2-[(E)-(5-Amino-2,3-diphenyl­quinoxalin-6-yl)imino­meth­yl]-4-bromo­phenol

Fun, H.-K.; Kia, R.; Raithby, P.R.

doi:10.1107/S1600536808017716

organic compounds

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ISSN: 2056-9890

Volume 64| Part 7| July 2008| Pages o1271-o1272

doi:10.1107/S1600536808017716

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2-[(E)-(5-Amino-2,3-diphenylquinoxalin-6-yl)iminomethyl]-4-bromophenol

Hoong-Kun Fun,^a ^* Reza Kia ^a ‡ and Paul R. Raithby ^b §

^aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and ^bChemistry Department, University of Bath, Claverton Down, Bath BA2 7AY, England
^*Correspondence e-mail: hkfun@usm.my

(Received 9 June 2008; accepted 11 June 2008; online 13 June 2008)

The title compound, C₂₇H₁₉BrN₄O, is a mono-anil Schiff base ligand. Three intramolecular O—H⋯N and N—H⋯N hydrogen bonds involving the hydroxy and amino groups generate S(6) and S(5) ring motifs, respectively. In the crystal structure, weak intermolecular N—H⋯O and C—H⋯O hydrogen bonds together with π–π interactions [centroid–centroid distances = 3.628 (3)–3.729 (3) Å] link neighboring molecules.

Related literature

For details of hydrogen-bond motifs, see: Bernstein et al. (1995 ). For bond-length data, see: Allen et al. (1987 ). For related structures see, for example: Corden et al. (1996 ); Govindasamy et al. (1999 ). For applications and bioactivities see, for example: Blower (1998 ); Cohen & Schmidt (1964 ); Granovski et al. (1993 ); Kia et al. (2004 ); Li & Chang (1991 ); Shahrokhian et al. (2000 ); Uhlenbrock et al. (1996 ); Unaleroglu & Hokelek (2002 ). For related literature, see: Anderson et al. (1997 ); Blower (1998).

Experimental

Crystal data

C₂₇H₁₉BrN₄O
M_r = 495.37
Monoclinic, P 2₁ /c
a = 22.923 (5) Å
b = 7.344 (5) Å
c = 12.573 (5) Å
β = 92.070 (5)°
V = 2115.2 (17) Å³
Z = 4
Mo Kα radiation
μ = 1.97 mm⁻¹
T = 100.0 (1) K
0.39 × 0.37 × 0.08 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.510, T_max = 0.853
22554 measured reflections
6205 independent reflections
3722 reflections with I > 2σ(I)
R_int = 0.070

Refinement

R[F² > 2σ(F²)] = 0.045
wR(F²) = 0.142
S = 1.06
6205 reflections
305 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.61 e Å⁻³
Δρ_min = −1.07 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O1⋯N1	0.83	1.83	2.586 (4)	151
N2—H2N2⋯N4	0.88 (4)	2.35 (4)	2.740 (4)	107 (3)
N2—H1N2⋯N1	0.88 (4)	2.44 (4)	2.756 (4)	102 (3)

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005); 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, 2003 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808017716/sj2516sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808017716/sj2516Isup2.hkl

checkCIF report

Comment top

Schiff bases are among the most prevalent mixed-donor ligands in coordination chemistry. Schiff bases and their biologically active complexes have been studied over several decades (Anderson et al., 1997; Blower 1998; Corden et al., 1996; Govindasamy et al., 1999; Granovski et al., 1993; Li & Chang, 1991; Shahrokhian et al., 2000). 2-hydroxy Schiff base ligands are of interest mainly due to the existence of O—H···N and O···H—N type hydrogen bonds and tautomerization between the phenol-imine and keto-amine forms (Unaleroglu & Hokelek, 2002; Kia et al., 2004). This type of tautomerism plays an important role for distinguishing their photochromic and thermochromic properties (Cohen & Schmidt, 1964). Knowing the structures of free Schiff bases in solution and in the solid state is important in view of the intramolecular hydrogen bonding and comparison with the structure of Schiff base complexes. In view of the importance of these organic ligands, the title compound (I) was synthesized and its crystal structure is reported here.

In the title compound (Fig. 1), intramolecular O—H···N, and N—H···N hydrogen bonds form six and five-membered rings, producing S(6) and S(5) ring motifs, respectively (Bernstein et al., 1995). The two phenyl substituents on the quinoxaline unit are inclined at an angle of 17.87 (17)° to one another. They also form dihedral angles of 38.96 (15) and 44.46 (15)° with the ten–membered quinoxaline ring. In the crystal packing (Fig. 2), molecules are stacked along the b axis by π···π interactions with Cg2···Cg3 distances ranging from 3.628 (3) – 3.729 (3) Å: symmetry codes 1 - x, 1/2 + y, 3/2 - z and 1 - x, -1/2 + y, 3/2 - z; Cg2 and Cg3 are the centroids of the C1–C6 and C8/C9/C10/C11/C14/C15 phenyl rings, respectively. The crystal structure is stabilized by intramolecular O—H···N, and N—H···N hydrogen bonds, weak intermolecular N—H···O and C—H···O hydrogen bonds, and π···π interactions.

Related literature top

For details of hydrogen-bond motifs, see: Bernstein et al. (1995). For bond-length data, see: Allen et al. (1987). For related structures see, for example: Corden et al. (1996); Govindasamy et al. (1999). For applications and bioactivities see, for example: Blower (1998); Cohen & Schmidt, (1964); Granovski et al., (1993); Kia et al., (2004) Li & Chang, (1991); Shahrokhian et al., (2000); ; Uhlenbrock et al., (1996); Unaleroglu & Hokelek, (2002).

For related literature, see: Anderson et al. (1997); Blower (1998).

Experimental top

A mixture of o-diaminoquinoxaline (313 mg, 1 mmol) and 5-bromo salicylaldehyde (210 mg, 1 mmol) was suspended in 30 ml absolute ethanol. The reaction mixture was stirred under reflux for 1 h. After cooling, the precipitate was filtered, washed with ethanol and ether and dried under vacuum. Single crystals suitable for X-ray diffraction were obtained by evaporation of a mixed chloroform-ethanol (3/1, v/v) solution at room temperature.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT (Bruker, 2005); 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, 2003).

Figures top

	Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atomic numbering. Intramolecular interactions are drawn as dashed lines.
	Fig. 2. The crystal packing of (I), viewed along the b-axis with hydrogen bonds drawn as dashed lines.

2-[(E)-(5-Amino-2,3-diphenylquinoxalin-6-yl)iminomethyl]-4-bromophenol top

Crystal data top

C₂₇H₁₉BrN₄O	F(000) = 1008
M_r = 495.37	D_x = 1.556 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2ybc	Cell parameters from 4509 reflections
a = 22.923 (5) Å	θ = 2.9–28.3°
b = 7.344 (5) Å	µ = 1.97 mm⁻¹
c = 12.573 (5) Å	T = 100 K
β = 92.070 (5)°	Block, yellow
V = 2115.2 (17) Å³	0.39 × 0.37 × 0.08 mm
Z = 4

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	6205 independent reflections
Radiation source: fine-focus sealed tube	3722 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.070
ϕ and ω scans	θ_max = 30.1°, θ_min = 0.9°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −32→32
T_min = 0.510, T_max = 0.853	k = −10→8
22554 measured reflections	l = −16→17

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.142	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ²(F_o²) + (0.0698P)²] where P = (F_o² + 2F_c²)/3
6205 reflections	(Δ/σ)_max = 0.001
305 parameters	Δρ_max = 0.62 e Å⁻³
0 restraints	Δρ_min = −1.07 e Å⁻³

Crystal data top

C₂₇H₁₉BrN₄O	V = 2115.2 (17) Å³
M_r = 495.37	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 22.923 (5) Å	µ = 1.97 mm⁻¹
b = 7.344 (5) Å	T = 100 K
c = 12.573 (5) Å	0.39 × 0.37 × 0.08 mm
β = 92.070 (5)°

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	6205 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	3722 reflections with I > 2σ(I)
T_min = 0.510, T_max = 0.853	R_int = 0.070
22554 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.045	0 restraints
wR(F²) = 0.142	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	Δρ_max = 0.62 e Å⁻³
6205 reflections	Δρ_min = −1.07 e Å⁻³
305 parameters

Special details top

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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
Br1	0.259515 (13)	0.53134 (5)	0.59180 (3)	0.02170 (12)
N1	0.52495 (11)	0.6363 (4)	0.7764 (2)	0.0171 (6)
N2	0.60814 (13)	0.5339 (4)	0.9285 (2)	0.0186 (6)
N4	0.72399 (11)	0.5294 (4)	0.8819 (2)	0.0154 (6)
N3	0.76064 (11)	0.6677 (4)	0.6873 (2)	0.0169 (6)
O1	0.44969 (9)	0.7345 (3)	0.91363 (18)	0.0206 (5)
H1O1	0.4813	0.7101	0.8877	0.025*
C1	0.40804 (13)	0.6934 (4)	0.8389 (3)	0.0177 (7)
C2	0.34965 (14)	0.7191 (4)	0.8608 (3)	0.0188 (7)
H2	0.3398	0.7694	0.9256	0.023*
C3	0.30643 (13)	0.6715 (5)	0.7882 (3)	0.0205 (8)
H3	0.2675	0.6883	0.8044	0.025*
C4	0.32022 (13)	0.5985 (5)	0.6910 (3)	0.0183 (7)
C5	0.37775 (13)	0.5769 (4)	0.6645 (3)	0.0176 (7)
H5	0.3866	0.5305	0.5982	0.021*
C6	0.42273 (13)	0.6246 (4)	0.7373 (3)	0.0162 (7)
C7	0.48319 (13)	0.6048 (5)	0.7087 (3)	0.0166 (7)
H7	0.4917	0.5688	0.6400	0.010 (8)*
C8	0.58402 (12)	0.6335 (4)	0.7490 (3)	0.0146 (7)
C9	0.60282 (13)	0.6891 (4)	0.6473 (3)	0.0174 (7)
H9	0.5752	0.7203	0.5945	0.021*
C10	0.66057 (13)	0.6973 (4)	0.6258 (3)	0.0170 (7)
H10	0.6721	0.7344	0.5591	0.020*
C11	0.70293 (13)	0.6494 (4)	0.7053 (3)	0.0159 (7)
C14	0.68498 (13)	0.5891 (4)	0.8062 (3)	0.0135 (6)
C15	0.62412 (13)	0.5842 (4)	0.8283 (3)	0.0157 (7)
C12	0.79874 (13)	0.6218 (5)	0.7641 (3)	0.0165 (7)
C13	0.78033 (13)	0.5390 (4)	0.8603 (3)	0.0161 (7)
C16	0.82122 (13)	0.4561 (5)	0.9406 (3)	0.0174 (7)
C17	0.81113 (14)	0.4750 (5)	1.0488 (3)	0.0185 (7)
H17	0.7793	0.5428	1.0702	0.022*
C18	0.84782 (13)	0.3944 (5)	1.1246 (3)	0.0199 (7)
H18	0.8408	0.4086	1.1965	0.024*
C19	0.89531 (14)	0.2918 (5)	1.0935 (3)	0.0223 (8)
H19	0.9205	0.2393	1.1444	0.027*
C20	0.90483 (14)	0.2686 (5)	0.9858 (3)	0.0224 (8)
H20	0.9358	0.1970	0.9645	0.027*
C21	0.86863 (13)	0.3509 (5)	0.9104 (3)	0.0196 (7)
H21	0.8758	0.3364	0.8386	0.024*
C22	0.86036 (13)	0.6776 (4)	0.7467 (3)	0.0166 (7)
C23	0.89337 (13)	0.7640 (5)	0.8263 (3)	0.0198 (7)
H23	0.8786	0.7758	0.8939	0.024*
C24	0.94824 (14)	0.8330 (5)	0.8060 (3)	0.0220 (8)
H24	0.9701	0.8916	0.8595	0.026*
C25	0.97015 (14)	0.8138 (5)	0.7048 (3)	0.0215 (8)
H25	1.0068	0.8603	0.6906	0.026*
C26	0.93829 (14)	0.7271 (5)	0.6262 (3)	0.0215 (8)
H26	0.9535	0.7137	0.5590	0.026*
C27	0.88320 (13)	0.6588 (5)	0.6463 (3)	0.0198 (7)
H27	0.8615	0.6004	0.5925	0.024*
H2N2	0.6362 (17)	0.487 (5)	0.970 (3)	0.024*
H1N2	0.5740 (17)	0.479 (5)	0.925 (3)	0.024*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.01741 (16)	0.02067 (18)	0.0269 (2)	−0.00067 (13)	−0.00060 (13)	0.00133 (17)
N1	0.0177 (13)	0.0150 (15)	0.0187 (16)	0.0014 (10)	0.0023 (11)	0.0015 (12)
N2	0.0185 (13)	0.0240 (15)	0.0134 (15)	−0.0013 (12)	0.0037 (11)	0.0011 (13)
N4	0.0168 (12)	0.0141 (13)	0.0152 (15)	−0.0001 (10)	0.0007 (10)	−0.0019 (12)
N3	0.0178 (13)	0.0166 (15)	0.0163 (15)	−0.0007 (10)	0.0011 (11)	−0.0018 (12)
O1	0.0200 (11)	0.0251 (14)	0.0169 (13)	−0.0002 (9)	0.0033 (10)	−0.0002 (11)
C1	0.0213 (16)	0.0129 (17)	0.0190 (19)	−0.0012 (12)	0.0019 (14)	0.0034 (14)
C2	0.0228 (16)	0.0151 (17)	0.0189 (19)	0.0015 (12)	0.0044 (14)	0.0051 (14)
C3	0.0166 (15)	0.0174 (18)	0.028 (2)	0.0021 (12)	0.0043 (14)	0.0079 (15)
C4	0.0191 (15)	0.0133 (16)	0.022 (2)	−0.0001 (12)	0.0016 (13)	0.0046 (15)
C5	0.0197 (15)	0.0155 (17)	0.0178 (19)	0.0018 (12)	0.0028 (13)	0.0011 (13)
C6	0.0186 (15)	0.0131 (17)	0.0168 (18)	−0.0003 (12)	0.0026 (13)	0.0018 (14)
C7	0.0198 (15)	0.0130 (16)	0.0171 (19)	0.0009 (12)	0.0010 (13)	0.0022 (14)
C8	0.0155 (14)	0.0128 (16)	0.0156 (18)	−0.0012 (11)	0.0012 (12)	−0.0013 (13)
C9	0.0194 (15)	0.0153 (17)	0.0174 (19)	−0.0003 (12)	0.0001 (13)	0.0022 (14)
C10	0.0190 (15)	0.0168 (17)	0.0155 (18)	−0.0007 (12)	0.0027 (13)	0.0025 (14)
C11	0.0179 (15)	0.0135 (16)	0.0163 (18)	−0.0003 (11)	0.0034 (13)	−0.0002 (13)
C14	0.0181 (15)	0.0085 (14)	0.0137 (17)	0.0002 (11)	−0.0012 (12)	−0.0002 (13)
C15	0.0216 (15)	0.0112 (15)	0.0145 (18)	−0.0016 (12)	0.0027 (13)	−0.0036 (13)
C12	0.0154 (14)	0.0182 (17)	0.0161 (18)	0.0002 (12)	0.0028 (13)	−0.0020 (14)
C13	0.0164 (14)	0.0151 (16)	0.0169 (18)	0.0011 (12)	0.0021 (12)	−0.0046 (15)
C16	0.0155 (14)	0.0176 (17)	0.0192 (19)	−0.0021 (12)	0.0018 (12)	0.0008 (15)
C17	0.0195 (15)	0.0181 (16)	0.0180 (19)	−0.0017 (13)	0.0024 (13)	−0.0013 (15)
C18	0.0201 (16)	0.0218 (18)	0.0179 (19)	−0.0010 (13)	0.0003 (13)	0.0030 (15)
C19	0.0174 (16)	0.025 (2)	0.024 (2)	0.0000 (13)	−0.0026 (14)	0.0043 (16)
C20	0.0173 (15)	0.0227 (19)	0.028 (2)	0.0054 (13)	0.0036 (14)	0.0021 (16)
C21	0.0201 (16)	0.0191 (18)	0.0198 (19)	0.0015 (12)	0.0037 (14)	0.0013 (15)
C22	0.0160 (14)	0.0162 (17)	0.0180 (18)	0.0006 (12)	0.0034 (13)	−0.0004 (14)
C23	0.0188 (15)	0.0250 (19)	0.0158 (19)	−0.0009 (13)	0.0034 (13)	−0.0012 (15)
C24	0.0202 (16)	0.0253 (19)	0.020 (2)	−0.0019 (13)	0.0001 (14)	0.0012 (16)
C25	0.0162 (15)	0.027 (2)	0.022 (2)	0.0006 (13)	0.0034 (14)	0.0050 (16)
C26	0.0203 (16)	0.028 (2)	0.0165 (19)	0.0026 (13)	0.0049 (14)	0.0002 (16)
C27	0.0210 (16)	0.0221 (19)	0.0164 (19)	0.0029 (13)	0.0015 (13)	−0.0019 (15)

Geometric parameters (Å, º) top

Br1—C4	1.900 (4)	C10—H10	0.9300
N1—C7	1.279 (4)	C11—C14	1.418 (4)
N1—C8	1.409 (3)	C14—C15	1.433 (4)
N2—C15	1.376 (4)	C12—C13	1.431 (4)
N2—H2N2	0.88 (4)	C12—C22	1.495 (4)
N2—H1N2	0.88 (4)	C13—C16	1.483 (5)
N4—C13	1.331 (4)	C16—C17	1.396 (5)
N4—C14	1.355 (4)	C16—C21	1.397 (4)
N3—C12	1.322 (4)	C17—C18	1.382 (5)
N3—C11	1.357 (4)	C17—H17	0.9300
O1—C1	1.350 (4)	C18—C19	1.391 (4)
O1—H1O1	0.8254	C18—H18	0.9300
C1—C2	1.389 (4)	C19—C20	1.390 (5)
C1—C6	1.425 (5)	C19—H19	0.9300
C2—C3	1.368 (5)	C20—C21	1.377 (5)
C2—H2	0.9300	C20—H20	0.9300
C3—C4	1.382 (5)	C21—H21	0.9300
C3—H3	0.9300	C22—C23	1.386 (5)
C4—C5	1.381 (4)	C22—C27	1.391 (4)
C5—C6	1.398 (5)	C23—C24	1.388 (4)
C5—H5	0.9300	C23—H23	0.9300
C6—C7	1.452 (4)	C24—C25	1.392 (5)
C7—H7	0.9300	C24—H24	0.9300
C8—C15	1.380 (5)	C25—C26	1.365 (5)
C8—C9	1.424 (4)	C25—H25	0.9300
C9—C10	1.362 (4)	C26—C27	1.390 (4)
C9—H9	0.9300	C26—H26	0.9300
C10—C11	1.413 (5)	C27—H27	0.9300

C7—N1—C8	122.5 (3)	N2—C15—C14	118.5 (3)
C15—N2—H2N2	116 (3)	C8—C15—C14	118.8 (3)
C15—N2—H1N2	110 (3)	N3—C12—C13	121.2 (3)
H2N2—N2—H1N2	118 (4)	N3—C12—C22	115.2 (3)
C13—N4—C14	117.4 (3)	C13—C12—C22	123.3 (3)
C12—N3—C11	118.3 (3)	N4—C13—C12	120.8 (3)
C1—O1—H1O1	106.6	N4—C13—C16	115.7 (3)
O1—C1—C2	119.6 (3)	C12—C13—C16	123.4 (3)
O1—C1—C6	121.3 (3)	C17—C16—C21	118.5 (3)
C2—C1—C6	119.1 (3)	C17—C16—C13	120.0 (3)
C3—C2—C1	120.9 (3)	C21—C16—C13	121.4 (3)
C3—C2—H2	119.6	C18—C17—C16	120.8 (3)
C1—C2—H2	119.6	C18—C17—H17	119.6
C2—C3—C4	120.4 (3)	C16—C17—H17	119.6
C2—C3—H3	119.8	C17—C18—C19	120.0 (3)
C4—C3—H3	119.8	C17—C18—H18	120.0
C5—C4—C3	120.6 (3)	C19—C18—H18	120.0
C5—C4—Br1	119.7 (3)	C20—C19—C18	119.5 (3)
C3—C4—Br1	119.7 (2)	C20—C19—H19	120.2
C4—C5—C6	120.1 (3)	C18—C19—H19	120.2
C4—C5—H5	119.9	C21—C20—C19	120.3 (3)
C6—C5—H5	119.9	C21—C20—H20	119.8
C5—C6—C1	118.9 (3)	C19—C20—H20	119.8
C5—C6—C7	120.0 (3)	C20—C21—C16	120.8 (3)
C1—C6—C7	121.1 (3)	C20—C21—H21	119.6
N1—C7—C6	121.0 (3)	C16—C21—H21	119.6
N1—C7—H7	119.5	C23—C22—C27	119.1 (3)
C6—C7—H7	119.5	C23—C22—C12	121.0 (3)
C15—C8—N1	116.6 (3)	C27—C22—C12	119.6 (3)
C15—C8—C9	120.6 (3)	C22—C23—C24	120.6 (3)
N1—C8—C9	122.7 (3)	C22—C23—H23	119.7
C10—C9—C8	121.2 (3)	C24—C23—H23	119.7
C10—C9—H9	119.4	C23—C24—C25	119.3 (3)
C8—C9—H9	119.4	C23—C24—H24	120.3
C9—C10—C11	119.8 (3)	C25—C24—H24	120.3
C9—C10—H10	120.1	C26—C25—C24	120.5 (3)
C11—C10—H10	120.1	C26—C25—H25	119.7
N3—C11—C10	120.4 (3)	C24—C25—H25	119.7
N3—C11—C14	119.8 (3)	C25—C26—C27	120.2 (3)
C10—C11—C14	119.8 (3)	C25—C26—H26	119.9
N4—C14—C11	121.6 (3)	C27—C26—H26	119.9
N4—C14—C15	118.6 (3)	C26—C27—C22	120.2 (3)
C11—C14—C15	119.8 (3)	C26—C27—H27	119.9
N2—C15—C8	122.7 (3)	C22—C27—H27	119.9

O1—C1—C2—C3	−177.3 (3)	C11—C14—C15—N2	−176.8 (3)
C6—C1—C2—C3	3.1 (5)	N4—C14—C15—C8	−175.8 (3)
C1—C2—C3—C4	−0.7 (5)	C11—C14—C15—C8	2.0 (5)
C2—C3—C4—C5	−1.7 (5)	C11—N3—C12—C13	5.7 (5)
C2—C3—C4—Br1	179.5 (2)	C11—N3—C12—C22	−169.0 (3)
C3—C4—C5—C6	1.6 (5)	C14—N4—C13—C12	4.5 (4)
Br1—C4—C5—C6	−179.5 (2)	C14—N4—C13—C16	−174.3 (3)
C4—C5—C6—C1	0.7 (5)	N3—C12—C13—N4	−9.6 (5)
C4—C5—C6—C7	−178.9 (3)	C22—C12—C13—N4	164.7 (3)
O1—C1—C6—C5	177.3 (3)	N3—C12—C13—C16	169.1 (3)
C2—C1—C6—C5	−3.1 (5)	C22—C12—C13—C16	−16.6 (5)
O1—C1—C6—C7	−3.1 (5)	N4—C13—C16—C17	−39.1 (4)
C2—C1—C6—C7	176.6 (3)	C12—C13—C16—C17	142.2 (3)
C8—N1—C7—C6	−174.5 (3)	N4—C13—C16—C21	137.8 (3)
C5—C6—C7—N1	−175.3 (3)	C12—C13—C16—C21	−40.9 (5)
C1—C6—C7—N1	5.0 (5)	C21—C16—C17—C18	1.2 (5)
C7—N1—C8—C15	−150.5 (3)	C13—C16—C17—C18	178.1 (3)
C7—N1—C8—C9	33.4 (5)	C16—C17—C18—C19	−0.4 (5)
C15—C8—C9—C10	−0.8 (5)	C17—C18—C19—C20	−1.2 (5)
N1—C8—C9—C10	175.2 (3)	C18—C19—C20—C21	2.0 (5)
C8—C9—C10—C11	0.3 (5)	C19—C20—C21—C16	−1.2 (5)
C12—N3—C11—C10	179.8 (3)	C17—C16—C21—C20	−0.4 (5)
C12—N3—C11—C14	2.5 (4)	C13—C16—C21—C20	−177.3 (3)
C9—C10—C11—N3	−175.9 (3)	N3—C12—C22—C23	132.1 (3)
C9—C10—C11—C14	1.4 (5)	C13—C12—C22—C23	−42.5 (5)
C13—N4—C14—C11	3.7 (5)	N3—C12—C22—C27	−41.7 (4)
C13—N4—C14—C15	−178.6 (3)	C13—C12—C22—C27	143.7 (3)
N3—C11—C14—N4	−7.5 (5)	C27—C22—C23—C24	0.8 (5)
C10—C11—C14—N4	175.2 (3)	C12—C22—C23—C24	−173.0 (3)
N3—C11—C14—C15	174.8 (3)	C22—C23—C24—C25	−0.4 (5)
C10—C11—C14—C15	−2.5 (5)	C23—C24—C25—C26	−0.4 (5)
N1—C8—C15—N2	2.1 (5)	C24—C25—C26—C27	0.7 (5)
C9—C8—C15—N2	178.4 (3)	C25—C26—C27—C22	−0.3 (5)
N1—C8—C15—C14	−176.6 (3)	C23—C22—C27—C26	−0.4 (5)
C9—C8—C15—C14	−0.3 (5)	C12—C22—C27—C26	173.4 (3)
N4—C14—C15—N2	5.5 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O1···N1	0.83	1.83	2.586 (4)	151
N2—H2N2···N4	0.88 (4)	2.35 (4)	2.740 (4)	107 (3)
N2—H1N2···N1	0.88 (4)	2.44 (4)	2.756 (4)	102 (3)

Experimental details

Crystal data
Chemical formula	C₂₇H₁₉BrN₄O
M_r	495.37
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	22.923 (5), 7.344 (5), 12.573 (5)
β (°)	92.070 (5)
V (Å³)	2115.2 (17)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	1.97
Crystal size (mm)	0.39 × 0.37 × 0.08

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.510, 0.853
No. of measured, independent and observed [I > 2σ(I)] reflections	22554, 6205, 3722
R_int	0.070
(sin θ/λ)_max (Å⁻¹)	0.707

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.142, 1.07
No. of reflections	6205
No. of parameters	305
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.62, −1.07

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O1···N1	0.8300	1.8300	2.586 (4)	151.00
N2—H2N2···N4	0.88 (4)	2.35 (4)	2.740 (4)	107 (3)
N2—H1N2···N1	0.88 (4)	2.44 (4)	2.756 (4)	102 (3)

Footnotes

‡Address of first post-doctoral position: Chemistry Department, University of Bath, Claverton Down, Bath BA2 7AY, England.

§Additional correspondence author, e-mail: p.r.raithby@bath.ac.uk.

Acknowledgements

HKF and RK thank the Malaysian Government and Universiti sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia and the University of Bath for a post-doctoral research fellowship.

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