N,N′-Bis(4-bromo­benzyl­idene)-2,2-dimethyl­propane-1,3-diamine

Reza Kia; Hoong-Kun Fun; Hadi Kargar

doi:10.1107/S1600536809008113

. 2009 Mar 14;65(Pt 4):o747. doi: 10.1107/S1600536809008113

N,N′-Bis(4-bromobenzylidene)-2,2-dimethylpropane-1,3-diamine

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

PMCID: PMC2968840 PMID: 21582479

Abstract

The molecule of the title compound, C₁₉H₂₀Br₂N₂, is a potential bidentate Schiff base ligand. The two benzene rings are inclined at a dihedral angle of 30.85 (8)°. An interesting feature of the crystal structure is a weak intermolecular Br⋯Br [3.4752 (4) Å] interaction which is shorter than the sum of the van der Waals radii of the Br atoms and links neighbouring molecules into chains along the c axis. The crystal structure is further stabilized by intermolecular C—H⋯π interactions.

Related literature

For details of hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For related structure see, for example: Li et al. (2005 ▶); Bomfim et al. (2005 ▶); Glidewell et al. (2005 ▶, 2006 ▶); Sun et al. (2004 ▶); Fun et al. (2008 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₉H₂₀Br₂N₂
M _r = 436.19
Orthorhombic,
a = 5.6687 (1) Å
b = 7.7919 (2) Å
c = 41.5932 (9) Å
V = 1837.17 (7) Å³
Z = 4
Mo Kα radiation
μ = 4.41 mm⁻¹
T = 100 K
0.45 × 0.44 × 0.12 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.229, T _max = 0.586
38732 measured reflections
9454 independent reflections
7585 reflections with I > 2σ(I)
R _int = 0.049

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.079
S = 1.03
9454 reflections
208 parameters
H-atom parameters constrained
Δρ_max = 1.04 e Å⁻³
Δρ_min = −0.61 e Å⁻³
Absolute structure: Flack (1983 ▶), 3971 Friedel pairs
Flack parameter: 0.019 (6)

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, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809008113/at2737sup1.cif

e-65-0o747-sup1.cif^{(19.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809008113/at2737Isup2.hkl

e-65-0o747-Isup2.hkl^{(462.4KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4A⋯Cg1ⁱ	0.95	2.85	3.5630 (18)	132
C13—H13A⋯Cg2ⁱⁱ	0.95	2.74	3.4648 (18)	134

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Symmetry codes: (i) Inline graphic ; (ii) . Cg1 and Cg2 are the centroids of the C1–C6 and C9–C17 benzene rings, respectively.

Acknowledgments

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 a post-doctoral research fellowship. HK thanks PNU for financial support. HKF also thanks Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

supplementary crystallographic information

Comment

Schiff bases are one of most prevalent mixed-donor ligands in the field of coordination chemistry. They play an important role in the development of coordination chemistry related to catalysis and enzymatic reactions, magnetism, and supramolecular architectures. Structures of Schiff bases derived from substituted benzaldehydes and closely related to the title compound have been reported previously (Li et al., 2005; Bomfim et al., 2005; Glidewell et al., 2005, 2006; Sun et al., 2004; Fun et al., 2008).

In the title compound, Fig. 1, intramolecular C—H···N hydrogen bonds forms five-membered rings, producing S(5) ring motifs (Bernstein et al., 1995). The two benzene rings make a dihedral angle of 30.85 (8)°. The crystal structure is further stabilized by weak intermolecular C—H···π interactions [Cg1 and Cg2 are the centroids of the C1–C6 and C12–C17 benzene rings] (Table 1). The interesting feature of the crystal structure is weak intermolecular Br···Br [3.4752 (4) Å; symmetry code: 5/2 - x, 1 - y, -1/2 + z] interaction which is shorter than the sum of the van der Waals radius of Br atoms and link neighbouring molecules into chains along the c axis (Fig. 2).

Experimental

The synthetic method has been described earlier (Fun et al., 2008), except that 4-bromobenzaldehyde was used. Single crystals suitable for X-ray diffraction were obtained by evaporation of an ethanol solution at room temperature.