2-Amino-5-methyl­pyridinium 4-hydroxy­benzoate

Hemamalini, M.; Fun, H.-K.

doi:10.1107/S1600536810009396

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 66| Part 4| April 2010| Pages o936-o937

doi:10.1107/S1600536810009396

Open

access

2-Amino-5-methylpyridinium 4-hydroxybenzoate

Madhukar Hemamalini ^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 4 March 2010; accepted 12 March 2010; online 27 March 2010)

In the title salt, C₆H₉N₂⁺·C₇H₅O₃⁻, the carboxylate mean plane of the 4-hydroxybenzoate anion is twisted by 13.07 (4)° from the attached ring. In the crystal structure, the ions are linked into a two-dimensional network by N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds. Within this network, the N—H⋯O hydrogen bonds generate R₂²(8) ring motifs. In addition, π–π interactions involving the pyridinium rings, with a centroid–centroid distance of 3.7599 (4) Å, are observed.

Related literature

For background to the chemistry of substituted pyridines, see: Pozharski et al. (1997 ); Katritzky et al. (1996 ). For related structures, see: Hemamalini & Fun (2010a ,b ,c ). For 4-hydroxybenzoic acid, see: Vishweshwar et al. (2003 ). For details of hydrogen bonding, see: Jeffrey & Saenger (1991 ); Jeffrey (1997 ); Scheiner (1997 ); Aakeröy et al. (2002 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ). For bond-length data, see: Allen et al. (1987 ). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ).

Experimental

Crystal data

C₆H₉N₂⁺·C₇H₅O₃⁻
M_r = 246.26
Monoclinic, P 2₁ /c
a = 12.9562 (6) Å
b = 8.7876 (4) Å
c = 11.3276 (5) Å
β = 108.397 (1)°
V = 1223.78 (10) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.39 × 0.33 × 0.27 mm

Data collection

Bruker APEX DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ) T_min = 0.963, T_max = 0.975
20102 measured reflections
5326 independent reflections
4662 reflections with I > 2σ(I)
R_int = 0.019

Refinement

R[F² > 2σ(F²)] = 0.039
wR(F²) = 0.137
S = 1.15
5326 reflections
219 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.60 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N1⋯O3	0.957 (17)	1.726 (17)	2.6738 (9)	170.4 (15)
N2—H1N2⋯O3ⁱ	0.905 (14)	1.967 (14)	2.8443 (9)	162.9 (13)
N2—H2N2⋯O2	0.922 (14)	1.876 (14)	2.7962 (9)	176.1 (13)
O1—H101⋯O2ⁱⁱ	0.892 (18)	1.779 (18)	2.6635 (8)	170.7 (19)
C3—H3A⋯O2ⁱⁱⁱ	1.016 (16)	2.476 (15)	3.1887 (9)	126.7 (10)
Symmetry codes: (i) $[x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ ; (ii) $[-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iii) $[-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

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/S1600536810009396/rz2424sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810009396/rz2424Isup2.hkl

checkCIF report

Comment top

In recent years, hydrogen bonds have attracted the interest of chemists and have been widely used to design and synthesize one, two and three-dimensional supramolecular compounds (Aakeröy et al., 2002). Pyridine and its derivatives play an important role in heterocyclic chemistry (Pozharski et al., 1997; Katritzky et al., 1996). They are often involved in hydrogen-bond interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). 4-Hydroxybenzoic acid is a good hydrogen-bond donor and can form cocrystals with other organic molecules (Vishweshwar et al., 2003). We have recently reported the crystal structures of 2-amino-5-methylpyridinium 3-aminobenzoate (Hemamalini & Fun, 2010a), 2-amino-5-methylpyridinium 4-nitrobenzoate (Hemamalini & Fun, 2010b) and 2-amino-5-methylpyridinium nicotinate (Hemamalini & Fun, 2010c). In continuation of our studies of pyrimidinium derivatives, the crystal structure determination of the title compound has been undertaken.

The asymmetric unit (Fig. 1) contains a 2-amino-5-methylpyridinium cation and a 4-hydroxybenzoate anion. In the 2-amino-5-methylpyridinium cation, a wide angle (122.65 (6)°) is subtended at the protonated N1 atom. The 2-amino-5-methylpyridinium cation is planar, with a maximum deviation of 0.024 (1)Å for atom N1. The bond lengths are normal (Allen et al., 1987). In the 4-hydroxybenzoate anion, the carboxylate group is twisted slightly from the attached ring; the dihedral angle between C7–C12 and O2/O3/C12–C13 planes is 13.07 (4)°.

In the crystal packing (Fig. 2), the protonated N1 atom and the 2-amino group N2 atom are hydrogen-bonded to the carboxylate oxygen atoms (O2 and O3) via a pair of N—H···O hydrogen bonds forming a ring motif R₂²(8) (Bernstein et al., 1995). The hydroxyl group hydrogen atom is also hydrogen-bonded to the carboxylate oxygen atom through O1—H1O1···O2 hydrogen bonds. The packing is further stabilized by weak C—H···O and π–π interactions involving the pyridinium (centroid Cg1) rings, with Cg1–Cg1 = 3.7599 (4)Å [symmetry codes: 1-x, 1-y, 1-z].

Related literature top

For background to the chemistry of substituted pyridines see: Pozharski et al. (1997); Katritzky et al. (1996). For related structures, see: Hemamalini & Fun (2010a,b,c). For 4-hydroxybenzoic acid see: Vishweshwar et al. (2003). For details of hydrogen bonding, see: Jeffrey & Saenger (1991); Jeffrey (1997); Scheiner (1997); Aakeröy et al. (2002). For hydrogen-bond motifs, see: Bernstein et al. (1995). For bond-length data, see: Allen et al. (1987). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

Experimental top

A hot methanol solution (20 ml) of 2-amino-5-methylpyridine (54 mg, Aldrich) and 4-hydroxybenzoic acid (69 mg, Merck) were mixed and warmed over a heating magnetic stirrer for a few minutes. The resulting solution was allowed to cool slowly at room temperature and crystals 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. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The crystal packing of the title compound, showing hydrogen-bonded (dashed lines) networks. H atoms are not involing the hydrogen bond interactions are omitted for clarity.

2-Amino-5-methylpyridinium 4-hydroxybenzoate top

Crystal data top

C₆H₉N₂⁺·C₇H₅O₃⁻	F(000) = 520
M_r = 246.26	D_x = 1.337 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9907 reflections
a = 12.9562 (6) Å	θ = 6.5–36.2°
b = 8.7876 (4) Å	µ = 0.10 mm⁻¹
c = 11.3276 (5) Å	T = 100 K
β = 108.397 (1)°	Blcok, colourless
V = 1223.78 (10) Å³	0.39 × 0.33 × 0.27 mm
Z = 4

Data collection top

Bruker APEX DUO CCD area-detector diffractometer	5326 independent reflections
Radiation source: fine-focus sealed tube	4662 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.019
ϕ and ω scans	θ_max = 35.0°, θ_min = 6.2°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −19→20
T_min = 0.963, T_max = 0.975	k = −14→11
20102 measured reflections	l = −18→15

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.137	H atoms treated by a mixture of independent and constrained refinement
S = 1.15	w = 1/[σ²(F_o²) + (0.0859P)² + 0.1288P] where P = (F_o² + 2F_c²)/3
5326 reflections	(Δ/σ)_max = 0.001
219 parameters	Δρ_max = 0.60 e Å⁻³
0 restraints	Δρ_min = −0.32 e Å⁻³

Crystal data top

C₆H₉N₂⁺·C₇H₅O₃⁻	V = 1223.78 (10) Å³
M_r = 246.26	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.9562 (6) Å	µ = 0.10 mm⁻¹
b = 8.7876 (4) Å	T = 100 K
c = 11.3276 (5) Å	0.39 × 0.33 × 0.27 mm
β = 108.397 (1)°

Data collection top

Bruker APEX DUO CCD area-detector diffractometer	5326 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	4662 reflections with I > 2σ(I)
T_min = 0.963, T_max = 0.975	R_int = 0.019
20102 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	0 restraints
wR(F²) = 0.137	H atoms treated by a mixture of independent and constrained refinement
S = 1.15	Δρ_max = 0.60 e Å⁻³
5326 reflections	Δρ_min = −0.32 e Å⁻³
219 parameters

Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	−0.07705 (4)	1.29454 (6)	0.44060 (5)	0.01923 (12)
O2	0.23879 (4)	0.85691 (6)	0.26656 (5)	0.01752 (11)
O3	0.34273 (4)	0.90704 (7)	0.45979 (5)	0.02001 (12)
C7	0.17088 (6)	1.07237 (8)	0.50635 (6)	0.01751 (13)
C8	0.08861 (6)	1.16244 (9)	0.52300 (6)	0.01815 (13)
C9	0.00128 (5)	1.20628 (7)	0.42014 (6)	0.01493 (12)
C10	−0.00280 (5)	1.15864 (8)	0.30079 (6)	0.01519 (12)
C11	0.07897 (5)	1.06554 (8)	0.28576 (6)	0.01482 (12)
C12	0.16699 (5)	1.02150 (7)	0.38786 (6)	0.01410 (11)
C13	0.25438 (5)	0.92210 (8)	0.37051 (6)	0.01435 (12)
N1	0.48836 (5)	0.71343 (7)	0.42194 (5)	0.01544 (11)
N2	0.39201 (5)	0.66496 (8)	0.21647 (6)	0.01851 (12)
C1	0.48185 (5)	0.64504 (7)	0.31296 (6)	0.01461 (12)
C2	0.57195 (6)	0.55617 (8)	0.30846 (6)	0.01732 (13)
C3	0.65954 (6)	0.53911 (8)	0.41374 (7)	0.01848 (13)
C4	0.66298 (5)	0.60787 (8)	0.52806 (6)	0.01614 (12)
C5	0.57535 (5)	0.69542 (8)	0.52670 (6)	0.01641 (12)
C6	0.75785 (6)	0.58625 (10)	0.64330 (7)	0.02191 (14)
H2A	0.5718 (11)	0.5103 (16)	0.2257 (12)	0.027 (3)*
H3A	0.7256 (12)	0.4762 (18)	0.4148 (13)	0.034 (3)*
H5A	0.5712 (11)	0.7533 (16)	0.5988 (13)	0.027 (3)*
H6A	0.7657 (12)	0.4804 (19)	0.6662 (14)	0.039 (4)*
H6B	0.8244 (13)	0.6124 (18)	0.6294 (14)	0.038 (4)*
H6C	0.7483 (13)	0.6507 (19)	0.7124 (16)	0.040 (4)*
H7A	0.2334 (11)	1.0425 (17)	0.5794 (13)	0.029 (3)*
H8A	0.0899 (13)	1.2010 (18)	0.6068 (15)	0.038 (4)*
H10A	−0.0628 (12)	1.1968 (16)	0.2289 (14)	0.030 (3)*
H11A	0.0758 (10)	1.0333 (15)	0.2012 (11)	0.021 (3)*
H101	−0.1257 (15)	1.3172 (19)	0.3673 (16)	0.045 (4)*
H1N1	0.4304 (13)	0.7749 (19)	0.4310 (14)	0.038 (4)*
H1N2	0.3819 (12)	0.6231 (15)	0.1407 (13)	0.028 (3)*
H2N2	0.3394 (11)	0.7245 (15)	0.2326 (12)	0.025 (3)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0165 (2)	0.0239 (3)	0.0175 (2)	0.00637 (17)	0.00561 (18)	0.00151 (18)
O2	0.0140 (2)	0.0240 (2)	0.0143 (2)	0.00056 (16)	0.00405 (16)	−0.00257 (17)
O3	0.0149 (2)	0.0292 (3)	0.0137 (2)	0.00667 (18)	0.00134 (16)	−0.00034 (18)
C7	0.0160 (3)	0.0233 (3)	0.0122 (2)	0.0047 (2)	0.0029 (2)	0.0015 (2)
C8	0.0176 (3)	0.0240 (3)	0.0124 (2)	0.0053 (2)	0.0041 (2)	0.0011 (2)
C9	0.0131 (2)	0.0166 (3)	0.0150 (2)	0.00114 (18)	0.00441 (19)	0.00139 (19)
C10	0.0128 (2)	0.0175 (3)	0.0136 (2)	0.00088 (19)	0.00182 (19)	0.00068 (19)
C11	0.0137 (2)	0.0171 (3)	0.0126 (2)	0.00074 (19)	0.00256 (19)	0.00033 (19)
C12	0.0123 (2)	0.0169 (2)	0.0127 (2)	0.00125 (18)	0.00344 (18)	0.00125 (19)
C13	0.0125 (2)	0.0180 (3)	0.0127 (2)	0.00072 (19)	0.00415 (19)	0.00162 (19)
N1	0.0147 (2)	0.0176 (2)	0.0136 (2)	0.00132 (17)	0.00391 (18)	−0.00160 (17)
N2	0.0164 (2)	0.0227 (3)	0.0144 (2)	0.00148 (19)	0.00197 (19)	−0.00235 (19)
C1	0.0152 (2)	0.0154 (2)	0.0135 (2)	−0.00101 (18)	0.0050 (2)	−0.00051 (19)
C2	0.0187 (3)	0.0187 (3)	0.0155 (3)	0.0024 (2)	0.0067 (2)	−0.0014 (2)
C3	0.0174 (3)	0.0202 (3)	0.0185 (3)	0.0030 (2)	0.0066 (2)	−0.0001 (2)
C4	0.0144 (2)	0.0177 (3)	0.0158 (3)	−0.0001 (2)	0.0041 (2)	0.0008 (2)
C5	0.0160 (3)	0.0193 (3)	0.0134 (2)	0.0003 (2)	0.0039 (2)	−0.0015 (2)
C6	0.0163 (3)	0.0271 (3)	0.0193 (3)	0.0001 (2)	0.0013 (2)	0.0036 (2)

Geometric parameters (Å, º) top

O1—C9	1.3541 (8)	N1—C5	1.3636 (9)
O1—H101	0.893 (18)	N1—H1N1	0.956 (16)
O2—C13	1.2670 (8)	N2—C1	1.3331 (9)
O3—C13	1.2728 (8)	N2—H1N2	0.904 (14)
C7—C8	1.3875 (9)	N2—H2N2	0.922 (14)
C7—C12	1.4004 (9)	C1—C2	1.4187 (9)
C7—H7A	0.993 (14)	C2—C3	1.3705 (10)
C8—C9	1.3978 (9)	C2—H2A	1.020 (13)
C8—H8A	1.003 (15)	C3—C4	1.4169 (10)
C9—C10	1.4003 (9)	C3—H3A	1.016 (15)
C10—C11	1.3909 (9)	C4—C5	1.3675 (9)
C10—H10A	0.990 (15)	C4—C6	1.4962 (10)
C11—C12	1.3984 (9)	C5—H5A	0.978 (14)
C11—H11A	0.987 (12)	C6—H6A	0.963 (16)
C12—C13	1.4912 (9)	C6—H6B	0.952 (16)
N1—C1	1.3516 (8)	C6—H6C	1.006 (17)

C9—O1—H101	108.4 (11)	C1—N2—H1N2	123.5 (9)
C8—C7—C12	121.04 (6)	C1—N2—H2N2	114.9 (8)
C8—C7—H7A	119.8 (8)	H1N2—N2—H2N2	121.6 (12)
C12—C7—H7A	119.1 (8)	N2—C1—N1	118.50 (6)
C7—C8—C9	119.89 (6)	N2—C1—C2	123.94 (6)
C7—C8—H8A	122.5 (9)	N1—C1—C2	117.56 (6)
C9—C8—H8A	117.6 (9)	C3—C2—C1	119.59 (6)
O1—C9—C8	117.93 (6)	C3—C2—H2A	121.2 (8)
O1—C9—C10	122.31 (6)	C1—C2—H2A	119.2 (8)
C8—C9—C10	119.76 (6)	C2—C3—C4	121.81 (6)
C11—C10—C9	119.73 (6)	C2—C3—H3A	122.2 (8)
C11—C10—H10A	122.0 (9)	C4—C3—H3A	116.0 (8)
C9—C10—H10A	118.2 (9)	C5—C4—C3	116.31 (6)
C10—C11—C12	121.02 (6)	C5—C4—C6	122.13 (6)
C10—C11—H11A	119.2 (7)	C3—C4—C6	121.56 (6)
C12—C11—H11A	119.7 (7)	N1—C5—C4	122.03 (6)
C11—C12—C7	118.53 (6)	N1—C5—H5A	114.7 (8)
C11—C12—C13	120.53 (6)	C4—C5—H5A	123.2 (8)
C7—C12—C13	120.94 (6)	C4—C6—H6A	110.2 (9)
O2—C13—O3	122.08 (6)	C4—C6—H6B	111.2 (9)
O2—C13—C12	118.84 (6)	H6A—C6—H6B	104.7 (13)
O3—C13—C12	119.08 (6)	C4—C6—H6C	109.8 (9)
C1—N1—C5	122.65 (6)	H6A—C6—H6C	111.4 (13)
C1—N1—H1N1	121.6 (9)	H6B—C6—H6C	109.5 (13)
C5—N1—H1N1	115.7 (9)

C12—C7—C8—C9	−1.35 (11)	C11—C12—C13—O3	166.93 (6)
C7—C8—C9—O1	−179.81 (6)	C7—C12—C13—O3	−13.29 (10)
C7—C8—C9—C10	0.17 (11)	C5—N1—C1—N2	177.71 (6)
O1—C9—C10—C11	−178.73 (6)	C5—N1—C1—C2	−2.43 (10)
C8—C9—C10—C11	1.29 (10)	N2—C1—C2—C3	−178.20 (7)
C9—C10—C11—C12	−1.60 (10)	N1—C1—C2—C3	1.94 (10)
C10—C11—C12—C7	0.44 (10)	C1—C2—C3—C4	0.08 (11)
C10—C11—C12—C13	−179.77 (6)	C2—C3—C4—C5	−1.66 (11)
C8—C7—C12—C11	1.05 (11)	C2—C3—C4—C6	178.74 (7)
C8—C7—C12—C13	−178.74 (6)	C1—N1—C5—C4	0.83 (11)
C11—C12—C13—O2	−12.12 (10)	C3—C4—C5—N1	1.25 (10)
C7—C12—C13—O2	167.67 (6)	C6—C4—C5—N1	−179.16 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···O3	0.957 (17)	1.726 (17)	2.6738 (9)	170.4 (15)
N2—H1N2···O3ⁱ	0.905 (14)	1.967 (14)	2.8443 (9)	162.9 (13)
N2—H2N2···O2	0.922 (14)	1.876 (14)	2.7962 (9)	176.1 (13)
O1—H101···O2ⁱⁱ	0.892 (18)	1.779 (18)	2.6635 (8)	170.7 (19)
C3—H3A···O2ⁱⁱⁱ	1.016 (16)	2.476 (15)	3.1887 (9)	126.7 (10)

Symmetry codes: (i) x, −y+3/2, z−1/2; (ii) −x, y+1/2, −z+1/2; (iii) −x+1, y−1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₆H₉N₂⁺·C₇H₅O₃⁻
M_r	246.26
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	12.9562 (6), 8.7876 (4), 11.3276 (5)
β (°)	108.397 (1)
V (Å³)	1223.78 (10)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.39 × 0.33 × 0.27

Data collection
Diffractometer	Bruker APEX DUO CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.963, 0.975
No. of measured, independent and observed [I > 2σ(I)] reflections	20102, 5326, 4662
R_int	0.019
(sin θ/λ)_max (Å⁻¹)	0.807

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.039, 0.137, 1.15
No. of reflections	5326
No. of parameters	219
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.60, −0.32

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
N1—H1N1···O3	0.957 (17)	1.726 (17)	2.6738 (9)	170.4 (15)
N2—H1N2···O3ⁱ	0.905 (14)	1.967 (14)	2.8443 (9)	162.9 (13)
N2—H2N2···O2	0.922 (14)	1.876 (14)	2.7962 (9)	176.1 (13)
O1—H101···O2ⁱⁱ	0.892 (18)	1.779 (18)	2.6635 (8)	170.7 (19)
C3—H3A···O2ⁱⁱⁱ	1.016 (16)	2.476 (15)	3.1887 (9)	126.7 (10)

Symmetry codes: (i) x, −y+3/2, z−1/2; (ii) −x, y+1/2, −z+1/2; (iii) −x+1, y−1/2, −z+1/2.

Footnotes

‡Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

MH and HKF thank the Malaysian Government and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. MH also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

References

Aakeröy, C. B., Beatty, A. M. & Helfrich, B. A. (2002). J. Am. Chem. Soc. 124, 14425–14432. Web of Science PubMed Google Scholar
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107. CrossRef CAS Web of Science IUCr Journals Google Scholar
Hemamalini, M. & Fun, H.-K. (2010a). Acta Cryst. E66, o623–o624. Web of Science CSD CrossRef IUCr Journals Google Scholar
Hemamalini, M. & Fun, H.-K. (2010b). Acta Cryst. E66, o621. Web of Science CSD CrossRef IUCr Journals Google Scholar
Hemamalini, M. & Fun, H.-K. (2010c). Acta Cryst. E66, o662. Web of Science CSD CrossRef IUCr Journals Google Scholar
Jeffrey, G. A. (1997). An Introduction to Hydrogen Bonding. Oxford University Press. Google Scholar
Jeffrey, G. A. & Saenger, W. (1991). Hydrogen Bonding in Biological Structures. Berlin: Springer. Google Scholar
Katritzky, A. R., Rees, C. W. & Scriven, E. F. V. (1996). Comprehensive Heterocyclic Chemistry II. Oxford: Pergamon Press. Google Scholar
Pozharski, A. F., Soldatenkov, A. T. & Katritzky, A. R. (1997). Heterocycles in Life and Society. New York: Wiley. Google Scholar
Scheiner, S. (1997). Hydrogen Bonding. A Theoretical Perspective. Oxford University Press. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Vishweshwar, P., Nangia, A. & Lynch, V. M. (2003). CrystEngComm. 5, 164–168. Web of Science CSD CrossRef CAS Google Scholar