Hydrogen-bonding patterns of 2-amino­pyridinium p-nitro­benzoate

In the title compound, C₅H₇N₂⁺·C₇H₄NO₄⁻, the asymmetric unit consists of an aminopyridinium cation and a p-nitro­benzoate anion, with proton transfer occurring to the aromatic N atom of the 2-amino­pyridine molecule. In the crystal structure, the two ions are inter­connected by N—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.053
• wR factor = 0.129
• Data-to-parameter ratio = 8.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          5

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           27.58
           From the CIF: _reflns_number_total               1463
           Count of symmetry unique reflns         1481
           Completeness (_total/calc)             98.78%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

---

Computing details

Data collection: COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

2-aminopyridinium p-nitrobenzoate

Crystal data

C5H7N2^+·C7H4NO4^−	F(000) = 272
Mr = 261.24	Dx = 1.471 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 25 reflections
a = 7.9403 (12) Å	θ = 1–27.5°
b = 6.7719 (6) Å	µ = 0.11 mm^−1
c = 11.1120 (15) Å	T = 120 K
β = 99.272 (6)°	Block, colourless
V = 589.70 (13) Å^3	0.3 × 0.13 × 0.06 mm
Z = 2

Data collection

Nonius KappaCCD? diffractometer	Rint = 0.071
φ and ω scans	θmax = 27.6°, θmin = 1.9°
7208 measured reflections	h = −10→10
1463 independent reflections	k = −8→8
1035 reflections with I > 2σ(I)	l = −14→12

Refinement

Refinement on F^2	H-atom parameters constrained
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0674P)^2 + 0.0892P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.053	(Δ/σ)max = 0.036
wR(F^2) = 0.129	Δρmax = 0.38 e Å^−3
S = 1.05	Δρmin = −0.31 e Å^−3
1463 reflections	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
173 parameters	Extinction coefficient: 0.041 (11)
1 restraint

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.6522 (3)	0.2889 (3)	0.6912 (2)	0.0293 (6)
O4	1.0654 (3)	1.2352 (4)	0.8212 (2)	0.0370 (7)
O3	1.0612 (4)	1.1706 (4)	0.6299 (2)	0.0405 (7)
C10	0.8234 (4)	0.6394 (5)	0.6599 (3)	0.0255 (8)
H10	0.7988	0.554	0.5939	0.031*
C11	0.9026 (4)	0.8193 (5)	0.6455 (3)	0.0253 (8)
H11	0.9301	0.8563	0.5705	0.03*
O2	0.6600 (3)	0.3487 (4)	0.8896 (2)	0.0331 (6)
C9	0.7809 (5)	0.5866 (5)	0.7717 (3)	0.0235 (8)
C6	0.9391 (4)	0.9408 (5)	0.7455 (3)	0.0251 (8)
C13	0.6911 (4)	0.3931 (5)	0.7860 (3)	0.0247 (8)
C8	0.8216 (4)	0.7131 (5)	0.8708 (3)	0.0259 (8)
H8	0.7954	0.6768	0.9464	0.031*
N3	1.0270 (4)	1.1284 (5)	0.7315 (3)	0.0297 (7)
C1	0.4211 (4)	0.8976 (5)	0.8091 (3)	0.0247 (8)
C2	0.3281 (4)	0.7180 (5)	0.8080 (3)	0.0291 (9)
H2	0.2966	0.6698	0.8796	0.035*
C3	0.2853 (4)	0.6168 (5)	0.7012 (3)	0.0297 (9)
H3	0.225	0.4989	0.7004	0.036*
C4	0.3311 (4)	0.6887 (6)	0.5932 (3)	0.0315 (9)
H4	0.2993	0.6218	0.52	0.038*
C5	0.4231 (4)	0.8582 (6)	0.5973 (3)	0.0276 (8)
H5	0.4562	0.906	0.5262	0.033*
N1	0.4676 (4)	0.9593 (4)	0.7034 (3)	0.0246 (7)
H1	0.5271	1.0654	0.7033	0.029*
N2	0.4648 (4)	1.0073 (5)	0.9079 (3)	0.0321 (8)
H2A	0.5213	1.1147	0.9038	0.039*
H2B	0.4366	0.9711	0.9761	0.039*
C7	0.9001 (5)	0.8916 (5)	0.8583 (3)	0.0277 (8)
H7	0.9261	0.9768	0.9243	0.033*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0408 (15)	0.0254 (13)	0.0224 (13)	−0.0070 (11)	0.0074 (11)	−0.0012 (11)
O4	0.0462 (17)	0.0297 (15)	0.0337 (16)	−0.0081 (13)	0.0025 (12)	−0.0040 (13)
O3	0.0543 (18)	0.0381 (16)	0.0326 (15)	−0.0129 (14)	0.0173 (13)	0.0039 (13)
C10	0.029 (2)	0.0260 (19)	0.0205 (19)	0.0041 (16)	0.0006 (15)	−0.0007 (17)
C11	0.0270 (19)	0.026 (2)	0.0236 (18)	0.0008 (15)	0.0052 (15)	0.0032 (15)
O2	0.0473 (15)	0.0272 (15)	0.0270 (13)	−0.0057 (12)	0.0131 (11)	−0.0008 (11)
C9	0.0265 (18)	0.0219 (18)	0.0223 (18)	0.0019 (15)	0.0041 (14)	0.0014 (14)
C6	0.0231 (18)	0.0210 (18)	0.031 (2)	0.0003 (14)	0.0056 (15)	0.0014 (16)
C13	0.0281 (19)	0.0210 (19)	0.026 (2)	0.0000 (15)	0.0072 (15)	0.0011 (15)
C8	0.032 (2)	0.027 (2)	0.0188 (18)	0.0016 (16)	0.0059 (15)	−0.0001 (15)
N3	0.0293 (17)	0.0255 (17)	0.0340 (19)	−0.0028 (14)	0.0044 (14)	0.0011 (15)
C1	0.0220 (18)	0.027 (2)	0.0253 (19)	0.0023 (15)	0.0040 (15)	0.0021 (16)
C2	0.030 (2)	0.028 (2)	0.030 (2)	−0.0027 (18)	0.0074 (16)	0.0050 (17)
C3	0.027 (2)	0.023 (2)	0.038 (2)	−0.0028 (17)	0.0034 (17)	0.0007 (17)
C4	0.0281 (19)	0.036 (2)	0.030 (2)	0.0008 (17)	0.0019 (16)	−0.0070 (17)
C5	0.0308 (19)	0.029 (2)	0.0221 (18)	0.0013 (17)	0.0027 (15)	0.0019 (16)
N1	0.0282 (16)	0.0215 (15)	0.0243 (16)	−0.0027 (13)	0.0053 (12)	0.0013 (13)
N2	0.046 (2)	0.0284 (18)	0.0239 (16)	−0.0055 (15)	0.0102 (14)	0.0014 (13)
C7	0.031 (2)	0.023 (2)	0.0292 (19)	−0.0025 (16)	0.0052 (16)	−0.0027 (16)

Geometric parameters (Å, º)

O1—C13	1.264 (4)	C1—N2	1.324 (4)
O4—N3	1.230 (4)	C1—N1	1.353 (4)
O3—N3	1.236 (4)	C1—C2	1.422 (5)
C10—C11	1.392 (5)	C2—C3	1.365 (5)
C10—C9	1.386 (5)	C2—H2	0.93
C10—H10	0.93	C3—C4	1.396 (5)
C11—C6	1.376 (5)	C3—H3	0.93
C11—H11	0.93	C4—C5	1.357 (5)
O2—C13	1.253 (4)	C4—H4	0.93
C9—C8	1.392 (5)	C5—N1	1.360 (4)
C9—C13	1.512 (5)	C5—H5	0.93
C6—C7	1.379 (5)	N1—H1	0.86
C6—N3	1.470 (5)	N2—H2A	0.86
C8—C7	1.377 (5)	N2—H2B	0.86
C8—H8	0.93	C7—H7	0.93
C11—C10—C9	120.6 (3)	N1—C1—C2	118.1 (3)
C11—C10—H10	119.7	C3—C2—C1	119.5 (3)
C9—C10—H10	119.7	C3—C2—H2	120.2
C6—C11—C10	118.1 (3)	C1—C2—H2	120.2
C6—C11—H11	121	C2—C3—C4	120.6 (3)
C10—C11—H11	121	C2—C3—H3	119.7
C10—C9—C8	119.4 (3)	C4—C3—H3	119.7
C10—C9—C13	120.3 (3)	C5—C4—C3	118.7 (3)
C8—C9—C13	120.3 (3)	C5—C4—H4	120.7
C11—C6—C7	122.7 (3)	C3—C4—H4	120.7
C11—C6—N3	118.2 (3)	C4—C5—N1	121.2 (3)
C7—C6—N3	119.1 (3)	C4—C5—H5	119.4
O1—C13—O2	125.0 (3)	N1—C5—H5	119.4
O1—C13—C9	116.9 (3)	C1—N1—C5	121.9 (3)
O2—C13—C9	118.1 (3)	C1—N1—H1	119.1
C7—C8—C9	120.8 (3)	C5—N1—H1	119.1
C7—C8—H8	119.6	C1—N2—H2A	120
C9—C8—H8	119.6	C1—N2—H2B	120
O4—N3—O3	122.8 (3)	H2A—N2—H2B	120
O4—N3—C6	118.8 (3)	C8—C7—C6	118.4 (3)
O3—N3—C6	118.4 (3)	C8—C7—H7	120.8
N2—C1—N1	118.3 (3)	C6—C7—H7	120.8
N2—C1—C2	123.6 (3)
C9—C10—C11—C6	0.9 (5)	C11—C6—N3—O3	1.4 (5)
C11—C10—C9—C8	−1.5 (5)	C7—C6—N3—O3	180.0 (3)
C11—C10—C9—C13	178.6 (3)	N2—C1—C2—C3	178.5 (3)
C10—C11—C6—C7	−0.2 (5)	N1—C1—C2—C3	−1.6 (5)
C10—C11—C6—N3	178.4 (3)	C1—C2—C3—C4	−0.4 (5)
C10—C9—C13—O1	−2.6 (5)	C2—C3—C4—C5	1.8 (5)
C8—C9—C13—O1	177.4 (3)	C3—C4—C5—N1	−1.2 (5)
C10—C9—C13—O2	177.8 (3)	N2—C1—N1—C5	−177.9 (3)
C8—C9—C13—O2	−2.2 (5)	C2—C1—N1—C5	2.2 (5)
C10—C9—C8—C7	1.4 (5)	C4—C5—N1—C1	−0.8 (5)
C13—C9—C8—C7	−178.6 (3)	C9—C8—C7—C6	−0.7 (5)
C11—C6—N3—O4	−177.6 (3)	C11—C6—C7—C8	0.1 (5)
C7—C6—N3—O4	1.0 (5)	N3—C6—C7—C8	−178.4 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^i	0.86	1.83	2.686 (4)	176
N2—H2A···O2^i	0.86	1.95	2.809 (4)	176
N2—H2B···O2^ii	0.86	1.97	2.814 (4)	168

Symmetry codes: (i) x, y+1, z; (ii) −x+1, y+1/2, −z+2.