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The crystal structure of 4-chloro­nitro­benzene, C6H4ClNO2, a material that exhibits disorder in the solid state, is re-examined using multiple-temperature single-crystal X-ray diffraction. Our results show a marked improvement on previous crystal structure determinations and our comprehensive multiple temperature measurements help to rationalize the structural anomalies. 4-Chloro­nitro­benzene exhibits twofold orientational disorder of the NO2/Cl substituents, with the mol­ecule lying across an inversion centre. There is also evidence of large thermal motion, which exists at all temperatures and reflects the presence of significant disorder in this material. The nitro group shows possible libration, with one O atom exhibiting larger thermal motion than the other across the whole temperature range. This is explained by a difference in hydrogen-bonding environment.

Supporting information

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Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270108008998/hj3058sup1.cif
Contains datablocks global, I_260, I_250, I_240, I_230, I_200, I_150, I_100

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Structure factor file (CIF format) https://doi.org/10.1107/S0108270108008998/hj3058I_260sup2.hkl
Contains datablock I_260

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Structure factor file (CIF format) https://doi.org/10.1107/S0108270108008998/hj3058I_250sup3.hkl
Contains datablock I_250

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Structure factor file (CIF format) https://doi.org/10.1107/S0108270108008998/hj3058I_240sup4.hkl
Contains datablock I_240

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Structure factor file (CIF format) https://doi.org/10.1107/S0108270108008998/hj3058I_230sup5.hkl
Contains datablock I_230

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Structure factor file (CIF format) https://doi.org/10.1107/S0108270108008998/hj3058I_200sup6.hkl
Contains datablock I_200

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Structure factor file (CIF format) https://doi.org/10.1107/S0108270108008998/hj3058I_150sup7.hkl
Contains datablock I_150

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Structure factor file (CIF format) https://doi.org/10.1107/S0108270108008998/hj3058I_100sup8.hkl
Contains datablock I_100

CCDC references: 690204; 690205; 690206; 690207; 690208; 690209; 690210

Comment top

4-Chloronitrobenzene (p-ClNB) is one in a series of chloronitrobenzene derivatives that have a disordered structure in their crystalline state. Phase transitions are commonly associated with this disorder in these materials. Furthermore, there appears to be a correlation between this molecular disorder and the unusual dielectric behaviour that this series of materials tend to exhibit (Hall & Horsfall, 1973; Tanaka et al., 1974; Khotsyanova et al., 1969; Sakurai, 1962). Hitherto, three attempts to determine the crystal structure of p-ClNB have been made.

An initial indication of the nature of the crystal structure of p-ClNB was given by Toussaint (1952) who postulated that the space group could be P21/c with Z = 2 and a disordered crystal structure, or Pc with an ordered structure. It was concluded that Pc was more likely than P21/c.

A subsequent study on p-ClNB at room temperature (Mak & Trotter, 1962) revealed that the crystal structure was disordered over two possible orientations. The resulting disordered model, once refined, yielded R = 0.23 in the [100] projection and R = 0.26 in the [010] projection. An accurate determination of the bond geometry was not possible because of the disorder. However, basic analysis of intermolecular separations was able to show that all such separations corresponded to expected sums of relevant van der Waals radii. This implied that the two disordered orientations existed in the crystal structure without any steric or electronic hindrance. The fact that no diffuse scattering was observed in the measurements also led to the conclusion that the two possible disordered orientations were randomly positioned throughout the crystal structure.

More recently, a third attempt was made to reveal the nature of disorder in p-ClNB (Meriles et al., 2000). This study employed powder X-ray diffraction at a range of temperatures. Meriles et al. determined that a first-order phase-transition exists in p-ClNB at 282 K. Above this temperature, the crystal structure was found to be disordered as determined by Mak & Trotter (1962). For T < 282 K, the powder study indicated an ordered structure in space group P21, Z = 2. It is worthy of note that the crystal structure of the ordered phase was derived from a sample that had been stored cryogenically at T = 250 K for three months prior to the experiment. Such storage conditions were deemed necessary in order to ensure complete transformation to the ordered phase. Furthermore, a much higher level of background, present with a marked modulated profile, was noted in the diffraction pattern of this disordered phase compared with the low background associated with data from the ordered structure. This was attributed to diffuse scattering caused by molecular disorder.

Previously, nuclear quadrupolar resonance (NQR) has also been used to investigate this disorder on a local scale, with somewhat contradictory results (Meriles et al., 1996, 1997; González & Pusiol, 1996). In light of the limitations of the powder diffraction study, and the uncertainties observed in the various NQR spectroscopy studies, the molecular disorder in p-ClNB has been reinvestigated using multi-temperature single-crystal X-ray diffraction.

We were interested in exploring changes in the structure as a function of temperature. Data were therefore collected at 260, 250, 240, 230, 200, 150 and 100 K, and then again at 260 K to check for any hysteresis effects. The crystal was also observed to show a significant degree of sublimation at 270 K, making it difficult to collect data at this temperature. Subsequent thermogravimetric analysis (TGA) indicated that a sample the size of that used would diminish to around 10% of its initial volume in 50 min when held at 310 K, confirming its propensity to sublimation. The crystal structure solves to a twofold orientationally disordered model with the molecule lying across an inversion centre, as shown in Fig. 1. As the most accurate available determination, the 100 K structure is discussed further.

Owing to the molecular disorder, the Cl and N atomic fractions on each benzene-substituted site lie very close to one another in the model, resulting in a severe overlap of electron density contributions to scattering on each site. This, combined with the fact that Cl possesses a much higher electron density, makes it difficult to determine accurately the position of the N atom (and hence to draw any conclusions on its thermal motion, see above). Fourier maps calculated in the region of the NO2/Cl groups, however, clearly confirm the presence of both groups on this site (Fig. 2).

The difficulty in assigning the electron density associated with the N and Cl atoms due to the presence of the disorder results in the apparent C—Cl distance from the refinement being longer than expected [1.903 (3) Å at100 K], whilst the apparent C—N distance is shorter than expected [1.330 (6) Å at 100 K]. The mean C—Cl distance in the Cambridge Structural Database (CSD; Allen, 2002; Bruno et al., 2002) for a Cl atom bonded to a benzene ring is 1.734 Å, the total range of values present being between 1.592 and 1.789 Å. The value found here is outside that range. The mean N—C bond length for an N atom within a nitro group bonded to a benzene ring is 1.467 Å, and the range found in the CSD is 1.396–1.544 Å. Again, the observed value for the unconstrained refinement here lies outside of this range. These bond lengths could be explained by consideration of the displacement ellipsoids of the C atoms in the benzene ring, as they are all elongated in the direction of the Cl atom/nitro group (Fig. 1). This could be interpreted in terms of the presence of two positions on each lattice point shifted relative to one another depending on the orientation of the molecule. The N atom is also located slightly off-centre, and thus one N—O bond length is considerably shorter than the other, with asymmetric O—N—C bond angles. The electron density associated with the O atoms is well defined and isolated from any other atoms, as shown in the difference Fourier maps (Fig. 2), and thus their positions could be considered to be more certain than the position of the N atom, whose electron density is located close to that of the Cl atom.

In the light of these abnormal bond lengths, a series of restraints and constraints were applied to the refinement to augment the initial unconstrained refinement and the visual information from the Fourier difference maps. Initially, the O—N bond lengths were restrained to take the same value – this geometry would be expected in a disorder-free symmetric nitro group (Fig. 3a). This restraint resulted in an increase in the R factor at 100 K from 0.0456 to 0.0464. The effect of applying this restraint is to equalize the N—O bond distances somewhat, but at the expense of shortening the N—C bond length further (Table 8). A stronger constraint could be applied, but this resulted in a further rise in the R factor and a further shortening of the N—C bond length, although it does force the O—N bond lengths to be equivalent and the O—N—C angles to be more similar (Fig. 3b). Application of the equivalent similarity restraints for the O—N—C angles resulted in similar effects. A refinement was also attempted to force the C—Cl and C—N bond lengths to take more conventional values (1.74 and 1.47 Å, respectively). This has the effect of shortening the N—O bond lengths to values shorter than those reported in the CSD (Bruno et al., 2002), but the values of the N—O distances and O—N—C angles are more symmetric. However, there is a significant rise in the R factor, and the Fourier difference map arising from the model clearly shows excess electron density around both the Cl and the N atoms, and some areas where too much electron density has been allocated (Fig. 3c). The anisotropic atomic displacement parameters also become extremely elongated, suggesting that this is not a good model. Fixing the N—O bond lengths to a more conventional value of 1.221 Å caused the R factor to rise to 0.0480 (Fig. 3d). However, the N—O bond lengths become relatively similar, as do the O—N—C bond angles. The N—C bond length is shorter than that found in the freely refined case, and the C—Cl bond length is slightly longer. This perhaps provides the best model for the molecule, as the nitro group is forced to adopt a more regular geometry. The model is still limited in the sense that it fails to deal adequately with the abnormal N—C and Cl—C bond lengths. This may suggest that the disorder is not simply a case of the molecule being flipped about a central point; rather, there is some translational component in the superposition of the two molecular orientations. Attempts were made to refine the structure in P21, but these gave a poorer agreement while not affecting the refined occupancies; P21/c appears to be the most appropriate space group for this refinement.

The average structure reveals two contacts that are shorter than the sum of the van der Waals radii (VDW). The first creates a dimer unit with a close O···H distance of 2.47 (2) Å at 100 K (VDW = 2.72 Å), and the second, a close O···Cl contact of 3.112 (4) Å (VDW = 3.27 Å). The dimers are not quite coplanar (Fig. 4). The O···Cl contact lies approximately along the line of the C—Cl bond (Fig. 5).

In general, the thermal motion of p-ClNB (Fig. 1) appears to be large at all temperatures (e.g. Table 9). It is possible that there is complex static disorder present, where two possible orientations that do not entirely overlap are are translationally displaced from one another. It is not possible to reach any firm conclusions regarding the potential disorder using standard Bragg scattering techniques – instead, modelling of diffuse scattering can yield information on this (e.g. Thomas et al., 2007). The most significant thermal motion of the NO2 group is observed in U33. The electron density spatial overlap problems corresponding to the N and Cl atoms may place some limitations on the accuracy of the atomic positions for these atoms (Fig. 2). However, atom O1 is found to be librating more than atom O2. This may be explained by considering the number of close intermolecular contacts in the packing of the molecules. Atom O2 [O1 according to Table 7; please check other references to O1 and O2 in this paragraph] is involved in a weak hydrogen bond (Desiraju & Steiner, 2001), where the interatomic distance [2.47 (2) Å] is less than the sum of the van der Waals radii of the twSD = Cambridge structural database.o atoms (2.72 Å) (Fig. 4). Atom O1 [O2?] has a close interatomic contact between the O and H atoms that is on the limit of the sum of the van der Waals radii [2.68 (2) Å]. There is also a close Cl···O intermolecular contact [3.112 (4) Å] involving O2 (Fig. 5). These interactions may place restrictions on the freedom of atom O2 to librate relative to that of O1, which may lead to the enhanced motion of one relative to the other.

Whilst no crystallographic phase transition was found in the temperature range 100–260 K, the possible drop in the cell parameter b (and possibly in c) at temperatures higher than 250 K (Fig. 6) hints at an incipient phase transition in this temperature region. This observation could relate to the phase transition revealed by Meriles et al. (2000), though there is a temperature mismatch. Analysis of Uii as a function of temperature also show nitrogen to behave slightly anomalously upon cooling, in the temperature region 230–250 K, though this effect can be complicated in this case as a result of the disorder present. We could not collect a corresponding single-crystal data set for this material at temperatures above 282 K, however, since we observed that the sample sublimed before a full data set could be collected.

In conclusion, the crystal structure of p-ClNB has been studied at multiple temperatures to investigate the possibility of a phase transition at low temperature. The structure was found to be the same at all the temperatures studied, with the orientational disorder persisting at least down to 100 K; the refined disordered structure is of far higher quality than that obtained previously. The freely refined structure finds the O—N bond lengths to be asymmetric, and the N—C and Cl—C distances to be shorter and longer, respectively, than would be expected. The application of a series of restraints and constraints addressed the asymmetry of the N—O bond lengths but at the expense of perturbing the Cl—C and N—C bond lengths. This result potentially highlights a translational component to the disorder. The material shows significant thermal motion, but hydrogen bonding places restrictions upon the movement of one O atom relative to the other, resulting in an asymmetric libration of the nitro group. It is noted that the displacment ellipsoid model does not provide a comprehensive description of the possible libration of the NO2 group of this compound. This fact suggests that a different modelling technique may be needed to understand better the thermal motion and possible libration observed. In this regard, total scattering studies of this material are in progress, since an analysis of both diffuse and Bragg scattering should also allow us to understand more fully the nature of the disorder – in particular, if there is a latent dynamic component of the disorder or a static translational shift in the positions of the two orientations. Indeed, structured diffuse scattering has already been observed in the diffraction pattern of p-ClNB (Thomas, 2007). These more sophisticated disorder models will be constructed using techniques similar to those in a study of the related compound pentachloronitrobenzene (Thomas et al., 2007).

Related literature top

For related literature, see: Bruno et al. (2002); Khotsyanova et al. (1969); Meriles et al. (1996); Meriles et al. (1997); Meriles et al. (2000); Thomas et al. (2007); Allen (2002); Desiraju & Steiner (2001); Hall & Horsfall (1973); Mak & Trotter (1962); Sakurai (1962); Sheldrick (1997); Thomas (2007); Toussaint (1952).

Experimental top

A single crystal of p-ClNB was grown from diethyl ether by slow evaporation at room temperature. Data were collected at 100, 150, 200, 230, 240, 250 and 260 K to check for any signs of a phase transition. Attempts were also made to collect data at room temperature but the crystal sublimed before a full data set could be collected. An open-flow nitrogen Oxford Cryosystems cryostream was used for the multiple-temperature measurements.

Refinement top

The molecule exhibits twofold disorder (50:50 Cl:N occupancy). This disorder persists to low temperature, at least to 100 K. H atoms were located from Fourier difference maps and their fractional coordinates and isotropic displacement parameters were refined.

Computing details top

For all compounds, data collection: COLLECT (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The disorder in 4-chloronitrobenzene at (a) 100 K, (b) 200 K and (c) 260 K. Displacement ellipsoids are plotted at the 50% probability level.
[Figure 2] Fig. 2. (a) A difference Fourier image showing the NO2 group calculated using a model with NO2 removed and (b) an Fobs image of the Cl atom in the structure of p-ClNB at 100 K. (Areas of high electron density are coloured red in the online version of the journal and areas of low electron density are blue.)
[Figure 3] Fig. 3. Fourier difference maps for the restrained and constrained models, with all atoms defined in the structure. (a) The restrained N—O bond lengths with 0.02 Å standard deviation; (b) the restrained N—O bond lengths with 0.002 Å standard deviation; (c) the case where the Cl—C and N—C bond lengths are forced to be close to their standard values; and (d) the case where the N—O bond lengths are restrained to be close to their standard values. The Fourier difference maps for (a), (b) and (d) are similar. The Fourier difference map for (c) clearly shows the unaccounted and over-accounted for electron density. (Areas of high electron density are coloured red in the online version of the journal and areas of low electron density are blue.)
[Figure 4] Fig. 4. The shortest hydrogen bonds in p-ClNB. (a) The chains of molecules connected by hydrogen bonds. Hydrogen bonding is shown with dashed lines. (b) The molecules are close to coplanar.
[Figure 5] Fig. 5. (a) The Cl—O close contacts between molecules in p-ClNB. (b) The nonplanar nature of the related molecules. Cl—O intermolecular interactions are represented by dashed lines. Adjacent molecules are related by the symmetry operation (-x, y + 1/2, -z + 1/2).
[Figure 6] Fig. 6. Unit-cell lengths of p-ClNB, normalized as length/(length at 100 K), as a function of temperature.
(I_260) 4-chloronitrobenzene top
Crystal data top
C6H4ClNO2F(000) = 160
Mr = 157.55Dx = 1.534 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 3.8011 (8) ÅCell parameters from 1163 reflections
b = 6.7639 (14) Åθ = 1.0–27.5°
c = 13.364 (3) ŵ = 0.49 mm1
β = 96.82 (3)°T = 260 K
V = 341.17 (12) Å3Needle, white
Z = 20.4 × 0.16 × 0.1 mm
Data collection top
Nonius KappaCCD
diffractometer
730 independent reflections
Radiation source: fine-focus sealed tube365 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.040
CCD scansθmax = 27.2°, θmin = 3.4°
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
h = 44
Tmin = 0.842, Tmax = 0.952k = 88
2014 measured reflectionsl = 1617
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.046Hydrogen site location: difference Fourier map
wR(F2) = 0.134All H-atom parameters refined
S = 1.04 w = 1/[σ2(Fo2) + (0.0562P)2 + 0.0122P]
where P = (Fo2 + 2Fc2)/3
730 reflections(Δ/σ)max < 0.001
72 parametersΔρmax = 0.17 e Å3
0 restraintsΔρmin = 0.20 e Å3
Crystal data top
C6H4ClNO2V = 341.17 (12) Å3
Mr = 157.55Z = 2
Monoclinic, P21/cMo Kα radiation
a = 3.8011 (8) ŵ = 0.49 mm1
b = 6.7639 (14) ÅT = 260 K
c = 13.364 (3) Å0.4 × 0.16 × 0.1 mm
β = 96.82 (3)°
Data collection top
Nonius KappaCCD
diffractometer
730 independent reflections
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
365 reflections with I > 2σ(I)
Tmin = 0.842, Tmax = 0.952Rint = 0.040
2014 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0460 restraints
wR(F2) = 0.134All H-atom parameters refined
S = 1.04Δρmax = 0.17 e Å3
730 reflectionsΔρmin = 0.20 e Å3
72 parameters
Special details top

Experimental. disordered material, sample sublimes at room temperature

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. The disordered model where the asymmetric unit is half a molecule has a 50% occupancy of chlorine:nitro group as the one non-hydrogen substituent.

Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cl10.1529 (11)0.3364 (8)0.3476 (4)0.1081 (16)0.50
C10.3526 (6)0.1339 (5)0.4342 (2)0.0752 (8)
C30.3945 (6)0.1828 (5)0.5336 (2)0.0808 (8)
C20.4554 (6)0.0456 (5)0.3993 (2)0.0848 (8)
O20.1509 (13)0.2141 (8)0.2787 (4)0.1142 (17)0.50
O10.1142 (19)0.4178 (10)0.4009 (8)0.149 (3)0.50
N10.196 (3)0.2529 (16)0.3630 (12)0.105 (4)0.50
H10.418 (6)0.064 (4)0.335 (2)0.093 (8)*
H20.321 (7)0.311 (4)0.5560 (19)0.110 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0848 (13)0.132 (5)0.1042 (19)0.008 (2)0.0009 (11)0.040 (3)
C10.0548 (13)0.094 (2)0.0775 (17)0.0127 (12)0.0123 (11)0.0012 (17)
C30.0710 (14)0.091 (2)0.0811 (19)0.0116 (13)0.0132 (11)0.0176 (17)
C20.0771 (14)0.115 (2)0.0632 (17)0.0191 (14)0.0125 (11)0.0222 (17)
O20.134 (4)0.118 (4)0.087 (3)0.010 (3)0.002 (3)0.021 (3)
O10.151 (5)0.087 (4)0.208 (7)0.028 (3)0.016 (5)0.015 (5)
N10.075 (5)0.069 (6)0.177 (13)0.005 (4)0.039 (7)0.012 (6)
Geometric parameters (Å, º) top
Cl1—C11.892 (4)C3—H20.97 (3)
C1—N11.332 (11)C2—C3i1.367 (4)
C1—C31.360 (3)C2—H10.87 (3)
C1—C21.374 (4)O2—N11.149 (17)
C3—C2i1.367 (4)O1—N11.279 (17)
N1—C1—C3122.8 (7)C2i—C3—H2121.2 (15)
N1—C1—C2114.4 (7)C3i—C2—C1119.4 (3)
C3—C1—C2122.8 (3)C3i—C2—H1124.2 (16)
C3—C1—Cl1114.4 (3)C1—C2—H1116.4 (16)
C2—C1—Cl1122.8 (3)O2—N1—O1125.0 (11)
C1—C3—C2i117.8 (3)O2—N1—C1124.3 (10)
C1—C3—H2120.9 (15)O1—N1—C1110.6 (12)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1ii0.97 (3)2.58 (3)3.493 (8)157 (2)
C2—H1···O2iii0.87 (3)2.80 (2)3.374 (6)125.3 (19)
Symmetry codes: (ii) x, y+1, z+1; (iii) x+1, y1/2, z+1/2.
(I_250) 4-chloronitrobenzene top
Crystal data top
C6H4ClNO2F(000) = 160
Mr = 157.55Dx = 1.534 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 3.7938 (3) ÅCell parameters from 1300 reflections
b = 6.7564 (6) Åθ = 1.0–27.5°
c = 13.3672 (15) ŵ = 0.49 mm1
β = 96.639 (3)°T = 250 K
V = 340.34 (6) Å3Needle, white
Z = 20.4 × 0.16 × 0.1 mm
Data collection top
Nonius KappaCCD
diffractometer
748 independent reflections
Radiation source: fine-focus sealed tube385 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.037
CCD scansθmax = 27.6°, θmin = 3.4°
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
h = 44
Tmin = 0.844, Tmax = 0.944k = 88
2071 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.052Hydrogen site location: difference Fourier map
wR(F2) = 0.139All H-atom parameters refined
S = 1.08 w = 1/[σ2(Fo2) + (0.0603P)2 + 0.002P]
where P = (Fo2 + 2Fc2)/3
748 reflections(Δ/σ)max = 0.001
72 parametersΔρmax = 0.13 e Å3
0 restraintsΔρmin = 0.15 e Å3
Crystal data top
C6H4ClNO2V = 340.34 (6) Å3
Mr = 157.55Z = 2
Monoclinic, P21/cMo Kα radiation
a = 3.7938 (3) ŵ = 0.49 mm1
b = 6.7564 (6) ÅT = 250 K
c = 13.3672 (15) Å0.4 × 0.16 × 0.1 mm
β = 96.639 (3)°
Data collection top
Nonius KappaCCD
diffractometer
748 independent reflections
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
385 reflections with I > 2σ(I)
Tmin = 0.844, Tmax = 0.944Rint = 0.037
2071 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0520 restraints
wR(F2) = 0.139All H-atom parameters refined
S = 1.08Δρmax = 0.13 e Å3
748 reflectionsΔρmin = 0.15 e Å3
72 parameters
Special details top

Experimental. disordered material, sample sublimes at room temperature

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. The disordered model where the asymmetric unit is half a molecule has a 50% occupancy of chlorine:nitro group as the one non-hydrogen substituent.

Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cl10.1499 (9)0.3349 (7)0.3480 (3)0.0999 (14)0.50
C10.3532 (6)0.1341 (5)0.43434 (19)0.0707 (7)
C30.3950 (6)0.1824 (5)0.5338 (2)0.0772 (8)
C20.4547 (6)0.0464 (5)0.3997 (2)0.0800 (8)
O20.1481 (13)0.2122 (8)0.2788 (4)0.1092 (17)0.50
O10.1115 (18)0.4201 (9)0.3984 (7)0.134 (3)0.50
N10.207 (3)0.2521 (15)0.3610 (11)0.106 (5)0.50
H10.418 (6)0.063 (4)0.336 (2)0.092 (8)*
H20.319 (6)0.311 (4)0.5554 (17)0.095 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0761 (15)0.123 (4)0.0984 (19)0.000 (2)0.0017 (11)0.033 (3)
C10.0473 (12)0.0897 (19)0.0759 (16)0.0104 (12)0.0110 (10)0.0021 (16)
C30.0673 (14)0.093 (2)0.0725 (18)0.0092 (13)0.0133 (11)0.0188 (15)
C20.0686 (14)0.113 (2)0.0592 (16)0.0162 (14)0.0115 (11)0.0173 (17)
O20.128 (4)0.113 (4)0.083 (3)0.010 (3)0.006 (2)0.024 (3)
O10.134 (5)0.077 (4)0.190 (7)0.027 (3)0.018 (4)0.014 (4)
N10.059 (5)0.066 (6)0.196 (14)0.003 (4)0.029 (6)0.005 (7)
Geometric parameters (Å, º) top
Cl1—C11.887 (4)C3—H20.97 (3)
C1—N11.334 (11)C2—C3i1.358 (4)
C1—C31.360 (3)C2—H10.86 (3)
C1—C21.375 (4)O2—N11.128 (16)
C3—C2i1.358 (4)O1—N11.308 (14)
N1—C1—C3124.5 (7)C1—C3—H2120.0 (14)
N1—C1—C2113.0 (6)C3i—C2—C1119.5 (3)
C3—C1—C2122.5 (3)C3i—C2—H1125.0 (17)
C3—C1—Cl1114.8 (3)C1—C2—H1115.5 (17)
C2—C1—Cl1122.8 (3)O2—N1—O1123.2 (11)
C2i—C3—C1118.1 (3)O2—N1—C1126.3 (10)
C2i—C3—H2122.0 (14)O1—N1—C1110.3 (11)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1ii0.97 (3)2.56 (3)3.482 (7)158 (2)
C2—H1···O2iii0.86 (3)2.82 (3)3.384 (6)124.9 (19)
Symmetry codes: (ii) x, y+1, z+1; (iii) x+1, y1/2, z+1/2.
(I_240) 4-chloronitrobenzene top
Crystal data top
C6H4ClNO2F(000) = 160
Mr = 157.55Dx = 1.540 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 3.7880 (3) ÅCell parameters from 1282 reflections
b = 6.7482 (6) Åθ = 1.0–27.5°
c = 13.3755 (14) ŵ = 0.49 mm1
β = 96.47 (3)°T = 240 K
V = 339.73 (5) Å3Needle, white
Z = 20.4 × 0.16 × 0.1 mm
Data collection top
Nonius KappaCCD
diffractometer
747 independent reflections
Radiation source: fine-focus sealed tube390 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.047
CCD scansθmax = 27.4°, θmin = 3.4°
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
h = 44
Tmin = 0.850, Tmax = 0.945k = 88
2069 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.045Hydrogen site location: difference Fourier map
wR(F2) = 0.122All H-atom parameters refined
S = 1.04 w = 1/[σ2(Fo2) + (0.0499P)2 + 0.0142P]
where P = (Fo2 + 2Fc2)/3
747 reflections(Δ/σ)max = 0.002
72 parametersΔρmax = 0.16 e Å3
0 restraintsΔρmin = 0.20 e Å3
Crystal data top
C6H4ClNO2V = 339.73 (5) Å3
Mr = 157.55Z = 2
Monoclinic, P21/cMo Kα radiation
a = 3.7880 (3) ŵ = 0.49 mm1
b = 6.7482 (6) ÅT = 240 K
c = 13.3755 (14) Å0.4 × 0.16 × 0.1 mm
β = 96.47 (3)°
Data collection top
Nonius KappaCCD
diffractometer
747 independent reflections
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
390 reflections with I > 2σ(I)
Tmin = 0.850, Tmax = 0.945Rint = 0.047
2069 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0450 restraints
wR(F2) = 0.122All H-atom parameters refined
S = 1.04Δρmax = 0.16 e Å3
747 reflectionsΔρmin = 0.20 e Å3
72 parameters
Special details top

Experimental. disordered material, sample sublimes at room temperature

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. The disordered model where the asymmetric unit is half a molecule has a 50% occupancy of chlorine:nitro group as the one non-hydrogen substituent.

Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cl10.1503 (8)0.3347 (6)0.3477 (2)0.0926 (11)0.50
C10.3528 (5)0.1331 (4)0.43350 (16)0.0668 (6)
C30.3944 (5)0.1831 (4)0.53347 (18)0.0739 (7)
C20.4538 (5)0.0470 (4)0.3993 (2)0.0752 (7)
O20.1471 (12)0.2114 (7)0.2783 (4)0.1030 (15)0.50
O10.1135 (16)0.4206 (8)0.3982 (6)0.127 (2)0.50
N10.201 (3)0.2496 (13)0.3606 (10)0.100 (4)0.50
H10.414 (5)0.075 (3)0.3311 (18)0.081 (6)*
H20.314 (6)0.311 (4)0.5574 (16)0.094 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0736 (12)0.111 (3)0.0912 (15)0.0028 (19)0.0002 (9)0.031 (2)
C10.0458 (11)0.0858 (18)0.0694 (15)0.0117 (11)0.0088 (9)0.0006 (14)
C30.0612 (12)0.0872 (19)0.0747 (17)0.0097 (12)0.0128 (10)0.0180 (14)
C20.0645 (12)0.105 (2)0.0569 (14)0.0142 (12)0.0107 (10)0.0238 (15)
O20.116 (3)0.108 (3)0.082 (3)0.004 (2)0.004 (2)0.021 (3)
O10.128 (4)0.073 (3)0.178 (6)0.022 (2)0.010 (4)0.004 (4)
N10.062 (4)0.050 (5)0.193 (12)0.001 (3)0.034 (6)0.006 (6)
Geometric parameters (Å, º) top
Cl1—C11.886 (3)C3—H20.98 (2)
C1—N11.331 (9)C2—C3i1.366 (3)
C1—C21.368 (3)C2—H10.93 (2)
C1—C31.371 (3)O2—N11.127 (14)
C3—C2i1.366 (3)O1—N11.316 (11)
N1—C1—C2113.2 (5)C1—C3—H2122.0 (13)
N1—C1—C3124.1 (6)C3i—C2—C1119.3 (2)
C2—C1—C3122.6 (3)C3i—C2—H1121.6 (13)
C2—C1—Cl1123.2 (2)C1—C2—H1119.1 (13)
C3—C1—Cl1114.2 (3)O2—N1—O1123.2 (9)
C2i—C3—C1118.0 (3)O2—N1—C1126.6 (8)
C2i—C3—H2119.9 (13)O1—N1—C1110.2 (10)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1ii0.98 (2)2.54 (3)3.476 (6)158.6 (19)
C2—H1···O2iii0.93 (2)2.75 (2)3.376 (5)126.0 (15)
Symmetry codes: (ii) x, y+1, z+1; (iii) x+1, y1/2, z+1/2.
(I_230) 4-chloronitrobenzene top
Crystal data top
C6H4ClNO2F(000) = 160
Mr = 157.55Dx = 1.546 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 3.7801 (3) ÅCell parameters from 1212 reflections
b = 6.7338 (6) Åθ = 1.0–27.5°
c = 13.3758 (15) ŵ = 0.49 mm1
β = 96.34 (3)°T = 230 K
V = 338.39 (6) Å3Needle, white
Z = 20.4 × 0.16 × 0.1 mm
Data collection top
Nonius KappaCCD
diffractometer
719 independent reflections
Radiation source: fine-focus sealed tube396 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.049
CCD scansθmax = 27.3°, θmin = 3.4°
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
h = 44
Tmin = 0.857, Tmax = 0.943k = 88
1934 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049Hydrogen site location: difference Fourier map
wR(F2) = 0.126All H-atom parameters refined
S = 1.06 w = 1/[σ2(Fo2) + (0.0475P)2 + 0.0323P]
where P = (Fo2 + 2Fc2)/3
719 reflections(Δ/σ)max = 0.003
72 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C6H4ClNO2V = 338.39 (6) Å3
Mr = 157.55Z = 2
Monoclinic, P21/cMo Kα radiation
a = 3.7801 (3) ŵ = 0.49 mm1
b = 6.7338 (6) ÅT = 230 K
c = 13.3758 (15) Å0.4 × 0.16 × 0.1 mm
β = 96.34 (3)°
Data collection top
Nonius KappaCCD
diffractometer
719 independent reflections
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
396 reflections with I > 2σ(I)
Tmin = 0.857, Tmax = 0.943Rint = 0.049
1934 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.126All H-atom parameters refined
S = 1.06Δρmax = 0.21 e Å3
719 reflectionsΔρmin = 0.25 e Å3
72 parameters
Special details top

Experimental. disordered material, sample sublimes at room temperature

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. The disordered model where the asymmetric unit is half a molecule has a 50% occupancy of chlorine:nitro group as the one non-hydrogen substituent.

Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cl10.1500 (8)0.3347 (6)0.3472 (3)0.0886 (11)0.50
C10.3513 (5)0.1336 (4)0.43346 (17)0.0635 (7)
C30.3942 (6)0.1839 (5)0.5331 (2)0.0707 (7)
C20.4544 (6)0.0479 (5)0.3997 (2)0.0735 (8)
O20.1468 (12)0.2115 (7)0.2784 (4)0.0964 (15)0.50
O10.1123 (16)0.4216 (8)0.3987 (6)0.120 (2)0.50
N10.198 (3)0.2499 (13)0.3612 (10)0.089 (3)0.50
H10.420 (6)0.072 (3)0.3351 (19)0.079 (7)*
H20.314 (7)0.314 (4)0.5534 (18)0.094 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0711 (12)0.107 (3)0.0858 (16)0.0033 (19)0.0012 (9)0.031 (2)
C10.0442 (12)0.0849 (18)0.0622 (15)0.0119 (11)0.0091 (9)0.0000 (14)
C30.0590 (13)0.0835 (19)0.0704 (17)0.0108 (12)0.0109 (11)0.0148 (14)
C20.0609 (14)0.105 (2)0.0554 (16)0.0157 (13)0.0113 (11)0.0222 (16)
O20.113 (3)0.099 (3)0.074 (3)0.007 (2)0.007 (2)0.021 (3)
O10.119 (4)0.069 (3)0.169 (6)0.018 (2)0.013 (4)0.002 (4)
N10.059 (4)0.051 (5)0.159 (10)0.001 (3)0.023 (5)0.010 (5)
Geometric parameters (Å, º) top
Cl1—C11.884 (4)C3—H20.98 (3)
C1—N11.326 (9)C2—C3i1.364 (4)
C1—C31.368 (3)C2—H10.87 (2)
C1—C21.374 (4)O2—N11.133 (13)
C3—C2i1.364 (4)O1—N11.315 (12)
N1—C1—C3124.0 (6)C1—C3—H2119.0 (15)
N1—C1—C2113.7 (6)C3i—C2—C1119.6 (2)
C3—C1—C2122.2 (3)C3i—C2—H1122.1 (15)
C3—C1—Cl1114.6 (3)C1—C2—H1118.2 (15)
C2—C1—Cl1123.2 (2)O2—N1—O1123.4 (9)
C2i—C3—C1118.2 (3)O2—N1—C1126.2 (8)
C2i—C3—H2122.8 (15)O1—N1—C1110.4 (9)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1ii0.98 (3)2.53 (3)3.455 (7)158 (2)
C2—H1···O2iii0.87 (2)2.77 (2)3.372 (5)127.4 (18)
Symmetry codes: (ii) x, y+1, z+1; (iii) x+1, y1/2, z+1/2.
(I_200) 4-chloronitrobenzene top
Crystal data top
C6H4ClNO2F(000) = 160
Mr = 157.55Dx = 1.556 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 3.7635 (3) ÅCell parameters from 1399 reflections
b = 6.7201 (6) Åθ = 1.0–27.5°
c = 13.3762 (14) ŵ = 0.50 mm1
β = 96.13 (3)°T = 200 K
V = 336.37 (5) Å3Needle, white
Z = 20.4 × 0.16 × 0.1 mm
Data collection top
Nonius KappaCCD
diffractometer
736 independent reflections
Radiation source: fine-focus sealed tube448 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.046
CCD scansθmax = 27.4°, θmin = 3.1°
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
h = 44
Tmin = 0.838, Tmax = 0.946k = 88
2051 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.047Hydrogen site location: difference Fourier map
wR(F2) = 0.119All H-atom parameters refined
S = 1.07 w = 1/[σ2(Fo2) + (0.0446P)2 + 0.0385P]
where P = (Fo2 + 2Fc2)/3
736 reflections(Δ/σ)max = 0.004
72 parametersΔρmax = 0.15 e Å3
0 restraintsΔρmin = 0.26 e Å3
Crystal data top
C6H4ClNO2V = 336.37 (5) Å3
Mr = 157.55Z = 2
Monoclinic, P21/cMo Kα radiation
a = 3.7635 (3) ŵ = 0.50 mm1
b = 6.7201 (6) ÅT = 200 K
c = 13.3762 (14) Å0.4 × 0.16 × 0.1 mm
β = 96.13 (3)°
Data collection top
Nonius KappaCCD
diffractometer
736 independent reflections
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
448 reflections with I > 2σ(I)
Tmin = 0.838, Tmax = 0.946Rint = 0.046
2051 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0470 restraints
wR(F2) = 0.119All H-atom parameters refined
S = 1.07Δρmax = 0.15 e Å3
736 reflectionsΔρmin = 0.26 e Å3
72 parameters
Special details top

Experimental. disordered material, sample sublimes at room temperature

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. The disordered model where the asymmetric unit is half a molecule has a 50% occupancy of chlorine:nitro group as the one non-hydrogen substituent.

Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cl10.1506 (8)0.3339 (5)0.3462 (2)0.0800 (9)0.50
C10.3508 (5)0.1338 (4)0.43350 (15)0.0586 (6)
C30.3939 (5)0.1847 (4)0.53332 (17)0.0639 (7)
C20.4536 (5)0.0484 (4)0.39946 (19)0.0657 (7)
O20.1452 (10)0.2104 (6)0.2780 (3)0.0837 (11)0.50
O10.1124 (13)0.4226 (7)0.3973 (5)0.1081 (19)0.50
N10.196 (2)0.2515 (12)0.3625 (8)0.080 (3)0.50
H10.420 (6)0.076 (3)0.3337 (18)0.073 (7)*
H20.323 (6)0.312 (4)0.5546 (15)0.074 (7)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0625 (10)0.099 (3)0.0771 (12)0.0048 (17)0.0003 (7)0.0296 (17)
C10.0396 (11)0.0776 (16)0.0593 (13)0.0102 (10)0.0089 (9)0.0004 (13)
C30.0519 (12)0.0769 (17)0.0642 (15)0.0093 (11)0.0118 (10)0.0189 (13)
C20.0543 (12)0.0953 (19)0.0482 (13)0.0141 (11)0.0093 (9)0.0194 (13)
O20.098 (3)0.085 (3)0.065 (2)0.0046 (19)0.0047 (19)0.019 (2)
O10.102 (3)0.063 (3)0.159 (5)0.020 (2)0.013 (3)0.002 (3)
N10.052 (4)0.052 (5)0.140 (9)0.007 (3)0.024 (5)0.011 (4)
Geometric parameters (Å, º) top
Cl1—C11.885 (3)C3—H20.95 (2)
C1—N11.323 (8)C2—C3i1.366 (3)
C1—C31.371 (3)C2—H10.89 (2)
C1—C21.376 (3)O2—N11.159 (11)
C3—C2i1.366 (3)O1—N11.291 (10)
N1—C1—C3123.2 (5)C1—C3—H2120.6 (13)
N1—C1—C2114.4 (5)C3i—C2—C1119.5 (2)
C3—C1—C2122.4 (2)C3i—C2—H1120.8 (14)
C3—C1—Cl1115.1 (2)C1—C2—H1119.7 (14)
C2—C1—Cl1122.5 (2)O2—N1—O1122.8 (8)
C2i—C3—C1118.1 (2)O2—N1—C1124.8 (8)
C2i—C3—H2121.3 (13)O1—N1—C1112.3 (9)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1ii0.95 (2)2.55 (2)3.440 (6)156.0 (18)
C2—H1···O2iii0.89 (2)2.74 (2)3.363 (5)128.1 (16)
Symmetry codes: (ii) x, y+1, z+1; (iii) x+1, y1/2, z+1/2.
(I_150) 4-chloronitrobenzene top
Crystal data top
C6H4ClNO2F(000) = 160
Mr = 157.55Dx = 1.574 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 3.7372 (2) ÅCell parameters from 1413 reflections
b = 6.6991 (5) Åθ = 1.0–27.5°
c = 13.3748 (13) ŵ = 0.50 mm1
β = 96.84 (3)°T = 150 K
V = 332.47 (4) Å3Needle, white
Z = 20.4 × 0.16 × 0.1 mm
Data collection top
Nonius KappaCCD
diffractometer
734 independent reflections
Radiation source: fine-focus sealed tube490 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.042
CCD scansθmax = 27.6°, θmin = 3.4°
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
h = 44
Tmin = 0.864, Tmax = 0.946k = 88
2046 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.046Hydrogen site location: difference Fourier map
wR(F2) = 0.113All H-atom parameters refined
S = 1.08 w = 1/[σ2(Fo2) + (0.0403P)2 + 0.0675P]
where P = (Fo2 + 2Fc2)/3
734 reflections(Δ/σ)max = 0.017
72 parametersΔρmax = 0.17 e Å3
0 restraintsΔρmin = 0.22 e Å3
Crystal data top
C6H4ClNO2V = 332.47 (4) Å3
Mr = 157.55Z = 2
Monoclinic, P21/cMo Kα radiation
a = 3.7372 (2) ŵ = 0.50 mm1
b = 6.6991 (5) ÅT = 150 K
c = 13.3748 (13) Å0.4 × 0.16 × 0.1 mm
β = 96.84 (3)°
Data collection top
Nonius KappaCCD
diffractometer
734 independent reflections
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
490 reflections with I > 2σ(I)
Tmin = 0.864, Tmax = 0.946Rint = 0.042
2046 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0460 restraints
wR(F2) = 0.113All H-atom parameters refined
S = 1.08Δρmax = 0.17 e Å3
734 reflectionsΔρmin = 0.22 e Å3
72 parameters
Special details top

Experimental. disordered material, sample sublimes at room temperature

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. The disordered model where the asymmetric unit is half a molecule has a 50% occupancy of chlorine:nitro group as the one non-hydrogen substituent.

Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cl10.1481 (6)0.3346 (5)0.3449 (2)0.0664 (8)0.50
C10.3501 (5)0.1339 (3)0.43288 (14)0.0493 (6)
C30.3945 (5)0.1869 (4)0.53304 (15)0.0532 (6)
C20.4532 (5)0.0503 (4)0.39927 (17)0.0556 (6)
O20.1452 (9)0.2088 (5)0.2771 (3)0.0663 (9)0.50
O10.1101 (11)0.4229 (6)0.3972 (5)0.0866 (14)0.50
N10.1947 (19)0.2540 (10)0.3626 (7)0.060 (2)0.50
H10.420 (6)0.078 (3)0.3323 (17)0.063 (6)*
H20.316 (6)0.318 (3)0.5549 (16)0.066 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0488 (9)0.087 (2)0.0616 (9)0.0051 (12)0.0002 (6)0.0262 (14)
C10.0284 (9)0.0709 (15)0.0489 (11)0.0116 (9)0.0055 (8)0.0030 (11)
C30.0403 (10)0.0674 (15)0.0529 (13)0.0091 (10)0.0087 (9)0.0155 (11)
C20.0432 (11)0.0834 (17)0.0414 (12)0.0145 (10)0.0097 (8)0.0199 (12)
O20.075 (2)0.071 (2)0.0507 (18)0.0037 (16)0.0023 (15)0.0140 (17)
O10.085 (3)0.055 (3)0.120 (4)0.0197 (19)0.010 (3)0.002 (3)
N10.038 (3)0.041 (4)0.106 (7)0.003 (2)0.019 (3)0.005 (3)
Geometric parameters (Å, º) top
Cl1—C11.884 (3)C3—H20.98 (2)
C1—N11.319 (7)C2—C3i1.363 (3)
C1—C31.377 (3)C2—H10.91 (2)
C1—C21.384 (3)O2—N11.176 (9)
C3—C2i1.363 (3)O1—N11.277 (9)
N1—C1—C3121.9 (4)C1—C3—H2120.9 (12)
N1—C1—C2115.4 (4)C3i—C2—C1119.6 (2)
C3—C1—C2122.7 (2)C3i—C2—H1120.8 (13)
C3—C1—Cl1114.6 (2)C1—C2—H1119.6 (13)
C2—C1—Cl1122.67 (19)O2—N1—O1124.3 (7)
C2i—C3—C1117.8 (2)O2—N1—C1122.8 (6)
C2i—C3—H2121.3 (12)O1—N1—C1112.9 (7)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1ii0.98 (2)2.49 (2)3.417 (5)157.5 (17)
C2—H1···O2iii0.91 (2)2.72 (2)3.356 (4)128.3 (16)
Symmetry codes: (ii) x, y+1, z+1; (iii) x+1, y1/2, z+1/2.
(I_100) 4-chloronitrobenzene top
Crystal data top
C6H4ClNO2F(000) = 160
Mr = 157.55Dx = 1.586 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 3.7139 (2) ÅCell parameters from 1816 reflections
b = 6.6746 (5) Åθ = 1.0–27.5°
c = 13.3712 (13) ŵ = 0.51 mm1
β = 95.49 (3)°T = 100 K
V = 329.93 (4) Å3Needle, white
Z = 20.4 × 0.16 × 0.1 mm
Data collection top
Nonius KappaCCD
diffractometer
745 independent reflections
Radiation source: fine-focus sealed tube534 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.042
CCD scansθmax = 27.4°, θmin = 3.1°
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
h = 44
Tmin = 0.860, Tmax = 0.942k = 88
2151 measured reflectionsl = 1517
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.046Hydrogen site location: difference Fourier map
wR(F2) = 0.106All H-atom parameters refined
S = 1.12 w = 1/[σ2(Fo2) + (0.0283P)2 + 0.1307P]
where P = (Fo2 + 2Fc2)/3
745 reflections(Δ/σ)max < 0.001
72 parametersΔρmax = 0.19 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
C6H4ClNO2V = 329.93 (4) Å3
Mr = 157.55Z = 2
Monoclinic, P21/cMo Kα radiation
a = 3.7139 (2) ŵ = 0.51 mm1
b = 6.6746 (5) ÅT = 100 K
c = 13.3712 (13) Å0.4 × 0.16 × 0.1 mm
β = 95.49 (3)°
Data collection top
Nonius KappaCCD
diffractometer
745 independent reflections
Absorption correction: multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
534 reflections with I > 2σ(I)
Tmin = 0.860, Tmax = 0.942Rint = 0.042
2151 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0460 restraints
wR(F2) = 0.106All H-atom parameters refined
S = 1.12Δρmax = 0.19 e Å3
745 reflectionsΔρmin = 0.30 e Å3
72 parameters
Special details top

Experimental. disordered material, sample sublimes at room temperature

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. The disordered model where the asymmetric unit is half a molecule has a 50% occupancy of chlorine:nitro group as the one non-hydrogen substituent.

Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cl10.1467 (5)0.3349 (4)0.34411 (15)0.0500 (5)0.50
C10.3492 (5)0.1342 (3)0.43270 (14)0.0410 (5)
C30.3948 (5)0.1885 (4)0.53263 (15)0.0440 (6)
C20.4517 (5)0.0517 (4)0.39913 (16)0.0454 (6)
O20.1429 (8)0.2064 (5)0.2761 (2)0.0516 (8)0.50
O10.1096 (10)0.4249 (6)0.3957 (4)0.0653 (11)0.50
N10.1931 (15)0.2529 (8)0.3617 (5)0.0454 (17)0.50
H10.418 (6)0.082 (3)0.3314 (18)0.055 (6)*
H20.317 (6)0.317 (4)0.5551 (16)0.052 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0362 (7)0.0663 (16)0.0467 (8)0.0048 (9)0.0002 (5)0.0199 (10)
C10.0215 (9)0.0630 (15)0.0389 (11)0.0116 (9)0.0053 (7)0.0065 (10)
C30.0291 (10)0.0617 (15)0.0424 (12)0.0094 (10)0.0093 (8)0.0156 (10)
C20.0317 (10)0.0734 (17)0.0320 (11)0.0147 (10)0.0083 (8)0.0190 (11)
O20.0561 (19)0.054 (2)0.0435 (18)0.0021 (15)0.0020 (13)0.0135 (15)
O10.063 (2)0.040 (2)0.094 (3)0.0125 (16)0.010 (2)0.002 (2)
N10.026 (2)0.023 (3)0.088 (5)0.003 (2)0.012 (3)0.005 (3)
Geometric parameters (Å, º) top
Cl1—C11.895 (3)C3—H20.96 (2)
C1—N11.326 (6)C2—C3i1.375 (3)
C1—C31.379 (3)C2—H10.92 (2)
C1—C21.386 (3)O2—N11.183 (7)
C3—C2i1.375 (3)O1—N11.284 (7)
N1—C1—C3122.8 (4)C1—C3—H2121.6 (13)
N1—C1—C2114.7 (3)C3i—C2—C1119.3 (2)
C3—C1—C2122.5 (2)C3i—C2—H1120.9 (14)
C3—C1—Cl1115.1 (2)C1—C2—H1119.8 (14)
C2—C1—Cl1122.38 (17)O2—N1—O1123.8 (6)
C2i—C3—C1118.2 (2)O2—N1—C1123.6 (5)
C2i—C3—H2120.1 (13)O1—N1—C1112.6 (6)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1ii0.96 (2)2.47 (2)3.381 (5)157.4 (18)
C2—H1···O2iii0.92 (2)2.68 (2)3.323 (4)127.6 (17)
Symmetry codes: (ii) x, y+1, z+1; (iii) x+1, y1/2, z+1/2.

Experimental details

(I_260)(I_250)(I_240)(I_230)
Crystal data
Chemical formulaC6H4ClNO2C6H4ClNO2C6H4ClNO2C6H4ClNO2
Mr157.55157.55157.55157.55
Crystal system, space groupMonoclinic, P21/cMonoclinic, P21/cMonoclinic, P21/cMonoclinic, P21/c
Temperature (K)260250240230
a, b, c (Å)3.8011 (8), 6.7639 (14), 13.364 (3)3.7938 (3), 6.7564 (6), 13.3672 (15)3.7880 (3), 6.7482 (6), 13.3755 (14)3.7801 (3), 6.7338 (6), 13.3758 (15)
β (°) 96.82 (3) 96.639 (3) 96.47 (3) 96.34 (3)
V3)341.17 (12)340.34 (6)339.73 (5)338.39 (6)
Z2222
Radiation typeMo KαMo KαMo KαMo Kα
µ (mm1)0.490.490.490.49
Crystal size (mm)0.4 × 0.16 × 0.10.4 × 0.16 × 0.10.4 × 0.16 × 0.10.4 × 0.16 × 0.1
Data collection
DiffractometerNonius KappaCCD
diffractometer
Nonius KappaCCD
diffractometer
Nonius KappaCCD
diffractometer
Nonius KappaCCD
diffractometer
Absorption correctionMulti-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
Multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
Multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
Multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
Tmin, Tmax0.842, 0.9520.844, 0.9440.850, 0.9450.857, 0.943
No. of measured, independent and
observed [I > 2σ(I)] reflections
2014, 730, 365 2071, 748, 385 2069, 747, 390 1934, 719, 396
Rint0.0400.0370.0470.049
(sin θ/λ)max1)0.6430.6520.6480.645
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.046, 0.134, 1.04 0.052, 0.139, 1.08 0.045, 0.122, 1.04 0.049, 0.126, 1.06
No. of reflections730748747719
No. of parameters72727272
H-atom treatmentAll H-atom parameters refinedAll H-atom parameters refinedAll H-atom parameters refinedAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.17, 0.200.13, 0.150.16, 0.200.21, 0.25


(I_200)(I_150)(I_100)
Crystal data
Chemical formulaC6H4ClNO2C6H4ClNO2C6H4ClNO2
Mr157.55157.55157.55
Crystal system, space groupMonoclinic, P21/cMonoclinic, P21/cMonoclinic, P21/c
Temperature (K)200150100
a, b, c (Å)3.7635 (3), 6.7201 (6), 13.3762 (14)3.7372 (2), 6.6991 (5), 13.3748 (13)3.7139 (2), 6.6746 (5), 13.3712 (13)
β (°) 96.13 (3) 96.84 (3) 95.49 (3)
V3)336.37 (5)332.47 (4)329.93 (4)
Z222
Radiation typeMo KαMo KαMo Kα
µ (mm1)0.500.500.51
Crystal size (mm)0.4 × 0.16 × 0.10.4 × 0.16 × 0.10.4 × 0.16 × 0.1
Data collection
DiffractometerNonius KappaCCD
diffractometer
Nonius KappaCCD
diffractometer
Nonius KappaCCD
diffractometer
Absorption correctionMulti-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
Multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
Multi-scan
multi-scan from symmetry-related measurements (SORTAV; Blessing, 1995)
Tmin, Tmax0.838, 0.9460.864, 0.9460.860, 0.942
No. of measured, independent and
observed [I > 2σ(I)] reflections
2051, 736, 448 2046, 734, 490 2151, 745, 534
Rint0.0460.0420.042
(sin θ/λ)max1)0.6470.6520.647
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.119, 1.07 0.046, 0.113, 1.08 0.046, 0.106, 1.12
No. of reflections736734745
No. of parameters727272
H-atom treatmentAll H-atom parameters refinedAll H-atom parameters refinedAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.15, 0.260.17, 0.220.19, 0.30

Computer programs: COLLECT (Nonius, 1998), HKL SCALEPACK (Otwinowski & Minor, 1997), HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL-Plus (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) for (I_260) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1i0.97 (3)2.58 (3)3.493 (8)157 (2)
C2—H1···O2ii0.87 (3)2.80 (2)3.374 (6)125.3 (19)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) for (I_250) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1i0.97 (3)2.56 (3)3.482 (7)158 (2)
C2—H1···O2ii0.86 (3)2.82 (3)3.384 (6)124.9 (19)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) for (I_240) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1i0.98 (2)2.54 (3)3.476 (6)158.6 (19)
C2—H1···O2ii0.93 (2)2.75 (2)3.376 (5)126.0 (15)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) for (I_230) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1i0.98 (3)2.53 (3)3.455 (7)158 (2)
C2—H1···O2ii0.87 (2)2.77 (2)3.372 (5)127.4 (18)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) for (I_200) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1i0.95 (2)2.55 (2)3.440 (6)156.0 (18)
C2—H1···O2ii0.89 (2)2.74 (2)3.363 (5)128.1 (16)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) for (I_150) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1i0.98 (2)2.49 (2)3.417 (5)157.5 (17)
C2—H1···O2ii0.91 (2)2.72 (2)3.356 (4)128.3 (16)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) for (I_100) top
D—H···AD—HH···AD···AD—H···A
C3—H2···O1i0.96 (2)2.47 (2)3.381 (5)157.4 (18)
C2—H1···O2ii0.92 (2)2.68 (2)3.323 (4)127.6 (17)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y1/2, z+1/2.
Table 1: The effect of applying various restraints and constraints. The restraints were applied such that the N—O distances were approximately equal, as would be expected in a disorder-free system. The N—O distances were restrained to be 1.221 Å, the N—C distances to be 1.47 Å and the C—Cl distances to be 1.74 Å. All bond distances and angles are given in Å and °, respectively. top
FreeRestrainedRestrainedConstrainedConstrainedCSD
refinementO-N (σ=O-N (σ=Cl, N-CN-Odata
0.02)0.002)(average)
N1-O11.300 (7)1.279 (7)1.240 (4)1.156 (6)1.240 (4)1.221
N1-O21.179 (7)1.201 (7)1.240 (4)1.157 (6)1.222 (4)1.221
N1-C11.330 (6)1.323 (6)1.319 (6)1.465 (6)1.326 (5)1.467
Cl1-C11.903 (3)1.904 (3)1.905 (3)1.811 (5)1.905 (3)1.734
O1-N1-O2124.2 (6)124.0 (6)124.0 (6)138.2 (9)124.6 (6)115.1*
O1-N1-C1113.4 (6)114.9 (5)117.4 (4)110.1 (6)116.6 (4)118.2
O2-N1-C1122.4 (5)121.1 (5)118.5 (4)111.7 (6)118.8 (4)118.2
R-factor0.04560.04640.04850.07850.0480-
* Range of values is markedly broad: 96–129°.
Table 2: The atomic displacement parameters for the librating group in p-ClNB, at selected temperatures that cover succinctly the full temperature range studied. top
TemperatureUiiC1C2C3Cl1O1O2N1
100KU110.0226 (9)0.033 (1)0.030 (1)0.0380 (8)0.066 (3)0.059 (2)0.027 (2)
100KU220.065 (1)0.075 (2)0.063 (2)0.068 (2)0.041 (2)0.055 (2)0.024 (3)'
100KU330.038 (1)0.031 (1)0.041 (1)0.0460 (8)0.092 (3)0.043 (2)0.086 (5)
100KUeq0.0417 (6)0.0463 (6)0.0448 (6)0.0510 (5)0.067 (1)0.0533 (8)0.045 (2)
200KU110.040 (1)0.056 (1)0.053 (1)0.063 (1)0.104 (4)0.100 (3)0.053 (4)
200KU220.079 (2)0.097 (2)0.078 (2)0.100 (3)0.064 (3)0.086 (3)0.053 (5)
200KU330.059 (1)0.048 (1)0.064 (1)0.076 (1)0.158 (5)0.065 (2)0.138 (9)
200KUeq0.0590 (6)0.0664 (7)0.0645 (7)0.0807 (9)0.109 (2)0.085 (1)0.080 (3)
260KU110.055 (1)0.077 (1)0.071 (1)0.085 (1)0.151 (5)0.134 (4)0.075 (5)
260KU220.094 (2)0.115 (2)0.091 (2)0.132 (5)0.087 (4)0.118 (4)0.069 (6)
260KU330.078 (2)0.063 (2)0.081 (2)0.104 (2)0.208 (7)0.087 (3)0.18 (1)
260KUeq0.0752 (8)0.0848 (9)0.0808 (8)0.108 (2)0.149 (3)0.114 (2)0.105 (4)
 

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