In the title compound, 2C
5H
7N
2+·C
4H
4O
42−·C
4H
6O
4, cyclic eight-membered hydrogen-bonded rings exist involving 2-aminopyridinium and succinate ions. The succinic acid and succinate moieties lie on inversion centres. Succinic acid molecules and succinate ions are linked into zigzag chains by O—H
O hydrogen bonds, with O
O distances of 2.6005 (16) Å.
Supporting information
CCDC reference: 199445
The title compound was prepared by mixing 2-aminopyridine and succinic acid in a
1:1 molar ratio in water at 353 K, and crystals of (I) were obtained by slow
evaporation of the solvent.
All H atom parameters were freely refined, with C—H distances in the range
0.92 (2)–0.982 (15) Å, and Uiso(H) in the range 0.039 (4)–0.075 (6) Å2.
Data collection: XSCANS (Siemens, 1991); cell refinement: XSCANS; data reduction: SHELXTL (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: WinGX (Farrugia, 1997).
2-Aminopyridinium-succinate-succinic acid (2/1/1)
top
Crystal data top
2C5H7N2+·C4H4O42−·C4H6O4 | Dx = 1.436 Mg m−3 |
Mr = 424.41 | Melting point = 433–436 K |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 10.228 (2) Å | Cell parameters from 35 reflections |
b = 5.184 (1) Å | θ = 5–25° |
c = 19.047 (4) Å | µ = 0.11 mm−1 |
β = 103.60 (3)° | T = 153 K |
V = 981.6 (4) Å3 | Rectangular, light yellow |
Z = 2 | 0.3 × 0.2 × 0.2 mm |
F(000) = 448 | |
Data collection top
Siemens P4 diffractometer | Rint = 0.000 |
Radiation source: fine-focus sealed tube | θmax = 28.0°, θmin = 2.1° |
Graphite monochromator | h = −13→13 |
ω scans | k = 0→6 |
2362 measured reflections | l = 0→25 |
2362 independent reflections | 1 standard reflections every 120 min |
1690 reflections with I > 2σ(I) | intensity decay: none |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.037 | All H-atom parameters refined |
wR(F2) = 0.104 | w = 1/[σ2(Fo2) + (0.0496P)2 + 0.0805P] where P = (Fo2 + 2Fc2)/3 |
S = 1.02 | (Δ/σ)max = 0.001 |
2362 reflections | Δρmax = 0.29 e Å−3 |
185 parameters | Δρmin = −0.19 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.015 (3) |
Crystal data top
2C5H7N2+·C4H4O42−·C4H6O4 | V = 981.6 (4) Å3 |
Mr = 424.41 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 10.228 (2) Å | µ = 0.11 mm−1 |
b = 5.184 (1) Å | T = 153 K |
c = 19.047 (4) Å | 0.3 × 0.2 × 0.2 mm |
β = 103.60 (3)° | |
Data collection top
Siemens P4 diffractometer | Rint = 0.000 |
2362 measured reflections | 1 standard reflections every 120 min |
2362 independent reflections | intensity decay: none |
1690 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.104 | All H-atom parameters refined |
S = 1.02 | Δρmax = 0.29 e Å−3 |
2362 reflections | Δρmin = −0.19 e Å−3 |
185 parameters | |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.30382 (13) | 0.4452 (3) | 0.76566 (7) | 0.0318 (3) | |
N1 | 0.25392 (12) | 0.6394 (2) | 0.71999 (6) | 0.0343 (3) | |
H1N | 0.2823 (17) | 0.661 (3) | 0.6753 (10) | 0.054 (5)* | |
O1 | 0.10349 (12) | 0.1882 (3) | 0.59636 (6) | 0.0568 (4) | |
C2 | 0.25934 (15) | 0.4253 (3) | 0.83038 (8) | 0.0365 (3) | |
H2 | 0.2968 (16) | 0.286 (3) | 0.8638 (9) | 0.043 (4)* | |
N2 | 0.39039 (14) | 0.2813 (3) | 0.74790 (8) | 0.0428 (3) | |
H2NA | 0.4196 (17) | 0.313 (3) | 0.7061 (10) | 0.049 (5)* | |
H2NB | 0.4221 (17) | 0.166 (4) | 0.7785 (10) | 0.049 (5)* | |
O2 | 0.21613 (12) | 0.1019 (2) | 0.51295 (6) | 0.0469 (3) | |
H6 | 0.255 (2) | −0.025 (4) | 0.5413 (11) | 0.073 (6)* | |
C3 | 0.16808 (15) | 0.5965 (3) | 0.84411 (8) | 0.0394 (4) | |
H3 | 0.1358 (15) | 0.584 (3) | 0.8886 (8) | 0.039 (4)* | |
O3 | 0.32876 (10) | 0.7216 (2) | 0.59400 (5) | 0.0411 (3) | |
C4 | 0.11800 (16) | 0.7937 (3) | 0.79499 (8) | 0.0410 (4) | |
H4 | 0.0564 (17) | 0.912 (3) | 0.8061 (9) | 0.049 (5)* | |
O4 | 0.49502 (10) | 0.4429 (2) | 0.62880 (5) | 0.0390 (3) | |
C5 | 0.16280 (15) | 0.8111 (3) | 0.73374 (8) | 0.0379 (4) | |
H5 | 0.1350 (15) | 0.941 (3) | 0.6971 (9) | 0.041 (4)* | |
C6 | 0.12474 (13) | 0.2267 (3) | 0.53772 (7) | 0.0327 (3) | |
C7 | 0.05024 (16) | 0.4226 (3) | 0.48564 (8) | 0.0371 (4) | |
H7A | 0.0095 (18) | 0.333 (4) | 0.4447 (10) | 0.055 (5)* | |
H7B | 0.1133 (19) | 0.528 (4) | 0.4726 (10) | 0.065 (6)* | |
C8 | 0.42447 (13) | 0.5836 (3) | 0.58213 (7) | 0.0293 (3) | |
C9 | 0.45189 (17) | 0.5993 (3) | 0.50755 (8) | 0.0376 (4) | |
H9A | 0.486 (2) | 0.773 (4) | 0.5036 (12) | 0.075 (6)* | |
H9B | 0.370 (2) | 0.600 (4) | 0.4732 (11) | 0.072 (6)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0311 (7) | 0.0360 (8) | 0.0286 (7) | −0.0042 (6) | 0.0074 (5) | 0.0027 (6) |
N1 | 0.0394 (6) | 0.0386 (7) | 0.0277 (6) | −0.0017 (5) | 0.0133 (5) | 0.0033 (5) |
O1 | 0.0629 (8) | 0.0689 (9) | 0.0474 (7) | 0.0282 (7) | 0.0305 (6) | 0.0284 (6) |
C2 | 0.0392 (8) | 0.0420 (9) | 0.0296 (7) | −0.0007 (7) | 0.0109 (6) | 0.0073 (7) |
N2 | 0.0467 (8) | 0.0481 (8) | 0.0382 (7) | 0.0115 (7) | 0.0194 (6) | 0.0099 (7) |
O2 | 0.0578 (7) | 0.0500 (7) | 0.0363 (6) | 0.0240 (6) | 0.0177 (5) | 0.0097 (5) |
C3 | 0.0434 (8) | 0.0472 (9) | 0.0309 (7) | −0.0033 (7) | 0.0158 (6) | 0.0009 (7) |
O3 | 0.0489 (6) | 0.0461 (6) | 0.0347 (5) | 0.0197 (5) | 0.0230 (5) | 0.0080 (5) |
C4 | 0.0459 (9) | 0.0402 (9) | 0.0407 (8) | 0.0049 (7) | 0.0177 (7) | 0.0008 (7) |
O4 | 0.0436 (6) | 0.0470 (6) | 0.0284 (5) | 0.0139 (5) | 0.0123 (4) | 0.0063 (5) |
C5 | 0.0435 (8) | 0.0352 (8) | 0.0355 (8) | 0.0019 (7) | 0.0101 (6) | 0.0061 (7) |
C6 | 0.0330 (7) | 0.0322 (7) | 0.0332 (7) | 0.0001 (6) | 0.0084 (6) | 0.0018 (6) |
C7 | 0.0416 (8) | 0.0389 (9) | 0.0319 (8) | 0.0074 (7) | 0.0112 (6) | 0.0071 (7) |
C8 | 0.0322 (7) | 0.0302 (7) | 0.0277 (6) | 0.0014 (6) | 0.0118 (5) | −0.0004 (6) |
C9 | 0.0447 (9) | 0.0432 (9) | 0.0297 (7) | 0.0140 (7) | 0.0182 (6) | 0.0069 (7) |
Geometric parameters (Å, º) top
C1—N2 | 1.3272 (19) | O3—C8 | 1.2747 (16) |
C1—N1 | 1.3500 (18) | C4—C5 | 1.353 (2) |
C1—C2 | 1.4145 (19) | C4—H4 | 0.937 (18) |
N1—C5 | 1.3578 (19) | O4—C8 | 1.2413 (16) |
N1—H1N | 0.969 (18) | C5—H5 | 0.962 (17) |
O1—C6 | 1.2038 (17) | C6—C7 | 1.497 (2) |
C2—C3 | 1.357 (2) | C7—C7i | 1.504 (3) |
C2—H2 | 0.978 (17) | C7—H7A | 0.920 (18) |
N2—H2NA | 0.929 (18) | C7—H7B | 0.92 (2) |
N2—H2NB | 0.84 (2) | C8—C9 | 1.5135 (18) |
O2—C6 | 1.3123 (17) | C9—C9ii | 1.498 (3) |
O2—H6 | 0.89 (2) | C9—H9A | 0.98 (2) |
C3—C4 | 1.399 (2) | C9—H9B | 0.94 (2) |
C3—H3 | 0.982 (15) | | |
| | | |
N2—C1—N1 | 119.15 (13) | C4—C5—H5 | 124.7 (9) |
N2—C1—C2 | 123.11 (14) | N1—C5—H5 | 114.7 (9) |
N1—C1—C2 | 117.73 (13) | O1—C6—O2 | 123.44 (14) |
C1—N1—C5 | 122.50 (12) | O1—C6—C7 | 123.55 (13) |
C1—N1—H1N | 120.4 (11) | O2—C6—C7 | 113.01 (12) |
C5—N1—H1N | 117.1 (11) | C6—C7—C7i | 113.93 (15) |
C3—C2—C1 | 119.81 (14) | C6—C7—H7A | 106.0 (12) |
C3—C2—H2 | 122.6 (9) | C7i—C7—H7A | 111.5 (11) |
C1—C2—H2 | 117.6 (9) | C6—C7—H7B | 107.5 (12) |
C1—N2—H2NA | 118.4 (11) | C7i—C7—H7B | 111.3 (13) |
C1—N2—H2NB | 116.6 (12) | H7A—C7—H7B | 106.2 (16) |
H2NA—N2—H2NB | 124.6 (16) | O4—C8—O3 | 122.95 (12) |
C6—O2—H6 | 113.7 (13) | O4—C8—C9 | 119.93 (12) |
C2—C3—C4 | 120.60 (14) | O3—C8—C9 | 117.11 (12) |
C2—C3—H3 | 120.6 (9) | C9ii—C9—C8 | 114.73 (16) |
C4—C3—H3 | 118.8 (9) | C9ii—C9—H9A | 111.1 (13) |
C5—C4—C3 | 118.71 (15) | C8—C9—H9A | 105.6 (13) |
C5—C4—H4 | 122.2 (11) | C9ii—C9—H9B | 113.0 (13) |
C3—C4—H4 | 119.1 (11) | C8—C9—H9B | 108.8 (12) |
C4—C5—N1 | 120.64 (15) | H9A—C9—H9B | 102.7 (18) |
| | | |
N2—C1—N1—C5 | 178.53 (14) | C3—C4—C5—N1 | 0.4 (2) |
C2—C1—N1—C5 | −0.8 (2) | C1—N1—C5—C4 | 0.1 (2) |
N2—C1—C2—C3 | −178.40 (15) | O1—C6—C7—C7i | 2.6 (3) |
N1—C1—C2—C3 | 0.9 (2) | O2—C6—C7—C7i | −177.09 (18) |
C1—C2—C3—C4 | −0.4 (2) | O4—C8—C9—C9ii | 11.1 (3) |
C2—C3—C4—C5 | −0.3 (2) | O3—C8—C9—C9ii | −169.72 (18) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O3 | 0.969 (18) | 1.751 (18) | 2.7185 (16) | 176.0 (17) |
N2—H2NA···O4 | 0.929 (18) | 1.936 (19) | 2.8521 (18) | 168.2 (16) |
N2—H2NB···O4iii | 0.84 (2) | 2.11 (2) | 2.9447 (19) | 167.7 (17) |
O2—H6···O3iv | 0.89 (2) | 1.72 (2) | 2.6005 (16) | 178 (2) |
Symmetry codes: (iii) −x+1, y−1/2, −z+3/2; (iv) x, y−1, z. |
Experimental details
Crystal data |
Chemical formula | 2C5H7N2+·C4H4O42−·C4H6O4 |
Mr | 424.41 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 153 |
a, b, c (Å) | 10.228 (2), 5.184 (1), 19.047 (4) |
β (°) | 103.60 (3) |
V (Å3) | 981.6 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.3 × 0.2 × 0.2 |
|
Data collection |
Diffractometer | Siemens P4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2362, 2362, 1690 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.660 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.104, 1.02 |
No. of reflections | 2362 |
No. of parameters | 185 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.29, −0.19 |
Selected geometric parameters (Å, º) topC1—N2 | 1.3272 (19) | O2—C6 | 1.3123 (17) |
C1—N1 | 1.3500 (18) | O3—C8 | 1.2747 (16) |
N1—C5 | 1.3578 (19) | O4—C8 | 1.2413 (16) |
O1—C6 | 1.2038 (17) | | |
| | | |
O1—C6—O2 | 123.44 (14) | O4—C8—O3 | 122.95 (12) |
| | | |
N2—C1—N1—C5 | 178.53 (14) | O4—C8—C9—C9ii | 11.1 (3) |
O1—C6—C7—C7i | 2.6 (3) | O3—C8—C9—C9ii | −169.72 (18) |
O2—C6—C7—C7i | −177.09 (18) | | |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O3 | 0.969 (18) | 1.751 (18) | 2.7185 (16) | 176.0 (17) |
N2—H2NA···O4 | 0.929 (18) | 1.936 (19) | 2.8521 (18) | 168.2 (16) |
N2—H2NB···O4iii | 0.84 (2) | 2.11 (2) | 2.9447 (19) | 167.7 (17) |
O2—H6···O3iv | 0.89 (2) | 1.72 (2) | 2.6005 (16) | 178 (2) |
Symmetry codes: (iii) −x+1, y−1/2, −z+3/2; (iv) x, y−1, z. |
Hydrogen bonding plays a key role in molecular recognition (Goswami & Ghosh, 1997) and crystal engineering research (Goswami et al., 1998). The design of highly specific solid-state structures is of considerable significance in organic chemistry, due to their important applications in the development of new optical, magnetic and electronic systems (Lehn, 1990). Our investigation of the title compound, (I), shows that the 2-aminopyridinium ions are linked to the succinate ions by N1—H···O3 and N2—H2NA···O4 hydrogen bonds, resulting in the formation of cyclic eight-membered hydrogen-bonded rings. \sch
Each amino H atom in (I) is involved in a single hydrogen bond, one in the cyclic eight-membered hydrogen-bonded ring system and the other to another succinate ion (Fig. 1). The 2-aminopyridinium-succinate-succinic acid units are arranged so that a two-dimensional network of intermolecular N2—H2NB···O4 and O2—H6···O3 hydrogen bonds exists on each nearly perpendicular 2-aminopyridinium-succinate-succinic acid unit [dihedral angle 84.34 (8)°] (Fig. 2).
2-Aminopyridine, like other organic bases, is protonated in acidic solutions. The bonding of the H atom to the ring N atom of 2-aminopyridine, but not to the amino N atom, gives an ion for which an additional resonance structure can be written. As this monocation has more resonance energy (additional ionic resonance) than 2-aminopyridine itself, 2-aminopyridine is a strong base, like amidines (Acheson, 1967).
The present investigation clearly shows that the positive charge in (I) is on the amino group in the crystal, with hydrogen bonds. The C1—N2 bond length is 1.3272 (19) Å, and this is approximately equal to the C═N double bond (Shanmuga Sundara Raj, Fun, Lu et al., 2000). This is also supported by the C1—N2—H2NA angle of 118.4 (11)° and by the fact that atoms C1, N2, H2NA and H2NB lie in the pyridine plane, with a maximum deviation of 0.04 (2) Å for atom H2NB. Similar C1—N2 bonds have also been observed in other 2-aminopyridine-containing molecules (Yang et al., 1995; Grobelny et al., 1995; Shanmuga Sundara Raj, Fun, Zhao et al., 2000).