N,N′-Bis(5-bromo-2-hydroxy­benzyl­idene)-2,2-dimethylpropane-1,3-diamine

Fun, H.-K.; Kia, R.; Kargar, H.

doi:10.1107/S160053680802816X

organic compounds

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ISSN: 2056-9890

Volume 64| Part 10| October 2008| Pages o1895-o1896

doi:10.1107/S160053680802816X

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N,N′-Bis(5-bromo-2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine

Hoong-Kun Fun,^a ^* Reza Kia ^a and Hadi Kargar ^b ‡

^aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and ^bDepartment of Chemistry, School of Science, Payame Noor University (PNU), Ardakan, Yazd, Iran
^*Correspondence e-mail: hkfun@usm.my

(Received 2 September 2008; accepted 3 September 2008; online 6 September 2008)

The crystal structure of the title Schiff base compound, C₁₉H₂₀Br₂N₂O₂, contains two crystallographically independent molecules (A and B) in the asymmetric unit, with similar conformations. Intramolecular O—H⋯N (× 4) and C—H⋯N (× 5) hydrogen bonds form six- and five-membered rings, producing S(6) and S(5) ring motifs, respectively. One of the N atoms in molecule A acts as a trifurcated acceptor, the rest of the N atoms being bifurcated acceptors. The dihedral angles between the benzene rings in molecules A and B are 47.83 (17) and 61.11 (17)°, respectively. The molecular conformation is stabilized by intramolecular O—H⋯N and C—H⋯N hydrogen bonds. The short distances between the centroids of the benzene rings [3.7799 (19)–3.890 (2) Å] indicate the existence of π–π interactions. In addition, the crystal structure is further stabilized by an intermolecular C—H⋯O hydrogen bond, C—H⋯π interactions, and short intermolecular Br⋯Br and Br⋯O contacts [3.4786 (5) and 3.149 (3) Å, respectively].

Related literature

For bond-length data, see: Allen et al. (1987 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ). For information on Schiff base ligands and complexes and their applications, see, for example: Fun, Kargar & Kia (2008 ); Fun, Kia & Kargar (2008 ); Fun, Mirkhani et al. (2008a ,b ); Calligaris & Randaccio (1987 ); Casellato & Vigato (1977 ); Pal et al. (2005 ); Reglinski et al. 2004 ; Hou et al. (2001 ); Ren et al. (2002 ).

Experimental

Crystal data

C₁₉H₂₀Br₂N₂O₂
M_r = 468.19
Monoclinic, C 2/c
a = 31.7684 (10) Å
b = 6.2436 (2) Å
c = 38.7287 (11) Å
β = 99.870 (2)°
V = 7568.1 (4) Å³
Z = 16
Mo Kα radiation
μ = 4.30 mm⁻¹
T = 100.0 (1) K
0.52 × 0.10 × 0.06 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.213, T_max = 0.782
47391 measured reflections
11172 independent reflections
6920 reflections with I > 2σ(I)
R_int = 0.080

Refinement

R[F² > 2σ(F²)] = 0.043
wR(F²) = 0.110
S = 1.01
11172 reflections
463 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.57 e Å⁻³
Δρ_min = −0.46 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1B—H1OB⋯N1B	0.85	1.81	2.580 (4)	151
O2A—H2OA⋯N2A	0.85 (4)	1.79 (4)	2.578 (4)	154 (4)
O1A—H1OA⋯N1A	0.79 (5)	1.85 (5)	2.572 (4)	153 (4)
O2B—H2OB⋯N2B	0.73 (5)	1.94 (5)	2.586 (4)	149 (5)
C8A—H8AA⋯N2A	0.99	2.58	2.960 (4)	103
C8B—H8BA⋯N2B	0.99	2.60	2.966 (4)	102
C16B—H16B⋯O2Bⁱ	0.95	2.58	3.290 (5)	131
C19A—H19B⋯N1A	0.98	2.58	2.918 (4)	100
C19A—H19C⋯N2A	0.98	2.58	2.933 (5)	101
C19B—H19F⋯N1B	0.98	2.60	2.926 (5)	100
C7B—H7BA⋯Cg1ⁱⁱ	0.95	2.96	3.571 (4)	123
C18B—H18D⋯Cg2ⁱⁱⁱ	0.98	2.77	3.652 (4)	151
Symmetry codes: (i) -x, -y+1, -z; (ii) x, y-1, z; (iii) $[x, -y-1, z-{\script{1\over 2}}]$ . Cg1 and Cg2 are the centroids of the C1A–C6A and C12A–C17A benzene rings, respectively.

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

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680802816X/at2626sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053680802816X/at2626Isup2.hkl

checkCIF report

Comment top

The condensation of primary amines with carbonyl compounds yields Schiff base (Casellato & Vigato, 1977) that are still now regarded as one of the most potential group of chelators for facile preparations of metallo-organic hybrid materials. In the past two decades, the synthesis, structure and properties of Schiff base complexes have stimulated much interest for their noteworthy contributions in single molecule-based magnetism, materials science, catalysis of many reactions like carbonylation, hydroformylation, reduction, oxidation, epoxidation and hydrolysis, etc. (Pal et al., 2005; Reglinski et al., 2004; Hou et al., 2001; Ren et al., 2002). Only a relatively small number of free Schiff base ligands have been characterized by X-ray crystallography (Calligaris & Randaccio, 1987). As an extension of our work (Fun, Kargar & Kia, 2008; Fun, Kia & Kargar, 2008; Fun, Mirkhani et al., 2008a,b) on the structural characterization of Schiff base compounds, the title compound (I), is reported here.

The crystal structure of the title compound (I) (Fig. I), contains two crystallographically independent molecules (A and B) in the asymmetric unit, with similar conformations. The bond lengths and angles are within normal ranges (Allen et al., 1987). Intramolecular O—H···N (x 4) and C—H···N (x 5) hydrogen bonds form six- and five-membered rings, producing S(6) and S(5) ring motifs, respectively (Bernstein et al. 1995) (Table 1). One of the nitrogen atoms in the molecule A acts as a trifurcated acceptor, but the rest of the nitrogen atoms are bifurcated acceptors. The dihedral angles between the benzene rings in molecule A and B is 47.83 (17)° and 61.11 (17)°. The molecular conformation is stabilized by intramolecular O—H···N and C—H···N hydrogen bonds. The short distances between the centroids of the benzene rings [Cg2–Cg2 = 3.7799 (19) Å and Cg3–Cg3 = 3.890 (2) Å] indicate the existence of π–π interactions. The Cg2 and Cg3 are the centroids of the C12A–C17A and C12B–C17B benzene rings. The interesting features of the crystal structure are short intermolecular Br···Br [symmetry code: 1/2 + x, -1/2 - y + 1/2 + z] and Br···O [symmetry code: -x, 1 + y, 1/2 - z] interactions, with distances of 3.4786 (5) and 3.149 (3) Å, respectively, which are significantly shorter than the sum of the van der Waals radii of the relevent atoms.

In addition, the crystal structure is further stabilized by intermolecular C—H···O hydrogen bond and C—H···π interactions.

Related literature top

For bond-length data, see: Allen et al. (1987). For hydrogen-bond motifs, see: Bernstein et al. (1995). For information on Schiff base ligands and complexes and their applications, see, for example: Fun, Kargar & Kia (2008); Fun, Kia & Kargar (2008); Fun, Mirkhani et al. (2008a,b); Calligaris & Randaccio (1987); Casellato & Vigato (1977); Pal et al. (2005); Reglinski et al. 2004; Hou et al. (2001); Ren et al. (2002).

Experimental top

The synthetic method has been described earlier (Reglinski et al., 2004). Single crystals suitable for X-ray diffraction were obtained by evaporation of an ethanol 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 (I), with atom labels and 50% probability ellipsoids for non-H atoms. Intramolecular interactions are shown as dashed lines.
	Fig. 2. The crystal packing of (I), showing stacking of molecules down the b-axis. Intramolecular and intermolecular interactions are shown as dashed lines.

N,N'-Bis(5-bromo-2-hydroxybenzylidene)-2,2-dimethylpropane- 1,3-diamine top

Crystal data top

C₁₉H₂₀Br₂N₂O₂	F(000) = 3744
M_r = 468.19	D_x = 1.644 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 5640 reflections
a = 31.7684 (10) Å	θ = 3.0–27.0°
b = 6.2436 (2) Å	µ = 4.30 mm⁻¹
c = 38.7287 (11) Å	T = 100 K
β = 99.870 (2)°	Needle, yellow
V = 7568.1 (4) Å³	0.52 × 0.10 × 0.06 mm
Z = 16

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	11172 independent reflections
Radiation source: fine-focus sealed tube	6920 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.080
ϕ and ω scans	θ_max = 30.2°, θ_min = 1.1°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −36→44
T_min = 0.213, T_max = 0.783	k = −8→8
47391 measured reflections	l = −54→54

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.110	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ²(F_o²) + (0.0443P)² + 4.1476P] where P = (F_o² + 2F_c²)/3
11172 reflections	(Δ/σ)_max = 0.001
463 parameters	Δρ_max = 0.57 e Å⁻³
0 restraints	Δρ_min = −0.46 e Å⁻³

Crystal data top

C₁₉H₂₀Br₂N₂O₂	V = 7568.1 (4) Å³
M_r = 468.19	Z = 16
Monoclinic, C2/c	Mo Kα radiation
a = 31.7684 (10) Å	µ = 4.30 mm⁻¹
b = 6.2436 (2) Å	T = 100 K
c = 38.7287 (11) Å	0.52 × 0.10 × 0.06 mm
β = 99.870 (2)°

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	11172 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	6920 reflections with I > 2σ(I)
T_min = 0.213, T_max = 0.783	R_int = 0.080
47391 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.043	0 restraints
wR(F²) = 0.110	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	Δρ_max = 0.57 e Å⁻³
11172 reflections	Δρ_min = −0.46 e Å⁻³
463 parameters

Special details top

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

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
Br1A	0.048763 (12)	0.47249 (7)	0.124135 (9)	0.02437 (10)
Br2A	0.330044 (11)	0.00679 (6)	0.479516 (9)	0.02179 (9)
O1A	0.06595 (9)	0.8408 (5)	0.26946 (7)	0.0269 (6)
O2A	0.18364 (8)	0.6081 (4)	0.43058 (7)	0.0214 (6)
N1A	0.09915 (9)	0.4834 (5)	0.29342 (7)	0.0207 (7)
N2A	0.14171 (9)	0.2889 (5)	0.39950 (7)	0.0185 (6)
C1A	0.06195 (11)	0.7509 (6)	0.23744 (9)	0.0197 (8)
C2A	0.04274 (11)	0.8701 (6)	0.20872 (10)	0.0231 (8)
H2AA	0.0321	1.0093	0.2121	0.028*
C3A	0.03900 (11)	0.7879 (6)	0.17532 (9)	0.0206 (8)
H3AA	0.0261	0.8709	0.1558	0.025*
C4A	0.05410 (11)	0.5838 (6)	0.17031 (9)	0.0202 (8)
C5A	0.07244 (11)	0.4615 (6)	0.19833 (9)	0.0191 (8)
H5AA	0.0825	0.3215	0.1946	0.023*
C6A	0.07639 (11)	0.5435 (6)	0.23258 (9)	0.0182 (8)
C7A	0.09411 (11)	0.4094 (6)	0.26223 (9)	0.0197 (8)
H7AA	0.1020	0.2657	0.2584	0.024*
C8A	0.11469 (11)	0.3431 (6)	0.32298 (9)	0.0200 (8)
H8AA	0.1426	0.3959	0.3353	0.024*
H8AB	0.1189	0.1969	0.3143	0.024*
C9A	0.08291 (11)	0.3352 (6)	0.34871 (9)	0.0178 (7)
C10A	0.10260 (11)	0.1953 (6)	0.37987 (9)	0.0191 (8)
H10A	0.0816	0.1765	0.3958	0.023*
H10B	0.1091	0.0520	0.3712	0.023*
C11A	0.17384 (11)	0.1677 (6)	0.40944 (8)	0.0182 (8)
H11A	0.1724	0.0207	0.4030	0.022*
C12A	0.21289 (11)	0.2529 (6)	0.43068 (8)	0.0168 (7)
C13A	0.24770 (11)	0.1167 (6)	0.44173 (8)	0.0174 (7)
H13A	0.2467	−0.0279	0.4340	0.021*
C14A	0.28333 (10)	0.1924 (6)	0.46376 (9)	0.0166 (7)
C15A	0.28534 (11)	0.4037 (6)	0.47528 (8)	0.0187 (8)
H15A	0.3097	0.4540	0.4909	0.022*
C16A	0.25179 (11)	0.5388 (6)	0.46392 (9)	0.0191 (8)
H16A	0.2534	0.6836	0.4715	0.023*
C17A	0.21539 (11)	0.4681 (6)	0.44144 (9)	0.0170 (7)
C18A	0.04145 (11)	0.2283 (7)	0.33119 (10)	0.0235 (8)
H18A	0.0211	0.2254	0.3476	0.035*
H18B	0.0475	0.0814	0.3245	0.035*
H18C	0.0291	0.3094	0.3102	0.035*
C19A	0.07370 (12)	0.5588 (6)	0.36131 (9)	0.0222 (8)
H19A	0.0532	0.5491	0.3775	0.033*
H19B	0.0617	0.6476	0.3412	0.033*
H19C	0.1003	0.6235	0.3734	0.033*
Br1B	0.203156 (14)	−0.21813 (7)	0.339930 (10)	0.03229 (11)
Br2B	−0.107371 (12)	−0.17661 (7)	0.040046 (10)	0.02582 (10)
O1B	0.18949 (9)	0.3706 (4)	0.21548 (7)	0.0311 (7)
H1OB	0.1733	0.3089	0.1988	0.047*
O2B	0.04871 (9)	0.3734 (5)	0.04206 (7)	0.0234 (6)
N1B	0.15040 (9)	0.0685 (5)	0.17729 (7)	0.0210 (7)
N2B	0.09435 (9)	0.0503 (5)	0.06810 (7)	0.0203 (7)
C1B	0.19306 (11)	0.2322 (6)	0.24240 (10)	0.0230 (8)
C2B	0.21359 (12)	0.2995 (7)	0.27530 (10)	0.0274 (9)
H2BA	0.2255	0.4392	0.2781	0.033*
C3B	0.21669 (12)	0.1653 (7)	0.30373 (10)	0.0260 (9)
H3BA	0.2306	0.2126	0.3261	0.031*
C4B	0.19961 (12)	−0.0384 (7)	0.29977 (9)	0.0241 (9)
C5B	0.17993 (11)	−0.1126 (6)	0.26741 (9)	0.0205 (8)
H5BA	0.1687	−0.2539	0.2650	0.025*
C6B	0.17662 (11)	0.0223 (6)	0.23812 (9)	0.0195 (8)
C7B	0.15596 (11)	−0.0552 (6)	0.20381 (9)	0.0185 (8)
H7BA	0.1466	−0.1997	0.2012	0.022*
C8B	0.13053 (11)	−0.0151 (6)	0.14318 (9)	0.0220 (8)
H8BA	0.1022	0.0522	0.1360	0.026*
H8BB	0.1263	−0.1716	0.1449	0.026*
C9B	0.15859 (11)	0.0308 (6)	0.11529 (9)	0.0202 (8)
C10B	0.13537 (11)	−0.0555 (7)	0.08002 (9)	0.0218 (8)
H10C	0.1539	−0.0355	0.0621	0.026*
H10D	0.1305	−0.2111	0.0822	0.026*
C11B	0.06085 (11)	−0.0637 (6)	0.06348 (9)	0.0193 (8)
H11B	0.0632	−0.2135	0.0676	0.023*
C12B	0.01870 (11)	0.0298 (6)	0.05198 (8)	0.0175 (7)
C13B	−0.01786 (11)	−0.0943 (6)	0.05134 (9)	0.0203 (8)
H13B	−0.0154	−0.2390	0.0590	0.024*
C14B	−0.05760 (11)	−0.0080 (6)	0.03961 (9)	0.0188 (8)
C15B	−0.06189 (11)	0.2017 (6)	0.02785 (9)	0.0213 (8)
H15B	−0.0894	0.2590	0.0193	0.026*
C16B	−0.02609 (11)	0.3268 (6)	0.02854 (9)	0.0212 (8)
H16B	−0.0290	0.4705	0.0204	0.025*
C17B	0.01438 (11)	0.2447 (6)	0.04102 (9)	0.0192 (8)
C18B	0.20099 (11)	−0.0906 (7)	0.12457 (10)	0.0249 (9)
H18D	0.2190	−0.0598	0.1070	0.037*
H18E	0.1953	−0.2448	0.1250	0.037*
H18F	0.2158	−0.0447	0.1477	0.037*
C19B	0.16738 (12)	0.2702 (6)	0.11289 (10)	0.0239 (8)
H19D	0.1402	0.3474	0.1069	0.036*
H19E	0.1849	0.2955	0.0948	0.036*
H19F	0.1827	0.3215	0.1355	0.036*
H2OA	0.1637 (13)	0.531 (7)	0.4195 (10)	0.027 (12)*
H1OA	0.0731 (13)	0.745 (8)	0.2823 (11)	0.031 (14)*
H2OB	0.0676 (14)	0.317 (8)	0.0506 (12)	0.043 (16)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1A	0.02596 (19)	0.0293 (2)	0.01827 (17)	0.00233 (18)	0.00511 (14)	0.00038 (16)
Br2A	0.01765 (17)	0.0224 (2)	0.02391 (17)	0.00251 (16)	−0.00050 (13)	0.00215 (16)
O1A	0.0358 (16)	0.0207 (16)	0.0234 (14)	0.0043 (14)	0.0028 (12)	−0.0006 (13)
O2A	0.0205 (13)	0.0148 (14)	0.0271 (13)	0.0027 (12)	−0.0014 (11)	−0.0022 (12)
N1A	0.0187 (15)	0.0206 (17)	0.0223 (14)	0.0010 (14)	0.0022 (12)	0.0022 (14)
N2A	0.0204 (15)	0.0166 (17)	0.0176 (14)	0.0015 (14)	0.0008 (12)	0.0022 (13)
C1A	0.0174 (17)	0.019 (2)	0.0241 (18)	−0.0018 (16)	0.0064 (14)	−0.0020 (16)
C2A	0.0231 (19)	0.017 (2)	0.030 (2)	0.0026 (17)	0.0064 (16)	0.0017 (17)
C3A	0.0163 (17)	0.021 (2)	0.0241 (18)	0.0019 (16)	0.0028 (14)	0.0081 (16)
C4A	0.0179 (17)	0.026 (2)	0.0179 (16)	−0.0035 (17)	0.0051 (14)	−0.0008 (16)
C5A	0.0158 (16)	0.017 (2)	0.0247 (18)	0.0005 (15)	0.0050 (14)	−0.0001 (16)
C6A	0.0155 (17)	0.0166 (19)	0.0224 (17)	−0.0002 (15)	0.0033 (13)	0.0023 (15)
C7A	0.0177 (18)	0.019 (2)	0.0235 (18)	0.0010 (16)	0.0055 (14)	−0.0019 (16)
C8A	0.0171 (17)	0.022 (2)	0.0195 (17)	−0.0012 (16)	0.0009 (14)	−0.0003 (16)
C9A	0.0184 (17)	0.0150 (19)	0.0192 (16)	0.0017 (16)	0.0008 (13)	0.0016 (15)
C10A	0.0166 (17)	0.018 (2)	0.0226 (17)	−0.0039 (16)	0.0030 (14)	−0.0010 (16)
C11A	0.0228 (18)	0.0174 (19)	0.0153 (16)	−0.0026 (16)	0.0057 (14)	0.0023 (15)
C12A	0.0161 (17)	0.0189 (19)	0.0156 (15)	−0.0010 (15)	0.0038 (13)	0.0017 (15)
C13A	0.0210 (18)	0.0150 (18)	0.0168 (16)	0.0014 (16)	0.0046 (13)	0.0014 (15)
C14A	0.0156 (16)	0.0180 (19)	0.0165 (15)	0.0023 (15)	0.0035 (13)	0.0048 (15)
C15A	0.0163 (17)	0.024 (2)	0.0154 (16)	−0.0002 (16)	0.0011 (13)	0.0013 (15)
C16A	0.0221 (18)	0.0167 (19)	0.0189 (16)	−0.0033 (16)	0.0044 (14)	−0.0019 (15)
C17A	0.0180 (17)	0.0147 (19)	0.0189 (16)	0.0001 (15)	0.0053 (13)	−0.0003 (15)
C18A	0.0173 (18)	0.024 (2)	0.0273 (19)	−0.0035 (17)	−0.0007 (15)	−0.0016 (17)
C19A	0.0231 (19)	0.020 (2)	0.0219 (17)	0.0019 (17)	−0.0021 (14)	−0.0003 (16)
Br1B	0.0397 (2)	0.0322 (3)	0.02182 (19)	0.0007 (2)	−0.00362 (16)	−0.00159 (18)
Br2B	0.01964 (18)	0.0264 (2)	0.0304 (2)	−0.00490 (17)	0.00142 (15)	−0.00229 (17)
O1B	0.0361 (16)	0.0214 (15)	0.0344 (15)	−0.0074 (13)	0.0022 (13)	0.0013 (13)
O2B	0.0202 (14)	0.0190 (16)	0.0299 (14)	−0.0024 (13)	0.0015 (12)	0.0058 (12)
N1B	0.0205 (16)	0.0222 (18)	0.0203 (15)	0.0028 (14)	0.0035 (12)	0.0007 (14)
N2B	0.0181 (15)	0.0252 (18)	0.0178 (14)	0.0016 (14)	0.0035 (11)	0.0028 (13)
C1B	0.0184 (18)	0.021 (2)	0.0294 (19)	−0.0007 (17)	0.0048 (15)	−0.0011 (17)
C2B	0.022 (2)	0.020 (2)	0.038 (2)	−0.0057 (18)	0.0029 (17)	−0.0074 (19)
C3B	0.0218 (19)	0.025 (2)	0.029 (2)	−0.0002 (18)	−0.0016 (15)	−0.0111 (18)
C4B	0.0221 (19)	0.027 (2)	0.0227 (17)	0.0073 (17)	0.0024 (15)	−0.0021 (17)
C5B	0.0186 (18)	0.0170 (19)	0.0257 (18)	0.0010 (16)	0.0036 (14)	−0.0027 (16)
C6B	0.0169 (17)	0.019 (2)	0.0221 (17)	0.0030 (16)	0.0030 (13)	−0.0014 (16)
C7B	0.0150 (17)	0.0178 (19)	0.0234 (17)	−0.0018 (15)	0.0052 (14)	−0.0034 (16)
C8B	0.0181 (17)	0.023 (2)	0.0243 (17)	−0.0025 (17)	0.0023 (14)	0.0014 (17)
C9B	0.0155 (17)	0.022 (2)	0.0234 (17)	0.0019 (16)	0.0030 (14)	0.0031 (16)
C10B	0.0210 (18)	0.024 (2)	0.0204 (17)	0.0026 (17)	0.0037 (14)	0.0003 (16)
C11B	0.0200 (18)	0.019 (2)	0.0194 (17)	0.0048 (16)	0.0037 (14)	0.0011 (15)
C12B	0.0171 (17)	0.020 (2)	0.0149 (15)	0.0001 (16)	0.0004 (13)	−0.0013 (15)
C13B	0.0222 (19)	0.018 (2)	0.0203 (17)	0.0013 (16)	0.0020 (14)	0.0023 (16)
C14B	0.0170 (17)	0.020 (2)	0.0187 (16)	−0.0024 (16)	0.0025 (13)	−0.0053 (16)
C15B	0.0184 (18)	0.024 (2)	0.0207 (17)	0.0037 (17)	−0.0004 (14)	0.0014 (16)
C16B	0.026 (2)	0.017 (2)	0.0205 (17)	0.0018 (17)	0.0038 (15)	0.0012 (16)
C17B	0.0231 (19)	0.019 (2)	0.0162 (16)	−0.0003 (16)	0.0048 (14)	−0.0010 (15)
C18B	0.0200 (19)	0.028 (2)	0.0261 (19)	0.0019 (18)	0.0016 (15)	−0.0024 (18)
C19B	0.0210 (19)	0.024 (2)	0.0267 (19)	−0.0024 (17)	0.0050 (15)	0.0042 (17)

Geometric parameters (Å, º) top

Br1A—C4A	1.899 (3)	Br1B—C4B	1.906 (4)
Br2A—C14A	1.899 (3)	Br2B—C14B	1.902 (4)
O1A—C1A	1.347 (4)	O1B—C1B	1.344 (5)
O1A—H1OA	0.79 (4)	O1B—H1OB	0.8464
O2A—C17A	1.347 (4)	O2B—C17B	1.350 (4)
O2A—H2OA	0.85 (4)	O2B—H2OB	0.73 (4)
N1A—C7A	1.278 (4)	N1B—C7B	1.273 (4)
N1A—C8A	1.459 (4)	N1B—C8B	1.460 (4)
N2A—C11A	1.276 (4)	N2B—C11B	1.267 (5)
N2A—C10A	1.462 (4)	N2B—C10B	1.463 (5)
C1A—C2A	1.390 (5)	C1B—C2B	1.393 (5)
C1A—C6A	1.397 (5)	C1B—C6B	1.410 (5)
C2A—C3A	1.378 (5)	C2B—C3B	1.374 (6)
C2A—H2AA	0.9500	C2B—H2BA	0.9500
C3A—C4A	1.387 (5)	C3B—C4B	1.381 (6)
C3A—H3AA	0.9500	C3B—H3BA	0.9500
C4A—C5A	1.372 (5)	C4B—C5B	1.381 (5)
C5A—C6A	1.407 (5)	C5B—C6B	1.402 (5)
C5A—H5AA	0.9500	C5B—H5BA	0.9500
C6A—C7A	1.454 (5)	C6B—C7B	1.460 (5)
C7A—H7AA	0.9500	C7B—H7BA	0.9500
C8A—C9A	1.536 (5)	C8B—C9B	1.540 (5)
C8A—H8AA	0.9900	C8B—H8BA	0.9900
C8A—H8AB	0.9900	C8B—H8BB	0.9900
C9A—C19A	1.524 (5)	C9B—C19B	1.527 (5)
C9A—C18A	1.528 (5)	C9B—C18B	1.533 (5)
C9A—C10A	1.534 (5)	C9B—C10B	1.534 (5)
C10A—H10A	0.9900	C10B—H10C	0.9900
C10A—H10B	0.9900	C10B—H10D	0.9900
C11A—C12A	1.466 (5)	C11B—C12B	1.458 (5)
C11A—H11A	0.9500	C11B—H11B	0.9500
C12A—C13A	1.403 (5)	C12B—C13B	1.393 (5)
C12A—C17A	1.405 (5)	C12B—C17B	1.407 (5)
C13A—C14A	1.379 (5)	C13B—C14B	1.376 (5)
C13A—H13A	0.9500	C13B—H13B	0.9500
C14A—C15A	1.391 (5)	C14B—C15B	1.385 (5)
C15A—C16A	1.371 (5)	C15B—C16B	1.376 (5)
C15A—H15A	0.9500	C15B—H15B	0.9500
C16A—C17A	1.395 (5)	C16B—C17B	1.391 (5)
C16A—H16A	0.9500	C16B—H16B	0.9500
C18A—H18A	0.9800	C18B—H18D	0.9800
C18A—H18B	0.9800	C18B—H18E	0.9800
C18A—H18C	0.9800	C18B—H18F	0.9800
C19A—H19A	0.9800	C19B—H19D	0.9800
C19A—H19B	0.9800	C19B—H19E	0.9800
C19A—H19C	0.9800	C19B—H19F	0.9800

C1A—O1A—H1OA	104 (3)	C1B—O1B—H1OB	105.1
C17A—O2A—H2OA	104 (3)	C17B—O2B—H2OB	109 (4)
C7A—N1A—C8A	119.7 (3)	C7B—N1B—C8B	119.5 (3)
C11A—N2A—C10A	119.0 (3)	C11B—N2B—C10B	118.2 (3)
O1A—C1A—C2A	118.2 (3)	O1B—C1B—C2B	118.7 (4)
O1A—C1A—C6A	121.9 (3)	O1B—C1B—C6B	121.7 (3)
C2A—C1A—C6A	119.9 (3)	C2B—C1B—C6B	119.6 (4)
C3A—C2A—C1A	120.5 (4)	C3B—C2B—C1B	120.5 (4)
C3A—C2A—H2AA	119.7	C3B—C2B—H2BA	119.7
C1A—C2A—H2AA	119.7	C1B—C2B—H2BA	119.8
C2A—C3A—C4A	119.8 (3)	C2B—C3B—C4B	120.0 (3)
C2A—C3A—H3AA	120.1	C2B—C3B—H3BA	120.0
C4A—C3A—H3AA	120.1	C4B—C3B—H3BA	120.0
C5A—C4A—C3A	120.7 (3)	C3B—C4B—C5B	121.2 (4)
C5A—C4A—Br1A	119.9 (3)	C3B—C4B—Br1B	119.0 (3)
C3A—C4A—Br1A	119.4 (3)	C5B—C4B—Br1B	119.8 (3)
C4A—C5A—C6A	120.0 (3)	C4B—C5B—C6B	119.5 (4)
C4A—C5A—H5AA	120.0	C4B—C5B—H5BA	120.2
C6A—C5A—H5AA	120.0	C6B—C5B—H5BA	120.2
C1A—C6A—C5A	119.1 (3)	C5B—C6B—C1B	119.2 (3)
C1A—C6A—C7A	121.3 (3)	C5B—C6B—C7B	119.8 (3)
C5A—C6A—C7A	119.7 (3)	C1B—C6B—C7B	121.0 (3)
N1A—C7A—C6A	120.5 (4)	N1B—C7B—C6B	120.8 (3)
N1A—C7A—H7AA	119.8	N1B—C7B—H7BA	119.6
C6A—C7A—H7AA	119.8	C6B—C7B—H7BA	119.6
N1A—C8A—C9A	110.9 (3)	N1B—C8B—C9B	110.8 (3)
N1A—C8A—H8AA	109.5	N1B—C8B—H8BA	109.5
C9A—C8A—H8AA	109.5	C9B—C8B—H8BA	109.5
N1A—C8A—H8AB	109.5	N1B—C8B—H8BB	109.5
C9A—C8A—H8AB	109.5	C9B—C8B—H8BB	109.5
H8AA—C8A—H8AB	108.0	H8BA—C8B—H8BB	108.1
C19A—C9A—C18A	110.1 (3)	C19B—C9B—C18B	109.6 (3)
C19A—C9A—C10A	110.2 (3)	C19B—C9B—C10B	110.8 (3)
C18A—C9A—C10A	107.8 (3)	C18B—C9B—C10B	107.7 (3)
C19A—C9A—C8A	111.2 (3)	C19B—C9B—C8B	111.0 (3)
C18A—C9A—C8A	109.8 (3)	C18B—C9B—C8B	109.5 (3)
C10A—C9A—C8A	107.7 (3)	C10B—C9B—C8B	108.1 (3)
N2A—C10A—C9A	112.1 (3)	N2B—C10B—C9B	112.9 (3)
N2A—C10A—H10A	109.2	N2B—C10B—H10C	109.0
C9A—C10A—H10A	109.2	C9B—C10B—H10C	109.0
N2A—C10A—H10B	109.2	N2B—C10B—H10D	109.0
C9A—C10A—H10B	109.2	C9B—C10B—H10D	109.0
H10A—C10A—H10B	107.9	H10C—C10B—H10D	107.8
N2A—C11A—C12A	120.7 (3)	N2B—C11B—C12B	121.6 (4)
N2A—C11A—H11A	119.7	N2B—C11B—H11B	119.2
C12A—C11A—H11A	119.7	C12B—C11B—H11B	119.2
C13A—C12A—C17A	119.2 (3)	C13B—C12B—C17B	119.1 (3)
C13A—C12A—C11A	119.9 (3)	C13B—C12B—C11B	120.1 (3)
C17A—C12A—C11A	120.9 (3)	C17B—C12B—C11B	120.7 (3)
C14A—C13A—C12A	120.1 (3)	C14B—C13B—C12B	120.2 (4)
C14A—C13A—H13A	119.9	C14B—C13B—H13B	119.9
C12A—C13A—H13A	119.9	C12B—C13B—H13B	119.9
C13A—C14A—C15A	120.8 (3)	C13B—C14B—C15B	120.8 (3)
C13A—C14A—Br2A	120.2 (3)	C13B—C14B—Br2B	119.8 (3)
C15A—C14A—Br2A	119.0 (2)	C15B—C14B—Br2B	119.4 (3)
C16A—C15A—C14A	119.3 (3)	C16B—C15B—C14B	119.7 (3)
C16A—C15A—H15A	120.3	C16B—C15B—H15B	120.1
C14A—C15A—H15A	120.3	C14B—C15B—H15B	120.1
C15A—C16A—C17A	121.4 (3)	C15B—C16B—C17B	120.6 (4)
C15A—C16A—H16A	119.3	C15B—C16B—H16B	119.7
C17A—C16A—H16A	119.3	C17B—C16B—H16B	119.7
O2A—C17A—C16A	119.1 (3)	O2B—C17B—C16B	119.0 (3)
O2A—C17A—C12A	121.8 (3)	O2B—C17B—C12B	121.5 (3)
C16A—C17A—C12A	119.1 (3)	C16B—C17B—C12B	119.5 (3)
C9A—C18A—H18A	109.5	C9B—C18B—H18D	109.5
C9A—C18A—H18B	109.5	C9B—C18B—H18E	109.5
H18A—C18A—H18B	109.5	H18D—C18B—H18E	109.5
C9A—C18A—H18C	109.5	C9B—C18B—H18F	109.5
H18A—C18A—H18C	109.5	H18D—C18B—H18F	109.5
H18B—C18A—H18C	109.5	H18E—C18B—H18F	109.5
C9A—C19A—H19A	109.5	C9B—C19B—H19D	109.5
C9A—C19A—H19B	109.5	C9B—C19B—H19E	109.5
H19A—C19A—H19B	109.5	H19D—C19B—H19E	109.5
C9A—C19A—H19C	109.5	C9B—C19B—H19F	109.5
H19A—C19A—H19C	109.5	H19D—C19B—H19F	109.5
H19B—C19A—H19C	109.5	H19E—C19B—H19F	109.5

O1A—C1A—C2A—C3A	178.1 (3)	O1B—C1B—C2B—C3B	177.9 (3)
C6A—C1A—C2A—C3A	−2.1 (5)	C6B—C1B—C2B—C3B	−2.1 (6)
C1A—C2A—C3A—C4A	0.7 (6)	C1B—C2B—C3B—C4B	0.4 (6)
C2A—C3A—C4A—C5A	0.6 (5)	C2B—C3B—C4B—C5B	1.2 (6)
C2A—C3A—C4A—Br1A	−180.0 (3)	C2B—C3B—C4B—Br1B	−178.4 (3)
C3A—C4A—C5A—C6A	−0.5 (5)	C3B—C4B—C5B—C6B	−1.0 (6)
Br1A—C4A—C5A—C6A	−179.9 (3)	Br1B—C4B—C5B—C6B	178.6 (3)
O1A—C1A—C6A—C5A	−178.0 (3)	C4B—C5B—C6B—C1B	−0.7 (5)
C2A—C1A—C6A—C5A	2.1 (5)	C4B—C5B—C6B—C7B	179.8 (3)
O1A—C1A—C6A—C7A	3.9 (5)	O1B—C1B—C6B—C5B	−177.7 (3)
C2A—C1A—C6A—C7A	−176.0 (3)	C2B—C1B—C6B—C5B	2.2 (5)
C4A—C5A—C6A—C1A	−0.9 (5)	O1B—C1B—C6B—C7B	1.7 (5)
C4A—C5A—C6A—C7A	177.2 (3)	C2B—C1B—C6B—C7B	−178.3 (3)
C8A—N1A—C7A—C6A	176.5 (3)	C8B—N1B—C7B—C6B	178.6 (3)
C1A—C6A—C7A—N1A	−4.1 (5)	C5B—C6B—C7B—N1B	175.9 (3)
C5A—C6A—C7A—N1A	177.8 (3)	C1B—C6B—C7B—N1B	−3.6 (5)
C7A—N1A—C8A—C9A	−122.4 (4)	C7B—N1B—C8B—C9B	−126.7 (4)
N1A—C8A—C9A—C19A	−56.1 (4)	N1B—C8B—C9B—C19B	−56.8 (4)
N1A—C8A—C9A—C18A	66.0 (4)	N1B—C8B—C9B—C18B	64.4 (4)
N1A—C8A—C9A—C10A	−176.9 (3)	N1B—C8B—C9B—C10B	−178.5 (3)
C11A—N2A—C10A—C9A	−136.7 (3)	C11B—N2B—C10B—C9B	−119.8 (4)
C19A—C9A—C10A—N2A	−57.3 (4)	C19B—C9B—C10B—N2B	−59.5 (4)
C18A—C9A—C10A—N2A	−177.5 (3)	C18B—C9B—C10B—N2B	−179.4 (3)
C8A—C9A—C10A—N2A	64.2 (4)	C8B—C9B—C10B—N2B	62.3 (4)
C10A—N2A—C11A—C12A	−176.9 (3)	C10B—N2B—C11B—C12B	179.4 (3)
N2A—C11A—C12A—C13A	179.2 (3)	N2B—C11B—C12B—C13B	−172.0 (3)
N2A—C11A—C12A—C17A	1.9 (5)	N2B—C11B—C12B—C17B	8.8 (5)
C17A—C12A—C13A—C14A	2.0 (5)	C17B—C12B—C13B—C14B	1.0 (5)
C11A—C12A—C13A—C14A	−175.4 (3)	C11B—C12B—C13B—C14B	−178.2 (3)
C12A—C13A—C14A—C15A	−0.1 (5)	C12B—C13B—C14B—C15B	0.9 (5)
C12A—C13A—C14A—Br2A	178.7 (3)	C12B—C13B—C14B—Br2B	−178.3 (3)
C13A—C14A—C15A—C16A	−1.4 (5)	C13B—C14B—C15B—C16B	−1.3 (5)
Br2A—C14A—C15A—C16A	179.8 (3)	Br2B—C14B—C15B—C16B	177.9 (3)
C14A—C15A—C16A—C17A	0.9 (5)	C14B—C15B—C16B—C17B	−0.2 (5)
C15A—C16A—C17A—O2A	−178.9 (3)	C15B—C16B—C17B—O2B	−178.5 (3)
C15A—C16A—C17A—C12A	1.0 (5)	C15B—C16B—C17B—C12B	2.0 (5)
C13A—C12A—C17A—O2A	177.5 (3)	C13B—C12B—C17B—O2B	178.1 (3)
C11A—C12A—C17A—O2A	−5.2 (5)	C11B—C12B—C17B—O2B	−2.7 (5)
C13A—C12A—C17A—C16A	−2.4 (5)	C13B—C12B—C17B—C16B	−2.4 (5)
C11A—C12A—C17A—C16A	174.9 (3)	C11B—C12B—C17B—C16B	176.8 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1B—H1OB···N1B	0.85	1.81	2.580 (4)	151
O2A—H2OA···N2A	0.85 (4)	1.79 (4)	2.578 (4)	154 (4)
O1A—H1OA···N1A	0.79 (5)	1.85 (5)	2.572 (4)	153 (4)
O2B—H2OB···N2B	0.73 (5)	1.94 (5)	2.586 (4)	149 (5)
C8A—H8AA···N2A	0.99	2.58	2.960 (4)	103
C8B—H8BA···N2B	0.99	2.60	2.966 (4)	102
C16B—H16B···O2Bⁱ	0.95	2.58	3.290 (5)	131
C19A—H19B···N1A	0.98	2.58	2.918 (4)	100
C19A—H19C···N2A	0.98	2.58	2.933 (5)	101
C19B—H19F···N1B	0.98	2.60	2.926 (5)	100
C7B—H7BA···Cg1ⁱⁱ	0.95	2.96	3.571 (4)	123
C18B—H18D···Cg2ⁱⁱⁱ	0.98	2.77	3.652 (4)	151

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

Experimental details

Crystal data
Chemical formula	C₁₉H₂₀Br₂N₂O₂
M_r	468.19
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	100
a, b, c (Å)	31.7684 (10), 6.2436 (2), 38.7287 (11)
β (°)	99.870 (2)
V (Å³)	7568.1 (4)
Z	16
Radiation type	Mo Kα
µ (mm⁻¹)	4.30
Crystal size (mm)	0.52 × 0.10 × 0.06

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.213, 0.783
No. of measured, independent and observed [I > 2σ(I)] reflections	47391, 11172, 6920
R_int	0.080
(sin θ/λ)_max (Å⁻¹)	0.708

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.043, 0.110, 1.01
No. of reflections	11172
No. of parameters	463
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.57, −0.46

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
O1B—H1OB···N1B	0.8500	1.8100	2.580 (4)	151.00
O2A—H2OA···N2A	0.85 (4)	1.79 (4)	2.578 (4)	154 (4)
O1A—H1OA···N1A	0.79 (5)	1.85 (5)	2.572 (4)	153 (4)
O2B—H2OB···N2B	0.73 (5)	1.94 (5)	2.586 (4)	149 (5)
C8A—H8AA···N2A	0.9900	2.5800	2.960 (4)	103.00
C8B—H8BA···N2B	0.9900	2.6000	2.966 (4)	102.00
C16B—H16B···O2Bⁱ	0.9500	2.5800	3.290 (5)	131.00
C19A—H19B···N1A	0.9800	2.5800	2.918 (4)	100.00
C19A—H19C···N2A	0.9800	2.5800	2.933 (5)	101.00
C19B—H19F···N1B	0.9800	2.6000	2.926 (5)	100.00
C7B—H7BA···Cg1ⁱⁱ	0.9500	2.9600	3.571 (4)	123.00
C18B—H18D···Cg2ⁱⁱⁱ	0.9800	2.7700	3.652 (4)	151.00

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

Footnotes

‡Additional correspondence author, tel: +98-352-7220011 ext. 157, fax: 98-352-7228110, e-mail: hkargar@pnu.ac.ir.

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 for an award of a post-doctoral research fellowship. HK thanks PNU for financial support.

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