4,4′-[2,2-Dimethyl­propane-1,3-diyl­bis(nitrilo­methyl­idyne)]dibenzonitrile

Hoong-Kun Fun; Hadi Kargar; Reza Kia

doi:10.1107/S1600536808018345

. 2008 Jun 19;64(Pt 7):o1308. doi: 10.1107/S1600536808018345

4,4′-[2,2-Dimethylpropane-1,3-diylbis(nitrilomethylidyne)]dibenzonitrile

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

PMCID: PMC2961864 PMID: 21202936

Abstract

The title compound, C₂₁H₂₀N₄, is a bidentate Schiff base ligand. An intramolecular C—H⋯N hydrogen bond forms a five-membered ring, producing an S(5) ring motif. The cyano and imino [–C(H₂)—N=C–] functional groups are coplanar with the benzene ring in each half of the molecule. The packing of the molecules is controlled by C—H⋯π and π–π interactions [centroid-to-centroid distance = 3.6944 (8) Å].

Related literature

For related literature on hydrogen-bond motifs, see Bernstein et al. (1995 ▶). For values of bond lengths, see Allen et al. (1987 ▶). For related structures, see, for example: Li et al. (2005 ▶); Bomfim et al. (2005 ▶); Glidewell et al. (2005 ▶, 2006 ▶); Sun et al. (2004 ▶); Habibi et al. (2007 ▶); Fun et al. (2008 ▶).

Experimental

Crystal data

C₂₁H₂₀N₄
M _r = 328.41
Monoclinic,
a = 6.3833 (2) Å
b = 34.0679 (8) Å
c = 8.5190 (2) Å
β = 100.654 (2)°
V = 1820.65 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 100.0 (1) K
0.42 × 0.20 × 0.19 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker 2005 ▶) T _min = 0.970, T _max = 0.986
21813 measured reflections
5329 independent reflections
3711 reflections with I > 2σ(I)
R _int = 0.046

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.139
S = 1.04
5329 reflections
228 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.20 e Å⁻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 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808018345/at2578sup1.cif

e-64-o1308-sup1.cif^{(19.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808018345/at2578Isup2.hkl

e-64-o1308-Isup2.hkl^{(261KB, hkl)}

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

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

Cg1 is the centroid of the C12–C17 benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C20—H20B⋯N2	0.96	2.57	2.923 (2)	102
C21—H21C⋯Cg1ⁱ	0.96	2.95	3.7193 (16)	138

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Symmetry code: (i) Inline graphic .

Acknowledgments

HKF and RK thank the Malaysian Government and Universiti sains Malaysia for Science Fund Grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia for a post-doctoral research fellowship. HK thanks PNU for financial support.

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 (Li et al., 2005; Bomfim et al., 2005; Glidewell et al., 2005, 2006; Sun et al., 2004; Habibi et al., 2007; Fun et al., 2008).

An intramolecular C—H···N hydrogen bond forms a five-membered ring, producing an S(5) ring motif (Bernstein et al., 1995). The bond lengths and angles in the molecule (Fig. 1) are within normal ranges (Allen et al., 1987). The cyano and imino (—C(H₂)—N═C—) functional groups are coplanar with the benzene ring in each half of the molcule. The torsion angles of C6—C7—N1—C8 and C12—C11—N2—C10 are -178.95 (13) and -179.43 (12)°, respectively. The packing of the molecule, (Fig. 2), is controlled by C—H···π and π–π interactions [centroid-centroid distance being 3.6944 (8) Å] (Table 1).

Experimental

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