Crystal structure of (E)-N-[(2-meth­oxy­naphthalen-1-yl)methyl­idene]-3-nitro­aniline

Devika Bhai R; C R Girija; Shalini Suresh; Ramakrishna Reddy

doi:10.1107/S2056989015020502

. 2015 Nov 14;71(Pt 12):o941–o942. doi: 10.1107/S2056989015020502

Crystal structure of (E)-N-[(2-methoxynaphthalen-1-yl)methylidene]-3-nitroaniline

Devika Bhai R ^a,^*, C R Girija ^b, Shalini Suresh ^c, Ramakrishna Reddy ^b

PMCID: PMC4719912 PMID: 26870540

Abstract

In the title compound, C₁₈H₁₄N₂O₃, the dihedral angle between the naphthalene ring system and the benzene ring is 59.99 (13)°. A short intramolecular C—H⋯N contact closes an S(6) ring. The nitro group is disordered over two orientations in a statistical ratio. In the crystal, weak C—H⋯O hydrogen bonds and very weak π–π stacking interactions [centroid–centroid separation = 3.9168 (17) Å] are observed.

Keywords: crystal structure, naphthaldimine Schiff base, hydrogen bonding

Related literature

For background to Schiff bases, see: Tolulope et al. (2013 ▸). graphic file with name e-71-0o941-scheme1.jpg

Experimental

Crystal data

C₁₈H₁₄N₂O₃
M _r = 306.31
Monoclinic,
a = 12.8481 (7) Å
b = 15.4085 (6) Å
c = 7.6232 (3) Å
β = 98.040 (4)°
V = 1494.33 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.35 × 0.30 × 0.25 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▸) T _min = 0.957, T _max = 0.989
21149 measured reflections
2622 independent reflections
1646 reflections with I > 2σ(I)
R _int = 0.046

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.143
S = 1.14
2622 reflections
227 parameters
42 restraints
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▸); cell refinement: APEX2 and SAINT (Bruker, 2004 ▸); data reduction: SAINT and XPREP (Bruker, 2004 ▸); program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▸); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015 ▸); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▸); software used to prepare material for publication: SHELXL2014.

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989015020502/hb7529sup1.cif

e-71-0o941-sup1.cif^{(804.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015020502/hb7529Isup2.hkl

e-71-0o941-Isup2.hkl^{(209.9KB, hkl)}

Click here for additional data file.^{(5.9KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015020502/hb7529Isup3.cml

Click here for additional data file.^{(1.1MB, tif)}

. DOI: 10.1107/S2056989015020502/hb7529fig1.tif

Plot of the title compound showing the intramolecular C—H⋯N interaction as a dashed line.

Click here for additional data file.^{(3.3MB, tif)}

. DOI: 10.1107/S2056989015020502/hb7529fig2.tif

Crystal packing diagram showing the C—H⋯N and C—H⋯O interactions as dashed lines

CCDC reference: 1429914

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
C16—H16⋯N2	0.93	2.31	2.961 (3)	127
C13—H13⋯O1′ⁱ	0.93	2.49	3.318 (14)	148
C18—H18A⋯O2ⁱⁱ	0.96	2.46	3.135 (18)	127

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

Acknowledgments

The authors thank the management RSST, R&D Centre Bharathiar University and the Principal of SSMRV Degree College for support. RDB thanks The Oxford College of Science for access to research facilities. The authors also thank the SAIF, IIT, Chennai for providing the XRD facility.

supplementary crystallographic information

S1. Chemical context

Schiff bases are considered an important class of organic compounds, which have wide applications. In recent years, they have gained significant interest in the area of drug research and development owing to the broad bioactivities such as insecticidal, antibacterial, antituberculosis and antimicrobial reported for the compounds and their metal complexes. These compounds play an important role in biological systems and are observed in various enzymes such as transaminases, tryptophan synthase etc. The important physical and biological properties of these compounds are related to the presence of the intramolecular hydrogen bond and proton transfer equilibrium. Schiff bases have also been utilized as ligands to synthesize metal complexes with interesting applications. The steric and inductive effects introduced by substituents present on the aromatic portion of the Schiff base can influence the properties of the ligand significantly. In continuation of our efforts in understanding the role of subtle electronic variations such as substituent effects on Chemistry and activity of Schiff bases and their metal complexes, we herein report the crystal structure of Schiff base derived from 3-nitroaniline and 2-methoxy naphthaldehyde (Tolulope et al., 2013).

S2. Structural commentary

The molecule of title compound is non-planar, with a dihedral angle between the naphthyl and phenyl aromatic rings of 59.99 (13)°, in which the two rings are twisted from one another. The C9—O3 single bond of 1.358 (3) Å and the C7═N2 double bond of 1.261 (3) Å .The bond angle of C5—N2—C7 of the imine group is 117.5 (2)°, less than 120°. The bond length of the nitro group is N1—O2(1.241 (6)Å) and N1—O1(1.239 (6)Å) and bond angle in O2—N1—O1 is 123.4 (12)° which is more than the planar bond angle of 120°. The torsion angles C8—C7—N2—C5 is 178.1 (2)°.These values support that the configurations about the N2=C7 bond is anti(E-form), which is in accordance with the enol-imine tautomeric form.

S3. Supramolecular features

The title compound has an intra molecular C16— H16···N2 hydrogen bond forming an S(6) motif (Table 2). Also there is a C—H···O intermolecular interaction, in which a C—H of the naphthyl ring of one molecule and O-atom of the nitro group of another molecule are linked to one another.

S4. Synthesis and crystallization

The block-like, yellow single crystals of the compound C₁₈ H₁₄ N₂ O₃, were grown using 1:1 mixture of CHCl₃ and methanol as solvent by slow evaporation technique.

S5. Refinement

The hydrogen atoms in the structure were positioned geometrically (C—H = 0.93–0.98 Å. N—H = 0.86Å) and were refined using a riding model with Uiso(H) = xUeq(C,N), where x = 1.5 for methyl and 1.2 for all other atoms. The two oxygen atoms of the nitro group are disordered over two orientations. The SADI, SIMU, and ISOR commands in SHELXL (Sheldrick, 2015) were used to model the disorder.

Crystal data, data collection and structure refinement details are summarized in Table 1.