Supramolecular structures of three isomeric (E,E)-1-(2-iodophenyl)-4- (nitrophenyl)-2,3-diaza-1,3-butadienes: Changes in intermolecular interactions consequent upon changes of substituent location

Article abstract of DOI:10.1107/S0108270105009248

The supramolecular structures of the three isomeric (E,E)-1-(2-iodophenyl)- 4-(2/3/4-nitrophenyl)-2,3-diaza-1,3-butadienes, C₁₄H ₁₀IN₃O₂, are compared. In the 2-nitro isomer, the molecules are disordered across centres of inversion in space group C2/c and are linked into chains by a two-centre iodo-nitro interaction. The molecules of the 3-nitro isomer are linked into a three-dimensional framework by a combination of C-H...O and C-H...I hydrogen bonds and aromatic π-π stacking interactions, while molecules of the 4-nitro isomer are linked into sheets by a C-H...O hydrogen bond and a two-centre iodo-nitro interaction.

Full text of DOI:10.1107/S0108270105009248

organic compounds
Acta Crystallographica Section C
Crystal Structure
2-nitrophenyl, 3-nitrophenyl, or 4-nitrophenyl substituents,
compounds (I)±(III), respectively (Figs. 1±3).
Communications
ISSN 0108-2701
Supramolecular structures of three
isomeric (E,E)-1-(2-iodophenyl)-
4-(nitrophenyl)-2,3-diaza-1,3-buta-
dienes: changes in intermolecular
interactions consequent upon changes
of substituent location
The crystallization characteristics of the three isomers (I)±
(III) are all different, with (I) crystallizing in C2/c with Z0 = 21,
and a value of Z0 = 1 for each of isomers (II) and (III), in space
groups P1 and C2/c, respectively. However, the intramolecular
geometries are all fairly similar. The central ±CH NÐ
Christopher Glidewell,a* John N. Low,b Janet M. S.
Skakleb and James L. Wardellc
aSchool of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland,
bDepartment of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen
N
CH± fragment is strictly planar in isomer (I) and
c
Â
Â
AB24 3UE, Scotland, and Instituto de Quõmica, Departamento de Quõmica
approximately so in isomers (II) and (III), and the substituents
at each of the C N bonds adopt E con®gurations. The
independent aryl rings are all twisted slightly away from this
plane, to the greatest extent in (I) and the least in (III), as
shown by the relevant torsion angles (Tables 1, 2 and 4). In
addition, the nitro groups are all rotated away from the planes
Ã
Inorganica, Universidade Federal do Rio de Janeiro, 21945-970 Rio de Janeiro,
RJ, Brazil
Correspondence e-mail: cg@st-andrews.ac.uk
Received 22 March 2005
Accepted 23 March 2005
Online 23 April 2005
The supramolecular structures of the three isomeric (E,E)-1-
(2-iodophenyl)-4-(2/3/4-nitrophenyl)-2,3-diaza-1,3-butadienes,
C14H10IN3O2, are compared. In the 2-nitro isomer, the mol-
ecules are disordered across centres of inversion in space
group C2/c and are linked into chains by a two-centre iodo±
nitro interaction. The molecules of the 3-nitro isomer are
linked into a three-dimensional framework by a combination
of CÐHÁ Á ÁO and CÐHÁ Á ÁI hydrogen bonds and aromatic ꢀ±ꢀ
stacking interactions, while molecules of the 4-nitro isomer are
linked into sheets by a CÐHÁ Á ÁO hydrogen bond and a two-
centre iodo±nitro interaction.
Figure 1
The molecule of compound (I), showing the atom-labelling scheme.
Displacement ellipsoids are drawn at the 30% probability level. For the
sake of clarity, only one orientation of the molecule is shown. Atoms
marked A are at the symmetry position (1 x, 1 y, 1 z).
Comment
In the course of our continuing investigation of the interplay
between hard and soft (Braga et al., 1995; Desiraju & Steiner,
1999) hydrogen bonds, aromatic ꢀ±ꢀ stacking interactions and
iodo±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 (Kelly et al., 2002),
benzylideneanilines (Glidewell, Howie et al., 2002; Wardell et
al., 2002), benzylanilines (Glidewell, Low et al., 2002; Glide-
well, Low, Skakle, Wardell & Wardell, 2004) benzenesul-
fanylanilines (Glidewell et al., 2003a) and phenylhydrazones
(Glidewell et al., 2003b; Glidewell, Low, Skakle & Wardell,
2004). We have now extended this study to the isomeric
(E,E)-1-(2-iodophenyl)-4-(2/3/4-nitrophenyl)-2,3-diaza-1,3-
butadienes, and report here on the molecular and supra-
molecular structures of three such isomers, containing the
Figure 2
The molecule of compound (II), showing the atom-labelling scheme.
Displacement ellipsoids are drawn at the 30% probability level.
o312 # 2005 International Union of Crystallography
DOI: 10.1107/S0108270105009248
Acta Cryst. (2005). C61, o312±o316

organic compounds
i
i
ꢀ
Ê
of the adjacent aryl rings, to the greatest extent in (I) and the
least in (II). Corresponding bond lengths and angles are all
very similar for the three isomers and there are no unusual
values. In isomer (I), the population of the iodo site was found
to exceed that of the nitro sites, with occupancy factors of
0.559 (3) and 0.441 (3), respectively. We conclude that some
reorganization of substituted aryl groups has occurred, either
during the synthesis of (I) or during its crystallization, such
that a small proportion of (E,E)-1,4-bis(2-iodophenyl)-2,3-
diaza-1,3-butadiene has co-crystallized with (I).
IÁ Á ÁO = 3.312 (8) A and CÐIÁ Á ÁO = 167.1 (2) [symmetry
3
2
code: (i) 1 x, y,
z]. It is convenient to consider ®rst the
possible consequences of these interactions in pure (I), and
then to consider the effects of the co-crystallized diiodo
compound. If adjacent molecules of (I) along [001] are
consistently aligned in a head-to-tail fashion, then the iodo±
nitro interaction generates a C(11) chain (Starbuck et al.,
1999) along [001]. If, however, adjacent molecules are aligned
in a head-to-head fashion, the IÁ Á ÁI contact can only link the
molecules together in pairs.
The molecules of compound (I) (Fig. 1) lie across inversion
centres in space group C2/c, with the iodo and nitro substi-
tuents disordered; the reference molecule was selected as that
lying across (12, 21, 12). The paucity of direction-speci®c inter-
molecular interactions in (I) is striking: there are no inter-
molecular hydrogen bonds of any kind and no aromatic ꢀ±ꢀ
stacking interactions are present. However, atom I2 at (x, y, z)
can make two possible contacts, with either another I2 or with
nitro atom O21, both at (1 x, y, 32 z), i.e. both components
of the molecule of (I) centred across (12, 21, 1), and with
The angular properties of this CÐIÁ Á ÁI interaction are
admirably consistent with generalizations proposed (Rama-
subbu et al., 1986) from the results of database analysis,
namely that in structures where XÁ Á ÁX distances (X =
halogen) are signi®cantly less than the van der Waals sum, the
observed CÐXÁ Á ÁX angles are clustered either around 180ꢀ or
around 90ꢀ. These authors also note that, in such interactions,
i
i
ꢀ
Ê
dimensions IÁ Á ÁI = 3.247 (2) A and CÐIÁ Á ÁI = 163.3 (2) , and
Figure 3
The molecule of compound (III), showing the atom-labelling scheme.
Displacement ellipsoids are drawn at the 30% probability level.
Figure 5
Stereoview of part of the crystal structure of compound (II), showing the
formation of a ꢀ-stacked chain of hydrogen-bonded dimers along [110].
For the sake of clarity, H atoms not involved in the hydrogen bonds
shown have been omitted.
Figure 4
Figure 6
Stereoview of part of the crystal structure of compound (II), showing the
formation of a hydrogen-bonded chain of edge-fused rings along [101].
For the sake of clarity, H atoms not involved in the hydrogen bonds
shown have been omitted.
Stereoview of part of the crystal structure of compound (II), showing the
formation of a ꢀ-stacked chain of hydrogen-bonded dimers along [010].
For the sake of clarity, H atoms not involved in the hydrogen bonds
shown have been omitted.
ꢁ
Acta Cryst. (2005). C61, o312±o316
Glidewell et al.
Three isomers of C14H10IN3O2 o313

organic compounds
Ê
XÁ Á ÁX distances are commonly observed ca 0.5 A below the
themselves linked by a further hydrogen bond, of the CÐ
HÁ Á ÁO type: the aryl atom C25 in the molecule at (x, y, z) acts
as donor to nitro atom O32 in the molecule at (1 + x, y, 1 + z),
so forming a C(13) chain running parallel to the [101] direc-
tion. Propagation of this hydrogen bond by translation and
inversion then links the dimers into a [101] ribbon, in the form
of a chain of edge-fused rings, with R44(22) rings centred at
(n, 12, n) (n = zero or integer), alternating with R22(10) rings
centred at (12 + n, 21, 21 + n) (n = zero or integer), with the R12(9)
rings on the two edges of the ribbon (Fig. 4).
Ê
conventional van der Waals sum of 3.90 A for IÁ Á ÁI (Bondi,
1964). The short IÁ Á ÁI contact distance here is well below the
van der Waals sum, even allowing for the polar ¯attening
effect (Nyburg & Faerman, 1985), and may point to an
avoidance of such IÁ Á ÁI contacts wherever possible. Such
avoidance is readily achieved by the head-to-tail alignment of
the molecules of (I) within an [001] chain, so that disorder of
the molecules is correlated in one direction. This neither
implies nor requires any correlation between adjacent [001]
chains. Such short contacts can be avoided, even when a
molecule of the diiodo analogue is present; such a molecule
can readily form two iodo±nitro interactions, one at each I
atom. Each such diiodo molecule would, in these circum-
stances, simply effect a reversal in the polarity of a chain
formed by molecules of (I). Overall, therefore, we conclude
that molecules of (I) are linked into [001] chains by a two-
centre iodo±nitro interaction, with no short IÁ Á ÁI contacts.
The molecules of compound (II) (Fig. 2) are linked into a
three-dimensional framework by a combination of CÐHÁ Á ÁO
and CÐHÁ Á ÁI hydrogen bonds and two independent aromatic
ꢀ±ꢀ stacking interactions. The hydrogen bonds together
generate a one-dimensional substructure, and each of the
stacking interactions in combination with the CÐHÁ Á ÁI
hydrogen bonds independently generates a further one-
dimensional substructure. Accordingly, the formation of the
framework is most readily analysed and discussed in terms of
these three simple substructures.
The dimers generated by the CÐHÁ Á ÁI hydrogen bonds in
(II) are also linked by two independent ꢀ±ꢀ stacking inter-
actions to form two further one-dimensional substructures.
The ®rst of these involves the centrosymmetric pair of mol-
ecules at (x, y, z) and ( x, y, 1 z), which are components
,
1
2
of the dimers centred at (12, 21, 21) and (
The nitrated ring at (x, y, z) and the iodinated ring at ( x, y,
12, 12), respectively.
1
planes of only 2.3 (2) . The interplanar spacing is ca 3.47 A
z) are nearly paraꢀllel, with a dihedral angle between their
Ê
Ê
and the ring-centroid separation is 3.767 (2) A, corresponding
Ê
to a near-ideal centroid offset of ca 1.47 A. Propagation of this
interaction by inversion then links the hydrogen-bonded
dimers into a ꢀ-stacked chain running parallel to the [110]
direction (Fig. 5).
The second stacking interaction involves the centrosym-
metric pair of molecules at (x, y, z) and (1 x, y, 1 z),
Aryl atom C12 and methine atom C27 in the molecule at
(x, y, z) both act as hydrogen-bond donors to iodine I22 in
the molecule at (1 x, 1 y, 1 z), thereby generating a
centrosymmetric dimer characterized by an array of three
edge-fused [R12(9)][R22(10)][R12(9)] rings (Bernstein et al.,
1995), centred at (12, 21, 21) (Fig. 4). These complex dimers are
Figure 8
Part of the crystal structure of compound (III), showing the formation of
an iodo±nitro chain along [101]. For the sake of clarity, H atoms have
been omitted. Atoms marked with an asterisk (*) or a hash (#) are at
3
2
1
2
3
the symmetry positions (12 + x,
y, 12 + z) and (x
,
2
y, z 12),
respectively.
Figure 7
Part of the crystal structure of compound (III), showing the formation of
a hydrogen-bonded chain along [010]. For the sake of clarity, H atoms not
involved in the motif shown have been omitted. Atoms marked with an
asterisk (*) or a hash (#) are at the symmetry positions (x, y 1, z) and
(x, 1 + y, z), respectively.
Figure 9
Stereoview of part of the crystal structure of compound (III), showing the
formation of a (101) sheet. For the sake of clarity, H atoms not involved in
the motifs shown have been omitted.
ꢁ
o314 Glidewell et al.
Three isomers of C14H10IN3O2
Acta Cryst. (2005). C61, o312±o316

organic compounds
components of hydrogen-bonded dimers centred at (12, 21, 21) and
(12, 12, 12). Again, the adjacent ring planes make a dihedral
Ê
angle of 2.3 (2) , but now the interplanar spacing is ca 3.42 A,
Ê
with a ring-centroid separation of 3.725 (2) A, giving a ring-
Ê
centroid offset of ca 1.48 A. Propagation of this interaction
then generates a chain of dimers along [010] (Fig. 6). The
combination of the independent chains along [101], [110] and
[010] is suf®cient to link all of the molecules of (II) into a
single three-dimensional framework. It is notable, however,
that iodo±nitro interactions are absent from the structure of
(II).
Data collection
Nonius KappaCCD area-detector
diffractometer
' and ! scans
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
Tmin = 0.815, Tmax = 0.901
6403 measured re¯ections
1482 independent re¯ections
1156 re¯ections with I > 2ꢅ(I)
Rint = 0.066
ꢃmax = 27.4ꢀ
ꢀ
h = 19 ! 19
k = 4 ! 4
l = 30 ! 30
Re®nement
Re®nement on F2
R[F2 > 2ꢅ(F2)] = 0.046
wR(F2) = 0.100
w = 1/[ꢅ2(Fo2) + (0.0232P)2
+ 8.8667P]
2
where P = (Fo + 2Fc2)/3
S = 1.07
1482 re¯ections
104 parameters
H-atom parameters constrained
(Á/ꢅ)max = 0.001
The molecules of compound (III) (Fig. 3) are linked into
sheets by a combination of a rather weak CÐHÁ Á ÁO hydrogen
bond and a two-centre iodo±nitro interaction, and again it is
convenient to consider the effect of each of these interactions
in turn. Aryl atom C12 in the molecule at (x, y, z) acts as
hydrogen-bond donor to nitro atom O42 in the molecule at (x,
3
Ê
Áꢆmax = 0.91 e A
3
Ê
0.82 e A
Áꢆmin
=
Table 1
Selected torsion angles (ꢀ) for (I).
y
1, z), so generating by translation a C(6) chain running
parallel to the [010] direction (Fig. 7); eight chains of this type
pass through each unit cell. In addition, atom I22 in the
molecule at (x, y, z) forms a nearly linear two-centre IÁ Á ÁO
interaction with nitro atom O41 in the molecule at (12 + x,
N1iÐN1ÐC7ÐC1
N1ÐC7ÐC1ÐC2
179.5 (5)
165.9 (4)
C1ÐC2ÐN2ÐO21
154.3 (7)
Symmetry code: (i) 1 x; 1 y; 1 z.
i
i
3
1
Ê
y, 2 + z), with dimensions IÁ Á ÁO = 3.362 (2) A, CÐIÁ Á ÁO =
2
171.62 (6)ꢀ and IÁ Á ÁOiÐNi = 113.6 (2)ꢀ [symmetry code: (i)
Compound (II)
12 + x,
chain is formed running parallel to the [101] direction and
y, + z]. In this way, a C(13) (Starbuck et al., 1999)
2
3
1
2
Crystal data
3
4
generated by the n-glide plane at y = (Fig. 8). The combi-
C14H10IN3O2
Mr = 379.15
Triclinic, P1
a = 7.2969 (3) A
Ê
b = 7.3235 (3) A
Mo Kꢂ radiation
Cell parameters from 3120
re¯ections
nation of the [010] and [101] chains generates a (101) sheet in
the form of a (4,4)-net built from a single type of R44(32) ring
(Fig. 9). Four sheets of this type pass through each unit cell,
but there are no direction-speci®c interactions between adja-
cent sheets. In particular, CÐHÁ Á Áꢀ(arene) hydrogen bonds
and aromatic ꢀ±ꢀ stacking interactions are absent from the
structure of (III).
ꢃ = 3.0±27.6ꢀ
ꢄ = 2.37 mm
T = 120 (2) K
Ê
1
Ê
c = 13.7939 (6) A
ꢂ = 97.405 (2)ꢀ
ꢁ = 100.410 (2)ꢀ
ꢇ = 107.590 (3)ꢀ
Plate, yellow
0.20 Â 0.12 Â 0.05 mm
3
Ê
V = 677.73 (5) A
Z = 2
Dx = 1.858 Mg m
3
Experimental
Data collection
An equimolar mixture of 2-iodobenzaldehyde and the appropriate
nitrobenzaldehyde hydrazone (3 mmol of each) in methanol (20 ml)
was heated under re¯ux for 30 min, cooled and then left at room
temperature. The precipitate from each reaction was collected after
24 h and recrystallized from 1,2-dichloroethane. While pure samples
of compounds (II) (m.p. 458±460 K) and (III) (m.p. 490±491 K) were
obtained in this way from 3- and 4-nitrobenzaldehyde hydrazone,
respectively, the X-ray analysis showed that the product (m.p. 471±
473 K) obtained using 2-nitrobenzaldehyde hydrazone was, in fact,
compound (I) co-crystallized with some (E,E)-1,4-bis(2-iodophenyl)-
2,3-diaza-1,3-butadiene, despite the sharp melting point.
Nonius KappaCCD area-detector
diffractometer
' and ! scans
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
Tmin = 0.649, Tmax = 0.891
13 382 measured re¯ections
3120 independent re¯ections
2909 re¯ections with I > 2ꢅ(I)
Rint = 0.029
ꢃmax = 27.6ꢀ
h = 9 ! 9
k = 9 ! 9
l = 17 ! 17
Re®nement
Re®nement on F2
R[F2 > 2ꢅ(F2)] = 0.023
wR(F2) = 0.085
w = 1/[ꢅ2(Fo2) + (0.0469P)2
+ 0.3339P]
2
where P = (Fo + 2Fc2)/3
S = 1.28
3120 re¯ections
181 parameters
H-atom parameters constrained
(Á/ꢅ)max = 0.001
3
Compound (I)
Ê
Áꢆmax = 1.06 e A
3
Ê
1.04 e A
Áꢆmin
=
Crystal data
3
C14H10I1.12N2.88O1.76
Mr = 388.69
Dx = 1.925 Mg m
Mo Kꢂ radiation
Cell parameters from 1482
re¯ections
Monoclinic, C2=c
Table 2
Ê
a = 15.3033 (8) A
Selected torsion angles (ꢀ) for (II).
b = 3.7952 (3) A
ꢃ = 3.0±27.4ꢀ
ꢄ = 2.66 mm
T = 120 (2) K
Ê
1
Ê
c = 23.3097 (16) A
C17ÐN17ÐN27ÐC27
N27ÐN17ÐC17ÐC11
N17ÐN27ÐC27ÐC21
177.5 (3)
179.4 (3)
180.0 (3)
N17ÐC17ÐC11ÐC12
N27ÐC27ÐC21ÐC22
C12ÐC13ÐN13ÐO31
8.9 (4)
171.0 (3)
5.3 (4)
ꢁ = 97.836 (4)ꢀ
V = 1341.16 (16) A
Z = 4
3
Ê
Block, colourless
0.08 Â 0.06 Â 0.04 mm
ꢁ
Acta Cryst. (2005). C61, o312±o316
Glidewell et al.
Three isomers of C14H10IN3O2 o315

organic compounds
Ê
Ê
Table 3
Hydrogen-bond geometry (A, ) for (II).
atoms, with CÐH distances of 0.95 A at 120 K and 0.93 A at 293 K,
and with Uiso(H) = 1.2Ueq(C).
ꢀ
Ê
Data collection: COLLECT (Nonius, 1998) for (I) and (II);
SMART (Bruker, 1998) for (III). Cell re®nement: DENZO (Otwin-
owski & Minor, 1997) and COLLECT for (I) and (II); SAINT
(Bruker, 2000) for (III). Data reduction: DENZO and COLLECT for
(I) and (II); SAINT (Bruker, 2000) for (III). For all three compounds,
structure solution: OSCAIL (McArdle, 2003) and SHELXS97
(Sheldrick, 1997); structure re®nement: OSCAIL and SHELXL97
(Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003);
publication software: SHELXL97 and PRPKAPPA (Ferguson,
1999).
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
C12ÐH12Á Á ÁI22i
C25ÐH25Á Á ÁO32ii
C27ÐH27Á Á ÁI22i
0.95
0.95
0.95
3.04
2.50
3.06
3.972 (3)
3.436 (4)
3.923 (3)
168
167
153
Symmetry codes: (i) 1 x; 1 y; 1 z; (ii) x ‡ 1; y; z ‡ 1.
Compound (III)
Crystal data
3
C14H10IN3O2
Mr = 379.15
Monoclinic, C2=c
a = 27.9470 (11) A
Dx = 1.833 Mg m
Mo Kꢂ radiation
Cell parameters from 4956
re¯ections
ꢃ = 2.7±32.5ꢀ
ꢄ = 2.34 mm
T = 293 (2) K
Plate, yellow
0.37 Â 0.25 Â 0.06 mm
X-ray data for (I) and (II) were collected at the EPSRC
X-ray Crystallographic Service, University of Southampton,
England; the authors thank the staff for all their help and
advice. X-ray data for (III) were collected at the University of
Aberdeen; the authors thank the University of Aberdeen for
funding the purchase of this instrument. JLW thanks CNPq
and FAPERJ for ®nancial support.
Ê
Ê
b = 8.0563 (3) A
1
Ê
c = 13.7464 (5) A
ꢁ = 117.4250 (10)ꢀ
3
Ê
V = 2747.16 (18) A
Z = 8
Data collection
Bruker SMART 1000 CCD area-
detector diffractometer
' and ! scans
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
Tmin = 0.479, Tmax = 0.873
15 927 measured re¯ections
4956 independent re¯ections
3759 re¯ections with I > 2ꢅ(I)
Rint = 0.024
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: SK1830). Services for accessing these data are
described at the back of the journal.
ꢃmax = 32.5ꢀ
h = 42 ! 40
k = 12 ! 12
References
l = 20 ! 17
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem.
Int. Ed. Engl. 34, 1555±1573.
Bondi, A. (1964). J. Phys. Chem. 68, 441±451.
Braga, D., Grepioni, F., Biradha, K., Pedireddi, V. R. & Desiraju, G. R. (1995).
J. Am. Chem. Soc. 117, 3156±3166.
Bruker (1998). SMART. Version 5.0. Bruker AXS Inc., Madison, Wisconsin,
USA.
Bruker (2000). SADABS (Version 2.03) and SAINT (Version 6.02a). Bruker
AXS Inc., Madison, Wisconsin, USA.
Desiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond. Oxford
University Press.
Ferguson, G. (1999). PRPKAPPA. University of Guelph, Canada.
Glidewell, C., Howie, R. A., Low, J. N., Skakle, J. M. S., Wardell, S. M. S. V. &
Wardell, J. L. (2002). Acta Cryst. B58, 864±876.
Glidewell, C., Low, J. N., Skakle, J. M. S. & Wardell, J. L. (2003a). Acta Cryst.
C59, o95±o97.
Glidewell, C., Low, J. N., Skakle, J. M. S. & Wardell, J. L. (2003b). Acta Cryst.
C59, o98±o101.
Re®nement
Re®nement on F2
R[F2 > 2ꢅ(F2)] = 0.030
wR(F2) = 0.079
S = 1.03
4956 re¯ections
w = 1/[ꢅ2(Fo2) + (0.0396P)2
+ 0.5558P]
where P = (Fo2 + 2Fc2)/3
(Á/ꢅ)max = 0.004
3
Ê
Áꢆmax = 0.82 e A
3
Ê
0.77 e A
181 parameters
H-atom parameters constrained
Áꢆmin
=
Table 4
Selected torsion angles (ꢀ) for (III).
C17ÐN17ÐN27ÐC27
N27ÐN17ÐC17ÐC11
N17ÐN27ÐC27ÐC21
172.5 (2)
178.31 (19)
178.14 (18)
N17ÐC17ÐC11ÐC12
N27ÐC27ÐC21ÐC22
C13ÐC14ÐN14ÐO41
175.3 (2)
173.5 (2)
6.9 (3)
Glidewell, C., Low, J. N., Skakle, J. M. S. & Wardell, J. L. (2004). Acta Cryst.
C60, o19±o23.
Glidewell, C., Low, J. N., Skakle, J. M. S., Wardell, S. M. S. V. & Wardell, J. L.
(2002). Acta Cryst. C58, o487±o490.
Table 5
Hydrogen-bond geometry (A, ) for (III).
ꢀ
Ê
Glidewell, C., Low, J. N., Skakle, J. M. S., Wardell, S. M. S. V. & Wardell, J. L.
(2004). Acta Cryst. B60, 472±480.
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
C12ÐH12Á Á ÁO42i
Symmetry code: (i) x; y 1; z.
0.93
2.58
3.430 (2)
153
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.
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Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of
For each of (I) and (III), the systematic absences permitted C2/c
and Cc as possible space groups. For each isomer, space group C2/c
was selected and con®rmed by the subsequent analysis. Crystals of
isomer (II) are triclinic. Space group P1 was selected and con®rmed
by the subsequent analysis. It became apparent at an early stage in
the re®nement of (I) that the occupancies of the iodo and nitro
substituents were not identical, as had been expected. The re®ned
occupancy factors were 0.559 (3) for the iodo substituent and
0.441 (3) for the nitro group; when (I) was re®ned with these occu-
pancies ®xed at 12, the R factors rose to R = 0.050 and wR2 = 0.133, with
unacceptable displacement parameters for the nitro N atom. All H
atoms were located from difference maps and then treated as riding
È
Gottingen, Germany.
Sheldrick, G. M. (2003). SADABS. Version 2.10. University of Gottingen,
È
Germany.
Spek, A. L. (2003). J. Appl. Cryst. 36, 7±13.
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(2002). Acta Cryst. C58, o428±o430.
ꢁ
o316 Glidewell et al.
Three isomers of C14H10IN3O2
Acta Cryst. (2005). C61, o312±o316