2-Amino-6-methyl­pyridinium 2-carb­oxy­benzoate

Hemamalini, M.; Razak, I.A.; Fun, H.-K.

doi:10.1107/S1600536811033174

organic compounds

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ISSN: 2056-9890

Volume 67| Part 9| September 2011| Page o2402

doi:10.1107/S1600536811033174

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2-Amino-6-methylpyridinium 2-carboxybenzoate

Madhukar Hemamalini,^a Ibrahim Abdul Razak ^a ‡ and Hoong-Kun Fun ^a ^*§

^aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
^*Correspondence e-mail: hkfun@usm.my

(Received 11 August 2011; accepted 16 August 2011; online 27 August 2011)

In the title molecular salt, C₆H₉N₂⁺·C₈H₅O₄⁻, an intramolecular O—H⋯O hydrogen bond occurs within the anion, thereby generating an S(7) ring, which may correlate with the fact that both the carboxylic acid and carboxylate groups are almost coplanar with their attached rings [dihedral angles = 2.9 (3) and 5.2 (3)°, respectively]. In the crystal, each cation is linked to its adjacent anion by two N—H⋯O hydrogen bonds; the dihedral angle between the pyridine and benzene rings is 2.22 (10)°. The ion pairs are linked by further N—H⋯O interactions.

Related literature

For related structures, see: Navarro Ranninger et al. (1985 ); Luque et al. (1997 ); Jin et al. (2000 ); Schuckmann et al. (1978 ); Küppers et al. (1985 ); Jessen (1990 ); Hemamalini & Fun (2010a ,b ); Quah et al. (2010 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ).

Experimental

Crystal data

C₆H₉N₂⁺·C₈H₅O₄⁻
M_r = 274.27
Triclinic, $[P \overline 1]$
a = 7.473 (2) Å
b = 8.386 (3) Å
c = 11.818 (4) Å
α = 97.401 (6)°
β = 102.940 (7)°
γ = 109.616 (6)°
V = 662.9 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
1.00 × 0.20 × 0.10 mm

Data collection

Bruker APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ) T_min = 0.905, T_max = 0.990
12166 measured reflections
3706 independent reflections
2219 reflections with I > 2σ(I)
R_int = 0.044

Refinement

R[F² > 2σ(F²)] = 0.055
wR(F²) = 0.190
S = 1.05
3706 reflections
194 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O1⋯O3	0.84	1.55	2.393 (2)	174
N1—H1N1⋯O4	0.98 (2)	1.71 (2)	2.692 (2)	175 (2)
N2—H1N2⋯O2ⁱ	0.96 (3)	1.99 (2)	2.940 (3)	172 (2)
N2—H2N2⋯O3	0.92 (2)	2.04 (2)	2.936 (3)	165 (2)
Symmetry code: (i) -x+1, -y+2, -z+1.

Data collection: APEX2 (Bruker, 2009); cell refinement: 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

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811033174/hb6359sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811033174/hb6359Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811033174/hb6359Isup3.cml

checkCIF report

Comment top

There are numerous examples of 2-amino-substituted pyridine compounds in which the 2-aminopyridines act as ligands (Navarro Ranninger et al., 1985) or as protonated cations (Luque et al., 1997; Jin et al., 2000). Phthalic acid forms hydrogenphthalate salts with various organic and other compounds. The crystal structures of hydrogenphthalates include calcium phthalate monohydrate (Schuckmann et al., 1978), lithium hydrogen phthalate monohydrate (Küppers et al., 1985) and tetramethylammonium hydrogen phthalate (Jessen, 1990) which have been reported in the literature. Recently, we have reported the crystal structures of 2-amino-5-chloro pyridinium 2-carboxybenzoate-benzene-1,2-dicarboxylic acid (Hemamalini & Fun, 2010a), 2-amino-5-bromopridinium 2-carboxybenzoate (Quah et al., 2010) and 2-amino-5-methylpyridinium 2-carboxybenzoate (Hemamalini & Fun, 2010b) from our laboratory. In a continuation of our studies of pyridinium derivatives, the crystal structure determination of the title compound (I) has been undertaken.

In the title salt, (I), the asymmetric unit contains a protonated 2-amino-6-methylpyridinium cation and a hydrogenphthalate anion as shown in Fig.1. In the 2-amino-6-methylpyridinium cation, a wider than normal angle [C1—N1—C5 = 123.64 (16)°] is subtended at the protonated N1 atom. The pyridine ring is essentially planar, with a maximum deviation of 0.007 (2) Å for atom C2. The dihedral angle between the pyridine (N1/C1–C5) and benzene (C7–C11/C13) rings is 2.22 (10)°.

In the crystal structure (Fig. 2), the cations and anions are connected via intermolecular N—H···O and intramolecular O—H···O (Table 1) hydrogen bonds forming dimers. These dimers contain R²₂(8), R¹₂(4) and S(7) ring motifs.

Related literature top

For related structures, see: Navarro Ranninger et al. (1985); Luque et al. (1997); Jin et al. (2000); Schuckmann et al. (1978); Küppers et al. (1985); Jessen (1990); Hemamalini & Fun (2010a,b); Quah et al. (2010). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

A hot methanol solution (20 ml) of 2-amino-6-methylpyridine (54 mg, Aldrich) and phthalic acid (41 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 colourless needles of the title compound appeared after a few days.

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: 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).

Figures top

	Fig. 1. The asymmetric unit of the title compound, showing 50% probability displacement ellipsoids. Intramolecular hydrogen bonds shown by dashed lines.
	Fig. 2. The crystal packing of title compound (I) showing a dimer. Dashed lines represents hydrogen bonding.

2-Amino-6-methylpyridinium 2-carboxybenzoate top

Crystal data top

C₆H₉N₂⁺·C₈H₅O₄⁻	Z = 2
M_r = 274.27	F(000) = 288
Triclinic, P1	D_x = 1.374 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.473 (2) Å	Cell parameters from 3645 reflections
b = 8.386 (3) Å	θ = 2.6–27.4°
c = 11.818 (4) Å	µ = 0.10 mm⁻¹
α = 97.401 (6)°	T = 296 K
β = 102.940 (7)°	Needle, colourless
γ = 109.616 (6)°	1.00 × 0.20 × 0.10 mm
V = 662.9 (4) Å³

Data collection top

Bruker APEXII DUO CCD diffractometer	3706 independent reflections
Radiation source: fine-focus sealed tube	2219 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.044
ϕ and ω scans	θ_max = 29.9°, θ_min = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −10→10
T_min = 0.905, T_max = 0.990	k = −11→11
12166 measured reflections	l = −16→16

Refinement top

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)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.190	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ²(F_o²) + (0.1052P)² + 0.0321P] where P = (F_o² + 2F_c²)/3
3706 reflections	(Δ/σ)_max < 0.001
194 parameters	Δρ_max = 0.20 e Å⁻³
0 restraints	Δρ_min = −0.24 e Å⁻³

Crystal data top

C₆H₉N₂⁺·C₈H₅O₄⁻	γ = 109.616 (6)°
M_r = 274.27	V = 662.9 (4) Å³
Triclinic, P1	Z = 2
a = 7.473 (2) Å	Mo Kα radiation
b = 8.386 (3) Å	µ = 0.10 mm⁻¹
c = 11.818 (4) Å	T = 296 K
α = 97.401 (6)°	1.00 × 0.20 × 0.10 mm
β = 102.940 (7)°

Data collection top

Bruker APEXII DUO CCD diffractometer	3706 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	2219 reflections with I > 2σ(I)
T_min = 0.905, T_max = 0.990	R_int = 0.044
12166 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.055	0 restraints
wR(F²) = 0.190	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 0.20 e Å⁻³
3706 reflections	Δρ_min = −0.24 e Å⁻³
194 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.3997 (3)	0.99186 (18)	0.64341 (12)	0.0720 (5)
H1O1	0.3652	0.8964	0.5951	0.108*
O2	0.4150 (3)	1.09584 (17)	0.82518 (13)	0.0727 (5)
O3	0.3231 (2)	0.71890 (18)	0.51427 (12)	0.0682 (4)
O4	0.2170 (2)	0.44177 (18)	0.51346 (12)	0.0694 (4)
N1	0.2619 (2)	0.33871 (18)	0.29978 (13)	0.0452 (3)
N2	0.3912 (3)	0.6236 (2)	0.28428 (16)	0.0562 (4)
C1	0.3333 (2)	0.4560 (2)	0.23665 (14)	0.0441 (4)
C2	0.3430 (3)	0.3937 (2)	0.12220 (15)	0.0504 (4)
H2A	0.3931	0.4707	0.0766	0.060*
C3	0.2783 (3)	0.2199 (3)	0.07971 (17)	0.0574 (5)
H3A	0.2823	0.1782	0.0039	0.069*
C4	0.2057 (3)	0.1023 (3)	0.14768 (18)	0.0584 (5)
H4A	0.1623	−0.0164	0.1174	0.070*
C5	0.1989 (3)	0.1630 (2)	0.25911 (17)	0.0503 (4)
C6	0.1328 (4)	0.0531 (3)	0.3429 (2)	0.0694 (6)
H6A	0.0575	−0.0647	0.2996	0.104*
H6B	0.0516	0.0958	0.3808	0.104*
H6C	0.2465	0.0575	0.4023	0.104*
C7	0.2521 (3)	0.7860 (2)	0.87715 (15)	0.0481 (4)
H7A	0.2875	0.8912	0.9299	0.058*
C8	0.1716 (3)	0.6332 (3)	0.91302 (16)	0.0539 (4)
H8A	0.1541	0.6364	0.9886	0.065*
C9	0.1182 (3)	0.4775 (3)	0.83617 (17)	0.0561 (5)
H9A	0.0626	0.3742	0.8589	0.067*
C10	0.1472 (3)	0.4744 (2)	0.72467 (16)	0.0511 (4)
H10A	0.1106	0.3678	0.6733	0.061*
C11	0.2297 (2)	0.6265 (2)	0.68645 (13)	0.0419 (4)
C12	0.2586 (3)	0.5937 (2)	0.56344 (15)	0.0481 (4)
C13	0.2820 (2)	0.7880 (2)	0.76533 (14)	0.0424 (4)
C14	0.3712 (3)	0.9700 (2)	0.74459 (16)	0.0498 (4)
H1N1	0.251 (3)	0.383 (3)	0.378 (2)	0.068 (6)*
H1N2	0.454 (4)	0.707 (3)	0.243 (2)	0.075 (7)*
H2N2	0.394 (3)	0.663 (3)	0.361 (2)	0.074 (7)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.1160 (13)	0.0466 (8)	0.0533 (8)	0.0208 (7)	0.0380 (8)	0.0130 (6)
O2	0.1115 (13)	0.0458 (8)	0.0560 (8)	0.0212 (8)	0.0330 (8)	0.0025 (6)
O3	0.0998 (11)	0.0543 (8)	0.0468 (8)	0.0175 (7)	0.0337 (7)	0.0086 (6)
O4	0.1065 (12)	0.0497 (8)	0.0519 (8)	0.0250 (8)	0.0338 (8)	0.0029 (6)
N1	0.0491 (8)	0.0417 (8)	0.0408 (7)	0.0147 (6)	0.0123 (6)	0.0028 (6)
N2	0.0740 (10)	0.0417 (8)	0.0501 (9)	0.0160 (7)	0.0239 (8)	0.0053 (7)
C1	0.0449 (8)	0.0456 (9)	0.0404 (8)	0.0185 (7)	0.0096 (6)	0.0052 (7)
C2	0.0558 (10)	0.0596 (11)	0.0411 (9)	0.0285 (8)	0.0149 (7)	0.0089 (8)
C3	0.0618 (11)	0.0663 (12)	0.0447 (9)	0.0328 (9)	0.0114 (8)	−0.0023 (8)
C4	0.0616 (11)	0.0504 (10)	0.0579 (11)	0.0235 (8)	0.0119 (9)	−0.0037 (8)
C5	0.0488 (9)	0.0428 (9)	0.0540 (10)	0.0153 (7)	0.0118 (7)	0.0038 (7)
C6	0.0795 (14)	0.0504 (11)	0.0794 (15)	0.0201 (10)	0.0301 (11)	0.0171 (10)
C7	0.0554 (10)	0.0511 (10)	0.0409 (9)	0.0231 (8)	0.0168 (7)	0.0065 (7)
C8	0.0629 (11)	0.0627 (12)	0.0449 (9)	0.0269 (9)	0.0250 (8)	0.0165 (8)
C9	0.0638 (11)	0.0508 (10)	0.0538 (11)	0.0150 (8)	0.0236 (8)	0.0184 (8)
C10	0.0577 (10)	0.0441 (9)	0.0453 (9)	0.0130 (7)	0.0149 (7)	0.0065 (7)
C11	0.0411 (8)	0.0473 (9)	0.0355 (8)	0.0165 (6)	0.0096 (6)	0.0062 (6)
C12	0.0519 (9)	0.0511 (10)	0.0378 (8)	0.0168 (7)	0.0120 (7)	0.0063 (7)
C13	0.0442 (8)	0.0451 (9)	0.0382 (8)	0.0183 (7)	0.0114 (6)	0.0072 (7)
C14	0.0596 (10)	0.0451 (9)	0.0452 (9)	0.0190 (7)	0.0171 (7)	0.0097 (7)

Geometric parameters (Å, º) top

O1—C14	1.286 (2)	C4—H4A	0.9300
O1—H1O1	0.8434	C5—C6	1.491 (3)
O2—C14	1.223 (2)	C6—H6A	0.9600
O3—C12	1.271 (2)	C6—H6B	0.9600
O4—C12	1.236 (2)	C6—H6C	0.9600
N1—C1	1.350 (2)	C7—C8	1.386 (3)
N1—C5	1.369 (2)	C7—C13	1.390 (2)
N1—H1N1	0.99 (3)	C7—H7A	0.9300
N2—C1	1.326 (2)	C8—C9	1.367 (3)
N2—H1N2	0.95 (3)	C8—H8A	0.9300
N2—H2N2	0.92 (3)	C9—C10	1.381 (3)
C1—C2	1.413 (2)	C9—H9A	0.9300
C2—C3	1.356 (3)	C10—C11	1.398 (2)
C2—H2A	0.9300	C10—H10A	0.9300
C3—C4	1.397 (3)	C11—C13	1.418 (2)
C3—H3A	0.9300	C11—C12	1.521 (2)
C4—C5	1.368 (3)	C13—C14	1.524 (3)

C14—O1—H1O1	111.8	H6A—C6—H6C	109.5
C1—N1—C5	123.64 (16)	H6B—C6—H6C	109.5
C1—N1—H1N1	117.4 (13)	C8—C7—C13	122.48 (17)
C5—N1—H1N1	118.9 (13)	C8—C7—H7A	118.8
C1—N2—H1N2	119.1 (15)	C13—C7—H7A	118.8
C1—N2—H2N2	122.3 (15)	C9—C8—C7	119.37 (17)
H1N2—N2—H2N2	118 (2)	C9—C8—H8A	120.3
N2—C1—N1	118.97 (16)	C7—C8—H8A	120.3
N2—C1—C2	122.93 (17)	C8—C9—C10	119.76 (17)
N1—C1—C2	118.09 (15)	C8—C9—H9A	120.1
C3—C2—C1	119.05 (18)	C10—C9—H9A	120.1
C3—C2—H2A	120.5	C9—C10—C11	122.13 (17)
C1—C2—H2A	120.5	C9—C10—H10A	118.9
C2—C3—C4	121.27 (18)	C11—C10—H10A	118.9
C2—C3—H3A	119.4	C10—C11—C13	118.15 (15)
C4—C3—H3A	119.4	C10—C11—C12	113.54 (15)
C5—C4—C3	119.58 (17)	C13—C11—C12	128.27 (15)
C5—C4—H4A	120.2	O4—C12—O3	121.50 (17)
C3—C4—H4A	120.2	O4—C12—C11	117.68 (15)
C4—C5—N1	118.35 (17)	O3—C12—C11	120.82 (16)
C4—C5—C6	125.27 (18)	C7—C13—C11	118.09 (15)
N1—C5—C6	116.36 (17)	C7—C13—C14	113.65 (15)
C5—C6—H6A	109.5	C11—C13—C14	128.25 (15)
C5—C6—H6B	109.5	O2—C14—O1	120.10 (17)
H6A—C6—H6B	109.5	O2—C14—C13	119.35 (16)
C5—C6—H6C	109.5	O1—C14—C13	120.55 (16)

C5—N1—C1—N2	−179.76 (16)	C10—C11—C12—O4	−3.4 (2)
C5—N1—C1—C2	0.1 (2)	C13—C11—C12—O4	174.11 (17)
N2—C1—C2—C3	−179.19 (17)	C10—C11—C12—O3	176.56 (16)
N1—C1—C2—C3	0.9 (2)	C13—C11—C12—O3	−5.9 (3)
C1—C2—C3—C4	−1.1 (3)	C8—C7—C13—C11	−0.8 (3)
C2—C3—C4—C5	0.2 (3)	C8—C7—C13—C14	179.70 (16)
C3—C4—C5—N1	0.8 (3)	C10—C11—C13—C7	1.3 (2)
C3—C4—C5—C6	−177.48 (18)	C12—C11—C13—C7	−176.07 (15)
C1—N1—C5—C4	−1.0 (3)	C10—C11—C13—C14	−179.27 (16)
C1—N1—C5—C6	177.44 (16)	C12—C11—C13—C14	3.3 (3)
C13—C7—C8—C9	−0.2 (3)	C7—C13—C14—O2	2.5 (3)
C7—C8—C9—C10	0.8 (3)	C11—C13—C14—O2	−176.88 (17)
C8—C9—C10—C11	−0.2 (3)	C7—C13—C14—O1	−177.23 (17)
C9—C10—C11—C13	−0.9 (3)	C11—C13—C14—O1	3.4 (3)
C9—C10—C11—C12	176.92 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O1···O3	0.84	1.55	2.393 (2)	174
N1—H1N1···O4	0.98 (2)	1.71 (2)	2.692 (2)	175 (2)
N2—H1N2···O2ⁱ	0.96 (3)	1.99 (2)	2.940 (3)	172 (2)
N2—H2N2···O3	0.92 (2)	2.04 (2)	2.936 (3)	165 (2)

Symmetry code: (i) −x+1, −y+2, −z+1.

Experimental details

Crystal data
Chemical formula	C₆H₉N₂⁺·C₈H₅O₄⁻
M_r	274.27
Crystal system, space group	Triclinic, P1
Temperature (K)	296
a, b, c (Å)	7.473 (2), 8.386 (3), 11.818 (4)
α, β, γ (°)	97.401 (6), 102.940 (7), 109.616 (6)
V (Å³)	662.9 (4)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	1.00 × 0.20 × 0.10

Data collection
Diffractometer	Bruker APEXII DUO CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.905, 0.990
No. of measured, independent and observed [I > 2σ(I)] reflections	12166, 3706, 2219
R_int	0.044
(sin θ/λ)_max (Å⁻¹)	0.702

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.055, 0.190, 1.05
No. of reflections	3706
No. of parameters	194
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.20, −0.24

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O1···O3	0.84	1.55	2.393 (2)	174
N1—H1N1···O4	0.98 (2)	1.71 (2)	2.692 (2)	175 (2)
N2—H1N2···O2ⁱ	0.96 (3)	1.99 (2)	2.940 (3)	172 (2)
N2—H2N2···O3	0.92 (2)	2.04 (2)	2.936 (3)	165 (2)

Symmetry code: (i) −x+1, −y+2, −z+1.

Footnotes

‡Thomson Reuters ResearcherID: A-5599-2009.

§Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

MH, HKF and IAR thank the Ministry of Higher Education, Malaysia, and Universiti Sains Malaysia for the Fundamental Research Grant Scheme (FRGS) grant No. 203/PFIZIK/6711171. MH also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

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