A new polymorph of N-phenyl­phthalimide

During an attempt to prepare a cocrystal of N-phenyl­phthalimide, C₁₄H₉NO₂, with N-(2,3,4,5,6-penta­fluoro­phen­yl)phthalimide, a new ortho­rhom­bic polymorph of the first component was obtained. This new form has Z′ = 0.5 and the mol­ecule is located around a twofold axis, whereas in the previously reported polymorph (space group Pbca), the mol­ecule has no crystallographically imposed symmetry. Pairs of C—H⋯O inter­actions between inversion-related phthalimide units arrange mol­ecules into tapes that are further assembled into (010) layers via stacking inter­actions between phthalimide fragments [inter­planar distance = 3.37 (5) Å].

Related literature

For the crystal structure of another polymorph of N-phenyl­phthalimide, see: Magomedova et al. (1981); Schwarzer & Weber (2008).

Experimental

Crystal data

• C₁₄H₉NO₂

• M_r = 223.22

• Orthorhombic, P b c n

• a = 5.5480 (11) Å

• b = 23.801 (5) Å

• c = 8.0250 (16) Å

• V = 1059.7 (4) ų

• Z = 4

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 293 K

• 0.2 × 0.05 × 0.05 mm

Data collection

• Stoe Stadi-4 diffractometer

• Absorption correction: none

• 1039 measured reflections

• 1039 independent reflections

• 662 reflections with I > 2σ(I)

• 3 standard reflections every 60 reflections intensity decay: 3.9%

Refinement

• R[F² > 2σ(F²)] = 0.067

• wR(F²) = 0.137

• S = 1.17

• 1039 reflections

• 80 parameters

• H-atom parameters constrained

• Δρ_max = 0.17 e Å⁻³

• Δρ_min = −0.15 e Å⁻³

Data collection: STADI4 (Stoe & Cie, 1997); cell refinement: STADI4; data reduction: X-RED (Stoe &Cie, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.

Supporting information

S1. Comment

The crystal structure of the polymorph I of the title compound has previously been reported [Magomedova et al., 1981; Schwarzer & Weber, 2008]. In the course of our studies on the crystal-engineering behaviour of N-aryl substituted phthalimides (Schwarzer & Weber, 2008) and on polymorphism in general a new polymorph of N-phenylphthalimide (designated as II), was obtained. The molecular structure of N-phenylphthalimide (Fig. 1) is similar to that in the polymorph I, exept the twist angle between the phenyl and phthalimide units which is larger in polymorph II [64.09 (10)°] than in polymorph I [56.73 (4)°] owing to differences in the crystal packing and intermolecular interactions. The most prominent interactions in the polymorph I are carbonyl-carbonyl interaction leading to a short C1=O1···C2=O2 contact (3.08 Å) and a weak C3—H1···O1 interaction (2.65 Å, 137°). In the form II molecules of N-phenylphthalimide related by inversion interact via C2—H2···O1ⁱ hydrogen bonds (2.66 Å, 145°; symmetry code: (i) 1 - x, 1 - y, -z) forming zigzag tapes parallel to the crystallographic (102) plane (Fig. 2). These tapes are arranged into (010) layers via stacking interactions between phthalimide units. Within the stacks, the distance between planes of phthalimide units of consecutive molecules is 3.37 (5) Å.

Related literature

For the crystal structure of another polymorph of N-phenylphthalimide, see: Magomedova et al. (1981); Schwarzer & Weber (2008).

S2. Experimental

N-Phenylphthalimide was synthesized from aniline and phthalic anhydride according to the procedure described by Schwarzer & Weber (2008). After evaporation of solvent from an acetone solution containing equimolar mixture of N-phenylphthalimide and N-(2,3,4,5,6,-pentafluorophenyl)phthalimide two types of crystals have deposited. The crystals of the plate form (m.p. 456.5 K) appeared to be the polymorph I of N-phenylphthalimide whereas bulky needles the polymorph II (m.p. 485 K). Both types of crystals were stable in the air.

S3. Refinement

All H-atoms were positioned geometrically (C—H 0.93 Å) and refined as riding on their carrier atoms with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: STADI4 (Stoe & Cie, 1997); cell refinement: STADI4 (Stoe & Cie, 1997); data reduction: X-RED (Stoe &Cie, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. Perspective view of the molecule showing 40% probability displacement ellipsoids for the non-hydrogen atoms.
	Fig. 2. Packing diagram for polymorph II; viewed down the c axis. Hydrogen bonds are shown as dashed lines.

N-phenylphthalimide

Crystal data

C14H9NO2	F(000) = 464
Mr = 223.22	Dx = 1.399 Mg m^−3
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 25 reflections
a = 5.5480 (11) Å	θ = 10–25°
b = 23.801 (5) Å	µ = 0.10 mm^−1
c = 8.0250 (16) Å	T = 293 K
V = 1059.7 (4) Å^3	Needle, colourless
Z = 4	0.2 × 0.05 × 0.05 mm

Data collection

Stoe Stadi-4 diffractometer	Rint = 0.000
Radiation source: fine-focus sealed tube	θmax = 26.0°, θmin = 1.7°
Graphite monochromator	h = 0→6
ω–2τ scans	k = −29→0
1039 measured reflections	l = 0→9
1039 independent reflections	3 standard reflections every 60 reflections
662 reflections with I > 2σ(I)	intensity decay: 3.9%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.067	H-atom parameters constrained
wR(F^2) = 0.137	w = 1/[σ^2(Fo^2) + (0.0266P)^2 + 0.8879P] where P = (Fo^2 + 2Fc^2)/3
S = 1.17	(Δ/σ)max < 0.001
1039 reflections	Δρmax = 0.17 e Å^−3
80 parameters	Δρmin = −0.15 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0123 (18)

Special details

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.0000	0.39051 (14)	0.2500	0.0475 (9)
O1	0.3444 (4)	0.40588 (9)	0.0909 (3)	0.0624 (7)
C1	0.1048 (7)	0.58237 (14)	0.2026 (4)	0.0740 (12)
H1	0.1731	0.6164	0.1709	0.089*
C2	0.2140 (6)	0.53244 (14)	0.1544 (4)	0.0626 (10)
H2	0.3548	0.5324	0.0916	0.075*
C3	0.1056 (5)	0.48304 (12)	0.2034 (3)	0.0491 (8)
C4	0.1752 (6)	0.42378 (12)	0.1702 (4)	0.0479 (8)
C5	0.0000	0.33042 (18)	0.2500	0.0498 (11)
C6	0.1868 (6)	0.30175 (13)	0.3253 (4)	0.0601 (9)
H6	0.3125	0.3213	0.3754	0.072*
C7	0.1855 (6)	0.24375 (14)	0.3257 (5)	0.0765 (12)
H7	0.3099	0.2241	0.3771	0.092*
C8	0.0000	0.2150 (2)	0.2500	0.0820 (19)
H8	0.0000	0.1759	0.2500	0.098*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.044 (2)	0.049 (2)	0.049 (2)	0.000	0.0052 (18)	0.000
O1	0.0502 (13)	0.0738 (15)	0.0631 (15)	0.0017 (12)	0.0078 (12)	0.0049 (12)
C1	0.088 (3)	0.0545 (19)	0.079 (3)	−0.0123 (18)	−0.033 (2)	0.0080 (18)
C2	0.063 (2)	0.066 (2)	0.059 (2)	−0.0128 (18)	−0.0198 (18)	0.0059 (18)
C3	0.0502 (17)	0.0543 (18)	0.0427 (18)	−0.0033 (14)	−0.0134 (15)	0.0018 (14)
C4	0.0409 (16)	0.0589 (19)	0.0438 (17)	−0.0017 (16)	−0.0061 (15)	0.0036 (15)
C5	0.048 (2)	0.050 (3)	0.052 (3)	0.000	0.003 (2)	0.000
C6	0.0476 (18)	0.062 (2)	0.070 (2)	0.0027 (17)	−0.0001 (18)	0.0049 (18)
C7	0.057 (2)	0.067 (2)	0.106 (3)	0.013 (2)	0.011 (2)	0.018 (2)
C8	0.058 (3)	0.057 (3)	0.130 (5)	0.000	0.033 (4)	0.000

Geometric parameters (Å, º)

N1—C4^i	1.408 (3)	C3—C4	1.487 (4)
N1—C4	1.408 (3)	C5—C6	1.380 (4)
N1—C5	1.430 (5)	C5—C6^i	1.380 (4)
O1—C4	1.211 (3)	C6—C7	1.380 (4)
C1—C2	1.389 (4)	C6—H6	0.9300
C1—C1^i	1.389 (8)	C7—C8	1.378 (4)
C1—H1	0.9300	C7—H7	0.9300
C2—C3	1.378 (4)	C8—C7^i	1.378 (4)
C2—H2	0.9300	C8—H8	0.9300
C3—C3^i	1.389 (6)
C4^i—N1—C4	111.6 (4)	N1—C4—C3	105.8 (3)
C4^i—N1—C5	124.22 (18)	C6—C5—C6^i	120.7 (4)
C4—N1—C5	124.22 (18)	C6—C5—N1	119.6 (2)
C2—C1—C1^i	121.2 (2)	C6^i—C5—N1	119.6 (2)
C2—C1—H1	119.4	C7—C6—C5	119.5 (4)
C1^i—C1—H1	119.4	C7—C6—H6	120.3
C3—C2—C1	117.4 (3)	C5—C6—H6	120.3
C3—C2—H2	121.3	C8—C7—C6	120.0 (4)
C1—C2—H2	121.3	C8—C7—H7	120.0
C2—C3—C3^i	121.4 (2)	C6—C7—H7	120.0
C2—C3—C4	130.2 (3)	C7—C8—C7^i	120.3 (5)
C3^i—C3—C4	108.40 (16)	C7—C8—H8	119.8
O1—C4—N1	125.2 (3)	C7^i—C8—H8	119.8
O1—C4—C3	129.0 (3)

Symmetry code: (i) −x, y, −z+1/2.