C3—H3 | 120.0 | C10—C11—H11 | 119.4 |
C2—C3—H3 | 120.0 | C12—C11—H11 | 119.4 |
C3—C4—C5 | 119.78 (8) | C11—C12—C7 | 119.03 (8) |
C3—C4—H4 | 120.1 | C11—C12—C13 | 119.80 (8) |
C5—C4—H4 | 120.1 | C7—C12—C13 | 121.11 (8) |
N2—C5—N1 | 119.03 (8) | O3—C13—O2 | 123.67 (8) |
N2—C5—C4 | 122.89 (8) | O3—C13—C12 | 119.32 (8) |
N1—C5—C4 | 118.08 (8) | O2—C13—C12 | 117.00 (7) |
C7—O1—H1B | 109.5 | ||
C5—N1—C1—C2 | 0.46 (14) | C8—C9—C10—C11 | −0.61 (15) |
N1—C1—C2—C3 | −0.25 (14) | C9—C10—C11—C12 | −0.31 (15) |
N1—C1—C2—Cl1 | −178.88 (7) | C10—C11—C12—C7 | 1.35 (14) |
C1—C2—C3—C4 | 0.27 (14) | C10—C11—C12—C13 | −175.67 (9) |
Cl1—C2—C3—C4 | 178.89 (7) | O1—C7—C12—C11 | 179.72 (8) |
C2—C3—C4—C5 | −0.47 (14) | C8—C7—C12—C11 | −1.48 (13) |
C1—N1—C5—N2 | 179.07 (9) | O1—C7—C12—C13 | −3.30 (14) |
C1—N1—C5—C4 | −0.64 (13) | C8—C7—C12—C13 | 175.51 (8) |
C3—C4—C5—N2 | −179.05 (9) | C11—C12—C13—O3 | 3.25 (13) |
C3—C4—C5—N1 | 0.64 (13) | C7—C12—C13—O3 | −173.71 (8) |
O1—C7—C8—C9 | 179.44 (9) | C11—C12—C13—O2 | −177.95 (8) |
C12—C7—C8—C9 | 0.58 (14) | C7—C12—C13—O2 | 5.09 (13) |
C7—C8—C9—C10 | 0.47 (15) |
Cg1 is the centroid of the C7–C12 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O2i | 0.86 | 1.83 | 2.6928 (10) | 178 |
O1—H1B···O2 | 0.82 | 1.82 | 2.5483 (11) | 147 |
N2—H2A···O3i | 0.86 | 1.96 | 2.8181 (11) | 178 |
N2—H2B···O3ii | 0.86 | 2.03 | 2.8321 (13) | 154 |
C1—H1A···Cg1iii | 0.93 | 2.57 | 3.3680 (11) | 144 |
Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) −x+2, y+1/2, −z+1/2; (iii) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C5H6ClN2+·C7H5O3− |
Mr | 266.68 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 6.7403 (6), 14.5574 (12), 13.2857 (9) |
β (°) | 115.550 (4) |
V (Å3) | 1176.13 (16) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.33 |
Crystal size (mm) | 0.38 × 0.34 × 0.23 |
Data collection | |
Diffractometer | Bruker APEXII DUO CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2009) |
Tmin, Tmax | 0.887, 0.929 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 19132, 5144, 4405 |
Rint | 0.026 |
(sin θ/λ)max (Å−1) | 0.808 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.124, 1.17 |
No. of reflections | 5144 |
No. of parameters | 164 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.66, −0.43 |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
Cg1 is the centroid of the C7–C12 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O2i | 0.8600 | 1.8300 | 2.6928 (10) | 178.30 |
O1—H1B···O2 | 0.8200 | 1.8200 | 2.5483 (11) | 147.00 |
N2—H2A···O3i | 0.8600 | 1.9600 | 2.8181 (11) | 178.00 |
N2—H2B···O3ii | 0.8600 | 2.0300 | 2.8321 (13) | 154.00 |
C1—H1A···Cg1iii | 0.9300 | 2.5700 | 3.3680 (11) | 144.00 |
Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) −x+2, y+1/2, −z+1/2; (iii) x−1, y, z. |
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.