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CHEMISTRY
ISSN: 2053-2296

Isomeric nitro­phthal­imides: sheets built from N—H⋯O and C—H⋯O hydrogen bonds

aSchool of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland, bDepartment of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE, Scotland, and cInstituto de Química, Departamento de Química Inorgânica, Universidade Federal do Rio de Janeiro, 21945-970 Rio de Janeiro, RJ, Brazil
*Correspondence e-mail: cg@st-andrews.ac.uk

(Received 11 October 2004; accepted 14 October 2004; online 11 November 2004)

Molecules of 3-nitro­phthal­imide, C8H4N2O4, are linked into sheets by a combination of one N—H⋯O hydrogen bond [H⋯O = 1.99 Å, N⋯O = 2.8043 (14) Å and N—H⋯O = 176°] and two independent C—H⋯O hydrogen bonds [H⋯O = 2.36 and 2.56 Å, C⋯O = 3.1639 (16) and 3.4386 (16) Å, and C—H⋯O = 142 and 153°], and these sheets are linked into pairs by a single ππ stacking interaction. Molecules of isomeric 4-nitro­phthal­imide are linked into sheets by a combination of one three-centre N—H⋯(O)2 hydrogen bond [H⋯O = 2.14 and 2.55 Å, N⋯O = 2.974 (3) and 3.231 (3) Å, N—H⋯O = 151 and 131°, and O⋯H⋯O = 76°] and two independent two-centre C—H⋯O hydrogen bonds [H⋯O = 2.38 and 2.54 Å, C⋯O = 3.257 (4) and 3.452 (4) Å, and C—H⋯O = 156 and 168°].

Comment

The isomeric title compounds 3-nitro­phthal­imide, (I[link]), and 4-nitro­phthal­imide, (II[link]), contain, within very compact mol­ecules, a wide variety of potential hydrogen-bond donors and acceptors (Fig. 1[link]). Both N—H and C—H bonds provide potential donors, while carbonyl and nitro O atoms and the arene ring all provide potential acceptors, although there is a [link]

[Scheme 1]
significant excess of hard acceptors over hard donors (Braga et al., 1995[Braga, D., Grepioni, F., Birdha, K., Pedireddi, V. R. & Desiraju, G. R. (1995). J. Am. Chem. Soc. 117, 3156-3166.]; Desiraju & Steiner, 1999[Desiraju, G. R. & Steiner, T. (1999). The Weak Hydro­gen Bond, pp. 86-89. Oxford University Press.]). In addition, aromatic ππ stacking interactions and non-bonded dipolar interactions (Allen et al., 1998[Allen, F. H., Baalham, C. A., Lommerse, J. P. M. & Raithby, P. R. (1998). Acta Cryst. B54, 320-329.]) involving both carbonyl and nitro groups are possible, in principle.

In the event, the supramolecular structure of (I[link]) (Fig. 1[link]) is dominated by a two-centre N—H⋯O hydrogen bond, in which the acceptor is a carbonyl O atom, and two independent C—H⋯O hydrogen bonds, one involving a carbonyl O atom and the other a nitro O atom as acceptor. By contrast, the supramolecular structure of (II[link]) (Fig. 2[link]) is dominated by one asymmetric three-centre N—H⋯(O)2 hydrogen bond, involving both of the carbonyl O atoms as the acceptors, and two independent two-centre C—H⋯O hydrogen bonds, one involving a carbonyl O atom and the other a nitro O atom as acceptor.

In isomer (I[link]), each of the independent hydrogen bonds (Table 1[link]) can be regarded as producing a one-dimensional substructure (Gregson et al., 2000[Gregson, R. M., Glidewell, C., Ferguson, G. & Lough, A. J. (2000). Acta Cryst. B56, 39-57.]), all parallel to the [100] direction but all generated by different symmetry operations; the combination of these three motifs generates a sheet. The formation of the sheets in (I[link]) is most readily analysed by considering, in turn, the action of each hydrogen bond. Amine atom N1 in the mol­ecule at (x, y, z) acts as a hydrogen-bond donor to carbonyl atom O1 in the mol­ecule at ([1 \over 2] + x, y, [1 \over 2] − z), so producing a C(4) chain running parallel to the [100] direction and generated by the a-glide plane at z = [1 \over 4] (Fig. 3[link]).

At the same time, aryl atom C6 in the mol­ecule at (x, y, z) acts as a hydrogen-bond donor to the second carbonyl O atom, O2, in the mol­ecule at (−1 + x, y, z), thus generating by translation a C(7) chain along [100]. The combination of the two motifs having carbonyl acceptors generates a column of R32(14) rings across z = [1\over4] (Fig. 3[link]). Finally, aryl atom C5 at (x, y, z) acts as a hydrogen-bond donor to nitro atom O41 in the mol­ecule at (−[1\over2] + x, y, [3 \over 2] − z), so forming a C(5) chain along [100], this time generated by the a-glide plane at z = [3 \over 4]. The combination of the two motifs involving aryl H atoms generates a column of R33(15) rings across z = [3 \over 4] (Fig. 3[link]). Neither of the rings utilizes all three independent hydrogen bonds. However, the combination of all three hydrogen bonds generates a (010) sheet in which columns of R33(14) rings across z = n + [1\over4] (n = zero or integer) alternate with columns of R33(15) rings across z = n + [3 \over 4] (n = zero or integer) (Fig. 3[link]). Four sheets of this type pass through each unit cell, and the sheets are linked weakly into pairs by a single aromatic ππ stacking interaction.

The C3–C8 aryl rings in the mol­ecules at (x, y, z) and (−x, −y, 1 − z) are strictly parallel, with an interplanar spacing of 3.309 (2) Å; the ring-centroid separation is 3.758 (2) Å, corresponding to a centroid offset of 1.781 (2) Å (Fig. 4[link]). These two mol­ecules lie in the (010) sheets within the domains 0.02 < y < 0.31 and −0.21 < y < −0.02, respectively, and these two sheets are thus linked into a bilayer. The formation of the bilayer is reinforced by a dipolar interaction between the negatively polarized nitro atom O42 in the mol­ecule at (x, y, z) and the positively polarized carbonyl atom C1 in the mol­ecule at ([1\over2] − x, −y, [1\over2] + z), which forms part of the sheet in the domain −0.21 < y < −0.02. The C⋯Oi distance [symmetry code: (i) [1\over2] − x, −y, [1\over2] + z] is 2.980 (2) Å and the C⋯Oi—Ni angle is 135.9 (2)°. However, there are no direction-specific interactions between adjacent bilayers

In isomer (II[link]), the hard and soft hydrogen bonds independently generate two one-dimensional substructures, each in the form of a chain of rings, and these chains combine to form sheets. Amine atom N1 in the mol­ecule of (II[link]) at (x, y, z) acts as a hydrogen-bond donor to carbonyl atoms O1 and O2 in the mol­ecules at (2 − x, −[1\over2] + y, [3 \over2] − z) and (2 − x, [1\over2] + y, [3\over2] − z), respectively. These two interactions (Table 2[link]) are the strong and weak components of a markedly asymmetric, but essentially planar, three-centre interaction. The sum of the angles at atom H1 is 358°. Together these interactions produce a chain of edge-fused R22(8) rings running parallel to the [010] direction and generated by the 21 screw axis along (1, y, [3 \over 4]) (Fig. 5[link]).

In addition, aryl atoms C4 and C7 in the mol­ecule at (x, y, z) act as donors, respectively, to atoms O1 and O51 in the mol­ecules at (−1 + x, −1 + y, z) and (1 + x, 1 + y, z), so generating two individual C(6) chains, whose combined action generates by translation a C(6)C(6)[R22(10)] chain of rings (Bernstein et al., 1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]) running parallel to the [110] direction (Fig. 6[link]). The combination of the [010] and [110] chains generates a (001) sheet, which is modestly reinforced by a dipolar interaction between the negatively polarized atom O2 at (x, y, z) and the positively polarized atom C2 at (1 − x, −[1\over2] + y, [3\over2] − z). The O2⋯C2ii distance is 2.906 (3) Å [symmetry code: (ii) 1 − x, −[1\over2] + y, [3\over2] − z] and the C2—O2⋯C2ii angle is 156.1 (2)°, indicating an interaction whose geometry is intermediate between the perpendicular motif I and the sheared motif III described by Allen et al. (1998[Allen, F. H., Baalham, C. A., Lommerse, J. P. M. & Raithby, P. R. (1998). Acta Cryst. B54, 320-329.]). The two mol­ecules involved in this interaction lie in the [010] chains along (1, y, [3 \over4]) and ([1\over2], y, [3 \over4]), so that this dipolar interaction generates a motif along [100] within the (010) sheet. There are no direction-specific interactions between adjacent sheets.

The bond distances and angles within the mol­ecules of (I[link]) and (II[link]) present no unusual values. The dihedral angle between the planes of the aryl ring and the nitro group is 31.6 (2)° in (I[link]) and 8.0 (2)° in (II[link]), so that each mol­ecule has point group C1; this is sufficient to render the mol­ecules of both isomers chiral. Isomer (I[link]) crystallizes in the centrosymmetric space group Pbca, as a racemate with equal numbers of both conformational enantiomers present in each single-crystal domain. Isomer (II[link]) crystallizes in space group P212121 as a fully ordered structure, having only one conformational enantiomer present in each single-crystal domain.

[Figure 1]
Figure 1
The mol­ecule of isomer (I[link]), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2]
Figure 2
The mol­ecule of isomer (II[link]), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 3]
Figure 3
A stereoview of part of the crystal structure of isomer (I[link]), showing the formation of a (010) sheet containing alternating columns of R33(14) and R33(15) rings.
[Figure 4]
Figure 4
Part of the crystal structure of isomer (I[link]), showing the ππ stacking interaction that links the (010) sheets into pairs. For clarity, H atoms have been omitted. Atoms marked with an asterisk (*) are at the symmetry position (−x, −y, 1 − z).
[Figure 5]
Figure 5
Part of the crystal structure of isomer (II[link]), showing the formation of a chain of edge-fused rings along [010]. For clarity, H atoms bonded to C atoms have been omitted. Atoms marked with an asterisk (*), a hash (#), a dollar sign ($) or an ampersand (&) are at the symmetry positions (2 − x, [1\over2] + y, [3\over2] − z), (2 − x, −[1\over2] + y, [3\over2] − z), (x, −1 + y, z) and (x, 1 + y, z), respectively.
[Figure 6]
Figure 6
Part of the crystal structure of isomer (II[link]), showing the formation of a chain of rings along [110]. Atoms marked with an asterisk (*) or a hash (#) are in the mol­ecules at (1 + x, 1 + y, z) and (−1 + x, −1 + y, z), respectively.

Experimental

Commercial samples of 3- and 4-nitro­phthal­imide were obtained from Aldrich, and crystals suitable for single-crystal X-ray diffraction were grown from solutions in ethyl acetate [for (I[link])] and acetone [for (II[link])].

Compound (I)[link]

Crystal data
  • C8H4N2O4

  • Mr = 192.13

  • Orthorhombic, Pbca

  • a = 8.2208 (2) Å

  • b = 13.0786 (4) Å

  • c = 13.9233 (4) Å

  • V = 1496.99 (7) Å3

  • Z = 8

  • Dx = 1.705 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 1703 reflections

  • θ = 3.1–27.5°

  • μ = 0.14 mm−1

  • T = 120 (2) K

  • Plate, colourless

  • 0.48 × 0.32 × 0.08 mm

Data collection
  • Nonius KappaCCD diffractometer

  • φ and ω scans

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2003[Sheldrick, G. M. (2003). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.954, Tmax = 0.989

  • 19 573 measured reflections

  • 1703 independent reflections

  • 1488 reflections with I > 2σ(I)

  • Rint = 0.037

  • θmax = 27.5°

  • h = −10 → 10

  • k = −16 → 15

  • l = −18 → 16

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.039

  • wR(F2) = 0.099

  • S = 1.10

  • 1703 reflections

  • 129 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.0527P)2 + 0.5962P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.33 e Å−3

  • Δρmin = −0.42 e Å−3

  • Extinction correction: SHELXL97

  • Extinction coefficient: 0.033 (4)

Table 1
Hydrogen-bonding geometry (Å, °) for (I)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O1iii 0.82 1.99 2.8043 (14) 176
C5—H5⋯O41iv 0.95 2.56 3.4386 (16) 153
C6—H6⋯O2v 0.95 2.36 3.1639 (16) 142
Symmetry codes: (iii) [{\script{1\over 2}}+x,y,{\script{1\over 2}}-z]; (iv) [x-{\script{1\over 2}},y,{\script{3\over 2}}-z]; (v) x-1,y,z.

Compound (II)[link]

Crystal data
  • C8H4N2O4

  • Mr = 192.13

  • Orthorhombic, P212121

  • a = 5.3114 (3) Å

  • b = 5.6812 (5) Å

  • c = 24.645 (2) Å

  • V = 743.67 (10) Å3

  • Z = 4

  • Dx = 1.716 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 1007 reflections

  • θ = 3.3–27.5°

  • μ = 0.14 mm−1

  • T = 291 (2) K

  • Plate, colourless

  • 0.26 × 0.22 × 0.04 mm

Data collection
  • Nonius KappaCCD diffractometer

  • φ scans, and ω scans with κ offsets

  • Absorption correction: multi-scan (SORTAV; Blessing, 1995[Blessing, R. H. (1995). Acta Cryst. A51, 33-37.], 1997[Blessing, R. H. (1997). J. Appl. Cryst. 30, 421-426.]) Tmin = 0.956, Tmax = 0.994

  • 6348 measured reflections

  • 1007 independent reflections

  • 804 reflections with I > 2σ(I)

  • Rint = 0.060

  • θmax = 27.5°

  • h = −6 → 6

  • k = −7 → 7

  • l = −31 → 31

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.043

  • wR(F2) = 0.110

  • S = 1.03

  • 1007 reflections

  • 127 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.0707P)2 + 0.0553P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.26 e Å−3

  • Δρmin = −0.27 e Å−3

Table 2
Hydrogen-bonding geometry (Å, °) for (II)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O2vi 0.92 2.55 3.231 (3) 131
N1—H1⋯O1vii 0.92 2.14 2.974 (3) 151
C4—H4⋯O1viii 0.93 2.54 3.452 (4) 168
C7—H7⋯O51ix 0.93 2.38 3.257 (4) 156
Symmetry codes: (vi) [2-x,{\script{1\over 2}}+y,{\script{3\over 2}}-z]; (vii) [2-x,y-{\script{1\over 2}},{\script{3\over 2}}-z]; (viii) x-1,y-1,z; (ix) 1+x,1+y,z.

Space group Pbca for (I[link]) and P212121 for (II[link]) were uniquely assigned from the systematic absences. All H atoms were located from difference maps and then treated as riding atoms, with C—H distances of 0.95 Å and N—H distances of 0.82 Å in (I[link]) at 120 (2) K, and C—H distances of 0.93 Å and N—H distances of 0.92 Å in (II[link]) at 291 (2) K, and with Uiso(H) values of 1.2Ueq(C,N). In the absence of any significant anomalous scattering, the Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]) parameter for isomer (II[link]) was indeterminate (Flack & Bernardinelli, 2000[Flack, H. D. & Bernardinelli, G. (2000). J. Appl. Cryst. 33, 1143-1148.]), and it was not possible to establish the absolute configuration (Jones, 1986[Jones, P. G. (1986). Acta Cryst. A42, 57.]). Accordingly, the Friedel equivalent reflections were merged prior to the final refinements.

For compound (I), data collection: COLLECT (Hooft, 1999[Hooft, R. W. W. (1999). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]) and COLLECT; data reduction: DENZO and COLLECT. For compound (II), data collection: KappaCCD Server Software (Nonius, 1997[Nonius (1997). KappaCCD Server Software. Windows 3.11 Version. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO–SMN (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]); data reduction: DENZO–SMN. For both compounds, program(s) used to solve structure: OSCAIL (McArdle, 2003[McArdle, P. (2003). OSCAIL for Windows. Version 10. Crystallography Centre, Chemistry Department, NUI Galway, Ireland.]) and SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999[Ferguson, G. (1999). PRPKAPPA. University of Guelph, Canada.]).

Supporting information


Comment top

The isomeric compounds 3-nitrophthalimide, (I), and 4-nitrophthalimide, (II), contain, within very compact molecules, a wide variety of potential hydrogen-bond donors and acceptors (Fig. 1). Both N—H and C—H bonds provide potential donors, while carbonyl O and nitro O atoms and the arene ring all provide potential acceptors, although there is a significant excess of hard (Braga et al., 1995; Desiraju & Steiner, 1999) acceptors over hard donors. In addition, aromatic ππ stacking interactions and non-bonded dipolar interactions (Allen et al., 1998) involving both carbonyl and nitro groups are possible in principle.

In the event, the supramolecular structure of (I) (Fig. 1) is dominated by a two-centre N—H···O hydrogen bond, in which the acceptor is a carbonyl O atom, and two independent C—H···O hydrogen bonds, one involving a carbonyl O and the other a nitro O atom as acceptor. By contrast, the supramolecular structure of (II) (Fig. 2) is dominated by one rather asymmetric three-centre N—H···(O)2 hydrogen bond, involving both of the carbonyl O atoms as the acceptors, and two independent two-centre C—H···O hydrogen bonds, one involving a carbonyl O and the other a nitro O atom as acceptor.

In isomer (I), each of the independent hydrogen bonds (Table 1) can be regarded as producing a one-dimensional sub-structure (Gregson et al., 2000), all parallel to the [100] direction but all generated by different symmetry operations; the combination of these three motifs generates a sheet. The formation of the sheets in (I) is most readily analysed by considering in turn the action of each hydrogen bond. Amine atom N1 in the molecule at (x, y, z) acts as a hydrogen-bond donor to carbonyl atom O1 in the molecule at (0.5 + x, y, 0.5 − z), so producing a C(4) chain running parallel to the [100] direction and generated by the a-glide plane at z = 0.25 (Fig. 3).

At the same time, aryl atom C6 in the molecule at (x, y, z) acts as a hydrogen-bond donor to the second carbonyl O atom, O2, in the molecule at (−1 + x, y, z), thus generating by translation a C(7) chain along [100]; the combination of the two motifs having carbonyl acceptors generates a column of R33(14) rings across z = 0.25 (Fig. 3). Finally, aryl atom C5 at (x, y, z) acts as a hydrogen-bond donor to nitro atom O41 in the molecule at (−0.5 + x, y, 1.5 − z), so forming a C(5) chain along [100], this time generated by the a-glide plane at z = 0.75; the combination of the two motifs involving aryl H atoms generates a column of R33(15) rings across z = 0.75 (Fig. 3). Neither of the rings utilizes all three independent hydrogen bonds. However, the combination of all three hydrogen bonds generates a (010) sheet in which columns of R33(14) rings across z = n + 0.25 (n = zero or integer) alternate with columns of R33(15) rings across z = n + 0.75 (n = zero or integer) (Fig. 3). Four sheets of this type pass through each unit cell, and the sheets are weakly linked into pairs by a single aromatic ππ stacking interaction.

The C3–C8 aryl rings in the molecules at (x, y, z) and (-x, −y, 1 − z) are strictly parallel, with an interplanar spacing of 3.309 (2) Å; the ring-centroid separation is 3.758 (2) Å, corresponding to a centroid offset of 1.781 (2) Å (Fig. 4). These two molecules lie in the (010) sheets within the domains 0.02 < y < 0.31 and −0.21 < y < −0.02, respectively, and these two sheets are thus linked into a bilayer. The formation of the bilayer is reinforced by a dipolar interaction between the negatively polarized nitro atom O42 in the molecule at (x, y, z) and the positively polarized carbonyl atom C1 in the molecule at (0.5 − x, −y, 0.5 + z), which forms part of the sheet in the domain −0.21 < y < −0.02. The C···Oi distance [symmetry code: (i) 0.5 − x, −y, 0.5 + z] is 2.980 (2) Å and the C···Oi—Ni angle is 135.9 (2)°. However, there are no direction-specific interactions between adjacent bilayers

In isomer (II), the hard and soft hydrogen bonds independently generate two one-dimensional sub-structures, each in the form of a chain of rings, and these chains combine to form sheets. Amine atom N1 in the molecule of (II) at (x, y, z) acts as a hydrogen-bond donor to carbonyl atoms O1 and O2 in the molecules at (2 − x, −0.5 + y, 1.5 − z) and (2 − x, 0.5 + y, 1.5 − z), respectively. These two interactions (Table 2) are the strong and weak components of a markedly-asymmetric, but essentially planar, three-centre interaction. The sum of the angles at atom H1 is 358°. Together these interactions produce a chain of edge-fused R22(8) rings running parallel to the [010] direction and generated by the 21 screw axis along (1, y, 3/4) (Fig. 5).

In addition, aryl atoms C4 and C7 in the molecule at (x, y, z) act as donors, respectively, to atoms O1 and O51 in the molecules at (−1 + x, −1 + y, z) and (1 + x, 1 + y, z), so generating two individual C(6) chains, whose combined action generates by translation a C(6) C(6)[R22(10)] chain of rings (Bernstein et al., 1995) running parallel to the [110] direction (Fig. 6). The combination of the [010] and [110] chains generates a (001) sheet, which is modestly reinforced by a dipolar interaction between the negatively polarized atom O2 at (x, y, z) and the positively polarized atom C2 at (1 − x, −0.5 + y, 1.5 − z). The O2···C2ii distance is 2.906 (3) Å [symmetry code: (ii) 1 − x, −0.5 + y, 1.5 − z] and the C2—O2···C2ii angle is 156.1 (2)°, indicating an interaction whose geometry is intermediate between the perpendicular motif (I) and the sheared motif (III) described by Allen et al. (1998). The two molecules involved in this interaction lie in the [010] chains along (1, y, 3/4) and (1/2, y, 3/4), so that this dipolar interaction generates a motif along [100] within the (010) sheet. There are no direction-specific interactions between adjacent sheets.

The bond distances and angles within the molecules of (I) and (II) present no unusual values. The dihedral angle between the planes of the aryl ring and the nitro group is 31.6 (2)° in (I) and 8.0 (2)° in (II), so that each molecule has point group C1; this is sufficient to render the molecules of both isomers chiral. Isomer (I) crystallizes in the centrosymmetric space group Pbca, as a racemate with equal numbers of both conformational enantiomers present in each single-crystal domain. Isomer (II) crystallizes in space group P212121 as a fully ordered structure, having only one conformational enantiomer present in each single-crystal domain.

Experimental top

Commercial samples of 3- and 4-nitrophthalimide (obtained from Aldrich) and crystals suitable for single-crystal X-ray diffraction were grown from solutions in ethyl acetate, for (I), and acetone, for (II).

Refinement top

The space groups Pbca for (I) and P212121 for (II) were uniquely assigned from the systematic absences. All H atoms were located from difference maps and then treated as riding atoms, with C—H distances 0.95 Å and N—H distances of 0.82 Å in (I) at 120 (2) K, and C—H distances of 0.93 Å and N—H distances of 0.92 Å in (II) at 291 (2) K, and with Uiso(H) values of 1.2Ueq(C,N). In the absence of any significant anomalous scattering, the Flack (1983) parameter for isomer (II) was indeterminate (Flack & Bernardinelli, 2000), and it was not possible to establish the absolute configuration (Jones, 1986). Accordingly, the Friedel equivalent reflections were merged prior to the final refinements.

Computing details top

Data collection: COLLECT (Hooft, 1999) for (I); KappaCCD Server Software (Nonius, 1997) for (II). Cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT for (I); DENZO–SMN (Otwinowski & Minor, 1997) for (II). Data reduction: DENZO and COLLECT for (I); DENZO–SMN for (II). For both compounds, program(s) used to solve structure: OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).

Figures top
[Figure 1] Fig. 1. The molecule of isomer (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. The molecule of isomer (II), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 3] Fig. 3. A stereoview of part of the crystal structure of isomer (I), showing the formation of a (010) sheet containing alternating columns of R33(14) and R33(15) rings.
[Figure 4] Fig. 4. Part of the crystal structure of isomer (I), showing the ππ stacking interaction that links the (010) sheets into pairs. For clarity, H atoms have been omitted. Atoms marked with an asterisk (*) are at the symmetry position (-x, −y, 1 − z).
[Figure 5] Fig. 5. Part of the crystal structure of isomer (II), showing the formation of a chain of edge-fused rings along [010]. For clarity, H atoms bonded to C atoms have been omitted. Atoms marked with an asterisk (*), a hash (#), a dollar sign () or an ampersand (&) are at the symmetry positions (2 − x, 0.5 + y, 1.5 − z), (2 − x, −0.5 + y, 1.5 − z), (x, −1 + y, z) and (x, 1 + y, z), respectively.
[Figure 6] Fig. 6. Part of the crystal structure of isomer (II), showing the formation of a chain of rings along [110]. Atoms marked with an asterisk (*) or a hash (#) are in the molecules at (1 + x, 1 + y, z) and (−1 + x, −1 + y, z), respectively.
(I) 3-Nitrophthalimide top
Crystal data top
C8H4N2O4F(000) = 784
Mr = 192.13Dx = 1.705 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 1703 reflections
a = 8.2208 (2) Åθ = 3.1–27.5°
b = 13.0786 (4) ŵ = 0.14 mm1
c = 13.9233 (4) ÅT = 120 K
V = 1496.99 (7) Å3Plate, colourless
Z = 80.48 × 0.32 × 0.08 mm
Data collection top
Bruker-Nonius 95mm CCD camera on κ-goniostat
diffractometer
1703 independent reflections
Radiation source: Bruker–Nonius FR591 rotating anode1488 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.037
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.1°
ϕ & ω scansh = 1010
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
k = 1615
Tmin = 0.954, Tmax = 0.989l = 1816
19573 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.039H-atom parameters constrained
wR(F2) = 0.099 w = 1/[σ2(Fo2) + (0.0527P)2 + 0.5962P]
where P = (Fo2 + 2Fc2)/3
S = 1.10(Δ/σ)max < 0.001
1703 reflectionsΔρmax = 0.33 e Å3
129 parametersΔρmin = 0.42 e Å3
0 restraintsExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.033 (4)
Crystal data top
C8H4N2O4V = 1496.99 (7) Å3
Mr = 192.13Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 8.2208 (2) ŵ = 0.14 mm1
b = 13.0786 (4) ÅT = 120 K
c = 13.9233 (4) Å0.48 × 0.32 × 0.08 mm
Data collection top
Bruker-Nonius 95mm CCD camera on κ-goniostat
diffractometer
1703 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
1488 reflections with I > 2σ(I)
Tmin = 0.954, Tmax = 0.989Rint = 0.037
19573 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0390 restraints
wR(F2) = 0.099H-atom parameters constrained
S = 1.10Δρmax = 0.33 e Å3
1703 reflectionsΔρmin = 0.42 e Å3
129 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.41423 (13)0.16003 (9)0.34763 (7)0.0189 (3)
C10.25286 (16)0.17714 (9)0.32887 (8)0.0172 (3)
O10.19836 (10)0.20978 (7)0.25357 (6)0.0209 (2)
C20.44360 (15)0.12650 (10)0.44109 (9)0.0173 (3)
O20.57573 (11)0.10362 (7)0.47130 (7)0.0229 (3)
C30.27874 (15)0.12461 (9)0.48828 (9)0.0162 (3)
C40.22350 (15)0.10039 (9)0.57975 (9)0.0169 (3)
C50.05837 (16)0.09960 (9)0.59990 (9)0.0190 (3)
C60.05338 (16)0.12442 (10)0.52875 (9)0.0194 (3)
C70.00199 (15)0.15097 (9)0.43675 (9)0.0180 (3)
C80.16350 (15)0.15055 (9)0.41884 (8)0.0160 (3)
N40.33533 (14)0.07751 (8)0.65906 (7)0.0202 (3)
O410.46763 (13)0.12029 (8)0.65980 (7)0.0284 (3)
O420.28788 (13)0.01824 (8)0.72135 (7)0.0292 (3)
H10.49500.17350.31590.037 (5)*
H50.02160.08210.66240.023*
H60.16640.12330.54310.023*
H70.07790.16870.38810.022*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0147 (5)0.0266 (6)0.0154 (5)0.0013 (4)0.0017 (4)0.0002 (4)
C10.0178 (6)0.0167 (6)0.0170 (6)0.0011 (5)0.0009 (5)0.0031 (5)
O10.0220 (5)0.0258 (5)0.0151 (4)0.0011 (4)0.0029 (3)0.0018 (4)
C20.0163 (6)0.0188 (6)0.0167 (6)0.0005 (5)0.0000 (5)0.0034 (5)
O20.0161 (5)0.0294 (5)0.0233 (5)0.0022 (4)0.0028 (4)0.0004 (4)
C30.0159 (6)0.0165 (6)0.0163 (6)0.0001 (5)0.0004 (5)0.0014 (5)
C40.0183 (6)0.0173 (6)0.0152 (6)0.0002 (5)0.0025 (5)0.0006 (5)
C50.0211 (7)0.0186 (6)0.0173 (6)0.0008 (5)0.0033 (5)0.0018 (5)
C60.0169 (6)0.0197 (6)0.0214 (6)0.0000 (5)0.0015 (5)0.0034 (5)
C70.0166 (6)0.0179 (6)0.0196 (6)0.0009 (5)0.0023 (5)0.0019 (5)
C80.0171 (6)0.0158 (6)0.0151 (6)0.0000 (4)0.0008 (5)0.0014 (4)
N40.0223 (6)0.0224 (6)0.0159 (5)0.0020 (5)0.0023 (4)0.0002 (4)
O410.0241 (5)0.0382 (6)0.0230 (5)0.0062 (4)0.0080 (4)0.0028 (4)
O420.0335 (6)0.0331 (6)0.0210 (5)0.0007 (4)0.0009 (4)0.0104 (4)
Geometric parameters (Å, º) top
N1—C11.3705 (16)C4—N41.4678 (15)
N1—C21.3943 (16)C5—C61.3895 (19)
N1—H10.8167C5—H50.95
C1—O11.2174 (15)C6—C71.3928 (18)
C1—C81.4933 (16)C6—H60.95
C2—O21.2026 (15)C7—C81.3832 (17)
C2—C31.5063 (17)C7—H70.95
C3—C41.3887 (17)N4—O411.2231 (15)
C3—C81.3954 (17)N4—O421.2269 (14)
C4—C51.3862 (17)
C1—N1—C2113.38 (10)C4—C5—C6120.09 (12)
C1—N1—H1130.4C4—C5—H5120.0
C2—N1—H1115.6C6—C5—H5120.0
O1—C1—N1125.29 (12)C5—C6—C7120.89 (12)
O1—C1—C8128.54 (12)C5—C6—H6119.6
N1—C1—C8106.16 (10)C7—C6—H6119.6
O2—C2—N1124.13 (12)C8—C7—C6117.59 (11)
O2—C2—C3131.00 (12)C8—C7—H7121.2
N1—C2—C3104.86 (10)C6—C7—H7121.2
C4—C3—C8117.96 (11)C7—C8—C3122.95 (11)
C4—C3—C2134.26 (12)C7—C8—C1129.36 (11)
C8—C3—C2107.74 (10)C3—C8—C1107.69 (11)
C5—C4—C3120.51 (11)O41—N4—O42124.46 (11)
C5—C4—N4117.36 (11)O41—N4—C4118.03 (10)
C3—C4—N4122.12 (11)O42—N4—C4117.48 (11)
C2—N1—C1—O1177.46 (12)C5—C6—C7—C80.70 (18)
C2—N1—C1—C81.07 (14)C6—C7—C8—C30.22 (18)
C1—N1—C2—O2177.25 (12)C6—C7—C8—C1178.73 (12)
C1—N1—C2—C31.49 (14)C4—C3—C8—C71.40 (18)
O2—C2—C3—C42.5 (2)C2—C3—C8—C7176.55 (11)
N1—C2—C3—C4178.89 (13)C4—C3—C8—C1177.75 (11)
O2—C2—C3—C8174.98 (14)C2—C3—C8—C14.30 (13)
N1—C2—C3—C83.63 (13)O1—C1—C8—C74.0 (2)
C8—C3—C4—C51.68 (18)N1—C1—C8—C7177.50 (12)
C2—C3—C4—C5175.60 (13)O1—C1—C8—C3175.05 (12)
C8—C3—C4—N4176.64 (11)N1—C1—C8—C33.42 (13)
C2—C3—C4—N46.1 (2)C5—C4—N4—O41146.87 (12)
C3—C4—C5—C60.82 (19)C3—C4—N4—O4131.51 (17)
N4—C4—C5—C6177.58 (11)C5—C4—N4—O4231.58 (16)
C4—C5—C6—C70.41 (19)C3—C4—N4—O42150.05 (12)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.821.992.8043 (14)176
C5—H5···O41ii0.952.563.4386 (16)153
C6—H6···O2iii0.952.363.1639 (16)142
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x1/2, y, z+3/2; (iii) x1, y, z.
(II) 4-Nitrophthalimide top
Crystal data top
C8H4N2O4F(000) = 392
Mr = 192.13Dx = 1.716 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 1007 reflections
a = 5.3114 (3) Åθ = 3.3–27.5°
b = 5.6812 (5) ŵ = 0.14 mm1
c = 24.645 (2) ÅT = 291 K
V = 743.67 (10) Å3Plate, colourless
Z = 40.26 × 0.22 × 0.04 mm
Data collection top
Nonius KappaCCD
diffractometer
1007 independent reflections
Radiation source: rotating anode804 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.060
ϕ scans, and ω scans with κ offsetsθmax = 27.5°, θmin = 3.3°
Absorption correction: multi-scan
(SORTAV; Blessing, 1995, 1997)
h = 66
Tmin = 0.956, Tmax = 0.994k = 77
6348 measured reflectionsl = 3131
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.043Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.110H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0707P)2 + 0.0553P]
where P = (Fo2 + 2Fc2)/3
1007 reflections(Δ/σ)max < 0.001
127 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.27 e Å3
Crystal data top
C8H4N2O4V = 743.67 (10) Å3
Mr = 192.13Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 5.3114 (3) ŵ = 0.14 mm1
b = 5.6812 (5) ÅT = 291 K
c = 24.645 (2) Å0.26 × 0.22 × 0.04 mm
Data collection top
Nonius KappaCCD
diffractometer
1007 independent reflections
Absorption correction: multi-scan
(SORTAV; Blessing, 1995, 1997)
804 reflections with I > 2σ(I)
Tmin = 0.956, Tmax = 0.994Rint = 0.060
6348 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0430 restraints
wR(F2) = 0.110H-atom parameters constrained
S = 1.03Δρmax = 0.26 e Å3
1007 reflectionsΔρmin = 0.27 e Å3
127 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.8528 (5)0.4545 (4)0.71294 (9)0.0268 (6)
C10.8471 (6)0.6382 (5)0.67636 (10)0.0242 (6)
O10.9844 (4)0.8077 (4)0.67667 (8)0.0306 (5)
C20.6641 (5)0.2892 (5)0.70364 (11)0.0257 (7)
O20.6265 (4)0.1134 (4)0.73007 (8)0.0336 (6)
C30.5294 (5)0.3736 (5)0.65413 (11)0.0236 (6)
C40.3286 (5)0.2744 (5)0.62623 (11)0.0243 (6)
C50.2516 (5)0.4022 (5)0.58086 (10)0.0234 (6)
N50.0417 (5)0.3041 (4)0.54841 (9)0.0277 (6)
O510.0327 (4)0.1058 (4)0.55967 (9)0.0377 (6)
O520.0481 (4)0.4261 (4)0.51226 (8)0.0320 (5)
C60.3542 (6)0.6110 (5)0.56411 (11)0.0251 (6)
C70.5546 (6)0.7071 (6)0.59283 (11)0.0269 (7)
C80.6376 (5)0.5839 (5)0.63799 (11)0.0233 (6)
H10.95730.42490.74180.032*
H40.25210.13460.63690.029*
H60.29040.68790.53380.030*
H70.62960.84770.58220.032*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0289 (13)0.0261 (14)0.0253 (12)0.0008 (12)0.0031 (10)0.0017 (10)
C10.0249 (14)0.0240 (15)0.0238 (13)0.0020 (14)0.0031 (11)0.0024 (12)
O10.0331 (12)0.0290 (12)0.0298 (10)0.0076 (11)0.0022 (9)0.0014 (9)
C20.0290 (15)0.0209 (15)0.0271 (13)0.0023 (14)0.0032 (13)0.0034 (12)
O20.0424 (14)0.0260 (11)0.0325 (11)0.0001 (11)0.0002 (9)0.0038 (10)
C30.0233 (14)0.0221 (15)0.0253 (12)0.0022 (13)0.0015 (11)0.0028 (13)
C40.0238 (14)0.0183 (14)0.0309 (13)0.0003 (13)0.0061 (12)0.0011 (12)
C50.0192 (13)0.0264 (16)0.0248 (13)0.0022 (13)0.0009 (11)0.0034 (12)
N50.0253 (12)0.0277 (14)0.0300 (12)0.0039 (13)0.0026 (11)0.0034 (12)
O510.0387 (12)0.0359 (13)0.0385 (11)0.0171 (12)0.0039 (10)0.0030 (10)
O520.0309 (11)0.0337 (13)0.0313 (10)0.0008 (11)0.0061 (9)0.0023 (9)
C60.0274 (14)0.0232 (16)0.0246 (13)0.0003 (14)0.0001 (11)0.0009 (12)
C70.0286 (15)0.0261 (16)0.0259 (13)0.0014 (14)0.0004 (12)0.0005 (13)
C80.0219 (14)0.0238 (16)0.0241 (13)0.0004 (13)0.0015 (11)0.0029 (12)
Geometric parameters (Å, º) top
N1—C11.379 (4)C4—H40.93
N1—C21.392 (4)C5—C61.369 (4)
N1—H10.92C5—N51.481 (4)
C1—O11.208 (3)N5—O521.225 (3)
C1—C81.493 (4)N5—O511.226 (3)
C2—O21.209 (3)C6—C71.390 (4)
C2—C31.494 (4)C6—H60.93
C3—C81.384 (4)C7—C81.387 (4)
C3—C41.388 (4)C7—H70.93
C4—C51.395 (4)
C1—N1—C2112.8 (2)C6—C5—C4125.2 (3)
C1—N1—H1131.2C6—C5—N5117.6 (3)
C2—N1—H1116.0C4—C5—N5117.3 (3)
O1—C1—N1125.9 (3)O52—N5—O51124.0 (3)
O1—C1—C8128.2 (3)O52—N5—C5118.2 (3)
N1—C1—C8105.9 (2)O51—N5—C5117.8 (3)
O2—C2—N1126.0 (3)C5—C6—C7119.5 (3)
O2—C2—C3128.7 (3)C5—C6—H6120.3
N1—C2—C3105.3 (2)C7—C6—H6120.3
C8—C3—C4121.8 (3)C8—C7—C6117.0 (3)
C8—C3—C2108.2 (3)C8—C7—H7121.5
C4—C3—C2130.0 (3)C6—C7—H7121.5
C3—C4—C5114.3 (3)C3—C8—C7122.3 (3)
C3—C4—H4122.9C3—C8—C1107.8 (2)
C5—C4—H4122.9C7—C8—C1129.9 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O2i0.922.553.231 (3)131
N1—H1···O1ii0.922.142.974 (3)151
C4—H4···O1iii0.932.543.452 (4)168
C7—H7···O51iv0.932.383.257 (4)156
Symmetry codes: (i) x+2, y+1/2, z+3/2; (ii) x+2, y1/2, z+3/2; (iii) x1, y1, z; (iv) x+1, y+1, z.

Experimental details

(I)(II)
Crystal data
Chemical formulaC8H4N2O4C8H4N2O4
Mr192.13192.13
Crystal system, space groupOrthorhombic, PbcaOrthorhombic, P212121
Temperature (K)120291
a, b, c (Å)8.2208 (2), 13.0786 (4), 13.9233 (4)5.3114 (3), 5.6812 (5), 24.645 (2)
V3)1496.99 (7)743.67 (10)
Z84
Radiation typeMo KαMo Kα
µ (mm1)0.140.14
Crystal size (mm)0.48 × 0.32 × 0.080.26 × 0.22 × 0.04
Data collection
DiffractometerBruker-Nonius 95mm CCD camera on κ-goniostat
diffractometer
Nonius KappaCCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2003)
Multi-scan
(SORTAV; Blessing, 1995, 1997)
Tmin, Tmax0.954, 0.9890.956, 0.994
No. of measured, independent and
observed [I > 2σ(I)] reflections
19573, 1703, 1488 6348, 1007, 804
Rint0.0370.060
(sin θ/λ)max1)0.6490.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.039, 0.099, 1.10 0.043, 0.110, 1.03
No. of reflections17031007
No. of parameters129127
H-atom treatmentH-atom parameters constrainedH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.33, 0.420.26, 0.27

Computer programs: COLLECT (Hooft, 1999), KappaCCD Server Software (Nonius, 1997), DENZO (Otwinowski & Minor, 1997) and COLLECT, DENZO–SMN (Otwinowski & Minor, 1997), DENZO and COLLECT, DENZO–SMN, OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997), OSCAIL and SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), SHELXL97 and PRPKAPPA (Ferguson, 1999).

Hydrogen-bond geometry (Å, º) for (I) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.821.992.8043 (14)176
C5—H5···O41ii0.952.563.4386 (16)153
C6—H6···O2iii0.952.363.1639 (16)142
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x1/2, y, z+3/2; (iii) x1, y, z.
Hydrogen-bond geometry (Å, º) for (II) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O2i0.922.553.231 (3)131
N1—H1···O1ii0.922.142.974 (3)151
C4—H4···O1iii0.932.543.452 (4)168
C7—H7···O51iv0.932.383.257 (4)156
Symmetry codes: (i) x+2, y+1/2, z+3/2; (ii) x+2, y1/2, z+3/2; (iii) x1, y1, z; (iv) x+1, y+1, z.
 

Acknowledgements

The authors thank a referee for helpful comments on conformational enantiomerism. X-ray data were collected at the EPSRC X-ray Crystallographic Service, University of Southampton, England; the authors thank the staff for all their help and advice. JNL thanks NCR Self-Service, Dundee, for grants which have provided computing facilities for this work. JLW thanks CNPq and FAPERJ for financial support.

References

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