4-Amino­pyridinium azide 4-amino­pyridine solvate

In the title compound, C₅H₇N₂⁺·N₃⁻·C₅H₆N₂, all N atoms of the azide anion are situated on a twofold rotational axis, so the 4-amino­pyridinium cation and 4-amino­pyridine mol­ecule, being related by symmetry, occupy one position in the asymmetric unit. Inter­molecular N—H...N hydrogen bonds generate a three-dimensional hydrogen-bonding network which consolidates the crystal packing.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.036
• wR factor = 0.105
• Data-to-parameter ratio = 13.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N4
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.595          4
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1
PLAT981_ALERT_1_G No non-zero f" Anomalous Scattering Values Found          ?

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

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The crystal structure of 4-aminopyridine hemiperchlorate, has been previously reported (Teulon et al., 1985). In this paper, we report the X-ray single-crystal structure of 4-aminopyridinium azide 4-aminopyridine (I).

The molecular structure of (I) is illustrated in Fig. 1. All N atoms of the azide anions are situated on a twofold rotational axis, so 4-aminopyridinium cation and 4-aminopyridine molecule being related by symmetry occupy one position in the asymmetric unit. Intermolecular N—H···N hydrogen bonds (Table 1) generate a three-dimensional hydrogen-bonding network which consolidate the crystal packing.

Related literature

For a related compound, see: Teulon et al. (1985).

S2. Experimental

The title compound (I) was prepared by the treatment of 4-aminopyridine (0.5 mmol, 0.041 g) and excess sodium azide (NaN₃) in 20 ml methanol with a few drops of acetate acid (HOAc). Colourless single crystals suitable for X-ray diffraction measurement were grown from its methanol solution after five days' slow evaporation at room temperature in air. Anal. Calcd. for C₁₀H₁₃N₇: C, 51.94; H, 5.66; N, 42.40%. Found: C, 51.85; H, 5.81; N, 42.29%. FT–IR (KBr pellets, cm^-1): 3447 (vs), 2057 (s), 1645 (s), 1463 (m), 1202 (w), 1202 (w), 840 (w), and 590 (w).

S3. Refinement

One restraint (DELU 0.001 C1 C2) was used to reduce the components of the anisotropic displacement parameters along chemical C—C bond. The H atoms were placed in geometrically idealized positions and refined as riding, with C—H = 0.93 Å and N—H = 0.86 Å, U_iso(H) = 1.2U_eq(C) and U_iso(H) = 1.2U_eq(N).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); 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).

Figures

Fig. 1. Molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

4-Aminopyridinium azide 4-aminopyridine solvate

Crystal data

C5H7N2^+·N3^−·C5H6N2	F(000) = 488
Mr = 231.27	Dx = 1.242 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1359 reflections
a = 7.507 (3) Å	θ = 3.0–25.4°
b = 12.247 (5) Å	µ = 0.08 mm^−1
c = 13.634 (5) Å	T = 291 K
β = 99.278 (5)°	Block, colourless
V = 1237.0 (8) Å^3	0.14 × 0.11 × 0.10 mm
Z = 4

Data collection

Bruker SMART 1K CCD area-detector diffractometer	1096 independent reflections
Radiation source: fine-focus sealed tube	852 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.072
φ and ω scans	θmax = 25.0°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −8→8
Tmin = 0.988, Tmax = 0.992	k = −12→14
3027 measured reflections	l = −16→15

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.036	H-atom parameters constrained
wR(F^2) = 0.105	w = 1/[σ^2(Fo^2) + (0.0493P)^2 + 0.0478P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
1096 reflections	Δρmax = 0.11 e Å^−3
80 parameters	Δρmin = −0.11 e Å^−3
1 restraint	Extinction correction: SHELXTL (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.042 (5)

Special details

Experimental. The structure was solved by direct methods (Bruker, 2000) and successive difference Fourier syntheses.

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.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.1721 (2)	0.05406 (12)	−0.09812 (12)	0.0879 (5)
H1	0.2321	0.0033	−0.1316	0.106*
C2	0.22248 (18)	0.06466 (10)	0.00146 (11)	0.0780 (4)
H2	0.3145	0.0214	0.0350	0.094*
C3	0.13523 (16)	0.14103 (10)	0.05345 (9)	0.0699 (4)
C4	−0.00162 (18)	0.20282 (11)	−0.00180 (11)	0.0791 (4)
H4	−0.0635	0.2547	0.0294	0.095*
C5	−0.0439 (2)	0.18672 (13)	−0.10131 (12)	0.0932 (5)
H5	−0.1355	0.2286	−0.1371	0.112*
N1	0.18164 (16)	0.15416 (9)	0.15211 (9)	0.0858 (4)
H1A	0.1265	0.2016	0.1828	0.103*
H1B	0.2665	0.1151	0.1846	0.103*
N2	0.04055 (19)	0.11306 (11)	−0.15027 (9)	0.0948 (4)
H2A	0.0108	0.1042	−0.2134	0.114*	0.50
N3	0.5000	−0.02503 (17)	0.7500	0.1009 (6)
N4	0.5000	0.07152 (17)	0.7500	0.0760 (5)
N5	0.5000	0.16656 (17)	0.7500	0.1062 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0948 (10)	0.0867 (9)	0.0891 (8)	−0.0181 (8)	0.0353 (8)	−0.0118 (8)
C2	0.0744 (8)	0.0752 (8)	0.0879 (8)	−0.0108 (6)	0.0231 (6)	−0.0057 (6)
C3	0.0681 (7)	0.0682 (7)	0.0762 (9)	−0.0163 (6)	0.0206 (6)	−0.0037 (6)
C4	0.0765 (8)	0.0799 (8)	0.0834 (9)	−0.0071 (6)	0.0205 (7)	−0.0009 (7)
C5	0.0938 (10)	0.1000 (11)	0.0854 (11)	−0.0100 (8)	0.0132 (8)	0.0090 (8)
N1	0.0900 (8)	0.0873 (8)	0.0803 (8)	0.0016 (5)	0.0144 (6)	−0.0086 (6)
N2	0.1105 (10)	0.1050 (9)	0.0714 (8)	−0.0251 (7)	0.0223 (7)	−0.0032 (7)
N3	0.0964 (13)	0.0868 (12)	0.1185 (15)	0.000	0.0141 (10)	0.000
N4	0.0626 (9)	0.0993 (13)	0.0671 (9)	0.000	0.0139 (6)	0.000
N5	0.1123 (14)	0.0918 (14)	0.1242 (16)	0.000	0.0488 (12)	0.000

Geometric parameters (Å, º)

C1—N2	1.333 (2)	C4—H4	0.9300
C1—C2	1.356 (2)	C5—N2	1.341 (2)
C1—H1	0.9300	C5—H5	0.9300
C2—C3	1.3985 (18)	N1—H1A	0.8600
C2—H2	0.9300	N1—H1B	0.8600
C3—N1	1.3437 (17)	N2—H2A	0.8600
C3—C4	1.395 (2)	N3—N4	1.182 (3)
C4—C5	1.357 (2)	N4—N5	1.164 (2)
N2—C1—C2	123.06 (14)	C3—C4—H4	120.2
N2—C1—H1	118.5	N2—C5—C4	122.83 (15)
C2—C1—H1	118.5	N2—C5—H5	118.6
C1—C2—C3	119.58 (14)	C4—C5—H5	118.6
C1—C2—H2	120.2	C3—N1—H1A	120.0
C3—C2—H2	120.2	C3—N1—H1B	120.0
N1—C3—C4	121.68 (12)	H1A—N1—H1B	120.0
N1—C3—C2	121.36 (13)	C1—N2—C5	117.93 (13)
C4—C3—C2	116.97 (13)	C1—N2—H2A	121.0
C5—C4—C3	119.63 (14)	C5—N2—H2A	121.0
C5—C4—H4	120.2	N5—N4—N3	180.000 (1)
N2—C1—C2—C3	−0.5 (2)	C2—C3—C4—C5	0.10 (18)
C1—C2—C3—N1	−179.81 (11)	C3—C4—C5—N2	0.0 (2)
C1—C2—C3—C4	0.11 (17)	C2—C1—N2—C5	0.6 (2)
N1—C3—C4—C5	−179.98 (11)	C4—C5—N2—C1	−0.3 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···N5^i	0.86	2.15	3.008 (2)	174
N1—H1B···N3^ii	0.86	2.14	2.9942 (18)	172
N2—H2A···N2^iii	0.86	1.84	2.689 (3)	169

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