organic compounds
2-Amino-5-bromopyridinium 3-carboxyprop-2-enoate
aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my
In the title salt, C5H6BrN2+·C4H3O4−, the 2-amino-5-bromopyridinium cation and hydrogen maleate anion are planar, with maximum deviations from their mean planes of 0.016 (1) and 0.039 (1) Å, respectively. An intramolecular O—H⋯O hydrogen bond generates an S(7) ring motif in the anion. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen-bonded to the carboxylate O atoms of the anion via a pair of N—H⋯O hydrogen bonds, forming an R22(8) ring motif. The motifs are linked into a two-dimensional network parallel to (011) by N—H⋯O and C—H⋯O hydrogen bonds.
Related literature
For background to the chemistry of substituted pyridines, see: Pozharski et al. (1997); Katritzky et al. (1996). For details of maleic acid, see; Bowes et al. (2003); Jin et al. (2003); Lah & Leban (2003); Allen (2002). For bond-length data, see: Allen et al. (1987). For details of hydrogen bonding, see: Jeffrey & Saenger (1991); Jeffrey (1997); Scheiner (1997). For hydrogen-bond motifs, see: Bernstein et al. (1995). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).
Experimental
Crystal data
|
Refinement
|
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/S1600536810030059/ci5141sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810030059/ci5141Isup2.hkl
A hot methanol solution (20 ml) of 2-amino-5-bromopyridine (43 mg, Aldrich) and maleic acid (29 mg, Merck) were mixed and warmed over a heating 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.
Atoms H1N1, H1N2 and H2N2 were located in a difference Fourier map and were refined freely [N–H= 0.82 (2)–0.870 (19) Å ]. The remaining H atoms were positioned geometrically [O–H = 0.88 Å and C–H = 0.93 Å] and were refined using a riding model, with Uiso(H) = 1.2 Ueq(C).
Pyridine and its derivatives play an important role in heterocyclic chemistry (Pozharski et al., 1997; Katritzky et al., 1996). They are often involved in hydrogen-bonding interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). Maleic acid, the Z isomer of butenedioic acid, has been used as a simple building block in supramolecular architectures in two and three dimensions (Bowes et al., 2003; Jin et al., 2003). The maleic acid anion can exist in the fully deprotonated form or as hydrogen maleate with one of the carboxyl groups protonated (Lah & Leban, 2003). Several singly dissociated maleate salts are reported in the Cambridge Structural Database (Version 5.29; Allen, 2002). Since our aim is to study some interesting hydrogen-bonding interactions, the
of the title salt is presented here.The
(Fig. 1) contains one 2-amino-5-bromopyridinium cation and one hydrogen maleate anion, indicating that proton transfer has occurred during the co-crystallisation experiment. In the 2-amino-5-bromopyridinium cation, a wider than normal angle (C5—N1—C1 = 123.02 (9)°) is subtented at the protonated N1 atom. The 2-amino-5-bromopyridinium cation is essentially planar, with a maximum deviation of 0.016 (1) Å for atom Br1. 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 (O3 and O4) via a pair of intermolecular N1—H1N1···O4 and N2—H1N2···O3 hydrogen bonds forming an R22(8) ring motif (Bernstein et al., 1995). There is an intramolecular O1—H1O1···O3 hydrogen bond in the hydrogen maleate anion, which generates an S(7) ring motif. Furthermore these two motifs are connected via N2—H2N2···O2, C3—H3A···O2 and C5—H5A···O4 (Table 1) hydrogen bonds, forming a two-dimensional network parallel to the (011) plane.
For background to the chemistry of substituted pyridines, see: Pozharski et al. (1997); Katritzky et al. (1996). For details of maleic acid, see; Bowes et al. (2003); Jin et al. (2003); Lah & Leban (2003); Allen (2002). For bond-length data, see: Allen et al. (1987). For details of hydrogen bonding, see: Jeffrey & Saenger (1991); Jeffrey (1997); Scheiner (1997). For hydrogen-bond motifs, see: Bernstein et al. (1995). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).
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 asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 50% probability level. The dashed line indicates a intramolecular hydrogen bond. | |
Fig. 2. Part of the crystal structure of the title compound, showing S(7) and R22(8) ring motifs. |
C5H6BrN2+·C4H3O4− | Z = 2 |
Mr = 289.09 | F(000) = 288 |
Triclinic, P1 | Dx = 1.785 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 5.7434 (1) Å | Cell parameters from 9953 reflections |
b = 9.5871 (1) Å | θ = 2.8–35.2° |
c = 10.3034 (2) Å | µ = 3.82 mm−1 |
α = 80.455 (1)° | T = 100 K |
β = 74.175 (1)° | Plate, colourless |
γ = 85.123 (1)° | 0.55 × 0.26 × 0.17 mm |
V = 537.80 (2) Å3 |
Bruker SMART APEXII CCD area-detector diffractometer | 4705 independent reflections |
Radiation source: fine-focus sealed tube | 4235 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.020 |
φ and ω scans | θmax = 35.0°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | h = −9→8 |
Tmin = 0.226, Tmax = 0.554 | k = −15→15 |
17591 measured reflections | l = −16→15 |
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)] = 0.024 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.064 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0326P)2 + 0.177P] where P = (Fo2 + 2Fc2)/3 |
4705 reflections | (Δ/σ)max = 0.001 |
157 parameters | Δρmax = 1.11 e Å−3 |
0 restraints | Δρmin = −0.70 e Å−3 |
C5H6BrN2+·C4H3O4− | γ = 85.123 (1)° |
Mr = 289.09 | V = 537.80 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 5.7434 (1) Å | Mo Kα radiation |
b = 9.5871 (1) Å | µ = 3.82 mm−1 |
c = 10.3034 (2) Å | T = 100 K |
α = 80.455 (1)° | 0.55 × 0.26 × 0.17 mm |
β = 74.175 (1)° |
Bruker SMART APEXII CCD area-detector diffractometer | 4705 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | 4235 reflections with I > 2σ(I) |
Tmin = 0.226, Tmax = 0.554 | Rint = 0.020 |
17591 measured reflections |
R[F2 > 2σ(F2)] = 0.024 | 0 restraints |
wR(F2) = 0.064 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 1.11 e Å−3 |
4705 reflections | Δρmin = −0.70 e Å−3 |
157 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 | ||
Br1 | 0.08004 (2) | 0.537686 (13) | 0.294128 (12) | 0.02696 (4) | |
N1 | 0.42643 (16) | 0.83409 (10) | −0.01859 (9) | 0.01624 (14) | |
N2 | 0.81699 (17) | 0.85829 (11) | −0.15773 (10) | 0.02185 (17) | |
C1 | 0.65936 (17) | 0.78492 (11) | −0.05651 (10) | 0.01673 (16) | |
C2 | 0.72501 (19) | 0.65511 (12) | 0.01629 (11) | 0.01905 (18) | |
H2A | 0.8842 | 0.6194 | −0.0062 | 0.023* | |
C3 | 0.55552 (19) | 0.58268 (11) | 0.11897 (11) | 0.01939 (18) | |
H3A | 0.5979 | 0.4971 | 0.1659 | 0.023* | |
C4 | 0.31486 (19) | 0.63883 (11) | 0.15333 (11) | 0.01821 (17) | |
C5 | 0.25417 (18) | 0.76411 (11) | 0.08418 (10) | 0.01714 (16) | |
H5A | 0.0962 | 0.8017 | 0.1069 | 0.021* | |
O1 | 0.81743 (14) | 0.18263 (11) | 0.44160 (9) | 0.02726 (19) | |
H1O1 | 0.7489 | 0.1584 | 0.5288 | 0.041* | |
O2 | 0.68803 (15) | 0.26191 (9) | 0.25903 (8) | 0.02102 (15) | |
O3 | 0.63826 (14) | 0.09096 (10) | 0.68047 (9) | 0.02256 (16) | |
O4 | 0.27013 (14) | 0.06052 (9) | 0.82150 (8) | 0.01999 (14) | |
C6 | 0.64341 (18) | 0.21863 (11) | 0.38215 (10) | 0.01679 (16) | |
C7 | 0.38534 (18) | 0.20548 (12) | 0.46279 (11) | 0.01807 (17) | |
H7A | 0.2729 | 0.2353 | 0.4128 | 0.022* | |
C8 | 0.28808 (18) | 0.15795 (12) | 0.59511 (11) | 0.01824 (17) | |
H8A | 0.1197 | 0.1616 | 0.6220 | 0.022* | |
C9 | 0.40698 (18) | 0.09990 (11) | 0.70659 (10) | 0.01663 (16) | |
H1N1 | 0.381 (3) | 0.913 (2) | −0.0621 (19) | 0.026 (4)* | |
H1N2 | 0.769 (3) | 0.931 (2) | −0.2027 (19) | 0.028 (4)* | |
H2N2 | 0.956 (4) | 0.827 (2) | −0.183 (2) | 0.038 (5)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.02461 (6) | 0.02342 (6) | 0.02515 (6) | −0.00137 (4) | 0.00082 (4) | 0.00590 (4) |
N1 | 0.0158 (3) | 0.0172 (4) | 0.0146 (3) | 0.0015 (3) | −0.0040 (3) | −0.0003 (3) |
N2 | 0.0163 (3) | 0.0246 (4) | 0.0203 (4) | 0.0009 (3) | −0.0015 (3) | 0.0024 (3) |
C1 | 0.0153 (4) | 0.0190 (4) | 0.0154 (4) | 0.0006 (3) | −0.0039 (3) | −0.0021 (3) |
C2 | 0.0171 (4) | 0.0184 (4) | 0.0213 (4) | 0.0028 (3) | −0.0059 (3) | −0.0023 (3) |
C3 | 0.0209 (4) | 0.0162 (4) | 0.0206 (4) | 0.0022 (3) | −0.0067 (3) | −0.0009 (3) |
C4 | 0.0191 (4) | 0.0175 (4) | 0.0163 (4) | −0.0004 (3) | −0.0031 (3) | −0.0005 (3) |
C5 | 0.0164 (4) | 0.0179 (4) | 0.0158 (4) | 0.0006 (3) | −0.0031 (3) | −0.0015 (3) |
O1 | 0.0143 (3) | 0.0452 (5) | 0.0193 (4) | −0.0035 (3) | −0.0053 (3) | 0.0062 (3) |
O2 | 0.0205 (3) | 0.0239 (4) | 0.0163 (3) | 0.0014 (3) | −0.0039 (3) | 0.0010 (3) |
O3 | 0.0157 (3) | 0.0322 (4) | 0.0184 (3) | −0.0007 (3) | −0.0058 (3) | 0.0021 (3) |
O4 | 0.0193 (3) | 0.0209 (4) | 0.0162 (3) | 0.0023 (3) | −0.0016 (3) | 0.0008 (3) |
C6 | 0.0158 (4) | 0.0164 (4) | 0.0172 (4) | −0.0001 (3) | −0.0041 (3) | −0.0006 (3) |
C7 | 0.0146 (4) | 0.0213 (4) | 0.0178 (4) | 0.0011 (3) | −0.0053 (3) | −0.0006 (3) |
C8 | 0.0146 (4) | 0.0211 (4) | 0.0177 (4) | 0.0009 (3) | −0.0042 (3) | −0.0002 (3) |
C9 | 0.0171 (4) | 0.0164 (4) | 0.0161 (4) | 0.0006 (3) | −0.0046 (3) | −0.0017 (3) |
Br1—C4 | 1.8848 (11) | C4—C5 | 1.3609 (15) |
N1—C1 | 1.3540 (13) | C5—H5A | 0.93 |
N1—C5 | 1.3624 (13) | O1—C6 | 1.3032 (12) |
N1—H1N1 | 0.870 (19) | O1—H1O1 | 0.88 |
N2—C1 | 1.3237 (14) | O2—C6 | 1.2301 (13) |
N2—H1N2 | 0.842 (19) | O3—C9 | 1.2796 (12) |
N2—H2N2 | 0.82 (2) | O4—C9 | 1.2477 (12) |
C1—C2 | 1.4207 (15) | C6—C7 | 1.4929 (14) |
C2—C3 | 1.3633 (16) | C7—C8 | 1.3417 (15) |
C2—H2A | 0.93 | C7—H7A | 0.93 |
C3—C4 | 1.4126 (15) | C8—C9 | 1.4988 (14) |
C3—H3A | 0.93 | C8—H8A | 0.93 |
C1—N1—C5 | 123.02 (9) | C3—C4—Br1 | 119.31 (8) |
C1—N1—H1N1 | 119.6 (13) | C4—C5—N1 | 119.57 (9) |
C5—N1—H1N1 | 117.3 (13) | C4—C5—H5A | 120.2 |
C1—N2—H1N2 | 119.8 (13) | N1—C5—H5A | 120.2 |
C1—N2—H2N2 | 120.2 (15) | C6—O1—H1O1 | 106.9 |
H1N2—N2—H2N2 | 120 (2) | O2—C6—O1 | 120.95 (9) |
N2—C1—N1 | 119.76 (10) | O2—C6—C7 | 118.87 (9) |
N2—C1—C2 | 122.44 (9) | O1—C6—C7 | 120.17 (9) |
N1—C1—C2 | 117.79 (9) | C8—C7—C6 | 130.95 (9) |
C3—C2—C1 | 120.27 (9) | C8—C7—H7A | 114.5 |
C3—C2—H2A | 119.9 | C6—C7—H7A | 114.5 |
C1—C2—H2A | 119.9 | C7—C8—C9 | 130.44 (9) |
C2—C3—C4 | 119.36 (10) | C7—C8—H8A | 114.8 |
C2—C3—H3A | 120.3 | C9—C8—H8A | 114.8 |
C4—C3—H3A | 120.3 | O4—C9—O3 | 123.48 (10) |
C5—C4—C3 | 119.99 (10) | O4—C9—C8 | 116.75 (9) |
C5—C4—Br1 | 120.70 (8) | O3—C9—C8 | 119.77 (9) |
C5—N1—C1—N2 | 179.73 (10) | Br1—C4—C5—N1 | −178.99 (8) |
C5—N1—C1—C2 | −0.79 (15) | C1—N1—C5—C4 | 0.00 (16) |
N2—C1—C2—C3 | −179.37 (11) | O2—C6—C7—C8 | 177.71 (12) |
N1—C1—C2—C3 | 1.17 (16) | O1—C6—C7—C8 | −1.27 (19) |
C1—C2—C3—C4 | −0.77 (16) | C6—C7—C8—C9 | −1.0 (2) |
C2—C3—C4—C5 | −0.03 (17) | C7—C8—C9—O4 | −178.65 (11) |
C2—C3—C4—Br1 | 179.39 (8) | C7—C8—C9—O3 | 0.33 (18) |
C3—C4—C5—N1 | 0.43 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1O1···O3 | 0.88 | 1.57 | 2.4380 (13) | 171 |
N1—H1N1···O4i | 0.87 (2) | 1.88 (2) | 2.7426 (13) | 169 (2) |
N2—H1N2···O3i | 0.84 (2) | 2.01 (2) | 2.8495 (14) | 174 (2) |
N2—H2N2···O2ii | 0.82 (2) | 2.14 (2) | 2.9534 (13) | 176 (2) |
C3—H3A···O2 | 0.93 | 2.37 | 3.2937 (14) | 171 |
C5—H5A···O4iii | 0.93 | 2.39 | 3.3051 (14) | 167 |
Symmetry codes: (i) x, y+1, z−1; (ii) −x+2, −y+1, −z; (iii) −x, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C5H6BrN2+·C4H3O4− |
Mr | 289.09 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 100 |
a, b, c (Å) | 5.7434 (1), 9.5871 (1), 10.3034 (2) |
α, β, γ (°) | 80.455 (1), 74.175 (1), 85.123 (1) |
V (Å3) | 537.80 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 3.82 |
Crystal size (mm) | 0.55 × 0.26 × 0.17 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2009) |
Tmin, Tmax | 0.226, 0.554 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 17591, 4705, 4235 |
Rint | 0.020 |
(sin θ/λ)max (Å−1) | 0.807 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.024, 0.064, 1.06 |
No. of reflections | 4705 |
No. of parameters | 157 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 1.11, −0.70 |
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 |
O1—H1O1···O3 | 0.88 | 1.57 | 2.4380 (13) | 171 |
N1—H1N1···O4i | 0.87 (2) | 1.88 (2) | 2.7426 (13) | 169 (2) |
N2—H1N2···O3i | 0.84 (2) | 2.01 (2) | 2.8495 (14) | 174 (2) |
N2—H2N2···O2ii | 0.82 (2) | 2.14 (2) | 2.9534 (13) | 176 (2) |
C3—H3A···O2 | 0.93 | 2.37 | 3.2937 (14) | 171 |
C5—H5A···O4iii | 0.93 | 2.39 | 3.3051 (14) | 167 |
Symmetry codes: (i) x, y+1, z−1; (ii) −x+2, −y+1, −z; (iii) −x, −y+1, −z+1. |
Footnotes
‡Thomson Reuters ResearcherID: A-3561-2009.
Acknowledgements
MH and HKF thank the Malaysian Government and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. MH also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.
References
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Pyridine and its derivatives play an important role in heterocyclic chemistry (Pozharski et al., 1997; Katritzky et al., 1996). They are often involved in hydrogen-bonding interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). Maleic acid, the Z isomer of butenedioic acid, has been used as a simple building block in supramolecular architectures in two and three dimensions (Bowes et al., 2003; Jin et al., 2003). The maleic acid anion can exist in the fully deprotonated form or as hydrogen maleate with one of the carboxyl groups protonated (Lah & Leban, 2003). Several singly dissociated maleate salts are reported in the Cambridge Structural Database (Version 5.29; Allen, 2002). Since our aim is to study some interesting hydrogen-bonding interactions, the crystal structure of the title salt is presented here.
The asymmetric unit (Fig. 1) contains one 2-amino-5-bromopyridinium cation and one hydrogen maleate anion, indicating that proton transfer has occurred during the co-crystallisation experiment. In the 2-amino-5-bromopyridinium cation, a wider than normal angle (C5—N1—C1 = 123.02 (9)°) is subtented at the protonated N1 atom. The 2-amino-5-bromopyridinium cation is essentially planar, with a maximum deviation of 0.016 (1) Å for atom Br1. 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 (O3 and O4) via a pair of intermolecular N1—H1N1···O4 and N2—H1N2···O3 hydrogen bonds forming an R22(8) ring motif (Bernstein et al., 1995). There is an intramolecular O1—H1O1···O3 hydrogen bond in the hydrogen maleate anion, which generates an S(7) ring motif. Furthermore these two motifs are connected via N2—H2N2···O2, C3—H3A···O2 and C5—H5A···O4 (Table 1) hydrogen bonds, forming a two-dimensional network parallel to the (011) plane.