N 4,N 4′-Bis(4-meth­oxy­benzyl­idene)-3,3′-dimethyl­benzidine

Juangang Wang; Peipei Yang; Jin Yang

doi:10.1107/S1600536811023749

. 2011 Jun 22;67(Pt 7):o1753. doi: 10.1107/S1600536811023749

N ⁴,N ^4′-Bis(4-methoxybenzylidene)-3,3′-dimethylbenzidine

Juangang Wang ^a,^*, Peipei Yang ^a, Jin Yang ^a

PMCID: PMC3152131 PMID: 21837136

Abstract

The molecule of the title compund, C₃₀H₂₈N₂O₂, a Schiff base synthesised via a condensation reaction between 4-methoxybenzaldehyde and 3,3′-dimethylbenzidine, a crystallographic twofold rotation axis passes through the mid-point of the C—C bond of the biphenyl unit. Thus, the asymmetric unit comprises one half-molecule. In the biphenyl unit, the aromatic rings are twisted by 13.49 (7)° with respect to one another. The dihedral angles between the biphenyl and methoxybenzene rings are 49.95 (12) and 50.06 (12)°. In the crystal, weak intermolecular C—H⋯ O hydrogen bonds contribute to the stabilization of the packing.

Related literature

For the biological properties of Schiff base ligands, see: Bedia et al. (2006 ▶). For related structures, see: Harada et al. (2004 ▶); Nesterov (2004 ▶). For reference bond-length values, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₃₀H₂₈N₂O₂
M _r = 448.54
Monoclinic,
a = 11.644 (2) Å
b = 16.228 (3) Å
c = 12.431 (3) Å
β = 91.75 (3)°
V = 2347.9 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 93 K
0.38 × 0.34 × 0.22 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.703, T _max = 0.786
11279 measured reflections
2667 independent reflections
2350 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.111
S = 1.05
2667 reflections
210 parameters
All H-atom parameters refined
Δρ_max = 0.40 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811023749/kp2337sup1.cif

e-67-o1753-sup1.cif^{(15.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811023749/kp2337Isup2.hkl

e-67-o1753-Isup2.hkl^{(131.1KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811023749/kp2337Isup3.cml

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
C6—H6A⋯O1ⁱ	0.960 (13)	2.688 (13)	3.4462 (15)	136.32 (su?)

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

Financial support from Huaibei Normal University is gratefully acknowledged.

supplementary crystallographic information

Comment

Schiff base ligands have received considerable attention during the last decades, mainly because of their structures or their biological properties (Bedia et al., 2006). We report here the crystal structure of the title compound, (I), a novel Schiff base (Fig. 1). The bond lengths (Allen et al., 1987) and angles are normal and comparable to the values observed in similar compounds (Harada et al., 2004; Nesterov et al., 2004). In the biphenyl moiety, the aromatic rings are inclined by 13.49 (7)°. The dihedral angles between the biphenyl and methoxybenzal rings are 49.95 (12)° and 50.06 (12)°, respectively. In the crystal, weak intermolecular C—H··· O hydrogen bonds contribute to the stabilisation of the packing (Table 1).

Experimental

4-Methoxybenzaldehyde (0.272 g,2 mmol), 3,3'-Dimethylbenzidine (0.212 g,1 mmol) and 20 mL toluene were placed in a round-bottom flask equipped with a magnetic stirring bar. The reaction mixture was stirred at reflux for 4 h and then cooled.The solid that precipitated was filtered off and washed with methanol. This compound (0.224 g, 0.5 mmol) was dissolved in ethylacetate and left to crystallise. Crystals obtained were suitable for data collection.