Isomeric N-(iodophenyl)nitrophthalimides: Interplay of C - H...O hydrogen bonds, iodo...nitro and iodo...carbonyl interactions, and aromatic π...π stacking interactions

Article abstract of DOI:10.1107/S0108768105004234

The six isomeric N-(iodophenyl)nitrophthalimides, C₁₄H ₇IN₂O₄, have been synthesized and the structures of five of them are reported. In N-(4-iodophenyl)-4-nitrophthalimide [(I), orthorhombic P2₁2₁2₁] the molecules are linked into sheets by a combination of four independent C - H...O hydrogen bonds, but I...O interactions are absent. The isomers N-(3-iodophenyl)-4- nitrophthalimide [(II), monoclinic P2₁/c] and N-(2-iodophenyl)-4- nitrophthalimide [(III), monoclinic P2₁/n] both form sheets, but in (II) the molecules are linked by a combination of one two-centre iodo...nitro interaction and one C - H...O hydrogen bond into sheets containing R₄⁴(30) rings, while in (III) they are linked by an iodo...carbonyl interaction and a C - H...O hydrogen bond into sheets or R₄⁴(26) rings. Three-dimensional supramolecular structures are formed in both N-(4-iodophenyl)-3-nitrophthalimide [(IV), monoclinic P2₁/n] and N-(3-iodophenyl)-3-nitrophthalimide [(V), orthorhombic, P2₁2₁2₁]. In (IV) the molecules are linked by a three-centre iodo...nitro interaction, three C - H...O hydrogen bonds and an aromatic π...π stacking interaction, but the framework in (V) is generated by a two-centre iodo...nitro interaction and only two C - H...O hydrogen bonds: aromatic π...π stacking interactions are absent from (V).

Full text of DOI:10.1107/S0108768105004234

research papers
Acta Crystallographica Section B
Structural
Science
Isomeric N-(iodophenyl)nitrophthalimides: inter-
play of C—Hꢀ ꢀ ꢀO hydrogen bonds, iodoꢀ ꢀ ꢀnitro and
iodoꢀ ꢀ ꢀcarbonyl interactions, and aromatic pꢀ ꢀ ꢀp
stacking interactions
ISSN 0108-7681
Christopher Glidewell,a* John N.
Low,b‡ Janet M. S. Skakle,b
Solange M. S. V. Wardellc§ and
James L. Wardelld
The
six
isomeric
N-(iodophenyl)nitrophthalimides,
Received 29 November 2004
Accepted 7 February 2005
C14H7IN2O4, have been synthesized and the structures of five
of them are reported. In N-(4-iodophenyl)-4-nitrophthalimide
[(I), orthorhombic P212121] the molecules are linked into
sheets by a combination of four independent C—Hꢀ ꢀ ꢀO
hydrogen bonds, but Iꢀ ꢀ ꢀO interactions are absent. The
isomers N-(3-iodophenyl)-4-nitrophthalimide [(II), mono-
clinic P21/c] and N-(2-iodophenyl)-4-nitrophthalimide [(III),
monoclinic P21/n] both form sheets, but in (II) the molecules
are linked by a combination of one two-centre iodoꢀ ꢀ ꢀnitro
interaction and one C—Hꢀ ꢀ ꢀO hydrogen bond into sheets
containing R44ð30Þ rings, while in (III) they are linked by an
iodoꢀ ꢀ ꢀcarbonyl interaction and a C—Hꢀ ꢀ ꢀO hydrogen bond
into sheets or R44ð26Þ rings. Three-dimensional supramolecular
structures are formed in both N-(4-iodophenyl)-3-nitrophtha-
limide [(IV), monoclinic P21/n] and N-(3-iodophenyl)-3-
nitrophthalimide [(V), orthorhombic, P212121]. In (IV) the
molecules are linked by a three-centre iodoꢀ ꢀ ꢀnitro interac-
tion, three C—Hꢀ ꢀ ꢀO hydrogen bonds and an aromatic ꢀꢀ ꢀ ꢀꢀ
stacking interaction, but the framework in (V) is generated by
a two-centre iodoꢀ ꢀ ꢀnitro interaction and only two C—Hꢀ ꢀ ꢀO
hydrogen bonds: aromatic ꢀꢀ ꢀ ꢀꢀ stacking interactions are
absent from (V).
aSchool of Chemistry, University of St Andrews,
St Andrews, Fife KY16 9ST, Scotland,
bDepartment of Chemistry, University of
Aberdeen, Meston Walk, Old Aberdeen AB24
c
´
3UE, Scotland, Instituto de Quımica, Departa-
´
ˆ
mento de Quımica Organica, Universidade
´
Federal Fluminense, 24020-150 Niteroi, Rio de
d
´
Janeiro-RJ, Brazil, and Instituto de Quımica,
´
ˆ
Departamento de Quımica Inorganica, Univer-
sidade Federal do Rio de Janeiro, CP 68563,
21945-970 Rio de Janeiro-RJ, Brazil
‡ Postal address: School of Engineering,
University of Dundee, Dundee DD1 4HN,
Scotland.
§ Present address: Funda¸cao Oswaldo Cruz, Far
˜
Manguinhos, Rua Sizenando Nabuco, 100
Manguinhos, 21041-250 Rio de Janeiro-RJ,
Brazil.
Correspondence e-mail: cg@st-andrews.ac.uk
1. Introduction
In the course of our continuing investigation of the interplay
between hard and soft hydrogen bonds (Braga et al., 1995;
Desiraju & Steiner, 1999), aromatic ꢀꢀ ꢀ ꢀꢀ stacking interac-
tions and iodoꢀ ꢀ ꢀnitro interactions in simple bis-arene systems,
we have studied the supramolecular structures of an extensive
series of iodoaryl–nitroaryl compounds, many in several
isomeric forms, including examples of sulfonamides [(A), see
Scheme 1; Kelly et al., 2002], benzylideneanilines [(B) Glide-
well, Howie et al., 2002, and (C) Wardell et al., 2002], benzy-
lanilines [(D) Glidewell, Low et al., 2002; Glidewell, Low,
Skakle, Wardell & Wardell, 2004], benzenesulfanylanilines
[(E) Glidewell et al., 2003a], and phenylhydrazones [(F)
Glidewell et al., 2003b, 2004a].
For types (A), (B) and (D) we have been able to study an
extended series of isomeric compounds, including four
isomeric iodoarene–nitroarenesulfonamides (A), eight
isomeric nitrobenzylidene–iodoanilines (B) and six isomeric
iodo-N-(nitrobenzyl)anilines (D). Isomeric compounds of
type (A) can form molecular ladders built from N—
Hꢀ ꢀ ꢀO(nitro) and C—Hꢀ ꢀ ꢀO hydrogen bonds and
iodoꢀ ꢀ ꢀsulfonyl interactions; chains of edge-fused rings built
from N—Hꢀ ꢀ ꢀO S hydrogen bonds and iodoꢀ ꢀ ꢀnitro inter-
actions, which are further linked into sheets by C—Hꢀ ꢀ ꢀO
hydrogen bonds; and three-dimensional frameworks built
# 2005 International Union of Crystallography
Printed in Great Britain – all rights reserved
Acta Cryst. (2005). B61, 227–237
doi:10.1107/S0108768105004234 227

research papers
from C—Hꢀ ꢀ ꢀO hydrogen bonds and iodoꢀ ꢀ ꢀnitro interactions
from which, surprisingly, N—Hꢀ ꢀ ꢀO hydrogen bonds are
wholly absent. The isomers of type (B) can crystallize as
within each series, no one structure is readily predictable from
a knowledge of all the others. With these observations in mind,
we have now extended this study to isomeric examples of a
more rigid system, namely the isomeric N-(iodophenyl)ni-
trophthalimides (I)–(VI) (see Scheme 2).
isolated molecules with no direction-specific interactions
between them; they can form simple chains built from C—
Hꢀ ꢀ ꢀO hydrogen bonds which may, in some cases only, be
further linked by aromatic ꢀꢀ ꢀ ꢀꢀ stacking interactions; and
different combinations of C—Hꢀ ꢀ ꢀO hydrogen bonds and
iodoꢀ ꢀ ꢀnitro interactions can generate either sheets of three-
dimensional framework structures. Isomeric molecules of type
(D) can be linked into simple chains by C—Hꢀ ꢀ ꢀO hydrogen
bonds; into molecular ladders by a combination of N—Hꢀ ꢀ ꢀO
and C—Hꢀ ꢀ ꢀO hydrogen bonds and iodoꢀ ꢀ ꢀnitro and aromatic
ꢀꢀ ꢀ ꢀꢀ stacking interactions; into sheets either by the combi-
nation of C—Hꢀ ꢀ ꢀO and N—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds
and aromatic ꢀꢀ ꢀ ꢀꢀ stacking interactions or by the combina-
tion of N—Hꢀ ꢀ ꢀO, C—Hꢀ ꢀ ꢀO and C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen
bonds; or, finally, into three-dimensional frameworks
containing multiple direction-specific interactions which
sometimes include and sometimes exclude N—Hꢀ ꢀ ꢀO
hydrogen bonds. It is important to note that, within each series
of isomers, no two compounds manifest the same selection of
direction-specific intermolecular interactions and, again
These compounds have been selected for study for two
reasons. Firstly, because hard hydrogen bonds are excluded, so
that the only plausible direction-specific intermolecular
interactions are C—Hꢀ ꢀ ꢀO hydrogen bonds, albeit with two
possible types of acceptor O, carbonyl and nitro; Iꢀ ꢀ ꢀO inter-
actions, again with the same two types of acceptor; and
aromatic ꢀꢀ ꢀ ꢀꢀ stacking interactions. Secondly, because the
molecular frameworks have only a single degree of torsional
freedom, about the N-aryl bond, so restraining somewhat the
range of possible intermolecular contacts.
N-Arylphthalimides are formed in a very general reaction
between phthalic anhydrides and anilines. The primary inter-
mediate in such a reaction is an acid of type (G), see Scheme 3;
hydrolysis of (G) can give an anilinium salt (H) or, alter-
ꢁ
228 Christopher Glidewell et al.
Isomeric N-(iodophenyl)nitrophthalimides
Acta Cryst. (2005). B61, 227–237

research papers
natively, loss of water from (G) can give the N-arylphthalimide
(J). We have recently reported the supramolecular structures
of representative examples of type (G) (Glidewell et al.,
2004b) and (H) (Glidewell et al., 2003c), while the six isomeric
compounds (I)–(VI) discussed in this paper are representative
of form (J).
was removed from the filtrate and the resulting solids were
then recrystallized to give pure samples of the compounds (I)–
(VI). The solvents employed, m.p.s and ꢁ(CO) values (cmꢂ1
)
in KBr discs are as follows: For (I): ethyl acetate, 493–394 K,
1776w and 1723s; for (II): butanone, 549–553 K, 1780w, 1771w
and 1717s; for (III): 1,2-dichloroethane, 444–446 K, 1783m and
1728s,br; for (IV): ethanol, 461–463 K, 1780m, 1724s and
1698sh; for (V): ethanol, 524–526 K, 1783m, 1731s and 1720s;
for (VI): acetone, 432–433 K, 1784m and 1731s,br. Crystals of
(I)–(V) suitable for single-crystal X-ray diffraction were
selected directly from the prepared samples. Despite many
attempts using a wide range of solvents, no suitable crystals of
(VI) could be obtained.
2.2. Data collection, structure solution and refinement
Details of cell data, data collection and structure solution
and refinement are summarized in Table 1 (Blessing, 1995,
1997; Bruker, 1998, 2000; Ferguson, 1999; McArdle, 2003;
Nonius, 1997; Otwinowski & Minor, 1997; Sheldrick, 1997).
The space groups for (I)–(V) were all assigned uniquely from
the systematic absences. The structures were all solved by
direct methods using SHELXS97 (Sheldrick, 1997) and
refined on F2 with all data using SHELXL97 (Sheldrick, 1997).
A weighting scheme based upon P = (Fo2 + 2Fc2)/3 was
employed in order to reduce statistical bias (Wilson, 1976). All
H atoms were located from difference maps and all were
included in the refinements as riding atoms, with C—H
˚
˚
distances 0.93 A at 291 (2) K and 0.95 A at 120 (2) K, and with
Uiso(H) = 1.2Ueq(C). The molecules all lie in general positions
and are all fully ordered. For (I) and (V) the correct enan-
tiomorph was selected using the Flack parameter (Flack,
1983): the final values were ꢂ0.02 (3) and ꢂ0.03 (2), respec-
tively.
Supramolecular analyses were made and the diagrams were
prepared with the aid of PLATON (Spek, 2003). Figs. 1–16
show the independent components of (I)–(V) with the atom-
labelling schemes and aspects of their supramolecular struc-
tures. The dihedral angles are given in Table 2, details of the
hydrogen bonding are in Table 3 and details of the inter-
molecular Iꢀ ꢀ ꢀO contacts are in Table 4.1
2. Experimental
2.1. Synthesis
Finely ground intimate mixtures containing equimolar
quantities of a nitrophthalic anhydride and the appropriate
iodoaniline were heated, in the absence of solvent, until the
evolution of water had ceased. The resulting solids were
cooled and then heated in acetone containing activated
charcoal for 10 min. These solutions were filtered, the solvent
3. Results and discussion
3.1. Molecular conformations
The molecular conformations are defined by two dihedral
angles, that between the N-phenyl ring and the heterocyclic
ring, and that between the nitro group and the carbocyclic ring
of the phthalimido unit (Table 2). The dihedral angle between
the two ring planes varies over a rather wide range, between
40.2 (2) and 82.0 (2)ꢃ. For comparison, the corresponding
angle in the unsubstituted N-phenylphthalimide [CSD (Allen,
2002) refcode ZZZAWJ10; Magomedova et al., 1981] itself is
58.2ꢃ (no s.u.s were quoted). It may be noted here that the
1 Supplementary data for this paper are available from the IUCr electronic
archives (Reference: BM5022). Services for accessing these data are described
at the back of the journal.
Figure 1
A molecule of (I) showing the atom-labelling scheme. Displacement
ellipsoids are drawn at the 30% probability level.
ꢁ
Acta Cryst. (2005). B61, 227–237
Christopher Glidewell et al.
Isomeric N-(iodophenyl)nitrophthalimides 229

research papers
Table 1
Experimental details.
(I)
(II)
(III)
(IV)
(V)
Crystal data
Chemical formula
Mr
Cell setting, space
group
˚
a, b, c (A)
C14H7IN2O4
394.12
Orthorhombic, P212121
C14H7IN2O4
394.12
Monoclinic, P21/c
C14H7IN2O4
394.12
Monoclinic, P21/n
C14H7IN2O4
394.12
Monoclinic, P21/n
C14H7IN2O4
394.12
Orthorhombic, P212121
4.1092 (1), 6.7843 (1),
48.6775 (10)
90.00
1357.03 (5)
4
1.929
7.9592 (9), 6.5708 (7),
13.4591 (6), 7.6018 (3),
7.52380 (10), 22.6556 (5), 6.8070 (1), 13.0955 (2),
25.648 (3)
97.960 (3)
1328.4 (3)
4
1.971
Mo Kꢃ
4808
14.7086 (7)
110.592 (1)
1408.74 (11)
4
1.858
Mo Kꢃ
5040
7.92010 (10)
107.3824 (16)
1288.38 (4)
4
2.032
Mo Kꢃ
2918
14.8369 (3)
90.00
1322.58 (4)
4
1.979
ꢂ (ꢃ)
3
˚
V (A )
Z
Dx (Mg mꢂ3
)
Radiation type
No. of reflections for
cell parameters
ꢄ range (ꢃ)
Mo Kꢃ
3015
Mo Kꢃ
2984
3.0–27.5
2.38
2.6–32.6
2.43
2.5–32.5
2.29
3.0–27.5
2.50
3.1–27.5
2.44
ꢅ (mmꢂ1
)
Temperature (K)
Crystal form, colour
Crystal size (mm)
298 (2)
Plate, yellow
0.28 ꢄ 0.04 ꢄ 0.03
291 (2)
Plate, brown
0.29 ꢄ 0.11 ꢄ 0.02
291 (2)
Block, orange
0.40 ꢄ 0.32 ꢄ 0.30
120 (2)
Block, colourless
0.40 ꢄ 0.25 ꢄ 0.20
120 (2)
Block, colourless
0.50 ꢄ 0.40 ꢄ 0.40
Data collection
Diffractometer
Kappa-CCD
Bruker SMART
1000CCD area
detector
Bruker SMART
1000CCD area
detector
Kappa-CCD
Kappa-CCD
Data collection
method
’ and ! scans with ꢆ
offsets
’ and ! scans
’ and ! scans
’ and ! scans with ꢆ
offsets
’ and ! scans with ꢆ
offsets
Absorption correction
Tmin
Tmax
Multi-scan
0.749
0.936
Multi-scan
0.539
0.953
Multi-scan
0.424
0.503
Multi-scan
0.412
0.602
Multi-scan
0.319
0.376
No. of measured,
independent and
observed reflections
Criterion for observed
reflections
9768, 3015, 2760
13 842, 4808, 1564
14 517, 5040, 3064
7971, 2918, 2724
8214, 2984, 2880
I > 2ꢇ(I)
I > 2ꢇ(I)
I > 2ꢇ(I)
I > 2ꢇ(I)
I > 2ꢇ(I)
Rint
ꢄ
0.070
27.5
ꢂ3 ) h ) 5
ꢂ8 ) k ) 8
ꢂ63 ) l ) 62
0.086
32.6
ꢂ11 ) h ) 12
ꢂ6 ) k ) 9
ꢂ36 ) l ) 38
0.017
32.5
ꢂ20 ) h ) 20
ꢂ11 ) k ) 11
ꢂ18 ) l ) 22
0.039
27.5
ꢂ9 ) h ) 9
ꢂ29 ) k ) 27
ꢂ10 ) l ) 10
0.038
27.5
ꢂ8 ) h ) 8
ꢂ15 ) k ) 17
ꢂ17 ) l ) 19
max (ꢃ)
Range of h, k, l
Refinement
Refinement on
R[F2 > 2ꢇ(F2)],
wR(F2), S
F2
0.032, 0.119, 1.21
F2
0.049, 0.097, 0.77
F2
0.043, 0.134, 1.03
F2
0.022, 0.052, 1.09
F2
0.025, 0.054, 1.06
No. of reflections
No. of parameters
H-atom treatment
3015
190
4808
190
5040
190
2918
190
2984
190
Constrained to parent
site
Constrained to parent
site
Constrained to parent
site
Constrained to parent
site
Constrained to parent
site
Weighting scheme
w = 1/[ꢇ2(Fo2) +
(0.0631P)2 + 0.2598P],
where P = (Fo2 + 2Fc2)/3
<0.0001
w = 1/[ꢇ2(Fo2) +
(0.032P)2], where
P = (Fo2 + 2Fc2)/3
<0.0001
w = 1/[ꢇ2(Fo2) +
(0.0607P)2 + 0.5997P],
where P = (Fo2 + 2Fc2)/3
<0.0001
w = 1/[ꢇ2(Fo2) +
(0.0071P)2 + 1.5414P],
where P = (Fo2 + 2Fc2)/3
0.003
w = 1/[ꢇ2(Fo2) +
(0.0224P)2 + 0.3484P],
where P = (Fo2 + 2Fc2)/3
0.001
(Á/ꢇ)max
Áꢈmax, Áꢈmin (e A
Absolute structure
ꢂ3
˚
)
0.48, ꢂ0.63
0.70, ꢂ0.35
1.02, ꢂ0.58
0.45, ꢂ0.68
0.33, ꢂ0.75
Flack (1983), 1917
Friedel pairs
ꢂ0.02 (3)
–
–
–
Flack (1983), 1266
Friedel pairs
ꢂ0.028 (17)
Flack parameter
–
–
–
structure of N-phenylphthalimide contains no direction-
specific intermolecular interactions of any kind: C—Hꢀ ꢀ ꢀN,
C—Hꢀ ꢀ ꢀO and C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds and
aromatic ꢀꢀ ꢀ ꢀꢀ stacking interactions are all absent. Hence, it is
not necessarily appropriate to attempt a detailed interpreta-
tion of the variation in the inter-ring dihedral angle in terms of
direction-specific intermolecular forces.
expected to be fully planar, as for the archetypal compound
nitrobenzene. In gaseous nitrobenzene, the barrier to rotation
of the nitro group around the C—N bond is modest: deter-
minations based on microwave spectroscopy, Raman spec-
troscopy and electron diffraction broadly concur in estimating
this barrier at around 15 kJ molꢂ1 (Domenicano et al., 1990).
Thus, the minimum-energy planar conformation of nitro-
arenes can readily be perturbed, for example, by hydrogen
bonds or Iꢀ ꢀ ꢀO interactions involving the nitro O atoms. In
For a nitro group bonded directly to an aromatic ring, the
minimum energy conformation for the isolated molecules is
ꢁ
230 Christopher Glidewell et al.
Isomeric N-(iodophenyl)nitrophthalimides
Acta Cryst. (2005). B61, 227–237

research papers
Table 2
Table 3
Hydrogen-bonding geometry and short intermolecular contacts (A, ).
ꢃ
Dihedral angles (ꢃ).
˚
For (I)–(III) n = 5, for (IV) and (V) n = 4.
D—Hꢀ ꢀ ꢀA
Hꢀ ꢀ ꢀA Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA Motif
C(6)
Direction
(N1,C1,C2,C3,C8)^(C11–C16)
(Cn,Nn,On1,On2)^(C3–C8)
(I)
C4—H4ꢀ ꢀ ꢀO1i
C6—H6ꢀ ꢀ ꢀO51ii
C7—H7ꢀ ꢀ ꢀO52iii
C15—H15ꢀ ꢀ ꢀO2iv
2.61
2.50
2.46
2.61
3.531 (6) 171
3.219 (7) 134
3.342 (8) 159
3.211 (6) 123
ꢀ
[110]
[010]
ꢀ
[110]
[010]
[001]
[101]
(I)
61.1 (3)
51.7 (2)
82.0 (2)
40.2 (2)
48.1 (2)
8.9 (3)
12.8 (3)
7.7 (2)
34.8 (2)
30.6 (2)
C(5)
C(6)
C(7)
(II)
(III)
(IV)
(V)
(II)
C16—H16ꢀ ꢀ ꢀO2iv
2.47
2.60
3.181 (6) 133
3.449 (4) 152
C(7)
C(6)
(III)
C7—H7ꢀ ꢀ ꢀO2v
(I)–(V) the twist angles of the nitro groups appear to fall into
two groups: in (I)–(III) the twist does not exceed 13ꢃ, while for
both (IV) and (V) it exceeds 30ꢃ (Table 2). In the first of these
groups, nitro O atoms participate in C—Hꢀ ꢀ ꢀO hydrogen
bonds in (I) and in iodoꢀ ꢀ ꢀnitro interactions in (II) (see below,
x3.3), but in neither of these interactions in (III): of the second
group, the nitro O atoms participate in iodoꢀ ꢀ ꢀnitro interac-
tion in both (IV) and (V), but in C—Hꢀ ꢀ ꢀO hydrogen bonds
only in (IV). Again, it is difficult to discern any pattern in the
intermolecular interactions which can provide a convincing
interpretation of the conformational characteristics.
(IV)
C6—H6ꢀ ꢀ ꢀO2vi
C12—H12ꢀ ꢀ ꢀO41vii
C16—H16ꢀ ꢀ ꢀO1viii
2.57
2.56
2.54
3.177 (3) 122
3.487 (3) 166
3.484 (3) 170
C(7)
C(9)
R22ð12Þ
[001]
[101]
–
(V)
C6—H6ꢀ ꢀ ꢀO2ix
2.44
2.44
3.064 (3) 123
3.204 (3) 138
C(7)
C(6)
[001]
[100]
C16-H16...O2x
Symmetry codes: (i) 1 þ x; ꢂ1 þ y; z; (ii) 1 ꢂ x; 12 þ y; 23 ꢂ z; (iii) ꢂ1 þ x; 1 þ y; z; (iv)
x; 1 þ y; z; (v) þ x; 32 ꢂ y; 21 þ z; (vi) x; y; ꢂ1 þ z; (vii) þ x; 21 ꢂ y; 12 þ z; (viii)
1
2
1
2
1
2
1
2
1 ꢂ x; 1 ꢂ y; 1 ꢂ z; (ix) ꢂ x; ꢂy; ꢂ þ z; (x) 1 þ x; y; z.
One consequence of these conformations is that all the
molecules are chiral, although this chirality has no chemical
significance. Compounds (II), (III) and (IV) all crystallize in
centrosymmetric space groups containing equal numbers of
the two enantiomeric molecular forms, but for (I) and (V),
which both crystallize in the space group P212121, a given
crystal contains only one enantiomorph. Thus, these two
compounds are possible examples of conglomerate crystal-
lization (Bernal & Cetrullo, 1990).
3.2. Supramolecular structures
3.2.1. Hydrogen-bond dimensions. The question of whether
an intermolecular C—Hꢀ ꢀ ꢀO contact should or should not be
Figure 3
Part of the crystal structure of (I) showing the formation of a
C(5)C(7)[R33ð22Þ] chain of edge-fused rings along [010]. For the sake of
clarity, the H atoms not involved in the motifs shown are omitted, as is the
unit-cell outline. The atoms marked with an asterisk (*), a hash (#), a
dollar sign ($), an ampersand (&) or an at sign (@) are at the symmetry
Figure 2
Part of the crystal structure of (I) showing the formation of a chain of
ꢀ
rings along [110]. For the sake of clarity, the H atoms not involved in the
motifs shown have been omitted, as has the unit-cell box. The atoms
marked with an asterisk (*) or a hash (#) are at the symmetry positions
(ꢂ1 þ x; 1 þ y; z) and (1 þ x; ꢂ1 þ y; z), respectively.
1
positions (1 ꢂ x; 12 þ y; 23 ꢂ z), (1 ꢂ x; ꢂ þ y; 32 ꢂ z), (x; ꢂ1 þ y; z),
2
(x; 1 þ y; z) and (1 ꢂ x; 32 þ y; 32 ꢂ z), respectively.
ꢁ
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Christopher Glidewell et al.
Isomeric N-(iodophenyl)nitrophthalimides 231

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Table 4
regarded as a hydrogen bond is often in practice a matter of
judgement and preference. In Table 3 we list the results of a
search for all such contacts in the compounds whose structures
are described here for which the Hꢀ ꢀ ꢀO distances are less than
ꢃ
˚
Geometry of iodoꢀ ꢀ ꢀnitro and iodoꢀ ꢀ ꢀcarbonyl interactions (A, ).
Iꢀ ꢀ ꢀO C—Iꢀ ꢀ ꢀO Iꢀ ꢀ ꢀO—N/C Motif Direction
(II)
C13—I13ꢀ ꢀ ꢀO51i
ꢃ
˚
2.65 A and for which the C—Hꢀ ꢀ ꢀO angles are above 100 : in
the event no contact had a C—Hꢀ ꢀ ꢀO angle less than 120ꢃ.
While some of these interactions, for example that formed by
the C7 atom in (I), would probably find fairly general accep-
tance as hydrogen bonds, others, such as that involving the
C15 atom in the same compound, possibly might not. For this
reason, we consider these interactions as a whole as hydrogen
bonds and short intermolecular contacts. It is perhaps worth
pointing out here that in (I) the two longer interactions,
formed by the C4 and C15 atoms, have the effect of coop-
eratively reinforcing the shorter and therefore probably
stronger bonds formed by the C7 and C6 atoms, respectively: it
is recognized that these long interactions may, indeed, be
adventitious consequences of the shorter interactions.
3.443 (4) 152.5 (2)
3.269 (2) 153.4 (2)
104.1 (3)
142.8 (2)
C(11) [001]
(III)
C12—I12ꢀ ꢀ ꢀO1ii
C(6)
[010]
(IV)
C14—I14ꢀ ꢀ ꢀO41iii 3.451 (2) 154.92 (7) 97.4 (2)
C(11) [010]
C(11) [010]
C14—I14ꢀ ꢀ ꢀO42iii 3.416 (2) 166.64 (7) 99.2 (2)
(V)
C13—I13ꢀ ꢀ ꢀO42iv 3.385 (2) 155.08 (8) 107.4 (2)
C(10) [010]
Symmetry codes: (i) x; ꢂ ꢂ y; ꢂ þ z; (ii) ꢂ x; ꢂ þ y; 12 ꢂ z; (iii) ꢂ x; 21 þ y; 25 ꢂ z;
1
1
1
1
2
3
2
2
2
2
(iv) ꢂx; 12 þ y; 32 ꢂ z.
3.2.2. Compound (I). The supramolecular structure of (I)
(Fig. 1) depends solely upon C—Hꢀ ꢀ ꢀO hydrogen bonds: there
are no significant Iꢀ ꢀ ꢀO contacts present in the structure and
C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds and aromatic ꢀꢀ ꢀ ꢀꢀ
stacking interactions are also absent.
Atom C7 in the molecule at (x; y; z) acts as a hydrogen-
bond donor to the nitro O52 atom in the molecule at
(ꢂ1 þ x; 1 þ y; z), thereby generating by translation a C(6)
ꢀ
chain (Bernstein et al., 1995) running parallel to the [110]
direction. This chain is modestly reinforced by a second C—
Hꢀ ꢀ ꢀO interaction in which, although the Hꢀ ꢀ ꢀO and Cꢀ ꢀ ꢀO
distances are both rather long (Table 3), the C—Hꢀ ꢀ ꢀO frag-
ment is nearly linear: the C4 atom at (x; y; z) acts as a donor to
the carbonyl O1 atom in the
Figure 4
A molecule of (II) showing the atom-labelling scheme. Displacement
ellipsoids are drawn at the 30% probability level.
molecule at (1 þ x; ꢂ1 þ y;z), thus
generating by translation a second
ꢀ
C(6) chain parallel to [110]. The
ꢀ
combination of the two [110] motifs
then generates a C(6)C(6)[R22ð10Þ]
chain of rings (Fig. 2). This can
alternatively be regarded as a
molecular ladder, in which the C(6)
chains form the uprights and the
phthalimido units provide the
rungs.
A second pair of C—Hꢀ ꢀ ꢀO
interactions, albeit having much
smaller C—Hꢀ ꢀ ꢀO angles than
those found in the first pair,
generates a second chain of rings,
this time running parallel to the
[010] direction. The phthalimide C6
atom in the molecule at (x; y; z)
acts as a hydrogen-bond donor to
the nitro O51 atom in the molecule
at (1 ꢂ x; 12 þ y; 32 ꢂ z), thus produ-
cing a C(5) chain generated by the
21 screw axis along (12, y, 43) (Fig. 3).
This is reinforced by a second,
Figure 5
Part of the crystal structure of (II) showing the formation of a (100) sheet of R44ð30Þ rings by a
combination of [010] and [001] chains. The atoms marked with an asterisk (*), a hash (#), a dollar sign ($)
1
1
or an ampersand (&) are at the symmetry positions (x; 1 þ y; z), (x; ꢂ1 þ y; z), (x; ꢂ ꢂ y; ꢂ þ z) and
2
2
1
(x; ꢂ ꢂ y; 12 þ z), respectively.
2
ꢁ
232 Christopher Glidewell et al.
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Acta Cryst. (2005). B61, 227–237

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longer C—Hꢀ ꢀ ꢀO interaction in which the phenyl C15 atom at
(x; y; z) acts as a donor to the carbonyl O2 atom in the
molecule at (x; 1 þ y; z), thus generating by translation a C(7)
chain. The combination of the two [010] motifs then generates
a C(5)C(7)[R33ð22Þ] chain of edge-fused rings. The combination
related to the first by inversion, is generated by the c-glide
plane at y = 0.25 and it lies in the domain 0.55 < x < 0.93.
Within each of these domains the chains are linked by the C—
Hꢀ ꢀ ꢀO hydrogen bond: the phenyl C16 atom in the molecule at
(x; y; z) acts as a hydrogen-bond donor to the carbonyl O2
atom in the molecule at (x; 1 þ y; z), so generating by trans-
lation a C(6) chain running parallel to the [010] direction. The
combination of the [010] and [001] chains generates a (100)
sheet in the form of a (4,4) net (Batten & Robson, 1998) built
from a single type of R44ð30Þ ring (Fig. 5). One sheet lies in each
ꢀ
of the [010] and [110] chains generates a (001) sheet built
solely from C—Hꢀ ꢀ ꢀO interactions, but there are no direction-
specific interactions between adjacent sheets.
3.2.3. Compound (II). The supramolecular structure of (II)
(Fig. 4) is two-dimensional and it arises from a combination of
two simple chain motifs generated respectively by a two-
centre iodoꢀ ꢀ ꢀnitro interaction (Table 4) and a single C—
Hꢀ ꢀ ꢀO hydrogen bond (Table 3): there are neither C—
Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds nor aromatic ꢀꢀ ꢀ ꢀꢀ stacking
interactions in the structure of (II).
The I13 atom in the molecule at (x; y; z) forms a short
contact with the nitro O51 atom in the molecule at
1
1
(x; ꢂ ꢂ y; ꢂ þ z), thus producing a C(11) chain (Starbuck
2
2
et al., 1999) running parallel to the [001] direction: this chain is
generated by the c-glide plane at y = ꢂ0.25 and it lies in the
domain 0.07 < x < 0.45 (Fig. 5). A second antiparallel chain,
Figure 6
A molecule of (III) showing the atom-labelling scheme. Displacement
ellipsoids are drawn at the 30% probability level.
Figure 8
Part of the crystal structure of (III) showing the formation of a hydrogen-
bonded chain along [101]. For the sake of clarity, the H atoms not
involved in the motifs shown have been omitted. The atoms marked with
an asterisk (*) or
a hash (#) are at the symmetry positions
(12 þ x; 32 ꢂ y; 12 þ z) and (1 þ x; y; 1 þ z), respectively.
Figure 7
Part of the crystal structure of (III) showing the formation of an Iꢀ ꢀ ꢀO
chain along [010]. For the sake of clarity, the H atoms have been omitted.
The atoms marked with an asterisk (*) or a hash (#) are at the symmetry
Figure 9
Stereoview of the crystal structure of (III) showing the formation of a
ꢀ
(4,4) net parallel to (101). For the sake of clarity, the H atoms not
involved in the motifs shown have been omitted.
1
positions (12 ꢂ x; ꢂ þ y; 12 ꢂ z) and (x; ꢂ1 þ y; z), respectively.
2
ꢁ
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Isomeric N-(iodophenyl)nitrophthalimides 233

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of the domains 0.07 < x < 0.45 and 0.55 < x < 0.93, but there are
no direction-specific interactions between adjacent sheets.
3.2.4. Compound (III). The supramolecular structure of
(III) (Fig. 6) is two-dimensional. There are two significant
direction-specific interactions between the molecules, an Iꢀ ꢀ ꢀO
interaction involving one of the carbonyl O atoms (although
iodoꢀ ꢀ ꢀnitro interactions are absent) and a rather long C—
Hꢀ ꢀ ꢀO hydrogen bond involving the second carbonyl O atom
as the acceptor. The nitro group thus plays no role whatsoever
in the supramolecular aggregation.
The I14 atom in the molecule at (x; y; z) forms an essen-
tially planar and only slightly asymmetric three-centre
Iꢀ ꢀ ꢀ(O)2 interaction with the two nitro O atoms of the mole-
cule at (32 ꢂ x; 21 þ y; 52 ꢂ z). Propagation of this interaction
The I12 atom in the molecule at (x; y; z) forms a short Iꢀ ꢀ ꢀO
contact with the carbonyl O1 atom in the molecule at
1
(12 ꢂ x; ꢂ þ y; 12 ꢂ z), so forming a C(6) chain (Starbuck et al.,
2
1999) running parallel to the [010] direction and generated by
the 21 screw axis along (14, y, 41) (Fig. 7). Two chains of this type
pass through each unit cell and adjacent chains are linked by a
single, rather weak C—Hꢀ ꢀ ꢀO hydrogen bond. The phthali-
mide C7 atom in the molecule at (x; y; z) acts as a hydrogen-
bond donor to the carbonyl O2 atom in the molecule at
(12 þ x; 32 ꢂ y; 12 þ z), so forming a C(6) chain running parallel
to the [101] direction and generated by the n-glide plane at y =
0.75 (Fig. 8). The combination of the [010] and [101] chains
ꢀ
generates a (101) sheet in the form of a (4,4) net (Batten &
Robson, 1998) built from a single type of R44ð26Þ ring (Fig. 9).
There are no direction-specific interactions between adjacent
sheets: in particular, both C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds
and aromatic ꢀꢀ ꢀ ꢀꢀ stacking interactions are absent from the
structure of (III).
3.2.5. Compound (IV). In (II) a combination of a two-centre
iodoꢀ ꢀ ꢀnitro interaction and a single C—Hꢀ ꢀ ꢀO hydrogen
bond links the molecules into sheets, but the supramolecular
structure of (IV) (Fig. 10), in contrast, is dominated by a
nearly symmetrical three-centre iodoꢀ ꢀ ꢀnitro interaction and
two nearly linear C—Hꢀ ꢀ ꢀO hydrogen bonds. The iodoꢀ ꢀ ꢀnitro
interaction generates chains, while the hydrogen bonds link all
of these chains into a single three-dimensional framework.
The formation of this framework is most readily considered in
terms of the effect of the three intermolecular interactions
taken in turn, and of their pairwise combinations.
Figure 11
Part of the crystal structure of (IV) showing the formation of an Iꢀ ꢀ ꢀO
chain along [010]. For the sake of clarity, the H atoms have been omitted.
The atoms marked with an asterisk (*) or a hash (#) are at the symmetry
positions (32 ꢂ x; 21 þ y; 25 ꢂ z) and (23 ꢂ x; ꢂ þ y; 52 ꢂ z), respectively.
1
2
Figure 12
Part of the crystal structure of (IV) showing the formation of a hydrogen-
bonded chain along [101]. For the sake of clarity, the H atoms not
involved in the motif shown have been omitted. The atoms marked with
Figure 10
A molecule of (IV) showing the atom-labelling scheme. Displacement
ellipsoids are drawn at the 30% probability level.
an asterisk (*) or a hash (#) are at the symmetry positions
3
1
(12 þ x; 21 ꢂ y; 21 þ z) and (ꢂ þ x; 12 ꢂ y; ꢂ þ z), respectively.
2
2
ꢁ
234 Christopher Glidewell et al.
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produces a C(11)[R12ð4Þ] chain of rings running parallel to the
[010] direction and generated by the 21 screw axis along (34, y, 45)
(Fig. 11). A second such chain, antiparallel to the first and
related to it by inversion, is generated by the 21 screw axis
Finally, the combination of the two hydrogen bonds
ꢀ
generates a second type of (101) sheet, this time in the form of
ꢀ
a (6,3) net, as opposed to the (4,4) net structure of the (101)
sheet which involves the iodoꢀ ꢀ ꢀnitro interaction. The refer-
ence C(9) chain is generated by the n-glide plane at y = 0.25
and the R22ð12Þ ring serves to link this chain to two antiparallel
chains, generated respectively by the n-glide planes at y =
ꢂ0.25 and y = 0.75.
3
along (14, ꢂy, ).
4
The phenyl C12 atom in the molecule at (x; y; z) acts as a
hydrogen-bond donor to the nitro O41 atom in the molecule at
(12 þ x; 12 ꢂ y; 21 þ z), while C12 at (21 ; þx; 21 ꢂ y; 21 þ z), in turn
acts as a donor to O41 at (1 þ x; y; 1 þ z). This hydrogen bond
thus produces a simple C(9) chain running parallel to the [101]
direction, which is generated by the n-glide plane at y = 0.25
(Fig. 12). The combination of the [101] chain generated by the
iodoꢀ ꢀ ꢀnitro interaction and the [101] chain of hydrogen bonds
Thus, each of the three intermolecular interactions alone
generates its characteristic sub-structure, one-dimensional or
finite (zero-dimensional) as the case may be; each of the
pairwise combinations generates a different two-dimensional
sub-structure; and the combination of all three interactions
generates a single three-dimensional framework which is, in
fact, reinforced by a weak C—Hꢀ ꢀ ꢀO interaction and a single
aromatic ꢀꢀ ꢀ ꢀꢀ stacking interaction. The C6 atom in the
molecule at (x; y; z) forms a weak hydrogen bond with O2 in
the molecule at (x; y; ꢂ1 þ z), so generating by translation a
C(7) chain running parallel to the [001] direction. In addition,
the phenyl rings of the molecules at (x; y; z) and
(2 ꢂ x; 1 ꢂ y; 2 ꢂ z) are parallel, with a centroid separation of
ꢀ
generates a (101) sheet in the form of a (4,4) net. Within the
3
ꢀ
(101) sheet the iodoꢀ ꢀ ꢀnitro chain along (4, y, 1.25) is directly
linked to the two chains along (14, ꢂy, ) and (1.25, ꢂy, 1.75).
3
4
In addition, the phenyl C16 atom in the molecule at (x; y; z)
acts as a hydrogen-bond donor to the carbonyl O1 atom in the
molecule at (1 ꢂ x; 1 ꢂ y; 1 ꢂ z), so generating a centrosym-
metric R22ð12Þ motif (Fig. 13): in a similar way, the C16 atom in
the molecule at (32 ꢂ x; 21 þ y; 52 ꢂ z) acts as a donor to O1 in the
molecule at (12 þ x; 23 ꢂ y; 32 þ z). The molecules at (x; y; z) and
(32 ꢂ x; 21 þ y; 25 ꢂ z) both lie in the iodoꢀ ꢀ ꢀnitro chain along (34,
y, 1.25), whereas the molecules at (1 ꢂ x; 1 ꢂ y; 1 ꢂ z) and
(12 þ x; 32 ꢂ y; 32 þ z) lie respectively in the iodoꢀ ꢀ ꢀnitro chains
˚
˚
3.738 (2) A; the interplanar spacing is 3.400 (2) A, corre-
˚
sponding to a centroid offset of 1.553 (2) A.
3.2.6. Compound (V). The three-dimensional structure of
(V) (Fig. 14) is determined by two C—Hꢀ ꢀ ꢀO hydrogen bonds,
one of them rather weak and a two-centre iodoꢀ ꢀ ꢀnitro
interaction. However, C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds and
aromatic ꢀꢀ ꢀ ꢀꢀ stacking interactions are both absent from the
structure. The construction of the three-dimensional frame-
work is most readily analysed and described in terms of the
three individual one-dimensional substructures generated by
each of the individual intermolecular interactions.
1
along (14, ꢂy, ꢂ ) and (1.25, ꢂy, 2.75). Hence, the combination
4
of the R22ð12Þ hydrogen-bond motif with the iodoꢀ ꢀ ꢀnitro
ꢀ
chains parallel to [010] generates a (301) sheet in the form of a
(6,3) net.
The I13 atom in the molecule at (x; y; z) makes a short
Iꢀ ꢀ ꢀO contact with the nitro O42 atom in the molecule at
(ꢂx; 12 þ y; 32 ꢂ z), so producing a C(10) chain running parallel
to the [010] direction which is generated by the 21 screw axis
along (0, y, 34). A second antiparallel chain is generated by the
1
screw axis along (12, ꢂy, ).
4
Figure 13
Part of the crystal structure of (IV) showing the formation of an R22(12)
hydrogen-bonded dimer. For the sake of clarity, the H atoms not involved
in the motif shown have been omitted. The atoms marked with an asterisk
(*) are at the symmetry position (1 ꢂ x; 1 ꢂ y; 1 ꢂ z).
Figure 14
A molecule of (V) showing the atom-labelling scheme. Displacement
ellipsoids are drawn at the 30% probability level.
ꢁ
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Christopher Glidewell et al.
Isomeric N-(iodophenyl)nitrophthalimides 235

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The set of C(10) chains which are generated by screw axes
having y = 34 and related by translation along [100] are linked
by the stronger of the two hydrogen bonds. The phenyl C16
atom in the molecule at (x; y; z) acts as a hydrogen-bond
donor to the carbonyl O2 atom in the molecule at (1 þ x; y; z),
so producing a C(6) chain parallel to [100]. The combination
of C(6) chains parallel to [100] and C(10) chains parallel to
[010] generates a (001) sheet, in the form of a (4,4) net built
from a single type of R44ð28Þ ring (Fig. 15). Two sheets of this
type pass through each unit cell, generated respectively by 21
However, iodoꢀ ꢀ ꢀnitro interactions are present only in the
structures of isomers (II), (IV) and (V), and only in (IV) is a
three-centre Iꢀ ꢀ ꢀ(O)2 interaction present. An iodoꢀ ꢀ ꢀcarbonyl
interaction occurs only in isomer (III), while there are no
Iꢀ ꢀ ꢀO interactions of any kind in isomer (I). Aromatic ꢀꢀ ꢀ ꢀꢀ
stacking interactions occur only in isomer (IV) and C—
Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds do not occur at all.
While none of the isomers (I)–(V) crystallizes either as an
isolated molecule or with a one-dimensional supramolecular
structure, the sheet structures of (I)–(III) all differ from one
another, as do the two framework structures in (IV) and (V).
Thus, not only do the number and identity of the types of
intermolecular interaction vary, but the structural conse-
quences of these interactions also show a wide range of
behaviour. As we have noted previously (Glidewell, Low,
Skakle, Wardell & Wardell, 2004), there is no correlation
between the number of different types of direction-specific
interaction manifest in a given structure and its overall
complexity, in particular its supramolecular dimensionality.
Finally, we may note that unlike the three isomeric series
(A), (B) and (D), all of the isomers (I)–(V) crystallize with
Z0 = 1.
3
1
axes along [010] having y = and , and the successive (001)
sheets are weakly linked by the second C—Hꢀ ꢀ ꢀO hydrogen
4
4
bond.
The phthalimide C6 atom in the molecule at (x; y; z) acts as
a hydrogen-bond donor to the carbonyl O2 atom in the
1
molecule at (12 ꢂ x; ꢂy; ꢂ þ z), so forming a C(7) chain
2
running parallel to the [001] direction which is generated by
the 21 screw axis along (14, 0, z) (Fig. 16). The two molecules at
1
(x; y; z) and (12 ꢂ x; ꢂy; ꢂ þ z) lie, respectively, in the (001)
2
3
1
sheets generated by screw axes at y = and y = , and
propagation of the C(7) chain motif links all the (001) sheets
into a continuous framework structure.
4
4
3.3. General discussion of the supramolecular structures
The supramolecular analyses described above (xx3.2.2–
3.2.6) for (I)–(V) show that as in the three series of isomeric
compounds of types (A), (B) and (D) (see x1), no two isomers
from (I)–(V) exhibit the same combination of direction-
specific intermolecular forces. C—Hꢀ ꢀ ꢀO hydrogen bonds are
present in all structures (I)–(V), but the numbers of such
hydrogen bonds vary from only one each in isomers (II) and
(III), through two in (V) and three in (IV), to a total of four
independent hydrogen bonds in isomer (I). Moreover, in
isomers (II), (II) and (V) the hydrogen-bond acceptors are all
carbonyl O atoms, whereas in isomers (I) and (IV) both
carbonyl O and nitro O atoms are involved (Table 3).
Figure 16
Part of the crystal structure of (V) showing the formation of the [001]
Figure 15
Stereoview of part of the crystal structure of (V) showing the formation
of a (001) sheet of R44ð28Þ rings by a combination of the C(6) and C(10)
chains along [100] and [010].
chain which links adjacent (001) sheets. The atoms marked with an
asterisk (*) or
a hash (#) are at the symmetry positions
1
(12 ꢂ x; ꢂy; ꢂ þ z) and (21 ꢂ x; ꢂy; 12 þ z), respectively.
2
ꢁ
236 Christopher Glidewell et al.
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4. Concluding comments
In previous studies of the extended series of isomeric
compounds, such as those of types (A), (B) and (D) (see
Scheme 1, x1), we have found in each such series that the
patterns of supramolecular aggregation are never the same in
any two isomers. Moreover, where a rather large variety of
direction-specific intermolecular interactions is potentially
available, as in series (A), even the types of individual inter-
actions present differ in every isomer studied. As with those
series, so too with the present isomer series (I)–(V), where no
two isomers use the same spectrum of intermolecular inter-
actions or give similar supramolecular structures. Weak forces
of the types manifest here, dependent upon molecular polar-
izability and polarization, are not easy to model computa-
tionally. Variations in the supramolecular aggregation
behaviour within an extended series of isomeric compounds,
such as those described here, provide a keen test of compu-
tational methods for crystal-structure prediction (Lommerse
et al., 2000; Motherwell et al., 2002): the accurate prediction of
behaviour across such a series of isomeric species would
generate real confidence in the efficacy of the predictive
methods employed.
Kelly, C. J., Skakle, J. M. S., Wardell, J. L., Wardell, S. M. S. V., Low,
J. N. & Glidewell, C. (2002). Acta Cryst. B58, 94–108.
Lommerse, J. P. M., Motherwell, W. D. S., Ammon, H. L., Dunitz, J. D.,
Gavezzotti, A., Hofmann, D. W. M., Leusen, F. J. J., Mooij, W. T. M.,
Price, S. L., Schweizer, B., Schmidt, M. U., van Eijck, B. P., Verwer,
P. & Williams, D. E. (2000). Acta Cryst. B56, 697–714.
Magomedova, N. S., Neigauz, M. G., Zavodnik, V. E. & Bel’skii, V. K.
(1981). Kristallographiya, 26, 841–844.
McArdle, P. (2003). OSCAIL for Windows, Version 10. Crystal-
lography Centre, Chemistry Department, NUI Galway, Ireland.
Motherwell, W. D. S., Ammon, H. L., Dunitz, J. D., Dzyabchenko, A.,
Erk, P., Gavezzotti, A., Hofmann, D. W. M., Leusen, F. J. J.,
Lommerse, J. P. M., Mooij, W. T. M., Price, S. L., Schweizer, B.,
Schmidt, M. U., van Eijck, B. P., Verwer, P. & Williams, D. E. (2002).
Acta Cryst. B58, 647–761.
X-ray data for (I), (IV) and (V) were collected at the
EPSRC X-ray Crystallographic Service, University of South-
ampton, England, using a Nonius Kappa-CCD diffractometer:
the authors thank the staff of the Service for all their help and
advice. Data for (II) and (III) were collected at the University
of Aberdeen using a Bruker SMART 1000CCD diffract-
ometer and the authors thank the University of Aberdeen for
funding the purchase of the diffractometer. JNL thanks NCR
Self-Service, Dundee, for grants which have provided
computing facilities for this work. JLW and SMSVW thank
CNPq and FAPERJ for financial support.
Nonius (1997). Kappa-CCD Server Software, Windows 3.11 Version.
Nonius BV, Delft, The Netherlands.
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Isomeric N-(iodophenyl)nitrophthalimides 237