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2-Chloro-4-nitro­benzoic acid and 2-chloro-5-nitro­benzoic acid form O—H...N hydrogen bonds with pyrazine to afford 2:1 complexes of 2C7H4ClNO4·C4H4N2, (I) and (II), respectively, that are located on inversion centers. The 2C7H4ClNO4·­C4H4N2 units in both complexes are connected by weak C—H...O hydrogen bonds; the units build a three-dimensional hydrogen-bond network in (I) and a ribbon structure in (II).

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101007016/bk1601sup1.cif
Contains datablocks global, I, II

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270101007016/bk1601Isup2.hkl
Contains datablock I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270101007016/bk1601IIsup3.hkl
Contains datablock II

CCDC references: 169962; 169963

Comment top

Several hydrogen-bonded complexes composed of 2-chloro-4-nitrobenzoic acid and amines were studied by Habeeb et al. using 35Cl NQR and IR techniques (Kalenik et al., 1989; Habeeb & Awad, 1995; Awad & Habeeb, 1996). They reported that the hydrogen bonds formed between the benzoic acid and the amines vary from an O—H···N to an O···H—N type with increasing proton affinities (PA) of the amines and that the critical (inversion) point at 50% proton transfer exists in the complex of 3,5-dimethylpyridine. However, there is not yet any crystallographic evidence supporting these findings. Moreover, the shapes of the proton donor and acceptor molecules may be important as the PA in determining the proton transfer. This prompted us to carry out studies on the structure of chloro- and nitro-substituted benzoic acid-amine complexes. In addition to the O—H···N/O···H—N hydrogen bond, other weak intermolecular interactions, such as C—H···O and C—H···Cl interactions, may be expected in these complexes, because the nitro group and the chlorine atom of these benzoic acids can act as a weak hydrogen bond acceptor (Robinson et al., 2000; Desiraju & Steiner, 1999). It is of relevance, therefore, in the context of crystal engineering and supramolecular architecture to investigate the role of the weak hydrogen-bond acceptors playing in the crystal packing of the title complexes. In the present study, we undertook pyrazine as an amine having a quite small PA value and prepared 2-chloro-4-nitrobenzoic acid-pyrazine and 2-chloro-5-nitrobenzoic acid-pyrazine complexes; their crystal structures were determined at room temperature. To our knowledge, this is the first crystallographic report of 2-chloro-4-nitrobenzoic acid-amine and 2-chloro-5-nitrobenzoic acid-amine systems; no structural data of compounds composed of 2-chloro-4-nitrobenzoic acid and 2-chloro-5-nitrobenzoic acid except 2-chloro-5-nitrobenzoic acid itself are recorded in Cambridge Structural Database (Version 5.20, October 2000). \sch

The pyrazine molecule in both 2-chloro-4-nitrobenzoic acid-pyrazine 2:1 complex, (I), and 2-chloro-5-nitrobenzoic acid-pyrazine 2:1 complex, (II), occupies a center of symmetry, and asymmetric units of (I) and (II) are composed of C7H4ClNO4.1/2C4H4N2. In both crystals the two components are held together by a short O—H···N hydrogen bond (Tables 2 and 4), forming the unit of 2C7H4ClNO4·C4H4N2 (Figs 1 and 2). No acid-base interaction involving a proton transfer is observed as expected from the small PA value of pyrazine. The O···N distances are long compared with the shortest expected O···N distance of ca 2.45 Å (Jerzykiewicz et al., 1998), which may be realised in the vicinity of the critical point.

In (I), the dihedral angle between the nitro group and the benzene ring is 18.97 (13)° and that between the carboxyl group and the benzene ring is 32.77 (12)°. The dihedral angle between the planes of the pyrazine ring and the benzene ring by 19.56 (12)°. On the other hand, in (II), all the atoms locate almost on a plane; the benzene ring makes small angles of 3.19 (13), 9.17 (13) and 5.56 (13)° with the nitro group, the carboxyl group and the pyrazine ring, respectively. To compare these geometries with those of the isolated molecules in gas phase, we carried out ab initio MO calculations at the HF/6–31G** level of theory by using the computer program Gaussian 98 (Frisch et al., 1998). The optimized geometries were confirmed to correspond to a potential energy minimum from vibrational analysis. The calculated dihedral angles of the nitro group and the carboxyl group made by the benzene ring are 0.3° and 30.1°, respectively, for 2-chloro-4-nitrobenzoic acid and 0.5° and 20.0° for 2-chloro-5-nitrobenzoic acid. We also obtained flat structures for both benzoic acids, which were found not as a stable form but at a saddle point of first order. The angles of the nitro group in (I) and the carboxyl group in (II) are much larger and smaller, respectively, compared with the calculated values, the former and the latter of which may be interpreted as arising from intermolecular C—H···O interactions involving the nitro groups and aromatic π-π stacking interactions, respectively, as mentioned below.

In (I), an intermolecular C—H···O interaction (Table 2) is observed between the benzene ring and the nitro group, forming a centrosymmetric ring with graph-set descriptor R22(10) (Bernstein et al., 1995). The interaction connects the units of 2[C7H4ClNO4]·C4H4N2 to build a zigzag chain running along the [101] direction. The chains are linked by a C—H···O hydrogen bond formed between the benzene ring and the carboxyl group and a C—H···O interaction between the pyrazine and the nitro group (Table 2), generating a three-dimensional hydrogen-bond network (Fig. 3).

In (II), a C—H···O interaction (Table 4) between the benzoic acids related by an inversion center forms the R22(10) ring with a similar geometry to that in (I) and links the units of 2[C7H4ClNO4]·C4H4N2, resulting in the formation of ribbons running parallel to the [210] and [210] directions. An additional weak C—H···O interaction (Table 4) and a Cl···Cli contact at 3.7378 (12) Å [symmetry code: (i) -x, 1/2 + y, 1/2 - z] is found between the ribbons running different directions. The ribbons are stacked along the b axis, forming two kinds of layer (Fig. 4), in which the benzoic acids related by an inversion center are stacked through the π-π interactions with the interplanar spacing of 3.397 (5) Å and the centroid offset of 2.57 Å.

Experimental top

The prismatic crystals of (I) and (II) were obtained by slow evaporation from benzene solutions of pyrazine with 2-chloro-4-nitrobenzoic acid or 2-chloro-5-nitrobenzoic acid (molar ratio 2:1) at room temperature.

Refinement top

H atoms were found in a difference Fourier map and refined isotropically. Refined distances: C—H = 0.896–0.99 and O—H = 0.84 Å for (I), and C—H = 0.951–1.00 and O—H = 1.00 Å for (II).

Computing details top

For both compounds, data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1990); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN for Windows (Molecular Structure Corporation, 1997-1999). Program(s) used to solve structure: SIR92 (Altomare et al., 1993) for (I); SAPI90 (Fan, 1990) for (II). For both compounds, program(s) used to refine structure: TEXSAN for Windows; software used to prepare material for publication: TEXSAN for Windows.

Figures top
[Figure 1] Fig. 1. ORTEP-3 (Farrugia, 1997) drawing of (I) showing the atom labelling. Displacement ellipsoids of non-H atoms are drawn at the 50% probability level and H atoms are drawn as circles of arbitrary size. Hydrogen bonds are indicated by dashed lines.
[Figure 2] Fig. 2. ORTEP-3 drawing of a molecular ribbon of (II) showing the atomic labelling and hydrogen-bonding scheme. Displacement ellipsoids of non-H atoms are drawn at the 50% probability level and H atoms are drawn as circles of arbitrary size. Hydrogen bonds are indicated by dashed lines (symmetry codes are as in Table 4).
[Figure 3] Fig. 3. Part of the crystal structure of (I) showing a three-dimensional hydrogen-bond network formed via N—H···O and C—H···O hydrogen bonds indicated by dashed lines (symmetry codes are as in Table 2).
[Figure 4] Fig. 4. Part of the crystal structure of (II) showing the formation of the molecular layers built from flat ribbons. Hydrogen bonds are indicated by dashed lines (symmetry codes are as in Table 4).
(I) top
Crystal data top
C4H4N2·2C7H4ClNO4F(000) = 492
Mr = 483.22Dx = 1.548 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 3.8280 (5) ÅCell parameters from 25 reflections
b = 12.7738 (16) Åθ = 11.1–12.4°
c = 21.203 (3) ŵ = 0.37 mm1
β = 91.118 (14)°T = 296 K
V = 1036.6 (2) Å3Prismatic, colorless
Z = 20.40 × 0.30 × 0.30 mm
Data collection top
Rigaku AFC5R
diffractometer
1275 reflections with I > 2.0σ(I)
Radiation source: Rigaku rotating anodeRint = 0.031
Graphite monochromatorθmax = 27.5°, θmin = 1.6°
ω–2θ scansh = 14
Absorption correction: ψ scans
(North et al., 1968)
k = 016
Tmin = 0.862, Tmax = 0.895l = 2727
3559 measured reflections3 standard reflections every 97 reflections
2477 independent reflections intensity decay: 1.6%
Refinement top
Refinement on F20 restraints
Least-squares matrix: full0 constraints
R[F2 > 2σ(F2)] = 0.057All H-atom parameters refined
wR(F2) = 0.063Weighting scheme based on measured s.u.'s w = 1/[σ2(Fo) + 0.00003|Fo|2]
S = 1.38(Δ/σ)max = 0.01
2360 reflectionsΔρmax = 0.39 e Å3
169 parametersΔρmin = 0.49 e Å3
Crystal data top
C4H4N2·2C7H4ClNO4V = 1036.6 (2) Å3
Mr = 483.22Z = 2
Monoclinic, P21/nMo Kα radiation
a = 3.8280 (5) ŵ = 0.37 mm1
b = 12.7738 (16) ÅT = 296 K
c = 21.203 (3) Å0.40 × 0.30 × 0.30 mm
β = 91.118 (14)°
Data collection top
Rigaku AFC5R
diffractometer
1275 reflections with I > 2.0σ(I)
Absorption correction: ψ scans
(North et al., 1968)
Rint = 0.031
Tmin = 0.862, Tmax = 0.8953 standard reflections every 97 reflections
3559 measured reflections intensity decay: 1.6%
2477 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0570 restraints
wR(F2) = 0.063All H-atom parameters refined
S = 1.38Δρmax = 0.39 e Å3
2360 reflectionsΔρmin = 0.49 e Å3
169 parameters
Special details top

Experimental. The scan width was (1.31 + 0.30tanθ)° with an ω scan speed of 6° per minute (up to 3 scans to achieve I/σ(I) > 10). Stationary background counts were recorded at each end of the scan, and the scan time:background time ratio was 2:1.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cl0.38589 (16)0.65568 (5)0.18102 (3)0.0650 (2)
O10.2745 (5)0.41390 (14)0.32294 (8)0.0704 (6)
O20.4581 (5)0.57765 (14)0.31430 (8)0.0900 (7)
O30.7819 (6)0.40493 (17)0.00424 (9)0.1141 (9)
O41.0445 (5)0.27749 (14)0.04790 (8)0.0950 (8)
N10.8701 (6)0.35573 (17)0.05023 (9)0.0637 (8)
N20.0822 (5)0.46729 (16)0.43978 (9)0.0572 (7)
C10.5269 (5)0.45966 (17)0.22771 (10)0.0444 (7)
C20.5288 (5)0.52768 (15)0.17643 (10)0.0450 (7)
C30.6393 (6)0.49367 (18)0.11818 (11)0.0499 (8)
C40.7520 (5)0.39189 (17)0.11241 (10)0.0475 (7)
C50.7579 (6)0.32239 (18)0.16191 (11)0.0519 (8)
C60.6388 (6)0.35739 (18)0.21922 (11)0.0505 (8)
C70.4168 (6)0.49255 (19)0.29238 (11)0.0549 (8)
C80.0792 (8)0.5669 (2)0.45539 (13)0.0721 (10)
C90.0007 (8)0.5995 (2)0.51499 (13)0.0738 (10)
H10.216 (7)0.434 (2)0.3588 (13)0.135 (11)*
H20.629 (5)0.5377 (13)0.0853 (8)0.044 (6)*
H30.833 (5)0.2524 (16)0.1561 (9)0.069 (7)*
H40.633 (4)0.3070 (14)0.2545 (8)0.048 (6)*
H50.134 (6)0.6151 (18)0.4241 (10)0.093 (9)*
H60.019 (6)0.6703 (18)0.5264 (11)0.094 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl0.0778 (5)0.0432 (3)0.0743 (4)0.0124 (4)0.0084 (3)0.0066 (3)
O10.0996 (14)0.0639 (11)0.0485 (11)0.0191 (10)0.0234 (10)0.0047 (10)
O20.1423 (18)0.0617 (12)0.0675 (13)0.0312 (12)0.0375 (12)0.0219 (10)
O30.171 (2)0.1232 (17)0.0492 (12)0.0631 (15)0.0201 (13)0.0047 (12)
O40.1302 (18)0.0785 (14)0.0772 (14)0.0403 (13)0.0230 (12)0.0206 (11)
N10.0760 (16)0.0631 (15)0.0523 (14)0.0077 (13)0.0100 (12)0.0124 (12)
N20.0648 (14)0.0614 (14)0.0460 (12)0.0082 (11)0.0142 (10)0.0028 (11)
C10.0454 (15)0.0454 (13)0.0426 (14)0.0058 (11)0.0073 (11)0.0026 (11)
C20.0450 (14)0.0378 (12)0.0522 (15)0.0003 (10)0.0064 (11)0.0075 (11)
C30.0569 (16)0.0459 (14)0.0469 (16)0.0050 (12)0.0047 (12)0.0073 (12)
C40.0505 (15)0.0505 (14)0.0417 (13)0.0034 (12)0.0078 (11)0.0070 (12)
C50.0613 (17)0.0402 (14)0.0544 (16)0.0047 (12)0.0024 (13)0.0031 (12)
C60.0597 (16)0.0456 (15)0.0462 (15)0.0035 (12)0.0041 (12)0.0041 (12)
C70.0598 (17)0.0575 (16)0.0478 (16)0.0075 (14)0.0098 (13)0.0046 (13)
C80.107 (2)0.0611 (19)0.0490 (18)0.0130 (16)0.0204 (16)0.0107 (14)
C90.109 (2)0.0562 (18)0.0573 (19)0.0067 (18)0.0215 (17)0.0013 (16)
Geometric parameters (Å, º) top
Cl—C21.727 (2)C1—C71.502 (3)
O1—C71.319 (3)C2—C31.383 (3)
O1—H10.84 (3)C3—C41.376 (3)
O2—C71.191 (3)C3—H20.896 (19)
O3—N11.203 (3)C4—C51.375 (3)
O4—N11.204 (3)C5—C61.380 (3)
N1—C41.476 (3)C5—H30.95 (2)
N2—C81.315 (3)C6—H40.99 (2)
N2—C9i1.327 (3)C8—C91.370 (4)
C1—C21.392 (3)C8—H50.93 (3)
C1—C61.388 (3)C9—H60.94 (3)
O1···N22.686 (3)O3···O3v3.252 (5)
O1···C6ii3.327 (3)O3···C3v3.294 (4)
O2···C5iii3.345 (3)O4···C8vi3.053 (4)
O2···C83.352 (4)O4···C9vi3.173 (4)
O3···O3iv2.955 (6)O4···N1vii3.314 (4)
C7—O1—H1109 (2)C3—C4—C5122.9 (3)
O3—N1—O4123.2 (3)C4—C5—C6117.5 (3)
O3—N1—C4118.3 (3)C4—C5—H3120.7 (15)
O4—N1—C4118.5 (3)C6—C5—H3121.7 (15)
C8—N2—C9i115.9 (3)C1—C6—C5121.8 (3)
C2—C1—C6118.7 (2)C1—C6—H4120.3 (12)
C2—C1—C7123.0 (2)C5—C6—H4117.9 (12)
C6—C1—C7118.3 (2)O1—C7—O2123.8 (3)
Cl—C2—C1122.71 (19)O1—C7—C1111.2 (2)
Cl—C2—C3116.8 (2)O2—C7—C1125.0 (3)
C1—C2—C3120.5 (2)N2—C8—C9122.0 (3)
C2—C3—C4118.6 (3)N2—C8—H5117.2 (17)
C2—C3—H2119.2 (14)C9—C8—H5120.8 (17)
C4—C3—H2122.2 (14)N2—C9i—C8i122.1 (3)
N1—C4—C3118.5 (2)N2—C9i—H6i114.4 (18)
N1—C4—C5118.6 (2)C8—C9—H6123.3 (18)
Cl—C2—C1—C6178.5 (2)N1—C4—C3—C2180.0 (2)
Cl—C2—C1—C73.0 (4)N1—C4—C5—C6178.6 (2)
Cl—C2—C3—C4179.4 (2)C1—C2—C3—C41.0 (4)
O1—C7—C1—C2149.1 (3)C1—C6—C5—C42.0 (4)
O1—C7—C1—C632.4 (4)C2—C1—C6—C51.4 (4)
O2—C7—C1—C232.5 (4)C2—C3—C4—C50.3 (4)
O2—C7—C1—C6146.1 (3)C3—C2—C1—C60.2 (4)
O3—N1—C4—C319.0 (4)C3—C2—C1—C7178.7 (3)
O3—N1—C4—C5160.7 (3)C3—C4—C5—C61.2 (4)
O4—N1—C4—C3162.3 (3)C5—C6—C1—C7177.2 (3)
O4—N1—C4—C518.0 (4)
Symmetry codes: (i) x, y+1, z+1; (ii) x1, y, z; (iii) x+3/2, y+1/2, z+1/2; (iv) x+2, y+1, z; (v) x+1, y+1, z; (vi) x+3/2, y1/2, z+1/2; (vii) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N20.84 (3)1.85 (3)2.686 (3)175 (3)
C3—H2···O3v0.90 (2)2.55 (2)3.294 (4)141 (2)
C5—H3···O2vi0.95 (2)2.45 (2)3.345 (3)158 (2)
C8—H5···O4iii0.93 (3)2.48 (3)3.053 (4)120 (2)
Symmetry codes: (iii) x+3/2, y+1/2, z+1/2; (v) x+1, y+1, z; (vi) x+3/2, y1/2, z+1/2.
(II) top
Crystal data top
C4H4N2·2C7H4ClNO4F(000) = 492
Mr = 483.22Dx = 1.606 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 10.293 (4) ÅCell parameters from 25 reflections
b = 7.276 (2) Åθ = 10.0–12.5°
c = 13.818 (6) ŵ = 0.38 mm1
β = 105.17 (3)°T = 293 K
V = 998.9 (6) Å3Prismatic, colorless
Z = 20.40 × 0.30 × 0.20 mm
Data collection top
Rigaku AFC5R
diffractometer
1268 reflections with I > 2.0σ(I)
Radiation source: Rigaku rotating anodeRint = 0.039
Graphite monochromatorθmax = 27.5°, θmin = 1.5°
ω–2θ scansh = 113
Absorption correction: ψ scans
(North et al., 1968)
k = 09
Tmin = 0.810, Tmax = 0.926l = 1717
2887 measured reflections3 standard reflections every 97 reflections
2293 independent reflections intensity decay: 1.6%
Refinement top
Refinement on F20 constraints
Least-squares matrix: fullAll H-atom parameters refined
R[F2 > 2σ(F2)] = 0.051Weighting scheme based on measured s.u.'s w = 1/[σ2(Fo) + 0.00001|Fo|2]
wR(F2) = 0.061(Δ/σ)max = 0.01
S = 1.33Δρmax = 0.44 e Å3
2292 reflectionsΔρmin = 0.61 e Å3
170 parametersExtinction correction: Zachariasen (1967), equ(3) Acta Cryst.(1968) A24, p213.
0 restraintsExtinction coefficient: 2.48 (9)×10-6
Crystal data top
C4H4N2·2C7H4ClNO4V = 998.9 (6) Å3
Mr = 483.22Z = 2
Monoclinic, P21/cMo Kα radiation
a = 10.293 (4) ŵ = 0.38 mm1
b = 7.276 (2) ÅT = 293 K
c = 13.818 (6) Å0.40 × 0.30 × 0.20 mm
β = 105.17 (3)°
Data collection top
Rigaku AFC5R
diffractometer
1268 reflections with I > 2.0σ(I)
Absorption correction: ψ scans
(North et al., 1968)
Rint = 0.039
Tmin = 0.810, Tmax = 0.9263 standard reflections every 97 reflections
2887 measured reflections intensity decay: 1.6%
2293 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0510 restraints
wR(F2) = 0.061All H-atom parameters refined
S = 1.33Δρmax = 0.44 e Å3
2292 reflectionsΔρmin = 0.61 e Å3
170 parameters
Special details top

Experimental. The scan width was (1.52 + 0.30tanθ)° with an ω scan speed of 6° per minute (up to 3 scans to achieve I/σ(I) > 10). Stationary background counts were recorded at each end of the scan, and the scan time:background time ratio was 2:1.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cl0.02826 (7)0.10612 (10)0.27895 (5)0.0535 (2)
O10.12332 (17)0.3384 (3)0.00595 (13)0.0590 (7)
O20.20442 (16)0.2408 (3)0.16189 (13)0.0633 (6)
O30.45413 (17)0.0651 (3)0.14017 (13)0.0761 (7)
O40.30575 (18)0.2081 (3)0.19589 (13)0.0734 (7)
N10.3433 (2)0.1338 (3)0.12914 (15)0.0523 (8)
N20.37543 (19)0.4335 (3)0.00226 (16)0.0503 (7)
C10.0288 (2)0.1914 (3)0.07882 (16)0.0318 (7)
C20.0734 (2)0.1155 (3)0.15764 (16)0.0344 (7)
C30.2028 (3)0.0470 (4)0.14345 (19)0.0438 (9)
C40.2909 (2)0.0510 (4)0.04937 (18)0.0429 (8)
C50.2489 (2)0.1275 (3)0.02785 (16)0.0368 (7)
C60.1211 (2)0.1962 (3)0.01528 (17)0.0359 (8)
C70.1126 (2)0.2608 (4)0.08890 (18)0.0388 (8)
C80.4022 (3)0.4841 (4)0.0834 (2)0.0559 (10)
C90.4738 (3)0.4488 (4)0.0859 (2)0.0522 (9)
H10.218 (3)0.372 (4)0.010 (2)0.113 (11)*
H20.228 (2)0.001 (3)0.2005 (14)0.046 (7)*
H30.3819 (18)0.004 (3)0.0371 (14)0.039 (7)*
H40.0982 (17)0.250 (3)0.0713 (13)0.018 (5)*
H50.335 (2)0.469 (3)0.1431 (15)0.046 (7)*
H60.4542 (19)0.414 (3)0.1505 (14)0.040 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl0.0531 (4)0.0694 (5)0.0341 (3)0.0077 (4)0.0045 (3)0.0039 (4)
O10.0318 (11)0.0914 (17)0.0534 (12)0.0155 (11)0.0104 (9)0.0172 (11)
O20.0355 (10)0.1071 (18)0.0424 (10)0.0106 (11)0.0018 (8)0.0016 (12)
O30.0356 (11)0.125 (2)0.0604 (13)0.0259 (13)0.0003 (9)0.0014 (14)
O40.0600 (14)0.1105 (19)0.0428 (11)0.0215 (13)0.0013 (10)0.0148 (12)
N10.0419 (14)0.0687 (19)0.0431 (13)0.0010 (13)0.0053 (11)0.0028 (13)
N20.0343 (12)0.0613 (18)0.0567 (14)0.0073 (12)0.0146 (11)0.0052 (14)
C10.0324 (13)0.0323 (15)0.0328 (13)0.0006 (12)0.0122 (10)0.0059 (12)
C20.0373 (14)0.0333 (16)0.0311 (12)0.0012 (13)0.0062 (10)0.0058 (13)
C30.0437 (16)0.048 (2)0.0432 (15)0.0046 (14)0.0187 (13)0.0034 (14)
C40.0320 (15)0.052 (2)0.0453 (15)0.0062 (14)0.0118 (12)0.0026 (14)
C50.0321 (13)0.0408 (17)0.0359 (13)0.0017 (13)0.0062 (10)0.0001 (13)
C60.0383 (15)0.0368 (17)0.0346 (14)0.0016 (13)0.0130 (12)0.0008 (13)
C70.0376 (15)0.0395 (17)0.0420 (15)0.0059 (13)0.0151 (12)0.0094 (14)
C80.0411 (18)0.077 (3)0.0458 (17)0.0088 (16)0.0041 (14)0.0007 (17)
C90.0420 (16)0.069 (2)0.0469 (17)0.0024 (16)0.0139 (13)0.0089 (17)
Geometric parameters (Å, º) top
Cl—C21.730 (3)C1—C71.512 (3)
O1—C71.308 (3)C2—C31.387 (4)
O1—H11.00 (3)C3—C41.377 (4)
O2—C71.197 (3)C3—H20.96 (2)
O3—N11.218 (3)C4—C51.370 (4)
O4—N11.216 (3)C4—H30.97 (2)
N1—C51.481 (3)C5—C61.375 (3)
N2—C81.335 (3)C6—H40.951 (19)
N2—C91.327 (4)C8—C9i1.376 (4)
C1—C21.401 (3)C8—H50.93 (2)
C1—C61.396 (3)C9—H61.00 (2)
O1···N22.699 (3)O3···C4iv3.301 (4)
O1···C6ii3.389 (4)O4···C3v3.234 (4)
O2···N1iii3.165 (4)O4···C8vi3.371 (4)
O2···C5iii3.357 (4)C5···C7iii3.359 (4)
C7—O1—H1111.3 (18)C5—C4—H3119.7 (13)
O3—N1—O4124.1 (3)N1—C5—C4119.1 (3)
O3—N1—C5117.8 (3)N1—C5—C6118.5 (3)
O4—N1—C5118.1 (2)C4—C5—C6122.4 (3)
C8—N2—C9117.5 (3)C1—C6—C5120.3 (3)
C2—C1—C6116.9 (3)C1—C6—H4121.1 (12)
C2—C1—C7124.3 (2)C5—C6—H4118.6 (12)
C6—C1—C7118.8 (2)O1—C7—O2124.2 (3)
Cl—C2—C1122.0 (2)O1—C7—C1111.3 (2)
Cl—C2—C3116.0 (2)O2—C7—C1124.5 (3)
C1—C2—C3122.0 (3)N2—C8—C9i121.9 (3)
C2—C3—C4119.8 (3)N2—C8—H5118.5 (16)
C2—C3—H2118.3 (15)C9—C8i—H5i119.5 (16)
C4—C3—H2121.9 (15)N2—C9—C8i120.6 (3)
C3—C4—C5118.6 (3)N2—C9—H6118.1 (13)
C3—C4—H3121.6 (13)C8—C9i—H6i121.3 (13)
Cl—C2—C1—C6178.2 (2)N1—C5—C4—C3179.5 (3)
Cl—C2—C1—C74.1 (4)N1—C5—C6—C1179.5 (3)
Cl—C2—C3—C4179.3 (3)C1—C2—C3—C40.7 (5)
O1—C7—C1—C2174.6 (3)C1—C6—C5—C40.6 (5)
O1—C7—C1—C67.7 (4)C2—C1—C6—C50.4 (4)
O2—C7—C1—C28.1 (5)C2—C3—C4—C51.6 (5)
O2—C7—C1—C6169.5 (3)C3—C2—C1—C60.4 (4)
O3—N1—C5—C42.1 (4)C3—C2—C1—C7177.3 (3)
O3—N1—C5—C6176.8 (3)C3—C4—C5—C61.6 (5)
O4—N1—C5—C4177.4 (3)C5—C6—C1—C7177.4 (3)
O4—N1—C5—C63.7 (4)
Symmetry codes: (i) x+1, y+1, z; (ii) x, y+1, z; (iii) x, y, z; (iv) x1, y, z; (v) x, y+1/2, z1/2; (vi) x, y1/2, z1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N21.00 (3)1.71 (3)2.699 (3)173 (3)
C3—H2···O2vii0.96 (2)2.64 (2)3.496 (4)149 (2)
C4—H3···O3iv0.97 (2)2.53 (2)3.301 (4)137 (2)
Symmetry codes: (iv) x1, y, z; (vii) x, y1/2, z+1/2.

Experimental details

(I)(II)
Crystal data
Chemical formulaC4H4N2·2C7H4ClNO4C4H4N2·2C7H4ClNO4
Mr483.22483.22
Crystal system, space groupMonoclinic, P21/nMonoclinic, P21/c
Temperature (K)296293
a, b, c (Å)3.8280 (5), 12.7738 (16), 21.203 (3)10.293 (4), 7.276 (2), 13.818 (6)
β (°) 91.118 (14) 105.17 (3)
V3)1036.6 (2)998.9 (6)
Z22
Radiation typeMo KαMo Kα
µ (mm1)0.370.38
Crystal size (mm)0.40 × 0.30 × 0.300.40 × 0.30 × 0.20
Data collection
DiffractometerRigaku AFC5R
diffractometer
Rigaku AFC5R
diffractometer
Absorption correctionψ scans
(North et al., 1968)
ψ scans
(North et al., 1968)
Tmin, Tmax0.862, 0.8950.810, 0.926
No. of measured, independent and
observed [I > 2.0σ(I)] reflections
3559, 2477, 1275 2887, 2293, 1268
Rint0.0310.039
(sin θ/λ)max1)0.6490.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.057, 0.063, 1.38 0.051, 0.061, 1.33
No. of reflections23602292
No. of parameters169170
H-atom treatmentAll H-atom parameters refinedAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.39, 0.490.44, 0.61

Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1990), MSC/AFC Diffractometer Control Software, TEXSAN for Windows (Molecular Structure Corporation, 1997-1999), SIR92 (Altomare et al., 1993), SAPI90 (Fan, 1990), TEXSAN for Windows.

Selected bond lengths (Å) for (I) top
Cl—C21.727 (2)C1—C21.392 (3)
O1—C71.319 (3)C1—C61.388 (3)
O2—C71.191 (3)C1—C71.502 (3)
O3—N11.203 (3)C2—C31.383 (3)
O4—N11.204 (3)C3—C41.376 (3)
N1—C41.476 (3)C4—C51.375 (3)
N2—C81.315 (3)C5—C61.380 (3)
N2—C9i1.327 (3)C8—C91.370 (4)
Symmetry code: (i) x, y+1, z+1.
Hydrogen-bond geometry (Å, º) for (I) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N20.84 (3)1.85 (3)2.686 (3)175 (3)
C3—H2···O3ii0.896 (19)2.55 (2)3.294 (4)140.9 (18)
C5—H3···O2iii0.95 (2)2.45 (2)3.345 (3)158 (2)
C8—H5···O4iv0.93 (3)2.48 (3)3.053 (4)120 (2)
Symmetry codes: (ii) x+1, y+1, z; (iii) x+3/2, y1/2, z+1/2; (iv) x+3/2, y+1/2, z+1/2.
Selected bond lengths (Å) for (II) top
Cl—C21.730 (3)C1—C21.401 (3)
O1—C71.308 (3)C1—C61.396 (3)
O2—C71.197 (3)C1—C71.512 (3)
O3—N11.218 (3)C2—C31.387 (4)
O4—N11.216 (3)C3—C41.377 (4)
N1—C51.481 (3)C4—C51.370 (4)
N2—C81.335 (3)C5—C61.375 (3)
N2—C91.327 (4)C8—C9i1.376 (4)
Symmetry code: (i) x+1, y+1, z.
Hydrogen-bond geometry (Å, º) for (II) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N21.00 (3)1.71 (3)2.699 (3)173 (3)
C3—H2···O2ii0.96 (2)2.64 (2)3.496 (4)149.3 (19)
C4—H3···O3iii0.97 (2)2.53 (2)3.301 (4)136.8 (17)
Symmetry codes: (ii) x, y1/2, z+1/2; (iii) x1, y, z.
 

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