(E)-2-{[4-(Di­methyl­amino)­benzyl­idene]amino}-5-nitro­phenol

Yousef Hijji; Ray J Butcher; Jerry P Jasinski

doi:10.1107/S160053681400871X

. 2014 Apr 26;70(Pt 5):o598–o599. doi: 10.1107/S160053681400871X

(E)-2-{[4-(Dimethylamino)benzylidene]amino}-5-nitrophenol

Yousef Hijji ^a,^‡, Ray J Butcher ^b,^*, Jerry P Jasinski ^c

PMCID: PMC4011306 PMID: 24860394

Abstract

The title Schiff base compound, C₁₅H₁₅N₃O₃, crystallizes with two molecules (A and B) in the asymmetric unit. Each molecule adopts an E conformation around the C= N imine bond. The two molecules have minor differences in their conformations. In molecule A, the dihedral angle between the nitro group and its benzene ring is 2.1 (2)° and that between the two benzene rings is 0.88 (7)°, while the corresponding angles for molecule B are 5.7 (1) and 2.45 (6)°, respectively. In each molecule, there is an intramolecular O—H⋯N hydrogen bond. In the crystal, inversion-related molecules are linked via O—H⋯O hydrogen bonds forming A–A and B–B dimers. These dimers are linked via C—H⋯O hydrogen bonds involving the nitro O atoms, forming A–A–A and B–B–B slabs that lie parallel to one another and to (010).

Related literature

For related structures, see: Rodríguez et al. (2012 ▶); Valkonen et al. (2012 ▶); Gül et al. (2007 ▶); Reyes et al. (2004 ▶); Hijji et al. (2014 ▶). For the applications of Schiff bases as anion sensors, see: Hijji et al. (2009 ▶), and in non-linear optics, see: Muñoz et al. (2008 ▶). graphic file with name e-70-0o598-scheme1.jpg

Experimental

Crystal data

C₁₅H₁₅N₃O₃
M _r = 285.30
Triclinic,
a = 6.1435 (3) Å
b = 14.3844 (8) Å
c = 15.8516 (9) Å
α = 108.038 (5)°
β = 91.258 (4)°
γ = 96.033 (4)°
V = 1322.37 (13) Å³
Z = 4
Cu Kα radiation
μ = 0.84 mm⁻¹
T = 123 K
0.32 × 0.24 × 0.19 mm

Data collection

Agilent Xcalibur (Ruby, Gemini) diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012 ▶) T _min = 0.938, T _max = 1.000
9056 measured reflections
9056 independent reflections
7791 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.119
S = 1.04
9056 reflections
392 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S160053681400871X/su2709sup1.cif

e-70-0o598-sup1.cif^{(408.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681400871X/su2709Isup2.hkl

e-70-0o598-Isup2.hkl^{(496KB, hkl)}

Click here for additional data file.^{(5.6KB, cml)}

Supporting information file. DOI: 10.1107/S160053681400871X/su2709Isup3.cml

CCDC reference: 997774

Additional supporting information: crystallographic information; 3D view; checkCIF report

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1A—H1A⋯N2A	0.85 (2)	1.99 (2)	2.5860 (16)	126 (2)
O1A—H1A⋯O1A ⁱ	0.85 (2)	2.41 (2)	2.8738 (16)	114.7 (19)
O1B—H1B⋯N2B	0.84 (2)	1.993 (19)	2.5896 (16)	127.5 (19)
O1B—H1B⋯O1B ⁱⁱ	0.84 (2)	2.45 (2)	2.8853 (15)	113.7 (17)
C7B—H7BA⋯O1B ⁱⁱⁱ	0.95	2.58	3.1870 (17)	122
C15A—H15C⋯O3A ^iv	0.98	2.59	3.3989 (19)	141

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

YH thanks the Department of Chemistry and Earth Sciences at Qatar University for support. RJB acknowledges the National Science Foundation MRI program (CHE0619278) for funds to purchase the diffractometer and the Howard University Nanoscience Facility for access to liquid nitrogen.

supplementary crystallographic information

1. Comment

Schiff bases are used as ligands to form complexes with metals and borane and such complexes have application in non-linear optical dyes (Rodríguez et al., 2012; Reyes et al., 2004) and as anion sensors (Hijji et al., 2009; Muñoz et al. 2008). Related structures were reported by (Gül et al., 2007; Muñoz et al., 2008; Valkonen et al., 2012; Hijji et al., 2014).

The title compound is a Schiff base prepared by the reaction of 4-dimethylaminobenzaldehyde with 2-amino-5-nitrophenol under microwave conditions.It crystallized with two molecules (A and B) in the asymmetric unit, Fig. 1. Each molecule adopts an E conformation about the C=N imine bond: C7A═N2A in A and C7B═N2B in B. The two molecules in the asymmetric unit have minor differences in their conformations: In molecule A the dihedral angle between the nitro group (N1A/O2A/O3A) and its benzene ring (C1A—C6A) is 2.1 (2)° and between the two benzene rings (C1A—C6A and C8A—C13A) is only 0.88 (7)°, while for molecule B the corresponding angles are 5.7 (1)° and 2.45 (6)°, respectively. For each molecule there is an intramolecular hydrogen bond (Table 1 and Fig. 1) involving the OH group.

In the crystal, inversion related individual molecules are linked via O—H···O hydrogen bonds forming A—A and B—B dimers (Table 1 and Fig. 2). These dimers are linked via C—H···O hydrogen bonds involving the nitro group O atoms forming -A—A—A- and -B—B—B- slabs that lie parallel to one another and to (010) - see Fig. 3.

In a related 4-nitrophenyl derivative (Hijji et al., 2014) there are no intermolecular C—H···O hydrogen bonds involving the nitro group.

2. Experimental

4-dimethaminobenzaldehyde (0.150 g, 1.0 mmol) and 5-nitro-2-amino phenol (0.15 g, 1.0mmol) were placed in a Biotage microwave tube. The mixture was heated in the Biotage initiator microwave for 5 min at 393 K. Upon cooling a brown solid formed. It was dissolved in ethanol and allowed to recrystallize to provide purple crystals (0.20g, 70% yield; M.p. 495-498 K). A sample was recrystallized from ethanol by slow evaporation to provide crystals suitable for X-ray diffraction analysis. Spectroscopic data for the title compound is available in the archived CIF.

3. Refinement

The hydroxyl H atoms were located in a difference Fourier map and freely refined. The C-bound H atoms were placed in calculated positions and treated as riding atoms: C—H = 0.95 and 0.99 Å for CH and CH₃ H atoms, respectively, with U_iso(H) = 1.5U_eq(C-methyl) and = 1.2U_eq(C) for other H atoms.