N-(2-Pyrid­yl)-4-toluidine

Fairuz, Z.A.; Aiyub, Z.; Abdullah, Z.; Ng, S.W.

doi:10.1107/S1600536808037306

organic compounds

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ISSN: 2056-9890

Volume 64| Part 12| December 2008| Page o2441

doi:10.1107/S1600536808037306

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N-(2-Pyridyl)-4-toluidine

Zainal Abidin Fairuz,^a Zaharah Aiyub,^a Zanariah Abdullah ^a and Seik Weng Ng ^a ^*

^aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
^*Correspondence e-mail: seikweng@um.edu.my

(Received 19 October 2008; accepted 11 November 2008; online 26 November 2008)

There are two molecules in the asymmetric unit of the title compound, C₁₂H₁₂N₂, with dihedral angles between the aromatic rings of 48.35 (12) and 51.02 (12)°. In the crystal structure, both molecules form inversion dimers, linked by pairs of N—H⋯N hydrogen bonds.

Related literature

For the crystal structure of N-(2-pyridyl)aniline, see: Polamo et al. (1997 )

Experimental

Crystal data

C₁₂H₁₂N₂
M_r = 184.24
Monoclinic, P 2₁ /c
a = 18.2260 (7) Å
b = 10.5680 (3) Å
c = 10.6005 (3) Å
β = 95.364 (2)°
V = 2032.9 (1) Å³
Z = 8
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 100 (2) K
0.30 × 0.10 × 0.05 mm

Data collection

Bruker SMART APEX diffractometer
Absorption correction: none
18430 measured reflections
4676 independent reflections
2774 reflections with I > 2σ(I)
R_int = 0.066

Refinement

R[F² > 2σ(F²)] = 0.070
wR(F²) = 0.206
S = 1.01
4676 reflections
263 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.64 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1n⋯N2ⁱ	0.88 (1)	2.06 (1)	2.944 (3)	174 (3)
N3—H3n⋯N4ⁱⁱ	0.91 (1)	2.08 (2)	2.949 (3)	159 (3)
Symmetry codes: (i) -x, -y+1, -z; (ii) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); 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, 2008 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808037306/sg2278sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808037306/sg2278Isup2.hkl

checkCIF report

Comment top

There are two molecules in the asymmetric unit (Fig. 1) of the title compound, C₁₂H₁₂N₂, with dihedral angles between the aromatic rings of 48.35 (12)° and 51.02 (12)°. In the crystal, both molecules form inversion dimers, linked by pairs of N—H···N hydrogen bonds (Table 1). For the related crystal structure of N-(2-pyridyl)aniline, see: Polamo et al. (1997)

Related literature top

For the crystal structure of N-(2-pyridyl)aniline, see: Polamo et al. (1997)

Experimental top

Chloropyridine (0.5 ml, 0.5 mmol) and 4-toluidine (0.6 g, 0.5 mmol) were heated at 423–433 K for 3 h. The solid was dissolved in water. The compound was extracted with ether. The ether extract was dried over sodium sulfate. The solvent was evaporated and the product recrystallized from ethanol to yield colorless prisms of (I) among some unidentified dark brown materials.

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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, 2008).

Figures top

Fig. 1. The molecular structure of (I), with displacement ellipsoids at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius.

N-(2-Pyridyl)-4-toluidine top

Crystal data top

C₁₂H₁₂N₂	F(000) = 784
M_r = 184.24	D_x = 1.204 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1819 reflections
a = 18.2260 (7) Å	θ = 2.2–24.4°
b = 10.5680 (3) Å	µ = 0.07 mm⁻¹
c = 10.6005 (3) Å	T = 100 K
β = 95.364 (2)°	Prism, colorless
V = 2032.9 (1) Å³	0.30 × 0.10 × 0.05 mm
Z = 8

Data collection top

Bruker SMART APEX diffractometer	2774 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.066
Graphite monochromator	θ_max = 27.5°, θ_min = 1.1°
ω scans	h = −23→23
18430 measured reflections	k = −13→13
4676 independent reflections	l = −13→13

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)] = 0.070	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.206	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ²(F_o²) + (0.0922P)² + 1.1608P] where P = (F_o² + 2F_c²)/3
4676 reflections	(Δ/σ)_max = 0.001
263 parameters	Δρ_max = 0.64 e Å⁻³
2 restraints	Δρ_min = −0.31 e Å⁻³

Crystal data top

C₁₂H₁₂N₂	V = 2032.9 (1) Å³
M_r = 184.24	Z = 8
Monoclinic, P2₁/c	Mo Kα radiation
a = 18.2260 (7) Å	µ = 0.07 mm⁻¹
b = 10.5680 (3) Å	T = 100 K
c = 10.6005 (3) Å	0.30 × 0.10 × 0.05 mm
β = 95.364 (2)°

Data collection top

Bruker SMART APEX diffractometer	2774 reflections with I > 2σ(I)
18430 measured reflections	R_int = 0.066
4676 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.070	2 restraints
wR(F²) = 0.206	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	Δρ_max = 0.64 e Å⁻³
4676 reflections	Δρ_min = −0.31 e Å⁻³
263 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.09908 (12)	0.46043 (18)	0.0668 (2)	0.0267 (5)
N2	−0.01070 (12)	0.37392 (18)	0.11163 (19)	0.0279 (5)
N3	0.40746 (13)	0.5526 (2)	0.5578 (2)	0.0350 (6)
N4	0.52478 (13)	0.60957 (18)	0.62565 (19)	0.0317 (5)
C1	0.17505 (14)	0.4657 (2)	0.0530 (2)	0.0258 (5)
C2	0.21791 (14)	0.3582 (2)	0.0393 (2)	0.0293 (6)
H2	0.1962	0.2766	0.0418	0.035*
C3	0.29141 (14)	0.3698 (3)	0.0221 (3)	0.0337 (6)
H3	0.3198	0.2954	0.0138	0.040*
C4	0.32560 (15)	0.4877 (3)	0.0164 (3)	0.0334 (6)
C5	0.28179 (15)	0.5943 (2)	0.0269 (3)	0.0340 (6)
H5	0.3031	0.6759	0.0208	0.041*
C6	0.20817 (15)	0.5841 (2)	0.0460 (2)	0.0312 (6)
H0	0.1798	0.6585	0.0543	0.037*
C7	0.40666 (16)	0.4993 (3)	0.0012 (3)	0.0419 (7)
H7A	0.4166	0.5822	−0.0350	0.063*
H7B	0.4213	0.4325	−0.0555	0.063*
H7C	0.4348	0.4907	0.0841	0.063*
C8	0.06324 (14)	0.3732 (2)	0.1354 (2)	0.0269 (6)
C9	0.09904 (15)	0.2931 (2)	0.2268 (2)	0.0311 (6)
H9	0.1512	0.2944	0.2431	0.037*
C10	0.05715 (17)	0.2127 (2)	0.2923 (3)	0.0371 (7)
H10	0.0804	0.1573	0.3544	0.045*
C11	−0.01855 (16)	0.2121 (2)	0.2684 (3)	0.0377 (7)
H11	−0.0482	0.1566	0.3126	0.045*
C12	−0.04948 (16)	0.2946 (2)	0.1783 (3)	0.0340 (6)
H12	−0.1016	0.2955	0.1624	0.041*
C13	0.32986 (15)	0.5449 (2)	0.5522 (3)	0.0324 (6)
C14	0.29295 (16)	0.5298 (3)	0.6599 (3)	0.0377 (7)
H14	0.3199	0.5265	0.7410	0.045*
C15	0.21749 (16)	0.5196 (3)	0.6495 (3)	0.0379 (7)
H15	0.1931	0.5108	0.7244	0.045*
C16	0.17531 (15)	0.5217 (2)	0.5326 (3)	0.0342 (6)
C17	0.21226 (16)	0.5333 (2)	0.4247 (3)	0.0343 (6)
H17	0.1853	0.5331	0.3436	0.041*
C18	0.28849 (16)	0.5451 (2)	0.4344 (3)	0.0357 (7)
H18	0.3129	0.5536	0.3595	0.043*
C19	0.09289 (16)	0.5105 (3)	0.5244 (3)	0.0446 (7)
H19A	0.0753	0.4663	0.4461	0.067*
H19B	0.0710	0.5951	0.5244	0.067*
H19C	0.0786	0.4626	0.5975	0.067*
C20	0.45389 (16)	0.6270 (2)	0.6362 (2)	0.0318 (6)
C21	0.42898 (18)	0.7175 (2)	0.7187 (3)	0.0388 (7)
H21	0.3779	0.7288	0.7261	0.047*
C22	0.48103 (17)	0.7898 (2)	0.7891 (3)	0.0391 (7)
H22	0.4653	0.8516	0.8458	0.047*
C23	0.55493 (18)	0.7741 (2)	0.7787 (3)	0.0412 (7)
H23	0.5908	0.8242	0.8264	0.049*
C24	0.57493 (18)	0.6821 (2)	0.6957 (3)	0.0404 (7)
H24	0.6258	0.6690	0.6874	0.049*
H1N	0.0699 (14)	0.510 (2)	0.017 (2)	0.047 (9)*
H3N	0.4165 (16)	0.495 (2)	0.498 (2)	0.045 (9)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0326 (12)	0.0186 (10)	0.0293 (12)	0.0017 (9)	0.0053 (9)	0.0041 (8)
N2	0.0344 (12)	0.0213 (10)	0.0291 (12)	0.0011 (9)	0.0080 (9)	0.0022 (8)
N3	0.0438 (14)	0.0293 (12)	0.0327 (13)	−0.0009 (10)	0.0075 (11)	−0.0068 (10)
N4	0.0537 (15)	0.0173 (10)	0.0240 (11)	−0.0013 (10)	0.0032 (10)	−0.0002 (8)
C1	0.0341 (14)	0.0227 (12)	0.0206 (12)	−0.0018 (10)	0.0022 (10)	−0.0012 (9)
C2	0.0361 (15)	0.0211 (12)	0.0302 (14)	−0.0005 (11)	0.0012 (11)	−0.0006 (10)
C3	0.0340 (15)	0.0325 (14)	0.0342 (15)	0.0038 (12)	0.0006 (12)	0.0000 (11)
C4	0.0347 (15)	0.0372 (15)	0.0279 (14)	−0.0031 (12)	0.0015 (11)	0.0026 (11)
C5	0.0437 (17)	0.0266 (13)	0.0316 (15)	−0.0074 (12)	0.0022 (12)	0.0034 (11)
C6	0.0413 (16)	0.0220 (12)	0.0306 (14)	−0.0002 (11)	0.0043 (12)	0.0015 (10)
C7	0.0378 (17)	0.0472 (17)	0.0410 (17)	−0.0038 (13)	0.0053 (13)	0.0045 (13)
C8	0.0414 (15)	0.0165 (11)	0.0237 (13)	−0.0001 (10)	0.0077 (11)	−0.0019 (9)
C9	0.0399 (16)	0.0256 (13)	0.0273 (14)	−0.0003 (11)	0.0009 (11)	0.0009 (10)
C10	0.0548 (19)	0.0287 (14)	0.0280 (15)	−0.0006 (13)	0.0046 (13)	0.0070 (11)
C11	0.0512 (18)	0.0289 (14)	0.0342 (16)	−0.0050 (13)	0.0112 (13)	0.0072 (11)
C12	0.0413 (16)	0.0302 (14)	0.0320 (15)	−0.0034 (12)	0.0103 (12)	0.0034 (11)
C13	0.0402 (16)	0.0240 (13)	0.0331 (15)	0.0023 (11)	0.0033 (12)	−0.0010 (11)
C14	0.0434 (17)	0.0361 (15)	0.0338 (15)	0.0017 (13)	0.0043 (13)	0.0060 (12)
C15	0.0438 (17)	0.0321 (14)	0.0383 (16)	0.0028 (12)	0.0069 (13)	0.0044 (12)
C16	0.0366 (16)	0.0218 (12)	0.0449 (17)	0.0031 (11)	0.0083 (13)	−0.0004 (11)
C17	0.0455 (17)	0.0228 (13)	0.0350 (15)	0.0008 (12)	0.0056 (12)	0.0003 (11)
C18	0.0477 (17)	0.0266 (14)	0.0343 (15)	−0.0010 (12)	0.0112 (13)	−0.0005 (11)
C19	0.0379 (17)	0.0482 (18)	0.0481 (19)	0.0053 (14)	0.0067 (14)	0.0015 (14)
C20	0.0491 (17)	0.0213 (12)	0.0253 (14)	−0.0014 (11)	0.0044 (12)	0.0031 (10)
C21	0.0591 (19)	0.0267 (14)	0.0309 (15)	−0.0007 (13)	0.0052 (13)	−0.0021 (11)
C22	0.065 (2)	0.0221 (13)	0.0298 (15)	0.0027 (13)	0.0000 (14)	−0.0040 (11)
C23	0.069 (2)	0.0218 (13)	0.0313 (16)	0.0038 (13)	−0.0040 (14)	−0.0044 (11)
C24	0.0553 (19)	0.0253 (13)	0.0404 (17)	0.0010 (13)	0.0025 (14)	−0.0005 (12)

Geometric parameters (Å, º) top

N1—C8	1.376 (3)	C10—C11	1.379 (4)
N1—C1	1.407 (3)	C10—H10	0.9500
N1—H1N	0.884 (10)	C11—C12	1.375 (4)
N2—C12	1.340 (3)	C11—H11	0.9500
N2—C8	1.348 (3)	C12—H12	0.9500
N3—C20	1.376 (3)	C13—C14	1.388 (4)
N3—C13	1.412 (3)	C13—C18	1.398 (4)
N3—H3N	0.911 (10)	C14—C15	1.374 (4)
N4—C20	1.320 (3)	C14—H14	0.9500
N4—C24	1.359 (3)	C15—C16	1.396 (4)
C1—C2	1.393 (3)	C15—H15	0.9500
C1—C6	1.395 (3)	C16—C17	1.385 (4)
C2—C3	1.374 (4)	C16—C19	1.501 (4)
C2—H2	0.9500	C17—C18	1.389 (4)
C3—C4	1.397 (4)	C17—H17	0.9500
C3—H3	0.9500	C18—H18	0.9500
C4—C5	1.391 (4)	C19—H19A	0.9800
C4—C7	1.506 (4)	C19—H19B	0.9800
C5—C6	1.380 (4)	C19—H19C	0.9800
C5—H5	0.9500	C20—C21	1.400 (4)
C6—H0	0.9500	C21—C22	1.381 (4)
C7—H7A	0.9800	C21—H21	0.9500
C7—H7B	0.9800	C22—C23	1.372 (4)
C7—H7C	0.9800	C22—H22	0.9500
C8—C9	1.400 (3)	C23—C24	1.382 (4)
C9—C10	1.374 (4)	C23—H23	0.9500
C9—H9	0.9500	C24—H24	0.9500

C8—N1—C1	127.0 (2)	C10—C11—H11	121.2
C8—N1—H1N	115 (2)	N2—C12—C11	124.1 (3)
C1—N1—H1N	117 (2)	N2—C12—H12	117.9
C12—N2—C8	117.7 (2)	C11—C12—H12	117.9
C20—N3—C13	128.0 (2)	C14—C13—C18	118.2 (3)
C20—N3—H3N	131.8 (19)	C14—C13—N3	122.2 (3)
C13—N3—H3N	100.2 (19)	C18—C13—N3	119.5 (2)
C20—N4—C24	119.2 (2)	C15—C14—C13	120.1 (3)
C2—C1—C6	118.4 (2)	C15—C14—H14	119.9
C2—C1—N1	123.1 (2)	C13—C14—H14	119.9
C6—C1—N1	118.4 (2)	C14—C15—C16	122.3 (3)
C3—C2—C1	120.3 (2)	C14—C15—H15	118.8
C3—C2—H2	119.9	C16—C15—H15	118.8
C1—C2—H2	119.9	C17—C16—C15	117.7 (3)
C2—C3—C4	122.0 (2)	C17—C16—C19	121.4 (3)
C2—C3—H3	119.0	C15—C16—C19	121.0 (3)
C4—C3—H3	119.0	C16—C17—C18	120.5 (3)
C5—C4—C3	117.2 (2)	C16—C17—H17	119.8
C5—C4—C7	121.3 (2)	C18—C17—H17	119.8
C3—C4—C7	121.5 (3)	C17—C18—C13	121.2 (3)
C6—C5—C4	121.5 (2)	C17—C18—H18	119.4
C6—C5—H5	119.3	C13—C18—H18	119.4
C4—C5—H5	119.3	C16—C19—H19A	109.5
C5—C6—C1	120.6 (2)	C16—C19—H19B	109.5
C5—C6—H0	119.7	H19A—C19—H19B	109.5
C1—C6—H0	119.7	C16—C19—H19C	109.5
C4—C7—H7A	109.5	H19A—C19—H19C	109.5
C4—C7—H7B	109.5	H19B—C19—H19C	109.5
H7A—C7—H7B	109.5	N4—C20—N3	114.9 (2)
C4—C7—H7C	109.5	N4—C20—C21	121.7 (3)
H7A—C7—H7C	109.5	N3—C20—C21	123.4 (3)
H7B—C7—H7C	109.5	C22—C21—C20	118.0 (3)
N2—C8—N1	114.4 (2)	C22—C21—H21	121.0
N2—C8—C9	121.7 (2)	C20—C21—H21	121.0
N1—C8—C9	123.8 (2)	C23—C22—C21	121.3 (3)
C10—C9—C8	118.6 (3)	C23—C22—H22	119.4
C10—C9—H9	120.7	C21—C22—H22	119.4
C8—C9—H9	120.7	C22—C23—C24	117.1 (3)
C9—C10—C11	120.3 (3)	C22—C23—H23	121.4
C9—C10—H10	119.9	C24—C23—H23	121.4
C11—C10—H10	119.9	N4—C24—C23	122.7 (3)
C12—C11—C10	117.6 (2)	N4—C24—H24	118.7
C12—C11—H11	121.2	C23—C24—H24	118.7

C8—N1—C1—C2	39.0 (4)	C20—N3—C13—C14	−48.6 (4)
C8—N1—C1—C6	−144.6 (2)	C20—N3—C13—C18	135.1 (3)
C6—C1—C2—C3	1.5 (4)	C18—C13—C14—C15	−2.0 (4)
N1—C1—C2—C3	177.9 (2)	N3—C13—C14—C15	−178.4 (2)
C1—C2—C3—C4	−0.7 (4)	C13—C14—C15—C16	1.1 (4)
C2—C3—C4—C5	−1.0 (4)	C14—C15—C16—C17	0.7 (4)
C2—C3—C4—C7	178.3 (2)	C14—C15—C16—C19	−179.9 (3)
C3—C4—C5—C6	1.9 (4)	C15—C16—C17—C18	−1.4 (4)
C7—C4—C5—C6	−177.4 (2)	C19—C16—C17—C18	179.2 (2)
C4—C5—C6—C1	−1.1 (4)	C16—C17—C18—C13	0.4 (4)
C2—C1—C6—C5	−0.6 (4)	C14—C13—C18—C17	1.3 (4)
N1—C1—C6—C5	−177.2 (2)	N3—C13—C18—C17	177.8 (2)
C12—N2—C8—N1	−177.6 (2)	C24—N4—C20—N3	177.5 (2)
C12—N2—C8—C9	−0.2 (3)	C24—N4—C20—C21	−0.7 (4)
C1—N1—C8—N2	−166.9 (2)	C13—N3—C20—N4	176.3 (2)
C1—N1—C8—C9	15.8 (4)	C13—N3—C20—C21	−5.5 (4)
N2—C8—C9—C10	0.7 (4)	N4—C20—C21—C22	0.5 (4)
N1—C8—C9—C10	177.8 (2)	N3—C20—C21—C22	−177.5 (2)
C8—C9—C10—C11	−0.3 (4)	C20—C21—C22—C23	0.1 (4)
C9—C10—C11—C12	−0.4 (4)	C21—C22—C23—C24	−0.6 (4)
C8—N2—C12—C11	−0.6 (4)	C20—N4—C24—C23	0.2 (4)
C10—C11—C12—N2	0.9 (4)	C22—C23—C24—N4	0.5 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1n···N2ⁱ	0.88 (1)	2.06 (1)	2.944 (3)	174 (3)
N3—H3n···N4ⁱⁱ	0.91 (1)	2.08 (2)	2.949 (3)	159 (3)

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

Experimental details

Crystal data
Chemical formula	C₁₂H₁₂N₂
M_r	184.24
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	18.2260 (7), 10.5680 (3), 10.6005 (3)
β (°)	95.364 (2)
V (Å³)	2032.9 (1)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.30 × 0.10 × 0.05

Data collection
Diffractometer	Bruker SMART APEX diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	18430, 4676, 2774
R_int	0.066
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.070, 0.206, 1.01
No. of reflections	4676
No. of parameters	263
No. of restraints	2
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.64, −0.31

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1n···N2ⁱ	0.88 (1)	2.06 (1)	2.944 (3)	174 (3)
N3—H3n···N4ⁱⁱ	0.91 (1)	2.08 (2)	2.949 (3)	159 (3)

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

Acknowledgements

We thank the University of Malaya for supporting this study (grant Nos. FS 358/2008 A and FP 067/2006 A).

References

Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Polamo, M., Repo, T. & Leskela, M. (1997). Acta Chem. Scand. 51, 325–329. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2008). publCIF. In preparation. Google Scholar