A second monoclinic polymorph for 3-amino-1-(4-meth­oxy­phen­yl)-9,10-dihydro­phenanthrene-2,4-dicarbonitrile

Abdullah M Asiri; Hassan M Faidallah; Khalid A Alamry; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812011798

. 2012 Mar 24;68(Pt 4):o1157–o1158. doi: 10.1107/S1600536812011798

A second monoclinic polymorph for 3-amino-1-(4-methoxyphenyl)-9,10-dihydrophenanthrene-2,4-dicarbonitrile

Abdullah M Asiri ^a,^b,^‡, Hassan M Faidallah ^a, Khalid A Alamry ^a, Seik Weng Ng ^c,^a, Edward R T Tiekink ^c,^*

PMCID: PMC3344100 PMID: 22606103

Abstract

The title compound, C₂₃H₁₇N₃O, has been previously described in a monoclinic P2₁/c polymorph with Z = 4 [Asiri, Al-Youbi, Faidallah, Ng & Tiekink (2011). Acta Cryst. E67, o2449]. In the new monoclinic P2₁/n form, with Z = 8, there are two independent molecules, A and B, in the asymmetric unit. In both molecules, the cyclohexa-1,3-diene ring has a screw-boat conformation, whereas it is a distorted half-chair in the original polymorph. There is a fold in each molecule, as indicated by the dihedral angle between the benzene rings of the 1,2-dihydronaphthalene and aniline residues of 33.19 (10)° (molecule A) and 30.6 (10)° (molecule B). The methoxybenzene ring is twisted out of the plane of the aniline residue to which it is connected [dihedral angles = 49.22 (10) and 73.27 (10)°, in A and B respectively]. In the crystal, the two independent molecules self-associate via N—H⋯N hydrogen bonds, generating a 12-membered {⋯HNC₃N}₂ synthon. These are connected into a supramolecular tape in the (-101) plane by N—H⋯O(methoxy) interactions. In the P2₁/c polymorph, supramolecular layers are formed by N—H⋯N and N—H⋯O interactions.

Related literature

For background to the biological activity of related phenanthrene compounds, see: Wang et al. (2010 ▶); Rostom et al. (2011 ▶). For related structures, see: Asiri et al. (2011a ▶,b ▶); Al-Youbi et al. (2012 ▶). For ring puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₂₃H₁₇N₃O
M _r = 351.40
Monoclinic,
a = 11.5197 (6) Å
b = 25.1585 (12) Å
c = 11.9564 (6) Å
β = 90.719 (5)°
V = 3464.9 (3) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 100 K
0.35 × 0.35 × 0.10 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T _min = 0.971, T _max = 0.992
20450 measured reflections
7990 independent reflections
5348 reflections with I > 2σ(I)
R _int = 0.055

Refinement

R[F ² > 2σ(F ²)] = 0.060
wR(F ²) = 0.156
S = 1.04
7990 reflections
503 parameters
4 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812011798/bt5850sup1.cif

e-68-o1157-sup1.cif^{(30.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812011798/bt5850Isup2.hkl

e-68-o1157-Isup2.hkl^{(390.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812011798/bt5850Isup3.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
N2—H2⋯N6	0.89 (1)	2.25 (2)	3.081 (3)	157 (3)
N5—H3⋯N1	0.88 (1)	2.36 (1)	3.213 (3)	162 (2)
N2—H1⋯O1ⁱ	0.88 (2)	2.56 (2)	3.271 (3)	139 (2)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are thankful to the Center of Excellence for Advanced Materials Research and the Chemistry Department at King Abdulaziz University for providing the research facilities. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

In connection with structural studies on phenanthrene compounds (Asiri et al., 2011a; Asiri et al., 2011b; Al-Youbi et al., 2012), of interest owing to biological activity (Wang et al. 2010; Rostom et al., 2011), a new monoclinic polymorph of the title compound 3-amino-1-(4-methoxyphenyl)-9,10-dihydrophenanthrene-2,4-dicarbonitrile (I) was found. Previously (I) was isolated in the monoclinic space group P2₁/c with Z = 4 (Asiri et al., 2011b). The new form crystallizes in the monoclinic space group P2₁/n with two independent molecules in the asymmetric unit, Fig. 1.

The conformations of the two independent molecules in (I) differ in two regions of the molecule. In the N1-containing molecule, the cyclohexa-1,3-diene ring has a screw-boat conformation as defined by the following geometric parameters (Cremer & Pople, 1975): puckering parameters q₂ = 0.527 (2) Å and q₃ = 0.156 (2) Å, and amplitudes: Q = 0.549 (2) Å, θ = 73.5 (2)° and φ₂ = 93.2 (3)°. By contrast, in the N4-containing molecule, the conformation is based on a distorted half-chair with puckering parameters: q₂ = 0.530 (2) Å, q₃ = -0.178 (2) Å, Q = 0.558 (2) Å, θ = 108.5 (2)° and φ₂ = 265.8 (3) °. In the P2₁/c polymorph of (I), the conformation matches more closely a distorted half-chair.

For the first independent molecule, the benzene rings of the 1,2-dihydronaphthalene and methoxybenzene residues form dihedral angles of 33.19 (10) and 49.22 (10)°, respectively, with the amino-benzene ring, indicating non-planarity in the fused ring system and a twist of the methoxybenzene out of the plane of the benzene ring to which it is connected. The comparable angles for the second independent molecule are 30.6 (10) and 73.27 (10)°, respectively. Figure 2 shows an overlay diagram for the three independent molecules of (I) characterized in the two polymorphs.

In the crystal structure of (I) the two independent molecules self-associate via N—H···N hydrogen bonds to generate 12-membered {···HNC₃N}₂ synthons, Fig. 3 and Table 1. One of the amino-H atoms forms a hydrogen bond to a methoxy-O atom leading to the formation of a supramolecular tape along [1 0 1], Fig. 3 and Table 1. The fourth independent amino-H atom does not participate in a significant intermolecular interaction. In the previously described P2₁/c form of (I), supramolecular arrays with a zigzag topology were formed through N—H···N hydrogen bonds, leading to {···HNC₃N}₂ synthons, as well N—H···O(methoxy) hydrogen bonding.

Experimental

A mixture of 4-methoxybenzaldehyde (1.38 g, 0.01 mmol), 1-tetralone (1.46 g, 0.01 mmol), malononitrile (0.66 g, 0.01 mmol) and ammonium acetate (6.2 g, 0.08 mmol) in absolute ethanol (50 ml) was refluxed for 6 h. The reaction mixture was allowed to cool, and the formed precipitate was filtered, washed with water, dried and recrystallized from ethanol. Yield: 69%. M.pt: 533–535 K.