Hydrogen-bonded structures of the isomeric compounds of phthalazine with 3-chloro-2-nitro-benzoic acid, 4-chloro-2-nitro-benzoic acid and 4-chloro-3-nitro-benzoic acid

Article abstract of DOI:10.1107/S0108270111044829

The structures of three isomeric compounds, C₇H ₄ClNO₄·C₈H₆N₂, of phthalazine with chloro-and nitro-substituted benzoic acid, namely, 3-chloro-2-nitro-benzoic acid-phthalazine (1/1), (I), 4-chloro-2-nitro-benzoic acid-phthalazine (1/1), (II), and 4-chloro-3-nitro-benzoic acid-phthalazine (1/1), (III), have been determined at 190 K. In the asymmetric unit of each compound, there are two crystallographically independent chloro-nitro-benzoic acid-phthalazine units, in each of which the two components are held together by a short hydrogen bond between an N atom of the base and a carboxyl O atom. In one hydrogen-bonded unit of (I) and in two units of (II), a weak C-H...O inter-action is also observed between the two components. The N...O distances are 2.5715 (15) and 2.5397 (17) A for (I), 2.5655 (13) and 2.6081 (13) A for (II), and 2.613 (2) and 2.589 (2) A for (III). In both hydrogen-bonded units of (I) and (II), the H atoms are each disordered over two positions with (N site):(O site) occupancies of 0.35 (3):0.65 (3) and 0.31 (3):0.69 (3) for (I), and 0.32 (3):0.68 (3) and 0.30 (3):0.70 (3) for (II). The H atoms in the hydrogen-bonded units of (III) are located at the O-atom sites.

Full text of DOI:10.1107/S0108270111044829

organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
substituted benzoic acid–pyridine derivative system, we have
shown that the three isomeric compounds 3-chloro-2-nitro-
benzoic acid–quinoline (1/1), (IV), 4-chloro-2-nitrobenzoic
acid–quinoline (1/1), (V), and 5-chloro-2-nitrobenzoic acid–
quinoline (1/1), (VI), are in a critical region and have a short
double-well Nꢀ ꢀ ꢀHꢀ ꢀ ꢀO hydrogen bond between the pyridine
N atom and the carboxyl group (Gotoh & Ishida, 2009). The
(N site):(O site) occupancies of the H atom are 0.39 (3):
0.61 (3), 0.47 (3):0.53 (3) and 0.65 (3):0.35 (3) for (IV), (V)
and (VI), respectively, and the ÁpKa values are 3.08, 2.93 and
3.04, respectively.
ISSN 0108-2701
Hydrogen-bonded structures of the
isomeric compounds of phthalazine
with 3-chloro-2-nitrobenzoic acid,
4-chloro-2-nitrobenzoic acid and
4-chloro-3-nitrobenzoic acid
Kazuma Gotoh and Hiroyuki Ishida*
Department of Chemistry, Faculty of Science, Okayama University, Okayama
700-8530, Japan
Correspondence e-mail: ishidah@cc.okayama-u.ac.jp
Received 28 September 2011
Accepted 26 October 2011
Online 31 October 2011
The structures of three isomeric compounds, C7H4ClNO4ꢀ-
C8H6N2, of phthalazine with chloro- and nitro-substituted
benzoic acid, namely, 3-chloro-2-nitrobenzoic acid–phthala-
zine (1/1), (I), 4-chloro-2-nitrobenzoic acid–phthalazine (1/1),
(II), and 4-chloro-3-nitrobenzoic acid–phthalazine (1/1), (III),
have been determined at 190 K. In the asymmetric unit of
each compound, there are two crystallographically indepen-
dent chloronitrobenzoic acid–phthalazine units, in each of
which the two components are held together by a short
hydrogen bond between an N atom of the base and a carboxyl
O atom. In one hydrogen-bonded unit of (I) and in two units
of (II), a weak C—Hꢀ ꢀ ꢀO interaction is also observed between
the two components. The Nꢀ ꢀ ꢀO distances are 2.5715 (15) and
In this communication, we report the three isomeric
compounds 3-chloro-2-nitrobenzoic acid–phthalazine (1/1),
(I), 4-chloro-2-nitrobenzoic acid–phthalazine (1/1), (II), and
4-chloro-3-nitrobenzoic acid–phthalazine (1/1), (III), in order
to extend our studies of the critical region and hydrogen
bonding in the chloro- and nitro-substituted benzoic acid–
pyridine derivative system (Gotoh & Ishida, 2007, 2009).
Phthalazine is a weaker base (pKa = 3.47) than quinoline
(pKa = 4.90), and the ÁpKa values are 1.65, 1.50 and 0.12 for
(I), (II) and (III), respectively.
˚
˚
2.5397 (17) A for (I), 2.5655 (13) and 2.6081 (13) A for (II),
˚
and 2.613 (2) and 2.589 (2) A for (III). In both hydrogen-
bonded units of (I) and (II), the H atoms are each disordered
over two positions with (N site):(O site) occupancies of
0.35 (3):0.65 (3) and 0.31 (3):0.69 (3) for (I), and 0.32 (3):
0.68 (3) and 0.30 (3):0.70 (3) for (II). The H atoms in the
hydrogen-bonded units of (III) are located at the O-atom sites.
Comment
The hydrogen bonds formed between organic acids and
organic bases vary from an O—Hꢀ ꢀ ꢀN to an Oꢀ ꢀ ꢀH—N type
with increasing pKa or proton affinities (PA) of the bases, and
at an appropriate ÁpKa [pKa(base) ꢁ pKa(acid)] the critical
(inversion) point at which 50% proton transfer occurs, in the
region of which a short strong hydrogen bond with a broad
single minimum potential-energy curve for the H atom or a
double-minimum potential is expected (Jerzykiewicz et al.,
1998; Kalenik et al., 1989; Steiner et al., 2001; Schmidtmann &
Wilson, 2008; Gilli & Gilli, 2009). For the chloro- and nitro-
Figure 1
The asymmetric unit of (I), showing the atom-numbering scheme.
Displacement ellipsoids are drawn at the 50% probability level. The
disordered O—Hꢀ ꢀ ꢀN/N—Hꢀ ꢀ ꢀO hydrogen bonds are indicated by
dashed lines.
Acta Cryst. (2011). C67, o473–o478
doi:10.1107/S0108270111044829
# 2011 International Union of Crystallography o473

organic compounds
The molecular structures of compounds (I), (II) and (III)
are shown in Figs. 1, 2 and 3, respectively. The asymmetric unit
of each compound consists of two crystallographically inde-
pendent chloronitrobenzoic acid–phthalazine units, where the
two components are held together by a short hydrogen bond
between one N atom of the base and the carboxyl group of the
acid. The Nꢀ ꢀ ꢀO distances are given in Tables 1–3. In the
hydrogen bonds of (I) and (II), the H atoms were found to be
disordered from difference Fourier maps (see supplementary
figure), each of which shows two distinct peaks. The site
occupancies refined to 0.35 (3):0.65 (3) (N2:O1) and 0.31 (3):
0.69 (3) (N5:O5) for (I), and 0.32 (3):0.68 (3) (N2:O1) and
0.30 (3):0.70 (3) (N5:O5) for (II). On the other hand, no
disordered H atom was observed in (III), even though one of
˚
the Oꢀ ꢀ ꢀN distances [2.589 (2) A] is shorter than the O5ꢀ ꢀ ꢀN5
˚
distance [2.6081 (13) A] in (I) and H atoms in the hydrogen
Figure 2
bonds are located at an O-atom site (Table 3). In addition, a
weak C—Hꢀ ꢀ ꢀO interaction is observed in one hydrogen-
bonded unit of (I) (C15—H15ꢀ ꢀ ꢀO2; Table 1) and in each unit of
(II) (C15—H15ꢀ ꢀ ꢀO2 and C30—H30ꢀ ꢀ ꢀO6; Table 2).
The asymmetric unit of (II), showing the atom-numbering scheme.
Displacement ellipsoids are drawn at the 50% probability level. The
disordered O—Hꢀ ꢀ ꢀN/N—Hꢀ ꢀ ꢀO hydrogen bonds are indicated by
dashed lines.
In the hydrogen-bonded units of (I) and (II), the benzene
(C1–C6 or C16–C21) ring, the carboxyl (O1/C7/O2 or O5/C22/
O6) plane and the phthalazine (N2/N3/C8–C15 or N5/N6/
C23–C30) ring system are twisted slightly relative to each
other. The dihedral angles between the C1–C6 and O1/C7/O2
planes, the C16–C21 and O5/C22/O6 planes, the O1/C7/O2
and N2/N3/C8–C15 planes, the O5/C22/O6 and N5/N6/C23–
C30 planes, the C1–C6 and N2/N3/C8–C15 planes, and the
C16–C21 and N5/N6/C23–C30 planes are 11.41 (14), 2.93 (15),
2.99 (14), 11.93 (15), 8.59 (5) and 9.02 (5)ꢂ, respectively, in (I),
and 2.75 (17), 18.76 (17), 14.24 (16), 22.03 (16), 16.84 (5) and
9.56 (5)ꢂ, respectively, in (II). By contrast, in (III), these three
planes are approximately coplanar with each other; the
corresponding dihedral angles are 2.2 (2), 2.1 (3), 1.3 (2),
1.5 (3), 1.03 (8) and 0.66 (8)ꢂ, respectively. The planarity in
both units of (III) may lead to a packing scheme accompanied
by ꢀ–ꢀ stacking interactions in the crystal structure, as
mentioned below.
Figure 3
The asymmetric unit of (III), showing the atom-numbering scheme.
Displacement ellipsoids are drawn at the 50% probability level. The
O—Hꢀ ꢀ ꢀN hydrogen bonds are indicated by dashed lines.
Figure 4
A packing diagram for (I), showing the hydrogen-bonded tape running along the [110] direction. H atoms not involved in the Oꢀ ꢀ ꢀHꢀ ꢀ ꢀN, C—Hꢀ ꢀ ꢀO and
C—Hꢀ ꢀ ꢀN hydrogen bonds (dashed lines) have been omitted. [Symmetry codes: (i) x ꢁ 1, y + 1, z; (iii) x + 1, y ꢁ 1, z.]
ꢃ
o474 Gotoh and Ishida Three isomers of C7H4ClNO4ꢀC8H6N2
Acta Cryst. (2011). C67, o473–o478

organic compounds
Figure 7
packing diagram for (II), showing the double-tape structure.
A
Nꢀ ꢀ ꢀHꢀ ꢀ ꢀO and C—Hꢀ ꢀ ꢀO hydrogen bonds are indicated by dashed
lines. H atoms not involved in the hydrogen bonds have been omitted.
[Symmetry codes: (i) x + 1, y, z; (ii) ꢁx, ꢁy + 1, ꢁz + 1; (iv) ꢁx + 1, ꢁy + 1,
ꢁz + 1.]
are further linked via C—Hꢀ ꢀ ꢀO and C—Hꢀ ꢀ ꢀCl hydrogen
bonds (C12—H12ꢀ ꢀ ꢀO3ii and C23—H23ꢀ ꢀ ꢀCl2ii; details and
symmetry code in Table 1) into a sheet expanding parallel to
the (110) plane (Fig. 5). Between these sheets, which are
related to each other by an inversion centre, a C—Hꢀ ꢀ ꢀO
interaction (C23—H23ꢀ ꢀ ꢀO3iv; see Table 1 for symmetry
code), and ꢀ–ꢀ stacking interactions between the C1–C6 and
N2/N3/C8/C9/C14/C15 rings and the C16–C21 and C24–C29
rings, are observed. The centroid–centroid distances are in the
Figure 5
A packing diagram for (I), showing the hydrogen-bonded sheet structure
parallel to the (110) plane. H atoms not involved in the Oꢀ ꢀ ꢀHꢀ ꢀ ꢀN, C—
Hꢀ ꢀ ꢀO, C—Hꢀ ꢀ ꢀN and C—Hꢀ ꢀ ꢀCl hydrogen bonds (dashed lines) have
been omitted. [Symmetry codes: (i) x ꢁ 1, y + 1, z; (ii) x, y, z ꢁ 1; (iii) x + 1,
y ꢁ 1, z.]
˚
The packing diagrams for the three compounds are given in
Figs. 4–9. In (I), the two crystallographically independent
hydrogen-bonded units are arranged alternately via C—
Hꢀ ꢀ ꢀO and C—Hꢀ ꢀ ꢀN hydrogen bonds (C5—H5ꢀ ꢀ ꢀO6, C8—
H8ꢀ ꢀ ꢀO5i, C20—H20ꢀ ꢀ ꢀO4iii, C21—H21ꢀ ꢀ ꢀN3iii and C28—
H28ꢀ ꢀ ꢀO2; details and symmetry codes in Table 1), forming a
tape structure along the [110] direction (Fig. 4). These tapes
range 3.5926 (9)–3.8215 (10) A and the detailed geometries
are given in Table 4.
In (II), there are fewer observable intermolecular hydrogen
bonds than in (I), which may reflect the fact that it is a less
Figure 8
Figure 6
A packing diagram for (III), showing the hydrogen-bonded sheet
structure parallel to the (101) plane. O—Hꢀ ꢀ ꢀN and C—Hꢀ ꢀ ꢀO hydrogen
bonds are indicated by dashed lines. H atoms not involved in the
hydrogen bonds have been omitted. [Symmetry codes: (ii) x ꢁ 1, y + 1,
z + 1; (iii) x, y + 1, z.]
A packing diagram for (II), showing the hydrogen-bonded tape running
along the a axis. Dashed lines indicate Nꢀ ꢀ ꢀHꢀ ꢀ ꢀO and C—Hꢀ ꢀ ꢀO
hydrogen bonds. H atoms not involved in the hydrogen bonds have been
omitted. [Symmetry codes: (i) x + 1, y, z; (iii) x ꢁ 1, y, z.]
ꢃ
Acta Cryst. (2011). C67, o473–o478
Gotoh and Ishida
Three isomers of C7H4ClNO4ꢀC8H6N2 o475

organic compounds
sheets, related to each other by an inversion centre, relatively
short ꢀ–ꢀ interactions between the acid rings and the phtha-
lazine ring systems are observed, with centroid–centroid
˚
distances of 3.5985 (12)–3.7248 (12) A (Table 4), and each
hydrogen-bonded unit is stacked in a column in an antiparallel
manner along the a axis (Fig. 9), resulting in the most dense
crystal of the three compounds.
We have thus shown the existence of short double-well
Nꢀ ꢀ ꢀHꢀ ꢀ ꢀO hydrogen bonds in the structures of (I) and (II).
Therefore, the critical region of chloronitrobenzoic acid–
phthalazine systems may be expected around ÁpKa = 1.6,
which is much smaller than ÁpKa = 2.93–3.08 found in
chloronitrobenzoic acid–quinoline systems.
Experimental
Crystals of all three compounds were obtained by slow evaporation
from acetonitrile solutions of phthalazine with the corresponding
chloro- and nitro-substituted benzoic acid in a 1:1 molar ratio at room
temperature [acetonitrile solution (50 ml) of phthalazine (0.200 g)
and 3-chloro-2-nitrobenzoic acid (0.310 g) for (I), acetonitrile solu-
tion (30 ml) of phthalazine (0.161 g) and 4-chloro-2-nitrobenzoic acid
(0.249 g) for (II), and acetonitrile solution (90 ml) of phthalazine
(0.096 g) and 4-chloro-3-nitrobenzoic acid (0.149 g) for (III)].
Compound (I)
Crystal data
C7H3.67ClNO4ꢀC8H6.33N2
ꢃ = 88.390 (5)ꢂ
3
˚
Mr = 331.71
Triclinic, P1
V = 1429.2 (3) A
Z = 4
˚
a = 9.7764 (15) A
b = 12.0384 (14) A
Mo Kꢁ radiation
ꢄ = 0.29 mmꢁ1
T = 190 K
0.40 ꢄ 0.28 ꢄ 0.18 mm
˚
Figure 9
˚
c = 12.8889 (15) A
A packing diagram for (III), showing the ꢀ–ꢀ stacking structures of the
two independent hydrogen-bonded units. Dashed lines indicate O—
Hꢀ ꢀ ꢀN hydrogen bonds and H atoms not involved in the hydrogen bonds
have been omitted. [Symmetry codes: (i) ꢁx + 1, ꢁy + 1, ꢁz + 1; (iv)
ꢁx + 1, ꢁy + 1, ꢁz; (v) ꢁx + 2, ꢁy + 1, ꢁz; (vi) ꢁx, ꢁy + 1, ꢁz + 1.]
ꢁ = 81.491 (3)ꢂ
ꢂ = 72.328 (5)ꢂ
Data collection
Rigaku R-AXIS RAPID II
diffractometer
Absorption correction: numerical
(NUMABS; Higashi, 1999)
Tmin = 0.874, Tmax = 0.949
31515 measured reflections
8271 independent reflections
6364 reflections with I > 2ꢅ(I)
Rint = 0.035
dense crystal than (I). The two independent hydrogen-bonded
units are alternately linked in a head-to-tail manner via C—
Hꢀ ꢀ ꢀO hydrogen bonds (C10—H10ꢀ ꢀ ꢀO7i and C25—
H25ꢀ ꢀ ꢀO3; details and symmetry code in Table 2), forming a
tape structure along the a axis (Fig. 6). These tapes, related to
each other by an inversion centre, are further linked by a weak
C—Hꢀ ꢀ ꢀO interaction (C15—H15ꢀ ꢀ ꢀO8ii; details and
symmetry code in Table 2) and a ꢀ–ꢀ stacking interaction
between the N2/N3/C8/C9/C14/C15 and C9–C14 rings
(Table 5), forming a double-tape structure (Fig. 7). Between
the double tapes, other ꢀ–ꢀ stacking interactions are also
observed (Table 4). The centroid–centroid distances are in the
Table 1
Hydrogen-bond geometry (A, ) for (I).
ꢂ
˚
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
O1—H1ꢀ ꢀ ꢀN2
0.86 (3)
0.84 (3)
0.89 (4)
0.88 (5)
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.95
1.71 (3)
1.71 (3)
1.69 (4)
1.66 (5)
2.56
2.5715 (15)
2.5397 (17)
2.5715 (15)
2.5397 (17)
3.4174 (17)
3.3560 (17)
3.4609 (15)
3.2204 (17)
3.2207 (17)
3.2952 (16)
3.4707 (14)
3.3131 (16)
3.3222 (17)
173 (3)
170 (4)
172 (4)
172 (6)
150
140
158
124
131
152
128
136
158
O5—H5Aꢀ ꢀ ꢀN5
N2—H2ꢀ ꢀ ꢀO1
N5—H5Bꢀ ꢀ ꢀO5
C5—H5ꢀ ꢀ ꢀO6
˚
C8—H8ꢀ ꢀ ꢀO5i
2.58
2.56
2.59
2.52
2.43
2.81
2.56
2.42
range 3.6109 (7)–3.8139 (7) A.
C12—H12ꢀ ꢀ ꢀO3ii
C15—H15ꢀ ꢀ ꢀO2
C20—H20ꢀ ꢀ ꢀO4iii
C21—H21ꢀ ꢀ ꢀN3iii
C23—H23ꢀ ꢀ ꢀCl2ii
C23—H23ꢀ ꢀ ꢀO3iv
C28—H28ꢀ ꢀ ꢀO2
In (III), the two hydrogen-bonded units are linked by C—
Hꢀ ꢀ ꢀO hydrogen bonds (C13—H13ꢀ ꢀ ꢀO6, C20—H20ꢀ ꢀ ꢀO2,
C26—H26ꢀ ꢀ ꢀO4ii and C27—H27ꢀ ꢀ ꢀO7iii; details and symmetry
codes in Table 3), forming a molecular sheet parallel to the
(101) plane (Fig. 8). The arrangement of the two components
in the sheet is similar to that in (I), but there are fewer
hydrogen bonds than in (I). On the other hand, between these
Symmetry codes: (i) x ꢁ 1; y þ 1; z; (ii) x; y; z ꢁ 1; (iii) x þ 1; y ꢁ 1; z; (iv) ꢁx þ 1,
ꢁy þ 1; ꢁz þ 1.
ꢃ
o476 Gotoh and Ishida Three isomers of C7H4ClNO4ꢀC8H6N2
Acta Cryst. (2011). C67, o473–o478

organic compounds
Refinement
Table 2
Hydrogen-bond geometry (A, ) for (II).
ꢂ
˚
R[F2 > 2ꢅ(F2)] = 0.037
wR(F2) = 0.112
S = 1.10
8271 reflections
429 parameters
4 restraints
H atoms treated by a mixture of
independent and constrained
refinement
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
ꢁ3
˚
Áꢆmax = 0.30 e A
O1—H1ꢀ ꢀ ꢀN2
0.85 (2)
0.86 (2)
0.88 (3)
0.89 (3)
0.95
0.95
0.95
0.95
0.95
1.72 (2)
1.75 (2)
1.70 (3)
1.73 (3)
2.56
2.52
2.54
2.47
2.57
2.5655 (13)
2.6081 (13)
2.5655 (13)
2.6081 (13)
3.4371 (18)
3.1832 (16)
3.1627 (17)
3.3602 (19)
3.2026 (16)
175 (3)
174 (2)
171 (6)
170 (6)
153
127
124
157
124
ꢁ3
˚
Áꢆmin = ꢁ0.41 e A
O5—H5Aꢀ ꢀ ꢀN5
N2—H2ꢀ ꢀ ꢀO1
N5—H5Bꢀ ꢀ ꢀO5
C10—H10ꢀ ꢀ ꢀO7i
C15—H15ꢀ ꢀ ꢀO2
C15—H15ꢀ ꢀ ꢀO8ii
C25—H25ꢀ ꢀ ꢀO3
C30—H30ꢀ ꢀ ꢀO6
Compound (II)
Crystal data
3
˚
V = 2870.7 (2) A
Z = 8
C7H3.69ClNO4ꢀC8H6.31N2
Mr = 331.71
Monoclinic, P21=c
a = 12.2261 (5) A
b = 16.9779 (7) A
Symmetry codes: (i) x þ 1; y; z; (ii) ꢁx; ꢁy þ 1; ꢁz þ 1.
Mo Kꢁ radiation
ꢄ = 0.29 mmꢁ1
T = 190 K
0.35 ꢄ 0.35 ꢄ 0.30 mm
˚
˚
˚
Table 3
Hydrogen-bond geometry (A, ) for (III).
c = 14.4537 (6) A
ꢂ = 106.8955 (13)ꢂ
ꢂ
˚
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
Data collection
O1—H1ꢀ ꢀ ꢀN2
1.01 (4)
1.02 (4)
0.95
0.95
0.95
1.61 (4)
1.58 (4)
2.57
2.52
2.51
2.613 (2)
2.589 (2)
3.316 (3)
3.203 (3)
3.220 (2)
3.441 (3)
3.340 (3)
171 (4)
172 (3)
136
129
132
Rigaku R-AXIS RAPID II
diffractometer
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
Tmin = 0.790, Tmax = 0.916
60079 measured reflections
8318 independent reflections
6797 reflections with I > 2ꢅ(I)
Rint = 0.030
O5—H5Aꢀ ꢀ ꢀN5
C13—H13ꢀ ꢀ ꢀO6
C20—H20ꢀ ꢀ ꢀO2
C23—H23ꢀ ꢀ ꢀO2i
C26—H26ꢀ ꢀ ꢀO4ii
C27—H27ꢀ ꢀ ꢀO7iii
0.95
0.95
2.53
2.46
160
155
Refinement
Symmetry codes: (i) ꢁx þ 1; ꢁy þ 1; ꢁz þ 1; (ii) x ꢁ 1; y þ 1; z þ 1; (iii) x; y þ 1; z.
R[F2 > 2ꢅ(F2)] = 0.042
wR(F2) = 0.123
S = 1.07
8318 reflections
429 parameters
4 restraints
H atoms treated by a mixture of
independent and constrained
refinement
Table 4
ꢁ3
˚
Áꢆmax = 0.71 e A
ꢂ
˚
Geometries of ꢀ–ꢀ stacking interactions (A, ) for compounds (I)–(III).
ꢁ3
˚
Áꢆmin = ꢁ0.41 e A
CgIꢀ ꢀ ꢀCgJ, ꢁ, CgI-Perp and CgJ-Perp are, respectively, the centroid–centroid
ꢂ
˚
distance between rings I and J (A), the inter-ring dihedral angle ( ), the
˚
perpendicular distance of CgI from ring J (A), and the perpendicular distance
˚
of CgJ from ring I (A). Cg1, Cg2, Cg3, Cg4, Cg5 and Cg6 are the centroids of
Compound (III)
the C1–C6, C16–C21, N2/N3/C8/C9/C14/C15, C9–C14, N5/N6/C23/C24/C29/
C30 and C24–C29 rings, respectively.
Crystal data
C7H4ClNO4ꢀC8H6N2
ꢃ = 85.647 (2)ꢂ
V = 1402.20 (17) A
Z = 4
Mo Kꢁ radiation
ꢄ = 0.30 mmꢁ1
T = 190 K
3
CgIꢀ ꢀ ꢀCgJ
ꢁ
CgI-Perp
CgJ-Perp
˚
Mr = 331.71
Triclinic, P1
(I)
˚
a = 6.9197 (5) A
Cg1ꢀ ꢀ ꢀCg3i
3.5926 (9)
3.8215 (9)
9.40 (6)
7.77 (6)
3.3707 (5)
3.4644 (5)
3.4833 (5)
3.5953 (6)
˚
b = 14.4263 (12) A
Cg2ꢀ ꢀ ꢀCg6ii
˚
c = 14.4750 (9) A
ꢁ = 81.704 (2)ꢂ
0.40 ꢄ 0.18 ꢄ 0.06 mm
ꢂ = 79.0781 (18)ꢂ
(II)
Cg1ꢀ ꢀ ꢀCg3iii
Cg1ꢀ ꢀ ꢀCg4iii
Cg2ꢀ ꢀ ꢀCg5iv
Cg2ꢀ ꢀ ꢀCg6iv
Cg3ꢀ ꢀ ꢀCg4v
3.6109 (7)
3.7346 (7)
3.8139 (7)
3.7051 (7)
3.6714 (7)
4.35 (6)
3.20 (6)
7.07 (6)
6.55 (6)
1.58 (6)
3.4477 (5)
3.4567 (5)
3.4937 (5)
3.4873 (5)
3.4791 (5)
3.4910 (5)
3.4135 (5)
3.4622 (5)
3.5827 (5)
3.4485 (5)
Data collection
Rigaku R-AXIS RAPID II
diffractometer
Absorption correction: numerical
(NUMABS; Higashi, 1999)
Tmin = 0.929, Tmax = 0.982
22476 measured reflections
7849 independent reflections
4765 reflections with I > 2ꢅ(I)
Rint = 0.056
(III)
Cg1ꢀ ꢀ ꢀCg3vi
Cg1ꢀ ꢀ ꢀCg3vii
Cg1ꢀ ꢀ ꢀCg4vi
Cg1ꢀ ꢀ ꢀCg4vii
Cg2ꢀ ꢀ ꢀCg5viii
Cg2ꢀ ꢀ ꢀCg5v
Cg2ꢀ ꢀ ꢀCg6viii
Cg2ꢀ ꢀ ꢀCg6v
3.7248 (12)
3.5985 (12)
3.6921 (13)
3.6698 (13)
3.6536 (12)
3.7211 (12)
3.6812 (13)
3.6555 (13)
0.78 (10)
0.78 (10)
1.29 (10)
1.29 (10)
0.89 (10)
0.89 (10)
0.60 (10)
0.60 (10)
3.5065 (4)
3.44488 (4)
3.4319 (4)
3.4485 (4)
3.3383 (4)
3.4475 (5)
3.4475 (5)
3.4475 (5)
3.5066 (4)
3.4722 (4)
3.4669 (4)
3.4336 (4)
3.3225 (5)
3.4475 (5)
3.4475 (5)
3.4475 (5)
Refinement
R[F2 > 2ꢅ(F2)] = 0.057
wR(F2) = 0.154
S = 0.99
7849 reflections
423 parameters
H atoms treated by a mixture of
independent and constrained
refinement
ꢁ3
˚
Áꢆmax = 0.53 e A
ꢁ3
˚
Áꢆmin = ꢁ0.48 e A
Symmetry codes: (i) ꢁx + 1, ꢁy + 2, ꢁz + 1; (ii) ꢁx + 2, ꢁy + 1, ꢁz + 1; (iii) ꢁx + 1, y + 12,
For all three compounds, all H atoms were found in difference
Fourier maps. H atoms in (I) and (II) which are involved in
Nꢀ ꢀ ꢀHꢀ ꢀ ꢀO hydrogen bonds were found to be disordered over two
positions in difference Fourier maps. Since the site-occupation factors
and isotropic displacement parameters were strongly correlated, the
positional parameters and occupation factors for these atoms were
refined with Uiso(H) = 1.5Ueq(N,O) and with bond-length restraints of
ꢁz + 32; (iv) ꢁx, y ꢁ , ꢁz + 32; (v) ꢁx + 1, ꢁy + 1, ꢁz + 1; (vi) ꢁx + 1, ꢁy + 1, ꢁz + 1; (vii)
1
2
ꢁx + 2, ꢁy + 1, ꢁz; (viii) ꢁx, ꢁy + 1, ꢁz + 1.
˚
˚
O—H = 0.84 (2) A and N—H = 0.88 (2) A. Atoms H1 and H5A in
(III) were refined isotropically. The refined distances are given in
Tables 1–3. The remaining H atoms of all compounds were positioned
ꢃ
Acta Cryst. (2011). C67, o473–o478
Gotoh and Ishida
Three isomers of C7H4ClNO4ꢀC8H6N2 o477

organic compounds
˚
geometrically (C—H = 0.95 A) and treated as riding, with Uiso(H) =
1.2Ueq(C).
References
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
For all compounds, data collection and cell refinement: PROCESS-
AUTO (Rigaku/MSC, 2004); data reduction: CrystalStructure
(Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97
(Sheldrick, 2008); program(s) used to refine structure: SHELXL97
(Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and
WinGX (Farrugia, 1999); software used to prepare material for
publication: CrystalStructure and PLATON (Spek, 2009).
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.
Gilli, G. & Gilli, P. (2009). The Nature of the Hydrogen Bond. Oxford
University Press.
Gotoh, K. & Ishida, H. (2007). Acta Cryst. E63, o4500.
Gotoh, K. & Ishida, H. (2009). Acta Cryst. C65, o534–o538.
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.
Higashi, T. (1999). NUMABS. Rigaku Corporation, Tokyo, Japan.
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This work was supported by a Grant-in-Aid for Scientific
Research (C) (No. 22550013) from the Japan Society for the
Promotion of Science.
Rigaku/MSC (2004). PROCESS-AUTO and CrystalStructure. Rigaku/MSC
Inc., The Woodlands, Texas, USA.
Schmidtmann, M. & Wilson, C. C. (2008). CrystEngComm, 10, 177–183.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Spek, A. L. (2009). Acta Cryst. D65, 148–155.
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: FG3232). Services for accessing these data are
described at the back of the journal.
Steiner, T., Majerz, I. & Wilson, C. C. (2001). Angew. Chem. Int. Ed. 40, 2651–
2654.
ꢃ
o478 Gotoh and Ishida Three isomers of C7H4ClNO4ꢀC8H6N2
Acta Cryst. (2011). C67, o473–o478