N,N′-Bis(2-phenyl­ethyl)naphthalene-1,8:4,5-bis­(dicarboximide)

Yuichiro Tsukada; Naoko Nishimura; Jin Mizuguchi

doi:10.1107/S1600536807060333

. 2007 Dec 6;64(Pt 1):o5. doi: 10.1107/S1600536807060333

N,N′-Bis(2-phenylethyl)naphthalene-1,8:4,5-bis(dicarboximide)

Yuichiro Tsukada ^a, Naoko Nishimura ^a, Jin Mizuguchi ^a,^*

PMCID: PMC2914895 PMID: 21200925

Abstract

The title compound, C₃₀H₂₂N₂O₄, is a derivative of the naphthalene–imide pigments that are characterized by significant overlap of the stacked molecules. The molecule has a centre of symmetry. Accordingly, the phenylethyl groups are arranged in a trans fashion across the skeleton. The phenyl rings are not parallel to the naphthaleneimide skeleton and are twisted in the same direction by 9.27 (7)°. The molecules are, however, stacked with insignificant overlap along the stacking axis, as characterized by appreciable slide in the direction of either the short or the long molecular axis, in marked contrast to the ordinary naphthalene–imide pigments.

Related literature

For perylene and perinone pigments, see: Herbst & Hunger (2004 ▶). Five structural studies of related compounds have been reported by Mizuguchi (2003a ▶,b ▶, 2004 ▶), Mizuguchi et al. (2005 ▶) and Tsukada et al. (2007 ▶). For ethyl phenylperyleneimide-related papers, see: Hädicke & Graser (1986 ▶), Mizuguchi (1998a ▶,b ▶, 2005a ▶,b ▶), Mizuguchi & Tojo (2002 ▶), Mizuguchi & Hino (2005 ▶), Mizuguchi et al. (2006 ▶). For related literature, see: Hino & Mizuguchi (2005 ▶); Mizuguchi (1981 ▶); Mizuguchi & Shimo (2006 ▶).

Experimental

Crystal data

C₃₀H₂₂N₂O₄
M _r = 474.50
Monoclinic,
a = 7.70264 (14) Å
b = 4.93695 (9) Å
c = 29.9857 (5) Å
β = 97.9096 (7)°
V = 1129.44 (3) Å³
Z = 2
Cu Kα radiation
μ = 0.76 mm⁻¹
T = 93 (1) K
0.5 × 0.14 × 0.06 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.790, T _max = 0.955
9315 measured reflections
1993 independent reflections
1723 reflections with F ² > 2σ(F ²)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.124
S = 1.13
1993 reflections
163 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: PROCESS-AUTO (Rigaku, 1998 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2006 ▶); program(s) used to solve structure: SIR2004 (Burla et al., 2005 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807060333/is2244sup1.cif

e-64-000o5-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807060333/is2244Isup2.hkl

e-64-000o5-Isup2.hkl^{(98.1KB, hkl)}

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

supplementary crystallographic information

Comment

The title compound (PhENI) is a derivative of the naphthalene-imides which belongs to the category of perylene and perinone pigments (Herbst & Hunger, 2004). The difference between the perylene and perinone pigments is whether the central skeleton is perylene or naphthalene. Both pigments are typically characterized by close π-π stacks (Hädicke & Graser, 1986; Mizuguchi, 1998a, 2004; Mizuguchi & Shimo, 2006), giving rise to an additional absorption band in the visible region due to intermolecular excitonic interactions (Mizuguchi, 1998b). However, the present band disappears in the amorphous state where the molecules are randomly arranged. Accordingly, the color varies drastically from an amorphous phase to the crystalline one, as found in ethylphenylperyleneimide (EPhP), in which the naphthalene skeleton in PhENI is replaced by the perylene one (Mizuguchi, 1998b). Then, we struck on an idea that it would be ideal for electronic paper applications if the color change occurs in much shorter wavelength (for example, between colorless and blue) with a smaller chromphore such as PhENI. In this connection, an attempt has been made to synthesize PhENI and determine its crystal structure.

The title molecule is centrosymmetric (Fig. 1) and an asymmetric unit comprises a half of the molecule. Therefore, ethylphenyl groups are arranged in a trans fashion across the naphthaleneimide skeleton. The naphthalene-imide skeleton is entirely planar as indicated by a small deviation of 0.018 Å from the least-squares plane defined by atoms C1—C7/N1. The phenyl rings and the napthaleneimide skeleton are not in parallel, but twisted by 9.27 (7)°. Fig. 2 shows the molecular packing of PhENI. The molecules are stacked with insignificant overlap as characterized by significant slide in the direction of the short-molecular axis, quite in contrast to the ordinary naphthalene-imides (Mizuguchi, 2003a,b) and peryelene- imide pigments (Hädicke & Graser, 1986; Mizuguchi, 1998a, 2005a,b) where the molecules are directly stacked with an interplanar distance of about 3.3 - 3.5 Å. Since the π-π interactions are insignificant in PhENI, this compound gives no additional absorption band in the visible region and cannot be applied to electronic paper applications.

Experimental

PhENI was synthesized by reaction of naphthalene-1,4,5,8-tetra-carboxylic-dianhydride with 2-phenylethylamine at 403 K for 5 h. Then, the products were purified two times by sublimation under vacuum, using a five-zone furnace (Mizuguchi, 1981). Single crystals of PhENI were grown from solution in dimethylsulfoxide. After 36 h, a number of single crystals were obtained in the form of needles.