Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807046934/hb2557sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807046934/hb2557Isup2.hkl |
CCDC reference: 663850
5-Bromo-N-methylnicotinamide (2.15 g, 0.01 mol) was dissolved in 25 ml of 1:1 v/v alcohol-water mixture and few drops of dilute HCl were added and stirred well. To this, picric acid (2.29 g, 0.01 mol) in 30 ml of water was added dropwise and stirred for few minutes. The precipitated salt was filtered, dried and yellow blocks of (I) were obtained by slow evaporation of the ethanol solution. (m. p.: 401–403 K). Analysis for C13H10BrN5O8: Found (Calculated): C 35.04 (35.15); H 2.24 (2.27); N 15.71% (15.77%).
The H atoms were geometrically placed (C—H = 0.95–0.98 Å, N—H = 0.88 Å) and refined as riding with Uiso(H) = 1.2Ueq(C,N) or 1.5Ueq(methyl C).
Nicotinamide, also known as niacinamide, is the amide of niacin (vitamin B3) and used for the treatment of arthritis by aiding the body in its production of cartilage. A different use for this compound is an additive in energy drinks (Aranda & Morlock, 2006). The crystal structures of N-(4-bromophenyl)-5,6-dichloronicotinamide and 6-chloro-5-fluoro-N-(3-pyridyl)nicotinamide (Jethmalani et al., 1996), the picrate salt of 1-methylnicotinamide (Freeman & Bugg, 1974) and nicotinium picrate (Anitha et al., 2005) have been reported. In continuation of our work on picrate salts (Yathirajan et al., 2007), the paper reports the crystal structure of the title compound, (I).
Compound (I), [C7H8BrN2O]+[C6H2N3O7]-, consists of discrete 5-bromo-N-methylnicotinamidium cations and picrate anions connected by N—H···O and bifurcated N—H···(O,O) hydrogen bonds. Whereas two nitro groups are almost coplanar with the aromatic ring of the picrate anion [dihedral angles 4(2)° and 11 (2)°], the third one is significantly twisted [dihedral angle 41 (2)°]. The non-H atoms of the side chain of the cation are almost coplanar (r.m.s. deviation 0.015 Å) and this plane is inclined by 28.9 (8)° with respect to the heterocycle. The ion pairs crystallize in sheets parallel to the (112) plane.
For related structures, see: Anitha et al. (2005); Freeman & Bugg (1974); Jethmalani et al. (1996); Yathirajan et al. (2007). For related literature, see: Kagabu et al. (1998); Aranda & Morlock (2006).
Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA (Stoe & Cie, 2001); data reduction: X-AREA (Stoe & Cie, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003) and XP in SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: PLATON (Spek, 2003).
C7H8BrN2O+·C6H2N3O7− | Z = 1 |
Mr = 444.17 | F(000) = 222 |
Triclinic, P1 | Dx = 1.791 Mg m−3 |
Hall symbol: P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 4.6684 (7) Å | Cell parameters from 5412 reflections |
b = 7.0328 (11) Å | θ = 3.5–25.7° |
c = 12.842 (2) Å | µ = 2.55 mm−1 |
α = 93.802 (13)° | T = 173 K |
β = 97.688 (13)° | Block, yellow |
γ = 98.280 (12)° | 0.22 × 0.20 × 0.19 mm |
V = 411.90 (11) Å3 |
Stoe IPDSII two-circle diffractometer | 2966 independent reflections |
Radiation source: fine-focus sealed tube | 2898 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.122 |
ω scans | θmax = 25.6°, θmin = 3.5° |
Absorption correction: multi-scan (MULABS; Spek, 2003; Blessing, 1995) | h = −5→5 |
Tmin = 0.604, Tmax = 0.643 | k = −8→8 |
6268 measured reflections | l = −15→15 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.103 | H-atom parameters constrained |
wR(F2) = 0.263 | w = 1/[σ2(Fo2) + (0.2P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.15 | (Δ/σ)max < 0.001 |
2966 reflections | Δρmax = 1.15 e Å−3 |
244 parameters | Δρmin = −1.30 e Å−3 |
3 restraints | Absolute structure: Flack (1983), 1416 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.06 (3) |
C7H8BrN2O+·C6H2N3O7− | γ = 98.280 (12)° |
Mr = 444.17 | V = 411.90 (11) Å3 |
Triclinic, P1 | Z = 1 |
a = 4.6684 (7) Å | Mo Kα radiation |
b = 7.0328 (11) Å | µ = 2.55 mm−1 |
c = 12.842 (2) Å | T = 173 K |
α = 93.802 (13)° | 0.22 × 0.20 × 0.19 mm |
β = 97.688 (13)° |
Stoe IPDSII two-circle diffractometer | 2966 independent reflections |
Absorption correction: multi-scan (MULABS; Spek, 2003; Blessing, 1995) | 2898 reflections with I > 2σ(I) |
Tmin = 0.604, Tmax = 0.643 | Rint = 0.122 |
6268 measured reflections |
R[F2 > 2σ(F2)] = 0.103 | H-atom parameters constrained |
wR(F2) = 0.263 | Δρmax = 1.15 e Å−3 |
S = 1.15 | Δρmin = −1.30 e Å−3 |
2966 reflections | Absolute structure: Flack (1983), 1416 Friedel pairs |
244 parameters | Absolute structure parameter: 0.06 (3) |
3 restraints |
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 | ||
Br1 | 0.80717 (7) | 0.12358 (7) | 0.79387 (6) | 0.0446 (4) | |
O1 | 0.0789 (16) | 0.8106 (13) | 0.8851 (7) | 0.0452 (18) | |
N1 | 0.547 (2) | 0.8204 (15) | 0.9724 (8) | 0.040 (2) | |
H1 | 0.7077 | 0.7676 | 0.9783 | 0.048* | |
C1 | 0.379 (2) | 0.5947 (18) | 0.8161 (10) | 0.041 (2) | |
C2 | 0.560 (3) | 0.4597 (17) | 0.8415 (10) | 0.042 (2) | |
H2 | 0.6673 | 0.4644 | 0.9102 | 0.050* | |
C3 | 0.582 (3) | 0.313 (2) | 0.7614 (10) | 0.050 (3) | |
C4 | 0.419 (2) | 0.3107 (16) | 0.6629 (9) | 0.041 (2) | |
H4 | 0.4312 | 0.2147 | 0.6088 | 0.050* | |
N5 | 0.240 (3) | 0.4456 (15) | 0.6434 (8) | 0.039 (2) | |
H5 | 0.1387 | 0.4418 | 0.5801 | 0.047* | |
C6 | 0.212 (3) | 0.584 (2) | 0.7170 (10) | 0.040 (2) | |
H6 | 0.0800 | 0.6728 | 0.7018 | 0.048* | |
C7 | 0.323 (2) | 0.7498 (19) | 0.8939 (11) | 0.038 (2) | |
C8 | 0.526 (3) | 0.979 (2) | 1.0457 (11) | 0.056 (3) | |
H8A | 0.3871 | 1.0576 | 1.0129 | 0.085* | |
H8B | 0.7186 | 1.0586 | 1.0651 | 0.085* | |
H8C | 0.4573 | 0.9299 | 1.1091 | 0.085* | |
C11 | −0.484 (3) | 0.7005 (19) | 0.3974 (11) | 0.047 (3) | |
C12 | −0.299 (3) | 0.5557 (19) | 0.4251 (11) | 0.046 (2) | |
C13 | −0.292 (2) | 0.4168 (19) | 0.3371 (9) | 0.045 (2) | |
C14 | −0.469 (2) | 0.4101 (18) | 0.2417 (8) | 0.042 (2) | |
H14 | −0.4666 | 0.3117 | 0.1876 | 0.051* | |
C15 | −0.649 (3) | 0.5457 (19) | 0.2252 (10) | 0.046 (2) | |
C16 | −0.654 (3) | 0.6999 (18) | 0.3012 (9) | 0.042 (2) | |
H16 | −0.7683 | 0.7986 | 0.2864 | 0.051* | |
N11 | −0.491 (3) | 0.8562 (17) | 0.4781 (10) | 0.049 (2) | |
N12 | −0.103 (3) | 0.2703 (18) | 0.3510 (8) | 0.051 (2) | |
N13 | −0.839 (3) | 0.5355 (19) | 0.1231 (10) | 0.055 (3) | |
O11 | −0.172 (3) | 0.553 (2) | 0.5176 (8) | 0.072 (3) | |
O12 | 0.081 (2) | 0.2845 (16) | 0.4273 (8) | 0.060 (2) | |
O13 | −0.115 (2) | 0.143 (2) | 0.2774 (9) | 0.068 (3) | |
O14 | −0.828 (3) | 0.416 (2) | 0.0549 (10) | 0.073 (4) | |
O15 | −1.009 (2) | 0.660 (2) | 0.1133 (10) | 0.068 (3) | |
O16 | −0.498 (6) | 1.018 (3) | 0.4500 (17) | 0.124 (7) | |
O17 | −0.488 (8) | 0.822 (3) | 0.5712 (18) | 0.162 (14) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0394 (5) | 0.0423 (5) | 0.0511 (6) | 0.0075 (3) | 0.0010 (3) | 0.0043 (3) |
O1 | 0.030 (4) | 0.049 (4) | 0.054 (5) | 0.008 (3) | −0.002 (3) | 0.002 (4) |
N1 | 0.031 (5) | 0.049 (5) | 0.038 (5) | 0.008 (4) | −0.002 (4) | −0.006 (4) |
C1 | 0.030 (5) | 0.045 (6) | 0.038 (6) | −0.008 (4) | −0.013 (4) | 0.007 (5) |
C2 | 0.040 (5) | 0.043 (5) | 0.038 (5) | −0.004 (4) | −0.001 (4) | 0.006 (4) |
C3 | 0.041 (6) | 0.062 (7) | 0.041 (6) | −0.011 (5) | −0.001 (5) | 0.013 (5) |
C4 | 0.039 (5) | 0.041 (5) | 0.040 (5) | 0.004 (4) | 0.001 (4) | −0.008 (4) |
N5 | 0.041 (5) | 0.038 (5) | 0.034 (5) | 0.007 (4) | −0.008 (4) | 0.004 (4) |
C6 | 0.040 (6) | 0.051 (7) | 0.031 (6) | 0.015 (5) | −0.002 (5) | 0.010 (5) |
C7 | 0.025 (5) | 0.041 (6) | 0.044 (6) | 0.000 (4) | −0.004 (5) | 0.007 (5) |
C8 | 0.050 (6) | 0.066 (8) | 0.049 (7) | 0.006 (6) | 0.004 (5) | −0.019 (6) |
C11 | 0.045 (6) | 0.052 (6) | 0.044 (7) | 0.011 (5) | −0.002 (5) | 0.008 (5) |
C12 | 0.047 (6) | 0.051 (6) | 0.036 (6) | 0.006 (5) | −0.002 (5) | 0.002 (5) |
C13 | 0.036 (5) | 0.057 (6) | 0.038 (5) | 0.000 (4) | −0.001 (4) | 0.006 (5) |
C14 | 0.040 (5) | 0.056 (6) | 0.026 (4) | −0.004 (5) | 0.002 (4) | 0.001 (4) |
C15 | 0.048 (6) | 0.048 (6) | 0.034 (6) | −0.006 (5) | −0.003 (5) | 0.002 (4) |
C16 | 0.049 (6) | 0.045 (5) | 0.030 (5) | 0.004 (4) | −0.003 (5) | 0.008 (4) |
N11 | 0.053 (6) | 0.044 (6) | 0.041 (6) | −0.005 (4) | −0.006 (4) | 0.003 (5) |
N12 | 0.053 (6) | 0.064 (7) | 0.032 (4) | 0.008 (5) | 0.001 (4) | −0.010 (4) |
N13 | 0.051 (6) | 0.066 (8) | 0.038 (6) | −0.008 (5) | −0.016 (5) | 0.006 (5) |
O11 | 0.075 (7) | 0.098 (9) | 0.038 (5) | 0.026 (6) | −0.019 (5) | −0.007 (5) |
O12 | 0.063 (6) | 0.065 (6) | 0.050 (5) | 0.020 (5) | −0.003 (4) | 0.001 (4) |
O13 | 0.063 (7) | 0.079 (7) | 0.058 (6) | 0.028 (6) | −0.011 (5) | −0.015 (5) |
O14 | 0.090 (9) | 0.079 (8) | 0.037 (6) | −0.016 (6) | 0.000 (6) | −0.008 (6) |
O15 | 0.047 (5) | 0.098 (9) | 0.055 (6) | 0.009 (5) | −0.013 (5) | 0.030 (6) |
O16 | 0.20 (2) | 0.078 (10) | 0.115 (13) | 0.060 (12) | 0.048 (14) | 0.026 (9) |
O17 | 0.30 (4) | 0.081 (12) | 0.080 (13) | −0.013 (17) | 0.014 (18) | −0.032 (11) |
Br1—C3 | 1.848 (15) | C11—C16 | 1.373 (17) |
O1—C7 | 1.268 (15) | C11—C12 | 1.461 (18) |
N1—C7 | 1.363 (15) | C11—N11 | 1.464 (19) |
N1—C8 | 1.436 (16) | C12—O11 | 1.257 (17) |
N1—H1 | 0.8800 | C12—C13 | 1.451 (18) |
C1—C2 | 1.386 (18) | C13—C14 | 1.377 (15) |
C1—C6 | 1.393 (17) | C13—N12 | 1.455 (18) |
C1—C7 | 1.51 (2) | C14—C15 | 1.367 (19) |
C2—C3 | 1.430 (19) | C14—H14 | 0.9500 |
C2—H2 | 0.9500 | C15—C16 | 1.414 (19) |
C3—C4 | 1.385 (16) | C15—N13 | 1.472 (15) |
C4—N5 | 1.367 (16) | C16—H16 | 0.9500 |
C4—H4 | 0.9500 | N11—O16 | 1.22 (2) |
N5—C6 | 1.343 (18) | N11—O17 | 1.23 (3) |
N5—H5 | 0.8800 | N12—O12 | 1.202 (15) |
C6—H6 | 0.9500 | N12—O13 | 1.246 (16) |
C8—H8A | 0.9800 | N13—O14 | 1.18 (2) |
C8—H8B | 0.9800 | N13—O15 | 1.265 (19) |
C8—H8C | 0.9800 | ||
C7—N1—C8 | 121.2 (11) | H8B—C8—H8C | 109.5 |
C7—N1—H1 | 119.4 | C16—C11—C12 | 124.6 (12) |
C8—N1—H1 | 119.4 | C16—C11—N11 | 117.9 (11) |
C2—C1—C6 | 121.3 (14) | C12—C11—N11 | 117.5 (11) |
C2—C1—C7 | 123.9 (10) | O11—C12—C13 | 125.6 (13) |
C6—C1—C7 | 114.6 (11) | O11—C12—C11 | 121.6 (13) |
C1—C2—C3 | 118.2 (11) | C13—C12—C11 | 112.8 (11) |
C1—C2—H2 | 120.9 | C14—C13—C12 | 123.0 (12) |
C3—C2—H2 | 120.9 | C14—C13—N12 | 117.8 (11) |
C4—C3—C2 | 118.8 (12) | C12—C13—N12 | 119.1 (10) |
C4—C3—Br1 | 121.6 (10) | C15—C14—C13 | 119.6 (11) |
C2—C3—Br1 | 119.6 (9) | C15—C14—H14 | 120.2 |
N5—C4—C3 | 120.2 (11) | C13—C14—H14 | 120.2 |
N5—C4—H4 | 119.9 | C14—C15—C16 | 122.6 (11) |
C3—C4—H4 | 119.9 | C14—C15—N13 | 118.9 (12) |
C6—N5—C4 | 122.6 (10) | C16—C15—N13 | 118.4 (12) |
C6—N5—H5 | 118.7 | C11—C16—C15 | 117.0 (12) |
C4—N5—H5 | 118.7 | C11—C16—H16 | 121.5 |
N5—C6—C1 | 118.8 (12) | C15—C16—H16 | 121.5 |
N5—C6—H6 | 120.6 | O16—N11—O17 | 122.2 (19) |
C1—C6—H6 | 120.6 | O16—N11—C11 | 117.8 (14) |
O1—C7—N1 | 122.7 (13) | O17—N11—C11 | 120.0 (16) |
O1—C7—C1 | 120.7 (11) | O12—N12—O13 | 120.9 (12) |
N1—C7—C1 | 116.6 (10) | O12—N12—C13 | 120.0 (11) |
N1—C8—H8A | 109.5 | O13—N12—C13 | 118.6 (10) |
N1—C8—H8B | 109.5 | O14—N13—O15 | 122.9 (13) |
H8A—C8—H8B | 109.5 | O14—N13—C15 | 120.6 (14) |
N1—C8—H8C | 109.5 | O15—N13—C15 | 116.5 (13) |
H8A—C8—H8C | 109.5 | ||
C6—C1—C2—C3 | 3.0 (16) | O11—C12—C13—N12 | −7 (2) |
C7—C1—C2—C3 | 176.6 (9) | C11—C12—C13—N12 | 176.4 (11) |
C1—C2—C3—C4 | −1.0 (16) | C12—C13—C14—C15 | 3.9 (18) |
C1—C2—C3—Br1 | −177.0 (8) | N12—C13—C14—C15 | −179.6 (11) |
C2—C3—C4—N5 | −0.2 (17) | C13—C14—C15—C16 | 2.7 (19) |
Br1—C3—C4—N5 | 175.7 (9) | C13—C14—C15—N13 | −179.5 (11) |
C3—C4—N5—C6 | −0.4 (18) | C12—C11—C16—C15 | 1 (2) |
C4—N5—C6—C1 | 2.3 (18) | N11—C11—C16—C15 | −178.5 (12) |
C2—C1—C6—N5 | −3.6 (17) | C14—C15—C16—C11 | −5 (2) |
C7—C1—C6—N5 | −177.8 (11) | N13—C15—C16—C11 | 177.1 (11) |
C8—N1—C7—O1 | −4.7 (19) | C16—C11—N11—O16 | −39 (2) |
C8—N1—C7—C1 | 174.8 (12) | C12—C11—N11—O16 | 140.9 (19) |
C2—C1—C7—O1 | −148.3 (11) | C16—C11—N11—O17 | 141 (2) |
C6—C1—C7—O1 | 25.6 (15) | C12—C11—N11—O17 | −39 (3) |
C2—C1—C7—N1 | 32.1 (16) | C14—C13—N12—O12 | 170.6 (12) |
C6—C1—C7—N1 | −153.9 (11) | C12—C13—N12—O12 | −12.7 (18) |
C16—C11—C12—O11 | −172.7 (15) | C14—C13—N12—O13 | −1.7 (18) |
N11—C11—C12—O11 | 7 (2) | C12—C13—N12—O13 | 174.9 (12) |
C16—C11—C12—C13 | 5 (2) | C14—C15—N13—O14 | −3 (2) |
N11—C11—C12—C13 | −175.8 (11) | C16—C15—N13—O14 | 175.1 (14) |
O11—C12—C13—C14 | 170.0 (14) | C14—C15—N13—O15 | 177.3 (12) |
C11—C12—C13—C14 | −7.1 (18) | C16—C15—N13—O15 | −4.9 (19) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1i | 0.88 | 2.23 | 2.865 (13) | 129 |
N1—H1···O15ii | 0.88 | 2.28 | 2.964 (14) | 135 |
N5—H5···O11 | 0.88 | 1.86 | 2.572 (15) | 137 |
N5—H5···O12 | 0.88 | 2.15 | 2.885 (15) | 140 |
Symmetry codes: (i) x+1, y, z; (ii) x+2, y, z+1. |
Experimental details
Crystal data | |
Chemical formula | C7H8BrN2O+·C6H2N3O7− |
Mr | 444.17 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 173 |
a, b, c (Å) | 4.6684 (7), 7.0328 (11), 12.842 (2) |
α, β, γ (°) | 93.802 (13), 97.688 (13), 98.280 (12) |
V (Å3) | 411.90 (11) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 2.55 |
Crystal size (mm) | 0.22 × 0.20 × 0.19 |
Data collection | |
Diffractometer | Stoe IPDSII two-circle |
Absorption correction | Multi-scan (MULABS; Spek, 2003; Blessing, 1995) |
Tmin, Tmax | 0.604, 0.643 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6268, 2966, 2898 |
Rint | 0.122 |
(sin θ/λ)max (Å−1) | 0.608 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.103, 0.263, 1.15 |
No. of reflections | 2966 |
No. of parameters | 244 |
No. of restraints | 3 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.15, −1.30 |
Absolute structure | Flack (1983), 1416 Friedel pairs |
Absolute structure parameter | 0.06 (3) |
Computer programs: X-AREA (Stoe & Cie, 2001), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003) and XP in SHELXTL-Plus (Sheldrick, 1991), PLATON (Spek, 2003).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1i | 0.88 | 2.23 | 2.865 (13) | 129 |
N1—H1···O15ii | 0.88 | 2.28 | 2.964 (14) | 135 |
N5—H5···O11 | 0.88 | 1.86 | 2.572 (15) | 137 |
N5—H5···O12 | 0.88 | 2.15 | 2.885 (15) | 140 |
Symmetry codes: (i) x+1, y, z; (ii) x+2, y, z+1. |
Nicotinamide, also known as niacinamide, is the amide of niacin (vitamin B3) and used for the treatment of arthritis by aiding the body in its production of cartilage. A different use for this compound is an additive in energy drinks (Aranda & Morlock, 2006). The crystal structures of N-(4-bromophenyl)-5,6-dichloronicotinamide and 6-chloro-5-fluoro-N-(3-pyridyl)nicotinamide (Jethmalani et al., 1996), the picrate salt of 1-methylnicotinamide (Freeman & Bugg, 1974) and nicotinium picrate (Anitha et al., 2005) have been reported. In continuation of our work on picrate salts (Yathirajan et al., 2007), the paper reports the crystal structure of the title compound, (I).
Compound (I), [C7H8BrN2O]+[C6H2N3O7]-, consists of discrete 5-bromo-N-methylnicotinamidium cations and picrate anions connected by N—H···O and bifurcated N—H···(O,O) hydrogen bonds. Whereas two nitro groups are almost coplanar with the aromatic ring of the picrate anion [dihedral angles 4(2)° and 11 (2)°], the third one is significantly twisted [dihedral angle 41 (2)°]. The non-H atoms of the side chain of the cation are almost coplanar (r.m.s. deviation 0.015 Å) and this plane is inclined by 28.9 (8)° with respect to the heterocycle. The ion pairs crystallize in sheets parallel to the (112) plane.