organic compounds
Bis(4-aminopyridinium) sulfate monohydrate
aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bOrganic Chemistry Division, Department of Chemistry, National Institute of Technology–Karnataka, Surathkal, Mangalore 575 025, India, and cBiotechnology Division, Chemical Engineering Department, National Institute of Technology–Karnataka, Surathkal, Mangalore 575 025, India
*Correspondence e-mail: hkfun@usm.my
The 5H7N2+·SO42−·H2O, contains two 4-aminopyridinium cations (A and B), a sulfate dianion and a water molecule. One of the 4-aminopyridinium cations (B) is disordered over two orientations with refined site occupancies of 0.568 (4) and 0.432 (4). The non-H atoms of the 4-aminopyridinium cations are essentially coplanar, with a maximum deviation of 0.055 (1) Å (in cation A), 0.022 (3) Å (for the major component in cation B) and 0.009 (3) Å (for the minor component in cation B). In the crystal, the sulfate O atoms link the 4-aminopyridinium cations and water molecules into a three-dimensional network via intermolecular O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds. The is further consolidated by N—H⋯O(water) and C—H⋯O(water) hydrogen bonds.
of the title compound, 2CRelated literature
For general background to and the applications of the title compound, see: Judge & Bever (2006); Schwid et al. (1997); Strupp et al. (2004); Onoda et al. (2001); Zhang et al. (2004); Pflugrath & Quiocho, (1985); Jacobson & Quiocho (1988). For related structures, see: Quah et al. (2008a,b, 2010). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986). For bond-length data, see: Allen et al. (1987).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2009); cell SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009).
Supporting information
https://doi.org/10.1107/S1600536810030941/bt5310sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810030941/bt5310Isup2.hkl
Few drops of concentrated sulfuric acid were added to a hot methanol solution of 4-aminopyridine (47 mg, Aldrich). The solution was warmed over a water bath for 1 h. The resulting solution was allowed to cool slowly to room temperature. Colourless crystals appeared from the mother liquor after a few days. Yield 60%.
Atoms H1NA, H2NA, H1NB, H2NB, H1AB and H1BA were located in a difference Fourier map and refined using a riding model with N–H = 0.7856 – 0.8900 Å. The remaining O– and N– bound H atoms were located in a difference Fourier map and allowed to refine freely. The rest of the hydrogen atoms were positioned geometrically and refined using a riding model with C–H = 0.93 Å and Uiso(H) = 1.2 Ueq(C). One of the 4-aminopyridinium cations is disordered over two positions with refined site-occupancies of 0.568 (4) and 0.432 (4). The same Uij parameters were used for atom pair C1A/C2A. The highest residual electron density peak is located at 0.72 Å from O1W and the deepest hole is located at 0.68 Å from O1W.
4-Aminopyridine (fampridine) is clinically used in the treatment of Lambert-Eaton myasthenic syndrome and multiple sclerosis. It prolongs action potentials by blocking potassium channels, thereby increases transmitter release at the neuromuscular junction (Judge & Bever, 2006; Schwid et al., 1997; Strupp et al., 2004). Hydrogen bonding patterns involving sulfate and sulfonate groups in biological systems and metal complexes are also of current interest (Onoda et al., 2001). Benzoic acid and sulfuric acid form a stable hydrogen-bonded complex that favors aerosol formation in the atmosphere (Zhang et al., 2004). In a sulfate-binding protein, the sulfate anion is mainly bonded by seven hydrogen bonds, five of which are from the main chain peptide NH groups (Pflugrath & Quiocho, 1985; Jacobson & Quiocho, 1988). The present study is aimed at understanding the hydrogen bonding network in the title compound (I).
The
of (I) contains two 4-aminopyridinium cations (A and B), a sulfate anion and a water molecule (Fig 1). The 4-aminopyridinium cation in molecule B is disordered over two positions with refined site-occupancies of 0.568 (4) and 0.432 (4). In the 4-aminopyridinium cations, the protonation of atoms N1 (molecule A), N1A (major component in molecule B) and N1B (minor component in molecule B) have lead to slight increase in C–N–C angles to 120.88 (13), 120.9 (4) and 119.7 (5)°, respectively. The non-H atoms of the 4-aminopyridinium cations are essentially co-planar, with a maximum deviation of 0.055 (1) Å for atom N2, 0.022 (3) Å for atom N2A and 0.009 (3) Å for atom N2B. The bond lengths (Allen et al., 1987) and angles are normal and comparable to the related structures (Quah et al., 2008a,b; 2010). The pyridine ring (N1/C1—C5) in molecule A makes dihedral angles of 68.46 (19) and 70.1 (2)°, respectively, with N1A/C1A—C5A and N1B/C1B—C5B rings.In the crystal packing (Fig. 2), oxygen atoms (O1, O2, O3 and O4) in sulfate anions link the 4-aminopyridinium cations and water molecules into three-dimensional network via intermolecular O–H···O, N–H···O and C–H···O hydrogen bonds (Table 1). The
is further consolidated by N2A–H1NA···O1W and C1A–H1AA···O1W hydrogen bonds.For general background to and the applications of the title compound, see: Judge & Bever (2006); Schwid et al. (1997); Strupp et al. (2004); Onoda et al. (2001); Zhang et al. (2004); Pflugrath & Quiocho, (1985); Jacobson & Quiocho (1988). For related structures, see: Quah et al. (2008a,b, 2010). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986). For bond-length data, see: Allen et al. (1987).
Data collection: APEX2 (Bruker, 2009); cell
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).Fig. 1. The molecular structure of the title compound showing 50% probability displacement ellipsoids for non-H atoms and the atom-numbering scheme. Both disordered components are shown. | |
Fig. 2. The crystal structure of the title compound viewed along the a axis. H atoms not involved in intermolecular interactions (dashed lines) have been omitted for clarity. Only major disorder component is shown. |
2C5H7N2+·SO42−·H2O | Z = 2 |
Mr = 304.33 | F(000) = 320 |
Triclinic, P1 | Dx = 1.529 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.4434 (1) Å | Cell parameters from 3597 reflections |
b = 8.4153 (1) Å | θ = 3.1–30.1° |
c = 12.4488 (2) Å | µ = 0.27 mm−1 |
α = 96.365 (1)° | T = 100 K |
β = 97.534 (1)° | Plate, colourless |
γ = 95.387 (1)° | 0.33 × 0.25 × 0.07 mm |
V = 661.02 (2) Å3 |
Bruker SMART APEXII CCD area-detector diffractometer | 3839 independent reflections |
Radiation source: fine-focus sealed tube | 3279 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.027 |
φ and ω scans | θmax = 30.0°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | h = −9→9 |
Tmin = 0.916, Tmax = 0.981 | k = −11→11 |
10717 measured reflections | l = −17→17 |
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)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.106 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0441P)2 + 0.4122P] where P = (Fo2 + 2Fc2)/3 |
3839 reflections | (Δ/σ)max < 0.001 |
259 parameters | Δρmax = 0.59 e Å−3 |
0 restraints | Δρmin = −0.55 e Å−3 |
2C5H7N2+·SO42−·H2O | γ = 95.387 (1)° |
Mr = 304.33 | V = 661.02 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.4434 (1) Å | Mo Kα radiation |
b = 8.4153 (1) Å | µ = 0.27 mm−1 |
c = 12.4488 (2) Å | T = 100 K |
α = 96.365 (1)° | 0.33 × 0.25 × 0.07 mm |
β = 97.534 (1)° |
Bruker SMART APEXII CCD area-detector diffractometer | 3839 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | 3279 reflections with I > 2σ(I) |
Tmin = 0.916, Tmax = 0.981 | Rint = 0.027 |
10717 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.106 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.59 e Å−3 |
3839 reflections | Δρmin = −0.55 e Å−3 |
259 parameters |
Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K. |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
S1 | 0.41695 (5) | 0.12500 (4) | 0.29301 (3) | 0.01520 (10) | |
O4 | 0.28974 (17) | 0.13054 (13) | 0.38487 (9) | 0.0210 (2) | |
O3 | 0.52927 (17) | 0.28476 (13) | 0.29263 (10) | 0.0217 (2) | |
O2 | 0.56565 (18) | 0.00390 (14) | 0.30613 (10) | 0.0256 (3) | |
O1 | 0.27120 (18) | 0.08095 (15) | 0.18901 (10) | 0.0277 (3) | |
N2 | −0.0310 (2) | 0.34101 (15) | 0.35023 (11) | 0.0172 (2) | |
C5 | 0.2971 (2) | 0.72142 (18) | 0.42897 (12) | 0.0182 (3) | |
H5A | 0.4373 | 0.7607 | 0.4527 | 0.022* | |
N1 | 0.1519 (2) | 0.82613 (16) | 0.41396 (11) | 0.0192 (3) | |
C3 | 0.0277 (2) | 0.49838 (17) | 0.37303 (11) | 0.0144 (3) | |
C2 | −0.1204 (2) | 0.61239 (18) | 0.36079 (12) | 0.0168 (3) | |
H2A | −0.2625 | 0.5775 | 0.3392 | 0.020* | |
O1W | 0.8386 (2) | 0.96841 (16) | 0.15025 (14) | 0.0355 (3) | |
C4 | 0.2413 (2) | 0.55943 (17) | 0.40997 (11) | 0.0160 (3) | |
H4A | 0.3428 | 0.4891 | 0.4212 | 0.019* | |
C1 | −0.0540 (2) | 0.77280 (18) | 0.38069 (12) | 0.0189 (3) | |
H1A | −0.1514 | 0.8467 | 0.3713 | 0.023* | |
C2A | 0.7722 (12) | 0.4735 (7) | 1.0588 (7) | 0.0238 (7) | 0.568 (4) |
H2AA | 0.8019 | 0.5311 | 1.1282 | 0.029* | 0.568 (4) |
C1A | 0.7613 (4) | 0.3094 (4) | 1.0482 (3) | 0.0238 (7) | 0.568 (4) |
H1AA | 0.7854 | 0.2567 | 1.1097 | 0.029* | 0.568 (4) |
C5A | 0.6790 (11) | 0.2982 (7) | 0.8591 (6) | 0.0237 (11) | 0.568 (4) |
H5AA | 0.6461 | 0.2370 | 0.7910 | 0.028* | 0.568 (4) |
C4A | 0.6891 (9) | 0.4594 (7) | 0.8661 (5) | 0.0175 (10) | 0.568 (4) |
H4AA | 0.6624 | 0.5082 | 0.8030 | 0.021* | 0.568 (4) |
N2A | 0.7527 (4) | 0.7162 (3) | 0.9771 (2) | 0.0185 (6) | 0.568 (4) |
H2NA | 0.7286 | 0.7515 | 0.9160 | 0.028* | 0.568 (4) |
H1NA | 0.7770 | 0.7672 | 1.0350 | 0.028* | 0.568 (4) |
C3A | 0.7401 (4) | 0.5559 (4) | 0.9691 (2) | 0.0134 (6) | 0.568 (4) |
N1A | 0.7155 (4) | 0.2243 (4) | 0.9482 (3) | 0.0263 (7) | 0.568 (4) |
H1AB | 0.7039 | 0.1217 | 0.9350 | 0.032* | 0.568 (4) |
N2B | 0.7174 (5) | 0.1525 (5) | 0.9860 (3) | 0.0219 (8) | 0.432 (4) |
H1NB | 0.7542 | 0.1178 | 1.0500 | 0.033* | 0.432 (4) |
H2NB | 0.7106 | 0.0855 | 0.9312 | 0.033* | 0.432 (4) |
C1B | 0.7723 (6) | 0.5882 (5) | 1.0409 (4) | 0.0270 (10) | 0.432 (4) |
H1BB | 0.7821 | 0.6760 | 1.0868 | 0.040* | 0.432 (4) |
N1B | 0.7377 (5) | 0.6283 (6) | 0.9395 (4) | 0.0257 (9) | 0.432 (4) |
H1BA | 0.7421 | 0.7279 | 0.9294 | 0.038* | 0.432 (4) |
C3B | 0.7256 (5) | 0.3062 (6) | 0.9719 (3) | 0.0173 (8) | 0.432 (4) |
C4B | 0.6880 (12) | 0.3543 (9) | 0.8640 (6) | 0.0168 (13) | 0.432 (4) |
H4BA | 0.6584 | 0.2771 | 0.8030 | 0.020* | 0.432 (4) |
C5B | 0.6959 (13) | 0.5103 (9) | 0.8524 (7) | 0.0208 (13) | 0.432 (4) |
H5BA | 0.6721 | 0.5400 | 0.7824 | 0.025* | 0.432 (4) |
C2B | 0.7688 (12) | 0.4344 (6) | 1.0631 (6) | 0.0153 (12) | 0.432 (4) |
H2BA | 0.7932 | 0.4112 | 1.1347 | 0.018* | 0.432 (4) |
H1W1 | 0.750 (5) | 0.985 (4) | 0.201 (3) | 0.067 (9)* | |
H2W1 | 0.963 (5) | 1.006 (3) | 0.172 (2) | 0.054 (8)* | |
H1N1 | 0.193 (3) | 0.929 (3) | 0.4163 (18) | 0.033 (6)* | |
H1N2 | 0.061 (4) | 0.275 (3) | 0.3623 (17) | 0.031 (6)* | |
H2N2 | −0.163 (3) | 0.309 (2) | 0.3310 (16) | 0.023 (5)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.01105 (16) | 0.01034 (16) | 0.02362 (18) | 0.00082 (11) | 0.00082 (12) | 0.00180 (12) |
O4 | 0.0194 (5) | 0.0152 (5) | 0.0305 (6) | 0.0027 (4) | 0.0077 (4) | 0.0058 (4) |
O3 | 0.0194 (5) | 0.0141 (5) | 0.0311 (6) | −0.0032 (4) | 0.0040 (4) | 0.0044 (4) |
O2 | 0.0208 (6) | 0.0197 (5) | 0.0401 (7) | 0.0100 (4) | 0.0077 (5) | 0.0098 (5) |
O1 | 0.0191 (5) | 0.0286 (6) | 0.0303 (6) | 0.0024 (5) | −0.0056 (5) | −0.0071 (5) |
N2 | 0.0142 (6) | 0.0140 (6) | 0.0232 (6) | 0.0016 (5) | 0.0031 (5) | 0.0004 (5) |
C5 | 0.0158 (6) | 0.0202 (7) | 0.0181 (6) | −0.0016 (5) | 0.0036 (5) | 0.0021 (5) |
N1 | 0.0226 (6) | 0.0137 (6) | 0.0217 (6) | −0.0008 (5) | 0.0062 (5) | 0.0027 (5) |
C3 | 0.0158 (6) | 0.0156 (6) | 0.0123 (6) | 0.0011 (5) | 0.0036 (5) | 0.0026 (5) |
C2 | 0.0152 (6) | 0.0182 (7) | 0.0176 (6) | 0.0024 (5) | 0.0028 (5) | 0.0032 (5) |
O1W | 0.0192 (6) | 0.0249 (6) | 0.0622 (10) | 0.0008 (5) | 0.0094 (6) | 0.0017 (6) |
C4 | 0.0145 (6) | 0.0175 (7) | 0.0163 (6) | 0.0025 (5) | 0.0024 (5) | 0.0029 (5) |
C1 | 0.0206 (7) | 0.0169 (7) | 0.0210 (7) | 0.0049 (5) | 0.0052 (5) | 0.0048 (5) |
C2A | 0.0165 (11) | 0.0299 (17) | 0.0289 (14) | 0.0066 (10) | 0.0065 (9) | 0.0130 (11) |
C1A | 0.0165 (11) | 0.0299 (17) | 0.0289 (14) | 0.0066 (10) | 0.0065 (9) | 0.0130 (11) |
C5A | 0.0209 (17) | 0.016 (3) | 0.0340 (19) | 0.003 (2) | 0.0088 (13) | −0.005 (2) |
C4A | 0.0193 (15) | 0.015 (3) | 0.0171 (19) | 0.001 (2) | 0.0023 (12) | −0.0004 (19) |
N2A | 0.0209 (11) | 0.0122 (13) | 0.0214 (11) | 0.0026 (8) | 0.0036 (8) | −0.0034 (9) |
C3A | 0.0089 (11) | 0.0152 (14) | 0.0161 (15) | 0.0024 (9) | 0.0029 (9) | 0.0000 (11) |
N1A | 0.0228 (13) | 0.0104 (15) | 0.0475 (19) | 0.0020 (11) | 0.0117 (12) | 0.0029 (15) |
N2B | 0.0266 (17) | 0.0202 (18) | 0.0188 (15) | 0.0024 (13) | 0.0015 (12) | 0.0037 (13) |
C1B | 0.0173 (18) | 0.025 (2) | 0.036 (3) | −0.0006 (14) | 0.0071 (16) | −0.0072 (18) |
N1B | 0.0165 (16) | 0.015 (2) | 0.047 (2) | 0.0037 (13) | 0.0092 (14) | 0.004 (2) |
C3B | 0.0114 (15) | 0.020 (2) | 0.020 (2) | 0.0028 (14) | 0.0025 (12) | 0.0010 (16) |
C4B | 0.019 (2) | 0.018 (4) | 0.016 (2) | 0.005 (3) | 0.0026 (15) | 0.007 (3) |
C5B | 0.018 (2) | 0.017 (4) | 0.030 (3) | 0.007 (3) | 0.0061 (17) | 0.008 (2) |
C2B | 0.0112 (16) | 0.029 (3) | 0.0062 (16) | 0.004 (2) | 0.0031 (12) | 0.002 (2) |
S1—O3 | 1.4666 (11) | C5A—N1A | 1.335 (9) |
S1—O2 | 1.4706 (11) | C5A—C4A | 1.345 (5) |
S1—O1 | 1.4849 (12) | C5A—H5AA | 0.9300 |
S1—O4 | 1.4909 (12) | C4A—C3A | 1.422 (6) |
N2—C3 | 1.3311 (18) | C4A—H4AA | 0.9300 |
N2—H1N2 | 0.86 (2) | N2A—C3A | 1.335 (4) |
N2—H2N2 | 0.86 (2) | N2A—H2NA | 0.8477 |
C5—N1 | 1.354 (2) | N2A—H1NA | 0.7856 |
C5—C4 | 1.363 (2) | N1A—H1AB | 0.8555 |
C5—H5A | 0.9300 | N2B—C3B | 1.321 (6) |
N1—C1 | 1.355 (2) | N2B—H1NB | 0.8900 |
N1—H1N1 | 0.88 (2) | N2B—H2NB | 0.8295 |
C3—C4 | 1.4208 (19) | C1B—N1B | 1.339 (6) |
C3—C2 | 1.421 (2) | C1B—C2B | 1.352 (6) |
C2—C1 | 1.362 (2) | C1B—H1BB | 0.8750 |
C2—H2A | 0.9300 | N1B—C5B | 1.367 (11) |
O1W—H1W1 | 0.91 (3) | N1B—H2NA | 1.1125 |
O1W—H2W1 | 0.83 (3) | N1B—H1BA | 0.8600 |
C4—H4A | 0.9300 | C3B—C4B | 1.443 (8) |
C1—H1A | 0.9300 | C3B—C2B | 1.456 (8) |
C2A—C1A | 1.366 (6) | C4B—C5B | 1.334 (7) |
C2A—C3A | 1.381 (8) | C4B—H4BA | 0.9300 |
C2A—H2AA | 0.9300 | C5B—H5BA | 0.9300 |
C1A—N1A | 1.347 (5) | C2B—H2BA | 0.9300 |
C1A—H1AA | 0.9300 | ||
O3—S1—O2 | 110.89 (7) | H1NA—N2A—H1BB | 46.1 |
O3—S1—O1 | 109.12 (7) | C3A—N2A—H1BA | 102.2 |
O2—S1—O1 | 109.99 (7) | H1NA—N2A—H1BA | 138.1 |
O3—S1—O4 | 109.09 (7) | H1BB—N2A—H1BA | 175.5 |
O2—S1—O4 | 109.35 (7) | N2A—C3A—C2A | 122.9 (4) |
O1—S1—O4 | 108.35 (7) | N2A—C3A—C4A | 121.2 (4) |
C3—N2—H1N2 | 119.4 (15) | C2A—C3A—C4A | 115.9 (4) |
C3—N2—H2N2 | 118.3 (13) | C2A—C3A—H1BA | 145.0 |
H1N2—N2—H2N2 | 121.9 (19) | C4A—C3A—H1BA | 99.1 |
N1—C5—C4 | 121.14 (13) | C5A—N1A—C1A | 120.9 (4) |
N1—C5—H5A | 119.4 | C5A—N1A—H1AB | 113.9 |
C4—C5—H5A | 119.4 | C1A—N1A—H1AB | 125.2 |
C5—N1—C1 | 120.88 (13) | C5A—N1A—H2NB | 114.7 |
C5—N1—H1N1 | 119.8 (15) | C1A—N1A—H2NB | 124.4 |
C1—N1—H1N1 | 118.7 (14) | C3B—N2B—H1AB | 98.6 |
N2—C3—C4 | 121.37 (13) | C3B—N2B—H1NB | 123.7 |
N2—C3—C2 | 121.41 (13) | H1AB—N2B—H1NB | 136.0 |
C4—C3—C2 | 117.21 (13) | C3B—N2B—H2NB | 117.9 |
C1—C2—H2A | 120.0 | H1NB—N2B—H2NB | 116.1 |
C3—C2—H2A | 120.0 | N1B—C1B—C2B | 123.4 (5) |
H1W1—O1W—H2W1 | 114 (3) | N1B—C1B—H1NA | 65.4 |
C5—C4—C3 | 119.81 (13) | C2B—C1B—H1NA | 171.1 |
C5—C4—H4A | 120.1 | N1B—C1B—H1BB | 108.0 |
C3—C4—H4A | 120.1 | C2B—C1B—H1BB | 128.3 |
N1—C1—C2 | 120.94 (14) | C1B—N1B—C5B | 119.7 (5) |
N1—C1—H1A | 119.5 | C1B—N1B—H2NA | 126.9 |
C2—C1—H1A | 119.5 | C5B—N1B—H2NA | 113.3 |
C1A—C2A—C3A | 121.7 (7) | C1B—N1B—H1BA | 120.0 |
C1A—C2A—H2AA | 119.1 | C5B—N1B—H1BA | 120.3 |
C3A—C2A—H2AA | 119.1 | N2B—C3B—C4B | 120.9 (5) |
N1A—C1A—C2A | 119.7 (5) | N2B—C3B—C2B | 122.3 (4) |
N1A—C1A—H1AA | 120.1 | C4B—C3B—C2B | 116.8 (5) |
C2A—C1A—H1AA | 120.1 | C4B—C3B—H1AB | 96.6 |
N1A—C5A—C4A | 121.2 (6) | C2B—C3B—H1AB | 146.6 |
N1A—C5A—H5AA | 119.4 | C5B—C4B—C3B | 119.5 (6) |
C4A—C5A—H5AA | 119.4 | C5B—C4B—H4BA | 120.2 |
C5A—C4A—C3A | 120.6 (5) | C3B—C4B—H4BA | 120.2 |
C5A—C4A—H4AA | 119.7 | C4B—C5B—N1B | 122.4 (7) |
C3A—C4A—H4AA | 119.7 | C4B—C5B—H5BA | 118.8 |
C3A—N2A—H2NA | 113.5 | N1B—C5B—H5BA | 118.8 |
C3A—N2A—H1NA | 119.5 | C1B—C2B—C3B | 118.2 (5) |
H2NA—N2A—H1NA | 127.0 | C1B—C2B—H2BA | 120.9 |
C3A—N2A—H1BB | 73.5 | C3B—C2B—H2BA | 120.9 |
H2NA—N2A—H1BB | 172.0 | ||
C4—C5—N1—C1 | 0.7 (2) | C5A—C4A—C3A—N2A | 179.3 (4) |
N2—C3—C2—C1 | −177.42 (14) | C5A—C4A—C3A—C2A | −1.6 (7) |
C4—C3—C2—C1 | 2.2 (2) | C4A—C5A—N1A—C1A | 0.7 (7) |
N1—C5—C4—C3 | 0.4 (2) | C2A—C1A—N1A—C5A | −0.5 (7) |
N2—C3—C4—C5 | 177.75 (13) | C2B—C1B—N1B—C5B | 0.1 (8) |
C2—C3—C4—C5 | −1.9 (2) | N2B—C3B—C4B—C5B | 179.5 (5) |
C5—N1—C1—C2 | −0.4 (2) | C2B—C3B—C4B—C5B | 0.6 (8) |
C3—C2—C1—N1 | −1.1 (2) | C3B—C4B—C5B—N1B | −0.3 (10) |
C3A—C2A—C1A—N1A | −0.9 (8) | C1B—N1B—C5B—C4B | 0.0 (9) |
N1A—C5A—C4A—C3A | 0.3 (8) | N1B—C1B—C2B—C3B | 0.2 (8) |
C1A—C2A—C3A—N2A | −179.1 (4) | N2B—C3B—C2B—C1B | −179.4 (5) |
C1A—C2A—C3A—C4A | 1.8 (8) | C4B—C3B—C2B—C1B | −0.5 (8) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2A—H2NA···O1i | 0.85 | 2.03 | 2.822 (3) | 156 |
N2A—H1NA···O1Wii | 0.79 | 2.07 | 2.812 (3) | 159 |
N1A—H1AB···O1iii | 0.86 | 2.20 | 2.938 (4) | 144 |
O1W—H1W1···O2iv | 0.91 (3) | 1.88 (3) | 2.7952 (19) | 176 (3) |
O1W—H2W1···O1v | 0.83 (3) | 2.00 (3) | 2.8195 (18) | 167 (2) |
N1—H1N1···O4iv | 0.88 (3) | 1.85 (2) | 2.7102 (17) | 165 (2) |
N2—H1N2···O4 | 0.86 (3) | 2.01 (3) | 2.8665 (17) | 176 (2) |
N2—H2N2···O3vi | 0.862 (19) | 1.96 (2) | 2.8118 (17) | 167.9 (16) |
C1—H1A···O2vii | 0.93 | 2.46 | 3.3688 (18) | 167 |
C1A—H1AA···O1Wviii | 0.93 | 2.58 | 3.318 (4) | 137 |
C5A—H5AA···O2iii | 0.93 | 2.44 | 3.228 (7) | 143 |
C4A—H4AA···O3i | 0.93 | 2.54 | 3.362 (6) | 147 |
C5—H5A···O4i | 0.93 | 2.52 | 3.3360 (18) | 146 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, y, z+1; (iii) −x+1, −y, −z+1; (iv) x, y+1, z; (v) x+1, y+1, z; (vi) x−1, y, z; (vii) x−1, y+1, z; (viii) x, y−1, z+1. |
Experimental details
Crystal data | |
Chemical formula | 2C5H7N2+·SO42−·H2O |
Mr | 304.33 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 100 |
a, b, c (Å) | 6.4434 (1), 8.4153 (1), 12.4488 (2) |
α, β, γ (°) | 96.365 (1), 97.534 (1), 95.387 (1) |
V (Å3) | 661.02 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.27 |
Crystal size (mm) | 0.33 × 0.25 × 0.07 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2009) |
Tmin, Tmax | 0.916, 0.981 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10717, 3839, 3279 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.703 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.106, 1.06 |
No. of reflections | 3839 |
No. of parameters | 259 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.59, −0.55 |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
N2A—H2NA···O1i | 0.8500 | 2.0300 | 2.822 (3) | 156.00 |
N2A—H1NA···O1Wii | 0.7900 | 2.0700 | 2.812 (3) | 159.00 |
N1A—H1AB···O1iii | 0.8600 | 2.2000 | 2.938 (4) | 144.00 |
O1W—H1W1···O2iv | 0.91 (3) | 1.88 (3) | 2.7952 (19) | 176 (3) |
O1W—H2W1···O1v | 0.83 (3) | 2.00 (3) | 2.8195 (18) | 167 (2) |
N1—H1N1···O4iv | 0.88 (3) | 1.85 (2) | 2.7102 (17) | 165 (2) |
N2—H1N2···O4 | 0.86 (3) | 2.01 (3) | 2.8665 (17) | 176 (2) |
N2—H2N2···O3vi | 0.862 (19) | 1.96 (2) | 2.8118 (17) | 167.9 (16) |
C1—H1A···O2vii | 0.9300 | 2.4600 | 3.3688 (18) | 167.00 |
C1A—H1AA···O1Wviii | 0.9300 | 2.5800 | 3.318 (4) | 137.00 |
C5A—H5AA···O2iii | 0.9300 | 2.4400 | 3.228 (7) | 143.00 |
C4A—H4AA···O3i | 0.9300 | 2.5400 | 3.362 (6) | 147.00 |
C5—H5A···O4i | 0.9300 | 2.5200 | 3.3360 (18) | 146.00 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, y, z+1; (iii) −x+1, −y, −z+1; (iv) x, y+1, z; (v) x+1, y+1, z; (vi) x−1, y, z; (vii) x−1, y+1, z; (viii) x, y−1, z+1. |
Acknowledgements
The authors thank Universiti Sains Malaysia (USM) for the Research University Golden Goose Grant (1001/PFIZIK/811012). CKQ also thanks USM for the award of USM fellowship. AMI thanks the Head of the Department of Chemistry Department and the Director of the National Institute of Technology–Karnataka for their encouragement. AMI also thanks Universiti Sains Malaysia for the partial sponsorship of a visit to the X-ray Crystallography Unit.
References
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CSD CrossRef Web of Science Google Scholar
Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107. CrossRef CAS Web of Science IUCr Journals Google Scholar
Jacobson, B. L. & Quiocho, F. A. (1988). J. Mol. Biol. 204, 783–787. CrossRef CAS PubMed Web of Science Google Scholar
Judge, S. & Bever, C. (2006). Pharmacol. Ther. 111, 224–259. Web of Science CrossRef PubMed CAS Google Scholar
Onoda, A., Yamada, Y., Doi, M., Okamura, T. & Ueyama, N. (2001). Inorg. Chem. 40, 516–521. Web of Science CSD CrossRef PubMed CAS Google Scholar
Pflugrath, J. W. & Quiocho, F. A. (1985). Nature (London), 314, 257–260. CrossRef CAS PubMed Web of Science Google Scholar
Quah, C. K., Hemamalini, M. & Fun, H.-K. (2010). Acta Cryst. E66, o1933–o1934. Web of Science CSD CrossRef IUCr Journals Google Scholar
Quah, C. K., Jebas, S. R. & Fun, H.-K. (2008a). Acta Cryst. E64, o1878–o1879. Web of Science CSD CrossRef IUCr Journals Google Scholar
Quah, C. K., Jebas, S. R. & Fun, H.-K. (2008b). Acta Cryst. E64, o2230. Web of Science CSD CrossRef IUCr Journals Google Scholar
Schwid, S. B., Petrie, M. D., McDermott, M. P., Tierney, D. S., Mason, D. H. & Goodman, A. D. (1997). Neurology, 48, 817–821. CrossRef CAS PubMed Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Strupp, M., Kalla, R., Dichgans, M., Fraitinger, T., Glasauer, S. & Brandt, T. (2004). Neurology, 62, 1623–1625. Web of Science CrossRef PubMed CAS Google Scholar
Zhang, R., Suh, I., Zhao, J., Zhang, D., Fortner, E. C., Tie, X., Molina, L. T. & Molina, M. J. (2004). Science, 304, 1487–1490. Web of Science CrossRef PubMed CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
4-Aminopyridine (fampridine) is clinically used in the treatment of Lambert-Eaton myasthenic syndrome and multiple sclerosis. It prolongs action potentials by blocking potassium channels, thereby increases transmitter release at the neuromuscular junction (Judge & Bever, 2006; Schwid et al., 1997; Strupp et al., 2004). Hydrogen bonding patterns involving sulfate and sulfonate groups in biological systems and metal complexes are also of current interest (Onoda et al., 2001). Benzoic acid and sulfuric acid form a stable hydrogen-bonded complex that favors aerosol formation in the atmosphere (Zhang et al., 2004). In a sulfate-binding protein, the sulfate anion is mainly bonded by seven hydrogen bonds, five of which are from the main chain peptide NH groups (Pflugrath & Quiocho, 1985; Jacobson & Quiocho, 1988). The present study is aimed at understanding the hydrogen bonding network in the title compound (I).
The asymmetric unit of (I) contains two 4-aminopyridinium cations (A and B), a sulfate anion and a water molecule (Fig 1). The 4-aminopyridinium cation in molecule B is disordered over two positions with refined site-occupancies of 0.568 (4) and 0.432 (4). In the 4-aminopyridinium cations, the protonation of atoms N1 (molecule A), N1A (major component in molecule B) and N1B (minor component in molecule B) have lead to slight increase in C–N–C angles to 120.88 (13), 120.9 (4) and 119.7 (5)°, respectively. The non-H atoms of the 4-aminopyridinium cations are essentially co-planar, with a maximum deviation of 0.055 (1) Å for atom N2, 0.022 (3) Å for atom N2A and 0.009 (3) Å for atom N2B. The bond lengths (Allen et al., 1987) and angles are normal and comparable to the related structures (Quah et al., 2008a,b; 2010). The pyridine ring (N1/C1—C5) in molecule A makes dihedral angles of 68.46 (19) and 70.1 (2)°, respectively, with N1A/C1A—C5A and N1B/C1B—C5B rings.
In the crystal packing (Fig. 2), oxygen atoms (O1, O2, O3 and O4) in sulfate anions link the 4-aminopyridinium cations and water molecules into three-dimensional network via intermolecular O–H···O, N–H···O and C–H···O hydrogen bonds (Table 1). The crystal structure is further consolidated by N2A–H1NA···O1W and C1A–H1AA···O1W hydrogen bonds.