Crystal structure of N,N'-di-benzyl-pyromellitic diimide.

The title compound, C24H16N2O4 [systematic name: 2,6-di-benzyl-pyrrolo-[3,4-f]iso-indole-1,3,5,7(2H,6H)-tetra-one], consists of a central pyromellitic di-imide moiety with terminal benzyl groups at the N-atom positions. The mol-ecule is located about an inversion centre, so the asymmetric unit contains one half-mol-ecule. In the mol-ecule, both terminal phenyl groups, tilted by 72.97 (4)° with respect to the mean plane of the central pyromellitic di-imide moiety (r.m.s. deviation = 0.0145 Å), are oriented away from each other, forming an elongated S-shaped conformation. In the crystal, mol-ecules are connected via weak C-H⋯O hydrogen bonds and C-H⋯π inter-actions, resulting in the formation of supra-molecular layers extending parallel to the ab plane.

Chemical context

As a result of their potential applications in organic photovoltaics (Huang et al., 2014 ▸) and as mol­ecular electronic devices (Guo et al., 2014 ▸) and energy storage devices (Song et al., 2010 ▸), several π-conjugated, redox-active aromatic di­imides including pyromellitic di­imides, naphthalene di­imides and perylene di­imides have received considerable attention from materials chemists. Additionally, π-conjugated aromatic di­imides and their derivatives are used as rigid structural components in supra­molecular assemblies for the exploitation of supra­molecular inter­actions such as hydrogen-bonding and halogen–π inter­actions (Hay & Custelcean, 2009 ▸; Lu et al., 2007 ▸; Gamez et al., 2007 ▸). Recently, our group reported a copper(I) coordination polymer with a pyromellitic di­imide ligand, namely N,N′-bis­[3-(methyl­thio)­prop­yl]pyromellitic di­imide, and revealed the presence of halogen–π inter­actions between the chlorine atoms of a di­chloro­methane solvent mol­ecule of crystallization and pyromellitic di­imide rings (Park et al., 2011 ▸). In an extension of our studies of pyromellitic di­imide derivatives, we have prepared the title compound by the reaction of pyromellitic dianhydride with 2-phenyethyl­amine and we report its crystal structure here.

Structural commentary

The mol­ecular structure of the title compound consists of a central pyromellitic di­imide ring system with terminal benzyl groups on each of the inversion-related nitro­gen atoms (Fig. 1 ▸). As the mol­ecule is located about a crystallographic inversion centre, the asymmetric unit of the compound comprises one half-mol­ecule. Short intramolecular C—H⋯O contacts (Table 1 ▸) enclose S(5) rings and may contribute to the planarity of the pyromellitic di­imide ring system (r.m.s. deviation = 0.0145 Å). The two terminal phenyl groups in the mol­ecule are oriented away from each other, forming an elongated S-shaped conformation. The terminal phenyl ring is tilted by 72.97 (4)° with respect to the mean plane of the central pyromellitic di­imide moiety.

Figure 1

A view of the mol­ecular structure of the title compound, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as small spheres of arbitrary radius and yellow dashed lines represent the intra­molecular C—H⋯O short contacts. [Symmetry code; (i) −x + 2, −y + 1, −z.]

Table 1

Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the C1–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7B⋯O1	0.99	2.53	2.917 (2)	103
C12—H12⋯O2i	0.95	2.45	3.401 (2)	178
C7—H7B⋯Cg1ii	0.99	2.60	3.478 (2)	148

Symmetry codes: (i) ; (ii) .

Supra­molecular features

In the crystal, adjacent mol­ecules are connected by weak C12—H12⋯O2 hydrogen bonds, Table 1 ▸ (yellow dashed lines in Fig. 2 ▸), forming inversion dimers. Inversion symmetry links these into a chain propagating along [10]. Neighboring chains are linked through inter­molecular C—H⋯π inter­actions between a methyl­ene H atom and the terminal phenyl ring, resulting in the formation of supra­molecular layers extending parallel to the ab plane (black dashed lines in Fig. 3 ▸ and Table 1 ▸). These layers are separated from each other by 3.104 (3) Å. No inter­molecular π–π inter­actions are found between the pyromellitic di­imide moieties.

Figure 2

Chains of the title compound formed through inter­molecular C—H⋯O hydrogen bonds (yellow dashed lines).

Figure 3

Supra­molecular layers of the title compound formed through inter­molecular C—H⋯π inter­actions (black dashed lines) between the chains generated by inter­molecular C—H⋯O hydrogen bonds (yellow dashed lines). H atoms not involved in inter­molecular inter­actions have been omitted for clarity.

Synthesis and crystallization

The title compound was synthesized by the reaction of pyromellitic dianhydride with 2-phenyl­ethyl­amine according to a literature procedure (Kang et al., 2015 ▸). X-ray quality single crystals were obtained by slow evaporation of a di­chloro­methane solution of the title compound.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. All H atoms were positioned geometrically with d(C—H) = 0.95 Å for Csp 2—H and 0.99 Å for methyl­ene, and were refined as riding with U iso(H) = 1.2U eq(C).

Table 2

Experimental details

Crystal data
Chemical formula	C24H16N2O4
M r	396.39
Crystal system, space group	Monoclinic, P21/n
Temperature (K)	173
a, b, c (Å)	6.1500 (5), 4.7475 (3), 31.002 (2)
β (°)	90.461 (3)
V (Å3)	905.14 (11)
Z	2
Radiation type	Mo Kα
μ (mm−1)	0.10
Crystal size (mm)	0.50 × 0.06 × 0.02
Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker 2013 ▸)
T min, T max	0.661, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	4593, 2016, 1444
R int	0.034
(sin θ/λ)max (Å−1)	0.650
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.048, 0.119, 1.04
No. of reflections	2016
No. of parameters	136
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.25, −0.22

Computer programs: APEX2 and SAINT (Bruker, 2013 ▸), SHELXS97 and SHELXTL (Sheldrick 2008 ▸), SHELXL2014 (Sheldrick, 2015 ▸) and DIAMOND (Brandenburg, 2010 ▸).

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S2056989016017710/sj5513sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989016017710/sj5513Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989016017710/sj5513Isup3.cml

CCDC reference: 1515263

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

C24H16N2O4	F(000) = 412
Mr = 396.39	Dx = 1.454 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 6.1500 (5) Å	Cell parameters from 874 reflections
b = 4.7475 (3) Å	θ = 2.6–24.8°
c = 31.002 (2) Å	µ = 0.10 mm−1
β = 90.461 (3)°	T = 173 K
V = 905.14 (11) Å3	Needle, colourless
Z = 2	0.50 × 0.06 × 0.02 mm

Bruker APEXII CCD diffractometer	1444 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.034
Absorption correction: multi-scan (SADABS; Bruker 2013)	θmax = 27.5°, θmin = 1.3°
Tmin = 0.661, Tmax = 0.746	h = −6→7
4593 measured reflections	k = −2→6
2016 independent reflections	l = −38→40

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.048	H-atom parameters constrained
wR(F2) = 0.119	w = 1/[σ2(Fo2) + (0.0529P)2 + 0.089P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
2016 reflections	Δρmax = 0.25 e Å−3
136 parameters	Δρmin = −0.22 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

	x	y	z	Uiso*/Ueq
O1	0.9145 (2)	0.9617 (3)	0.09759 (4)	0.0314 (4)
O2	0.4737 (2)	0.2514 (3)	0.04921 (4)	0.0282 (3)
N1	0.6589 (2)	0.6176 (3)	0.08217 (5)	0.0218 (4)
C1	0.2783 (3)	0.3279 (4)	0.15445 (6)	0.0303 (5)
H1	0.1617	0.3659	0.1350	0.036*
C2	0.2505 (4)	0.1311 (4)	0.18711 (7)	0.0363 (5)
H2	0.1157	0.0354	0.1901	0.044*
C3	0.4206 (4)	0.0760 (4)	0.21524 (7)	0.0399 (6)
H3	0.4021	−0.0568	0.2378	0.048*
C4	0.6175 (4)	0.2130 (4)	0.21071 (6)	0.0356 (5)
H4	0.7346	0.1724	0.2299	0.043*
C5	0.6439 (3)	0.4094 (4)	0.17812 (6)	0.0298 (5)
H5	0.7792	0.5036	0.1751	0.036*
C6	0.4739 (3)	0.4699 (4)	0.14973 (6)	0.0233 (4)
C7	0.4994 (3)	0.6895 (4)	0.11523 (6)	0.0252 (4)
H7A	0.3565	0.7201	0.1011	0.030*
H7B	0.5432	0.8691	0.1290	0.030*
C8	0.8499 (3)	0.7687 (3)	0.07548 (6)	0.0213 (4)
C9	0.9507 (3)	0.6455 (3)	0.03618 (5)	0.0199 (4)
C10	0.8168 (3)	0.4283 (3)	0.02169 (5)	0.0186 (4)
C11	0.6279 (3)	0.4093 (3)	0.05118 (5)	0.0211 (4)
C12	1.1389 (3)	0.7249 (3)	0.01520 (5)	0.0202 (4)
H12	1.2303	0.8725	0.0253	0.024*

	U11	U22	U33	U12	U13	U23
O1	0.0344 (9)	0.0305 (7)	0.0293 (7)	−0.0060 (6)	0.0023 (6)	−0.0098 (6)
O2	0.0247 (8)	0.0285 (7)	0.0316 (7)	−0.0056 (6)	0.0030 (6)	−0.0014 (6)
N1	0.0230 (9)	0.0219 (7)	0.0204 (8)	0.0001 (6)	0.0034 (6)	−0.0008 (6)
C1	0.0264 (11)	0.0300 (9)	0.0346 (11)	0.0002 (8)	0.0036 (9)	−0.0041 (9)
C2	0.0402 (14)	0.0287 (10)	0.0401 (12)	−0.0023 (10)	0.0169 (10)	−0.0015 (10)
C3	0.0580 (17)	0.0307 (10)	0.0313 (12)	0.0042 (11)	0.0151 (11)	0.0035 (9)
C4	0.0460 (14)	0.0341 (10)	0.0267 (10)	0.0039 (10)	−0.0045 (9)	0.0039 (9)
C5	0.0301 (12)	0.0315 (9)	0.0279 (10)	−0.0028 (9)	−0.0009 (9)	−0.0003 (9)
C6	0.0258 (11)	0.0228 (8)	0.0214 (9)	0.0009 (8)	0.0049 (8)	−0.0046 (7)
C7	0.0248 (11)	0.0269 (9)	0.0240 (9)	0.0025 (8)	0.0043 (8)	−0.0009 (8)
C8	0.0227 (10)	0.0198 (8)	0.0214 (9)	0.0011 (7)	−0.0010 (8)	0.0016 (7)
C9	0.0211 (10)	0.0184 (8)	0.0202 (9)	0.0011 (7)	−0.0025 (7)	0.0010 (7)
C10	0.0187 (9)	0.0181 (7)	0.0190 (8)	0.0005 (7)	0.0001 (7)	0.0024 (7)
C11	0.0239 (10)	0.0194 (8)	0.0199 (9)	0.0012 (8)	−0.0021 (7)	0.0027 (7)
C12	0.0229 (11)	0.0182 (7)	0.0195 (9)	−0.0014 (7)	−0.0019 (7)	0.0005 (7)

O1—C8	1.210 (2)	C4—H4	0.9500
O2—C11	1.210 (2)	C5—C6	1.391 (2)
N1—C11	1.391 (2)	C5—H5	0.9500
N1—C8	1.393 (2)	C6—C7	1.503 (2)
N1—C7	1.465 (2)	C7—H7A	0.9900
C1—C6	1.387 (3)	C7—H7B	0.9900
C1—C2	1.389 (3)	C8—C9	1.491 (2)
C1—H1	0.9500	C9—C12	1.385 (2)
C2—C3	1.382 (3)	C9—C10	1.392 (2)
C2—H2	0.9500	C10—C12i	1.384 (2)
C3—C4	1.383 (3)	C10—C11	1.487 (3)
C3—H3	0.9500	C12—C10i	1.384 (2)
C4—C5	1.385 (3)	C12—H12	0.9500
C11—N1—C8	111.98 (15)	N1—C7—C6	114.25 (14)
C11—N1—C7	124.05 (15)	N1—C7—H7A	108.7
C8—N1—C7	123.68 (14)	C6—C7—H7A	108.7
C6—C1—C2	121.05 (19)	N1—C7—H7B	108.7
C6—C1—H1	119.5	C6—C7—H7B	108.7
C2—C1—H1	119.5	H7A—C7—H7B	107.6
C3—C2—C1	119.4 (2)	O1—C8—N1	125.37 (17)
C3—C2—H2	120.3	O1—C8—C9	128.58 (17)
C1—C2—H2	120.3	N1—C8—C9	106.04 (14)
C2—C3—C4	120.40 (19)	C12—C9—C10	122.98 (16)
C2—C3—H3	119.8	C12—C9—C8	129.19 (15)
C4—C3—H3	119.8	C10—C9—C8	107.81 (16)
C3—C4—C5	119.9 (2)	C12i—C10—C9	122.44 (16)
C3—C4—H4	120.1	C12i—C10—C11	129.49 (16)
C5—C4—H4	120.1	C9—C10—C11	108.03 (15)
C4—C5—C6	120.59 (19)	O2—C11—N1	125.35 (18)
C4—C5—H5	119.7	O2—C11—C10	128.50 (16)
C6—C5—H5	119.7	N1—C11—C10	106.14 (15)
C1—C6—C5	118.72 (17)	C10i—C12—C9	114.59 (15)
C1—C6—C7	120.50 (17)	C10i—C12—H12	122.7
C5—C6—C7	120.77 (17)	C9—C12—H12	122.7
C6—C1—C2—C3	−0.1 (3)	N1—C8—C9—C12	178.00 (17)
C1—C2—C3—C4	−0.7 (3)	O1—C8—C9—C10	−179.63 (17)
C2—C3—C4—C5	0.8 (3)	N1—C8—C9—C10	−0.36 (18)
C3—C4—C5—C6	−0.2 (3)	C12—C9—C10—C12i	−0.4 (3)
C2—C1—C6—C5	0.7 (3)	C8—C9—C10—C12i	178.05 (15)
C2—C1—C6—C7	−177.86 (17)	C12—C9—C10—C11	−178.18 (15)
C4—C5—C6—C1	−0.6 (3)	C8—C9—C10—C11	0.31 (18)
C4—C5—C6—C7	178.03 (17)	C8—N1—C11—O2	−178.89 (16)
C11—N1—C7—C6	71.0 (2)	C7—N1—C11—O2	−4.8 (3)
C8—N1—C7—C6	−115.62 (18)	C8—N1—C11—C10	−0.08 (18)
C1—C6—C7—N1	−115.50 (19)	C7—N1—C11—C10	173.99 (14)
C5—C6—C7—N1	65.9 (2)	C12i—C10—C11—O2	1.1 (3)
C11—N1—C8—O1	179.57 (16)	C9—C10—C11—O2	178.61 (17)
C7—N1—C8—O1	5.5 (3)	C12i—C10—C11—N1	−177.67 (16)
C11—N1—C8—C9	0.27 (18)	C9—C10—C11—N1	−0.15 (18)
C7—N1—C8—C9	−173.83 (14)	C10—C9—C12—C10i	0.4 (3)
O1—C8—C9—C12	−1.3 (3)	C8—C9—C12—C10i	−177.73 (16)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7B···O1	0.99	2.53	2.917 (2)	103
C12—H12···O2ii	0.95	2.45	3.401 (2)	178
C7—H7B···Cg1iii	0.99	2.60	3.478 (2)	148