4-(Methyl­amino)pyridine

The non-H atoms of the title compound, C₆H₈N₂, lie in a common plane (r.m.s. deviation = 0.034 Å). In the crystal, adjacent mol­ecules are linked by inter­molecular N—H⋯N hydrogen bonds into a zigzag chain running along the c axis.

Related literature

For the non-linear optical activity of co-crystals with substituted 4-nitro­phenol, see; Huang et al. (1997). For the crystal structure of 4-amino­pyridine, see: Anderson et al. (2005) and for that of 4-dimethyl­pyridine, see: Ohms & Guth (1984).

Experimental

Crystal data

• C₆H₈N₂

• M_r = 108.14

• Orthorhombic, P n a 2₁

• a = 6.5645 (18) Å

• b = 7.1230 (19) Å

• c = 12.489 (4) Å

• V = 584.0 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.08 mm⁻¹

• T = 100 K

• 0.12 × 0.12 × 0.02 mm

Data collection

• Bruker SMART APEX diffractometer

• 5127 measured reflections

• 707 independent reflections

• 521 reflections with I > 2σ(I)

• R_int = 0.093

Refinement

• R[F² > 2σ(F²)] = 0.044

• wR(F²) = 0.102

• S = 0.99

• 707 reflections

• 78 parameters

• 2 restraints

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.18 e Å⁻³

• Δρ_min = −0.20 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯N2^i	0.88 (1)	2.06 (1)	2.930 (3)	168 (3)
Symmetry code: (i) .

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Supporting information

S1. Comment

The amino nitrogen atom in 4-aminopyridine, a drug used for treating multiple sclerosis, is pyramidal; the amino group engages in a N–H···N hydrogen bonding interaction with adjacent pyridyl rings to generate a chain. The amino group uses its other nitrogen atom to form an N–H···π interaction with other pyridyl rings (Anderson et al., 2005).

In the title monomethyl-substituted analogue (Scheme I, Fig. 1), all non-hydrogen atoms lie in a common plane. However, the amino nitrogen atom is slightly pyramidal, this being displaced out of the trigonal plane by 0.18 (2) Å (Σangles 353 °). On the other hand, the amino nitrogen atom in 4-dimethylaminopyridine has unambiguously planar configuration (Ohms & Guth, 1984). In the present structure, adjacent molecules are linked by an N–H···N hydrogen bond to generate a helical chain motif (Table 1).

The compound belongs to a non-centrosymmetric space group, a feature that may render it useful for second-harmonic generation, particularly as it co-crystal with 2-methoxy-4-nitrophenol shows NLO activity (Huang et al., 1997).

Related literature

For the non-linear optical activity of co-crystals with substituted 4-nitrophenol, see; Huang et al. (1997). For the crystal structure of 4-aminopyridine, see: Anderson et al. (2005) and for that of 4-dimethylpyridine, see: Ohms & Guth (1984).

S2. Experimental

4-Methylaminopyridine, as purchased from the Aldrich Chemical Company, is a crystalline material.

S3. Refinement

Due to the absence of anomalous scatterers, 644 Friedel pairs were merged. Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U_eq(C). The amino H-atom was located in a difference Fourier map and it was refined with a distance restraint of N–H 0.88±0.01 Å.

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

Fig. 1. Anisotropic displacement ellipsoid plot (Barbour, 2001) of a portion of the hydrogen-bonded chain structure of 4-methylaminopyridine at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius.

4-(Methylamino)pyridine

Crystal data

C6H8N2	F(000) = 232
Mr = 108.14	Dx = 1.230 Mg m^−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 379 reflections
a = 6.5645 (18) Å	θ = 3.3–21.5°
b = 7.1230 (19) Å	µ = 0.08 mm^−1
c = 12.489 (4) Å	T = 100 K
V = 584.0 (3) Å^3	Plate, colorless
Z = 4	0.12 × 0.12 × 0.02 mm

Data collection

Bruker SMART APEX diffractometer	521 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.093
Graphite monochromator	θmax = 27.5°, θmin = 3.3°
ω scans	h = −7→8
5127 measured reflections	k = −9→8
707 independent reflections	l = −16→16

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.102	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0518P)^2] where P = (Fo^2 + 2Fc^2)/3
707 reflections	(Δ/σ)max = 0.001
78 parameters	Δρmax = 0.18 e Å^−3
2 restraints	Δρmin = −0.20 e Å^−3

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

	x	y	z	Uiso*/Ueq
N1	0.2579 (4)	0.0086 (3)	0.49959 (18)	0.0219 (6)
H1	0.177 (4)	0.027 (5)	0.4440 (19)	0.036 (11)*
N2	−0.0105 (4)	−0.0122 (3)	0.8044 (2)	0.0232 (6)
C1	0.1745 (4)	−0.0004 (4)	0.5993 (2)	0.0193 (6)
C2	−0.0127 (4)	0.0889 (4)	0.6198 (2)	0.0217 (7)
H2	−0.0813	0.1550	0.5645	0.026*
C3	−0.0957 (5)	0.0794 (4)	0.7215 (2)	0.0256 (7)
H3	−0.2215	0.1417	0.7336	0.031*
C4	0.1690 (4)	−0.0944 (4)	0.7840 (2)	0.0220 (7)
H4	0.2337	−0.1593	0.8411	0.026*
C5	0.2673 (4)	−0.0917 (4)	0.6858 (2)	0.0207 (7)
H5	0.3959	−0.1511	0.6773	0.025*
C6	0.4412 (4)	−0.0966 (5)	0.4736 (2)	0.0302 (8)
H6A	0.5534	−0.0546	0.5195	0.045*
H6B	0.4772	−0.0753	0.3984	0.045*
H6C	0.4168	−0.2307	0.4853	0.045*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0237 (13)	0.0242 (14)	0.0178 (12)	0.0021 (12)	−0.0023 (10)	0.0025 (12)
N2	0.0277 (14)	0.0232 (12)	0.0189 (11)	0.0006 (12)	0.0005 (11)	−0.0001 (13)
C1	0.0189 (15)	0.0192 (15)	0.0198 (14)	−0.0048 (13)	−0.0055 (12)	−0.0010 (12)
C2	0.0231 (17)	0.0218 (16)	0.0201 (13)	0.0003 (13)	−0.0031 (12)	0.0033 (13)
C3	0.0293 (18)	0.0210 (16)	0.0264 (16)	0.0046 (14)	0.0013 (14)	−0.0005 (14)
C4	0.0248 (16)	0.0223 (16)	0.0188 (14)	−0.0016 (13)	−0.0039 (12)	0.0009 (13)
C5	0.0196 (16)	0.0205 (16)	0.0219 (14)	0.0009 (13)	−0.0024 (12)	−0.0011 (14)
C6	0.0242 (16)	0.0408 (19)	0.0256 (16)	0.0051 (14)	0.0028 (14)	0.0005 (14)

Geometric parameters (Å, º)

N1—C1	1.362 (4)	C2—H2	0.9500
N1—C6	1.454 (4)	C3—H3	0.9500
N1—H1	0.88 (1)	C4—C5	1.386 (4)
N2—C4	1.340 (4)	C4—H4	0.9500
N2—C3	1.345 (4)	C5—H5	0.9500
C1—C5	1.401 (4)	C6—H6A	0.9800
C1—C2	1.407 (4)	C6—H6B	0.9800
C2—C3	1.384 (4)	C6—H6C	0.9800
C1—N1—C6	120.8 (2)	N2—C4—C5	124.8 (3)
C1—N1—H1	119 (2)	N2—C4—H4	117.6
C6—N1—H1	113 (2)	C5—C4—H4	117.6
C4—N2—C3	115.6 (3)	C4—C5—C1	119.1 (3)
N1—C1—C5	123.5 (3)	C4—C5—H5	120.4
N1—C1—C2	119.8 (3)	C1—C5—H5	120.4
C5—C1—C2	116.7 (3)	N1—C6—H6A	109.5
C3—C2—C1	119.3 (3)	N1—C6—H6B	109.5
C3—C2—H2	120.4	H6A—C6—H6B	109.5
C1—C2—H2	120.4	N1—C6—H6C	109.5
N2—C3—C2	124.5 (3)	H6A—C6—H6C	109.5
N2—C3—H3	117.7	H6B—C6—H6C	109.5
C2—C3—H3	117.7
C6—N1—C1—C5	7.2 (4)	C1—C2—C3—N2	−0.6 (5)
C6—N1—C1—C2	−174.3 (3)	C3—N2—C4—C5	−0.5 (5)
N1—C1—C2—C3	−179.8 (3)	N2—C4—C5—C1	−1.2 (5)
C5—C1—C2—C3	−1.1 (4)	N1—C1—C5—C4	−179.4 (3)
C4—N2—C3—C2	1.5 (5)	C2—C1—C5—C4	2.0 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N2^i	0.88 (1)	2.06 (1)	2.930 (3)	168 (3)

Symmetry code: (i) −x, −y, z−1/2.