4-Hydrazinyl-1-isobutyl-1H-imidazo[4,5-c]quinoline

Loh, W.-S.; Fun, H.-K.; Kayarmar, R.; Viveka, S.; Nagaraja, G.K.

doi:10.1107/S1600536811001553

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 67| Part 2| February 2011| Page o406

doi:10.1107/S1600536811001553

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4-Hydrazinyl-1-isobutyl-1H-imidazo[4,5-c]quinoline

Wan-Sin Loh,^a ‡ Hoong-Kun Fun,^a ^*§ Reshma Kayarmar,^b S. Viveka ^b and G. K. Nagaraja ^b

^aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and ^bDepartment of Chemistry, Mangalore University, Karnataka, India
^*Correspondence e-mail: hkfun@usm.my

(Received 27 December 2010; accepted 11 January 2011; online 15 January 2011)

In the title compound, C₁₄H₁₇N₅, the 1H-imidazo[4,5-c]quinoline ring system is essentially planar, with a maximum deviation of 0.0325 (7) Å. In the crystal, a pair of intermolecular N—H⋯N hydrogen bonds link neighbouring molecules, forming an inversion dimer and generate an R₂²(10) ring motif. These dimers are further connected into a chain along the b axis via intermolecular C—H⋯N hydrogen bonds, resulting in an R₂²(14) ring motif.

Related literature

For background to quinolines and their microbial activity, see: Roth & Fenner (2000 ); Miller et al. (1999 ); Hirota et al. (2002 ). For bond-length data, see: Allen et al. (1987 ). For a related structure, see: Loh et al. (2011 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ).

Experimental

Crystal data

C₁₄H₁₇N₅
M_r = 255.33
Triclinic, $[P \overline 1]$
a = 5.4735 (2) Å
b = 9.1275 (3) Å
c = 13.3814 (5) Å
α = 98.076 (1)°
β = 101.787 (1)°
γ = 96.269 (1)°
V = 641.35 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 100 K
0.68 × 0.42 × 0.09 mm

Data collection

Bruker SMART APEXII DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ) T_min = 0.945, T_max = 0.992
20646 measured reflections
5797 independent reflections
4836 reflections with I > 2σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.040
wR(F²) = 0.137
S = 1.12
5797 reflections
240 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.53 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
N4—H1N4⋯N3ⁱ	0.883 (16)	2.130 (15)	2.9429 (9)	152.9 (15)
C5—H5⋯N5ⁱⁱ	1.012 (12)	2.437 (11)	3.3700 (10)	152.9 (10)
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x, -y, -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/S1600536811001553/is2657sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811001553/is2657Isup2.hkl

checkCIF report

Comment top

The quinoline scaffold is present in many classes of biologically active compounds (Roth & Fenner, 2000), as for example, in 1H-imidazo-[4,5-c]quinolines that induce IFN, as well as other cytokines, in mice, rats, guinea pigs, monkeys and humans (Miller et al., 1999). This initiated the syntheses of a series of compounds with differing substitution at N-1, C-2, C-4 and on substitution on the benzene ring. Phenoxymethyl and benzyl groups at C-2 increase the activity. All other C-4 substituents investigated fail to induce IFN production. This investigation encouraged us to substitute C-4 by- NHNH₂ in continuation of our research to explore novel series of immune response modifiers in an effort to find small molecules that treat diseases involving the immune system (Hirota et al., 2002).

In the title compound (Fig. 1), the 1H-imidazo[4,5-c]quinoline ring (C1–C6/N1/C7/C8/N3/C10/N2/C9) is approximately planar with a maximum deviation of 0.0325 (7) Å at atom C1. The torsion angle formed between this ring system and the isobutyl moiety, C10–N2–C11–C12, is 101.17 (8)°. Bond lengths (Allen et al., 1987) and angles are within the normal ranges and are comparable to the related structure (Loh et al., 2011).

In the crystal packing (Fig. 2), intermolecular N4—H1N4···N3 hydrogen bonds (Table 1) link the neighbouring molecules to form dimers and generate R₂²(10) ring motifs (Bernstein et al., 1995). These dimers are further connected into chains down the b axis via intermolecular C5—H5···N5 hydrogen bonds (Table 1), resulting in R₂²(14) ring motifs (Bernstein et al., 1995).

Related literature top

For background to quinolines and their microbial activity, see: Roth & Fenner (2000); Miller et al. (1999); Hirota et al. (2002). For bond-length data, see: Allen et al. (1987). For a related structure, see: Loh et al. (2011). For hydrogen-bond motifs, see: Bernstein et al. (1995). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

Experimental top

4-Chloro-1-(2-methylpropyl)-1H-imidazo[4,5-c]quinolone (10 g, 0.0385 mole) and hydrazine-hydrate (80%, 19.3 g, 0.385 mole) in ethanol was refluxed for 9 h during which white solids separated out. After cooling to room temperature, the resulting 4-hydrazinyl-1-(2-methylpropyl)-1H-imidazo[4,5-c]quinoline was filtered off, dried and crystallized from ethanol. Yield, 7.4 g (74%). Crystals suitable for X-ray analysis were obtained from ethanol by slow evaporation.

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 molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme.
	Fig. 2. The crystal packing of the title compound, showing the chains along the b axis. H atoms not involved in the intermolecular interactions (dashed lines) have been omitted for clarity.

4-Hydrazinyl-1-isobutyl-1H-imidazo[4,5-c]quinoline top

Crystal data top

C₁₄H₁₇N₅	Z = 2
M_r = 255.33	F(000) = 272
Triclinic, P1	D_x = 1.322 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.4735 (2) Å	Cell parameters from 9851 reflections
b = 9.1275 (3) Å	θ = 2.5–35.6°
c = 13.3814 (5) Å	µ = 0.08 mm⁻¹
α = 98.076 (1)°	T = 100 K
β = 101.787 (1)°	Plate, yellow
γ = 96.269 (1)°	0.68 × 0.42 × 0.09 mm
V = 641.35 (4) Å³

Data collection top

Bruker SMART APEXII DUO CCD area-detector diffractometer	5797 independent reflections
Radiation source: fine-focus sealed tube	4836 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
ϕ and ω scans	θ_max = 35.6°, θ_min = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −8→8
T_min = 0.945, T_max = 0.992	k = −14→14
20646 measured reflections	l = −21→21

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.137	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	w = 1/[σ²(F_o²) + (0.0821P)² + 0.0687P] where P = (F_o² + 2F_c²)/3
5797 reflections	(Δ/σ)_max = 0.001
240 parameters	Δρ_max = 0.53 e Å⁻³
0 restraints	Δρ_min = −0.32 e Å⁻³

Crystal data top

C₁₄H₁₇N₅	γ = 96.269 (1)°
M_r = 255.33	V = 641.35 (4) Å³
Triclinic, P1	Z = 2
a = 5.4735 (2) Å	Mo Kα radiation
b = 9.1275 (3) Å	µ = 0.08 mm⁻¹
c = 13.3814 (5) Å	T = 100 K
α = 98.076 (1)°	0.68 × 0.42 × 0.09 mm
β = 101.787 (1)°

Data collection top

Bruker SMART APEXII DUO CCD area-detector diffractometer	5797 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	4836 reflections with I > 2σ(I)
T_min = 0.945, T_max = 0.992	R_int = 0.023
20646 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.040	0 restraints
wR(F²) = 0.137	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	Δρ_max = 0.53 e Å⁻³
5797 reflections	Δρ_min = −0.32 e Å⁻³
240 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 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 (Å²) top

	x	y	z	U_iso*/U_eq
N3	0.66263 (12)	0.41343 (6)	0.40530 (5)	0.01739 (12)
N2	0.83913 (11)	0.28950 (6)	0.28779 (4)	0.01494 (11)
N1	0.29129 (11)	0.04458 (6)	0.39588 (4)	0.01382 (11)
N4	0.27467 (12)	0.27155 (7)	0.49606 (5)	0.01719 (12)
N5	0.09896 (12)	0.21044 (7)	0.54799 (5)	0.01683 (11)
C9	0.66447 (12)	0.18519 (7)	0.31040 (5)	0.01294 (11)
C1	0.58776 (12)	0.02794 (7)	0.27674 (5)	0.01284 (11)
C2	0.68633 (13)	−0.06582 (7)	0.20610 (5)	0.01545 (12)
C3	0.60210 (14)	−0.21733 (7)	0.18278 (5)	0.01727 (13)
C4	0.41445 (14)	−0.27919 (7)	0.22854 (6)	0.01769 (13)
C5	0.31322 (13)	−0.19005 (7)	0.29698 (5)	0.01611 (12)
C6	0.39780 (12)	−0.03437 (7)	0.32402 (5)	0.01301 (11)
C7	0.37122 (12)	0.18938 (7)	0.42576 (5)	0.01334 (11)
C8	0.55945 (13)	0.26428 (7)	0.38309 (5)	0.01385 (11)
C10	0.82902 (15)	0.42279 (7)	0.34703 (5)	0.01813 (13)
C11	1.00391 (12)	0.26889 (7)	0.21544 (5)	0.01498 (12)
C12	0.86854 (13)	0.26095 (7)	0.10230 (5)	0.01536 (12)
C13	1.04956 (16)	0.22187 (9)	0.03277 (6)	0.02337 (15)
C14	0.77216 (15)	0.40809 (8)	0.08500 (6)	0.02100 (14)
H12	0.714 (2)	0.1783 (13)	0.0858 (9)	0.022 (3)*
H5	0.188 (2)	−0.2330 (14)	0.3351 (9)	0.023 (3)*
H11A	1.082 (2)	0.1765 (14)	0.2249 (9)	0.021 (3)*
H11B	1.135 (2)	0.3583 (12)	0.2340 (8)	0.016 (2)*
H3	0.684 (3)	−0.2852 (15)	0.1362 (10)	0.030 (3)*
H14A	0.647 (2)	0.4297 (15)	0.1284 (10)	0.028 (3)*
H2	0.824 (3)	−0.0234 (15)	0.1744 (10)	0.028 (3)*
H14B	0.684 (2)	0.4015 (15)	0.0128 (10)	0.027 (3)*
H13A	1.198 (3)	0.3048 (16)	0.0476 (10)	0.035 (3)*
H13B	0.967 (3)	0.2083 (16)	−0.0425 (11)	0.042 (4)*
H14C	0.914 (3)	0.4902 (15)	0.1002 (10)	0.027 (3)*
H2N5	−0.034 (3)	0.1553 (16)	0.5007 (11)	0.034 (3)*
H1N5	0.168 (2)	0.1427 (14)	0.5847 (9)	0.026 (3)*
H4	0.351 (3)	−0.3897 (15)	0.2119 (11)	0.033 (3)*
H1N4	0.338 (3)	0.3668 (17)	0.5163 (11)	0.039 (4)*
H10	0.947 (2)	0.5153 (13)	0.3482 (9)	0.023 (3)*
H13C	1.111 (3)	0.1258 (16)	0.0456 (11)	0.036 (3)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N3	0.0241 (3)	0.0107 (2)	0.0180 (2)	−0.00015 (19)	0.0094 (2)	−0.00037 (18)
N2	0.0186 (2)	0.0106 (2)	0.0163 (2)	−0.00019 (17)	0.00804 (18)	0.00044 (17)
N1	0.0166 (2)	0.0107 (2)	0.0146 (2)	0.00162 (17)	0.00618 (18)	−0.00006 (16)
N4	0.0236 (3)	0.0116 (2)	0.0184 (2)	0.00107 (19)	0.0123 (2)	−0.00060 (18)
N5	0.0190 (3)	0.0158 (2)	0.0174 (2)	0.00174 (19)	0.00878 (19)	0.00190 (18)
C9	0.0160 (3)	0.0101 (2)	0.0132 (2)	0.00083 (19)	0.00551 (19)	0.00118 (17)
C1	0.0152 (3)	0.0103 (2)	0.0134 (2)	0.00142 (18)	0.00501 (19)	0.00076 (18)
C2	0.0191 (3)	0.0117 (2)	0.0168 (3)	0.0018 (2)	0.0085 (2)	0.00019 (19)
C3	0.0211 (3)	0.0121 (2)	0.0196 (3)	0.0017 (2)	0.0096 (2)	−0.0009 (2)
C4	0.0209 (3)	0.0107 (2)	0.0215 (3)	0.0000 (2)	0.0091 (2)	−0.0015 (2)
C5	0.0180 (3)	0.0112 (2)	0.0195 (3)	−0.0001 (2)	0.0082 (2)	−0.0001 (2)
C6	0.0145 (2)	0.0109 (2)	0.0140 (2)	0.00148 (18)	0.00531 (19)	0.00056 (18)
C7	0.0164 (3)	0.0112 (2)	0.0131 (2)	0.00201 (19)	0.00547 (19)	0.00073 (18)
C8	0.0180 (3)	0.0106 (2)	0.0135 (2)	0.00126 (19)	0.00616 (19)	0.00052 (18)
C10	0.0244 (3)	0.0108 (2)	0.0195 (3)	−0.0011 (2)	0.0096 (2)	−0.0006 (2)
C11	0.0157 (3)	0.0136 (2)	0.0166 (2)	0.0008 (2)	0.0067 (2)	0.00201 (19)
C12	0.0174 (3)	0.0133 (2)	0.0162 (2)	0.0012 (2)	0.0064 (2)	0.00193 (19)
C13	0.0275 (4)	0.0252 (3)	0.0210 (3)	0.0058 (3)	0.0129 (3)	0.0032 (2)
C14	0.0244 (3)	0.0170 (3)	0.0226 (3)	0.0049 (2)	0.0055 (2)	0.0048 (2)

Geometric parameters (Å, º) top

N3—C10	1.3179 (9)	C3—H3	1.020 (13)
N3—C8	1.3821 (8)	C4—C5	1.3798 (9)
N2—C10	1.3687 (9)	C4—H4	1.008 (14)
N2—C9	1.3828 (8)	C5—C6	1.4170 (9)
N2—C11	1.4590 (9)	C5—H5	1.011 (12)
N1—C7	1.3236 (8)	C7—C8	1.4322 (9)
N1—C6	1.3820 (8)	C10—H10	1.002 (12)
N4—C7	1.3484 (8)	C11—C12	1.5315 (9)
N4—N5	1.4085 (9)	C11—H11A	0.999 (12)
N4—H1N4	0.883 (15)	C11—H11B	0.993 (11)
N5—H2N5	0.909 (14)	C12—C14	1.5258 (10)
N5—H1N5	0.909 (13)	C12—C13	1.5282 (10)
C9—C8	1.3854 (9)	C12—H12	1.037 (12)
C9—C1	1.4314 (9)	C13—H13A	1.014 (14)
C1—C2	1.4138 (9)	C13—H13B	1.000 (14)
C1—C6	1.4302 (9)	C13—H13C	0.998 (14)
C2—C3	1.3795 (9)	C14—H14A	1.001 (13)
C2—H2	1.008 (14)	C14—H14B	0.978 (13)
C3—C4	1.4058 (10)	C14—H14C	0.985 (14)

C10—N3—C8	103.93 (5)	N1—C7—C8	121.10 (6)
C10—N2—C9	106.32 (6)	N4—C7—C8	117.90 (6)
C10—N2—C11	124.73 (6)	N3—C8—C9	111.27 (6)
C9—N2—C11	128.95 (5)	N3—C8—C7	128.47 (6)
C7—N1—C6	118.55 (6)	C9—C8—C7	120.25 (6)
C7—N4—N5	123.58 (6)	N3—C10—N2	113.44 (6)
C7—N4—H1N4	118.2 (10)	N3—C10—H10	124.7 (7)
N5—N4—H1N4	117.8 (10)	N2—C10—H10	121.7 (7)
N4—N5—H2N5	109.3 (9)	N2—C11—C12	113.35 (6)
N4—N5—H1N5	109.3 (8)	N2—C11—H11A	108.6 (7)
H2N5—N5—H1N5	104.1 (12)	C12—C11—H11A	110.6 (7)
N2—C9—C8	105.04 (5)	N2—C11—H11B	106.1 (6)
N2—C9—C1	134.08 (6)	C12—C11—H11B	107.6 (6)
C8—C9—C1	120.87 (6)	H11A—C11—H11B	110.5 (9)
C2—C1—C6	119.84 (6)	C14—C12—C13	111.16 (6)
C2—C1—C9	126.25 (6)	C14—C12—C11	110.90 (5)
C6—C1—C9	113.89 (6)	C13—C12—C11	108.94 (6)
C3—C2—C1	120.58 (6)	C14—C12—H12	107.7 (6)
C3—C2—H2	119.1 (7)	C13—C12—H12	110.1 (7)
C1—C2—H2	120.3 (7)	C11—C12—H12	108.0 (6)
C2—C3—C4	119.88 (6)	C12—C13—H13A	109.6 (8)
C2—C3—H3	120.0 (8)	C12—C13—H13B	112.4 (9)
C4—C3—H3	120.0 (8)	H13A—C13—H13B	108.1 (11)
C5—C4—C3	120.75 (6)	C12—C13—H13C	109.9 (8)
C5—C4—H4	118.6 (8)	H13A—C13—H13C	109.8 (12)
C3—C4—H4	120.6 (8)	H13B—C13—H13C	106.9 (12)
C4—C5—C6	120.97 (6)	C12—C14—H14A	110.3 (7)
C4—C5—H5	122.2 (7)	C12—C14—H14B	110.4 (8)
C6—C5—H5	116.6 (7)	H14A—C14—H14B	106.7 (10)
N1—C6—C5	116.69 (6)	C12—C14—H14C	110.4 (8)
N1—C6—C1	125.32 (6)	H14A—C14—H14C	111.1 (11)
C5—C6—C1	117.98 (6)	H14B—C14—H14C	107.9 (11)
N1—C7—N4	120.99 (6)

C10—N2—C9—C8	−0.05 (7)	C6—N1—C7—N4	−179.65 (6)
C11—N2—C9—C8	−179.38 (6)	C6—N1—C7—C8	1.52 (10)
C10—N2—C9—C1	−178.69 (7)	N5—N4—C7—N1	4.70 (11)
C11—N2—C9—C1	1.98 (12)	N5—N4—C7—C8	−176.43 (6)
N2—C9—C1—C2	0.80 (12)	C10—N3—C8—C9	−0.50 (8)
C8—C9—C1—C2	−177.67 (6)	C10—N3—C8—C7	178.70 (7)
N2—C9—C1—C6	178.97 (7)	N2—C9—C8—N3	0.34 (8)
C8—C9—C1—C6	0.50 (9)	C1—C9—C8—N3	179.20 (6)
C6—C1—C2—C3	−0.43 (10)	N2—C9—C8—C7	−178.94 (6)
C9—C1—C2—C3	177.64 (6)	C1—C9—C8—C7	−0.07 (10)
C1—C2—C3—C4	0.77 (11)	N1—C7—C8—N3	179.87 (6)
C2—C3—C4—C5	−0.14 (11)	N4—C7—C8—N3	1.00 (11)
C3—C4—C5—C6	−0.84 (11)	N1—C7—C8—C9	−0.99 (10)
C7—N1—C6—C5	177.81 (6)	N4—C7—C8—C9	−179.86 (6)
C7—N1—C6—C1	−1.08 (10)	C8—N3—C10—N2	0.48 (8)
C4—C5—C6—N1	−177.81 (6)	C9—N2—C10—N3	−0.28 (8)
C4—C5—C6—C1	1.16 (10)	C11—N2—C10—N3	179.09 (6)
C2—C1—C6—N1	178.35 (6)	C10—N2—C11—C12	−101.17 (8)
C9—C1—C6—N1	0.05 (10)	C9—N2—C11—C12	78.06 (8)
C2—C1—C6—C5	−0.52 (10)	N2—C11—C12—C14	63.65 (7)
C9—C1—C6—C5	−178.82 (6)	N2—C11—C12—C13	−173.69 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H1N4···N3ⁱ	0.883 (16)	2.130 (15)	2.9429 (9)	152.9 (15)
C5—H5···N5ⁱⁱ	1.012 (12)	2.437 (11)	3.3700 (10)	152.9 (10)

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

Experimental details

Crystal data
Chemical formula	C₁₄H₁₇N₅
M_r	255.33
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	5.4735 (2), 9.1275 (3), 13.3814 (5)
α, β, γ (°)	98.076 (1), 101.787 (1), 96.269 (1)
V (Å³)	641.35 (4)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.68 × 0.42 × 0.09

Data collection
Diffractometer	Bruker SMART APEXII DUO CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.945, 0.992
No. of measured, independent and observed [I > 2σ(I)] reflections	20646, 5797, 4836
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.819

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.137, 1.12
No. of reflections	5797
No. of parameters	240
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.53, −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
N4—H1N4···N3ⁱ	0.883 (16)	2.130 (15)	2.9429 (9)	152.9 (15)
C5—H5···N5ⁱⁱ	1.012 (12)	2.437 (11)	3.3700 (10)	152.9 (10)

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

Footnotes

‡Thomson Reuters ResearcherID: C-7581-2009.

§Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

HKF and WSL thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). WSL also thanks the Malaysian Government and USM for the award of a Research Fellowship.

References

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