Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
The title p-haloaceto­phenones, C8H7XO (X = Cl, Br and I), have different packing modes. The chloro compound contains H...O and H...Cl contacts, but no Cl...O contacts. The bromo compound and one polymorph (A) of the iodo compound are isomorphous, with significant X...O contacts [Br...O = 3.320 (4) Å and I...O = 3.374 (5) Å]. In the other polymorph (B) of the iodo compound, the I...O distance is 3.082 (4) Å. Both polymorphs contain C-H...[pi] contacts; these contacts are shorter in A than in B.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104013824/sq1158sup1.cif
Contains datablocks global, ClM, BrM, IM-A, IM-B

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104013824/sq1158ClMsup2.hkl
Contains datablock ClM

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104013824/sq1158BrMsup3.hkl
Contains datablock BrM

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104013824/sq1158IM-Asup4.hkl
Contains datablock IM-A

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104013824/sq1158IM-Bsup5.hkl
Contains datablock IM-B

CCDC references: 248149; 248150; 248151; 248152

Comment top

The structures of p-chloro-, p-bromo (Britton, 1994) and p-iodobenzaldehyde (Britton & Young, 1997) were undertaken in a search for examples of O···X interactions. The iodo compound exhibits such an interaction, with O···I distances of 3.07 Å, but the chloro and bromo compounds have X···X contacts at the halogens and weak C—H···O hydrogen bonds at the aldehyde. We report here the structures of the corresponding acetophenones. This work was undertaken with the expectation that the replacement of the aldehyde H atom with a methyl group would make the O···X interaction more likely in the chloro and bromo compounds. The structure of the bromo compound was reported previously (Lipkowski & Tabaszewska, 1992) but has been repeated here so that all the structure determinations are at the same temperature.

Fig. 1 shows the atom labeling scheme and anisotropic displacement ellipsoids for the chloro, bromo and two polymorphs of the iodo compound (ClM, BrM, IM—A and IM—B, respectively). All of the bond distances and angles are normal, and, with the exception of the C4—X distances, are the same, within experimental error, in all four compounds. The exocyclic C2—C1—C7 angles [mean 119.6 (4)°] are significantly smaller than the C6—C1—C7 angles [mean 121.9 (4)°] The dihedral angles between the rings and the acetyl groups are 4.2 (2) (in ClM), 9.4 (3) (in BrM), 10.6 (4) (in IM—A) and 2.9 (3)° (in IM—B).

ClM forms π stacks parallel to the a axis (see Fig. 2), in which the rings are 3.473 (2) Å apart. The molecules are held together by C—H···O and C—H···Cl interactions. All of the C—H···O interactions shorter than 2.8 Å and all of the C—H···Cl interactions shorter than 3.2 Å are shown as dotted lines in the figure. There are no short O···Cl or Cl···Cl contacts. The Cl atom appears to be a weaker Lewis acid than the CH group in this compound, which is somewhat surprising. The metric data for the interactions are given in Table 1; the intramolecular distances are given for comparision.

The packing in the remaining compounds is significantly different. The CH···Cl interactions in ClM are replaced by CX···OC interactions in BrM, IM—A and IM—B. These interactions are shown in Fig. 3 and the metric data are given in Table 2, along with comparison data from three other compounds with short I···O contacts.

BrM and IM—A are isomorphous, with chains of molecules parallel to the [101] direction held together by X···O interactions. In IM—B there are similar chains parallel to the [001] direction. Successive molecules in the chains are rotated with respect to each other by 44.9 (1)° in BrM, 44.0 (1)° in IM—A and 71.8 (1)° in IM—B. Metric details of intermolecular interactions involving CH groups are included in Table 1. Since the BrM and IM—A structures are isomorphous, further discussion will be confined to the two polymorphs of IM. The description of the packing for BrM is the same as that for IM—A.

In both IM—A and IM—B there are C—H···π interactions. In IM—A, these are from atoms H2 and H5 to the centers of adjoining C6 rings. The two interactions are virtually identical in distance and direction. In IM—A, the molecules pack in such a way as to form layers of molecules, with individual molecules perpendicular to the plane of the layer.

In Fig. 4, the packing in IM—A is shown perpendicular and parallel to one of the layers. As can be seen, the layers are such that one face contains the I atoms, separated by slightly more than the van der Waals distance from the other face, which contains CH3 groups and O atoms. It can also be seen that the C—H···π contacts are almost centric with respect to the benzene rings. In IM—B, there are also C—H···ring contacts, but these are are to individual ring C atoms and at longer distances than those in IM—A. For general discussions of C—H···π contacts see Malone et al. (1997), Nishio et al. (1998) and Desiraju & Steiner (1999).

The most surprising difference between the two polymorphs of IM is the large difference in the two I···O distances in going from IM—A to IM—B (see Table 2). The distance in IM—B is similar to the two independent distances found in p-iodobenzaldehyde (Britton & Young, 1997) and is toward the low end of I···O distances found, although by no means the lowest. A search of the Cambridge Structural Database (Allen, 2002) did not disclose any other examples of two polymorphs with short but differing I···O distances. However, two examples were found where crystallographically independent I···O distances in the same crystal differ by more than 0.1 Å. In ethyl(E)-4[N-(2'-iodophenyl)-N-methylamino]-4-oxabut-2-enoate (Horne et al., 1991), two crystallographically independent molecules form a dimer held together by two I···O interactions; these dimers have approximately twofold symmetry except for the terminal ethyl groups but the two distances are 2.987 (4) and 3.110 (4) Å. In (R,S)-2-methoxytetrahydrofuran-3R-ylmethyl-3,4,5-tri- iodobenzoate (Franssen et al., 1996), two crystallographically independent molecules again form a dimer, with local approximate twofold symmetry. In this case, the two I···O=C contacts in the dimer are similar, 3.229 (7) and 3.347 (7) Å, but two other contacts to O atoms in C/O/C groups are quite different, 3.092 (7) and 3.507 (7) Å. Overall, although the I···O interaction is relatively strong, it is weak enough to be significantly affected by the overall packing.

If the change in the I···C bond lengths were the only difference between the two structures, the volume of IM—B might be expected to be 3.16 (3)% smaller than that in IM—A because of the shortening of the chain length in the I···.·I direction. The experimental difference is that IM—B is larger by 0.76 (6)%; the decrease in the length of the chain is more than offset by increases in the other dimensions. Overall, the packings in the two polymorphs are about equally efficient.

There are no short X···X interactions in either structure. In the BrM and IM—A structures there are planes of Br or I atoms that are separated by slightly more than the usual X···X van der Waals differences. Although these contacts are not unusually short they contribute significantly to the packing energy. On the other hand, in the IM—B structure there are no short I···I distances at all.

Refinement top

For each of the four structures a complete sphere of data was collected and all possible Friedel pairs were measured. For ClM, 638 (62%) of the 1036 pairs contained information about which enantiomer was present; refinement as a racemic twin led to a minor twin fraction of 0.11 (8). For BrM [827 (96%) of 864 pairs], the refinement converged with a Flack (1983) parameter of −0.004 (14), and for IM—A [897 (97%) of 924 pairs], the refinement converged with a Flack parameter of −0.01 (13), indicating that the reported polarities are correct. In the refinement of BrM and IM—A, the origin restraints on x and z were made using the method of Flack & Schwarzenbach (1988). After the refinements were complete, the origin was shifted, in each case, to x = 0.5 and z = 1/2, to facilitate comparison between the two structures. In the final refinement of each of the four structures, the methyl H atoms were included with idealized distances and angles, since this treatment seems appropriate in the presence of the heavy atoms. However, in each case, the H atoms were also found from a difference Fourier map and the positions and Uiso values were refined; these results agreed with the group refinements within experimental error in every case.

Computing details top

For all compounds, data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. The X—C6H4COCH3 molecules. Top to bottom, X= Cl, Br, I (polymorph A) and I (polymorph B). Displacement ellipsoids are shown at the 50% probability level.
[Figure 2] Fig. 2. The packing of X—C6H4COCH3, viewed along a. The C—H···O and C—H···Cl contacts are shown as dashed lines.
[Figure 3] Fig. 3. The intermolecular contacts in IM—A (top) and IM—B (bottom), viewed normal to the plane of the central molecule. The X···O contacts are shown as double-dashed lines, and the H···X and H···π contacts as single dashed lines. The top drawing also describes BrM. The top view is approximately normal to (041), the bottom view to (110).
[Figure 4] Fig. 4. The H···π contacts in IM—A, viewed along c (top) and perpendicular to the top view (bottom). Only one layer is shown in the bottom view. The H···π contacts are shown as dashed lines.
(ClM) 4-chloroacetophenone top
Crystal data top
C8H7ClOF(000) = 320
Mr = 154.59Dx = 1.382 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 1949 reflections
a = 4.0079 (10) Åθ = 2.4–25.6°
b = 9.366 (2) ŵ = 0.44 mm1
c = 19.787 (5) ÅT = 173 K
V = 742.8 (3) Å3Irregular prism, colorless
Z = 40.50 × 0.40 × 0.30 mm
Data collection top
Siemens SMART area-detector
diffractometer
1674 independent reflections
Radiation source: fine-focus sealed tube1434 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.039
ω scansθmax = 27.5°, θmin = 2.1°
Absorption correction: multi-scan
SADABS; Sheldrick, 1996; Blessing, 1995
h = 55
Tmin = 0.81, Tmax = 0.88k = 1211
6382 measured reflectionsl = 2523
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.034H-atom parameters constrained
wR(F2) = 0.080 w = 1/[σ2(Fo2) + (0.037P)2 + 0.061P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max = 0.002
1674 reflectionsΔρmax = 0.17 e Å3
91 parametersΔρmin = 0.14 e Å3
0 restraintsAbsolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.11 (8)
Crystal data top
C8H7ClOV = 742.8 (3) Å3
Mr = 154.59Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 4.0079 (10) ŵ = 0.44 mm1
b = 9.366 (2) ÅT = 173 K
c = 19.787 (5) Å0.50 × 0.40 × 0.30 mm
Data collection top
Siemens SMART area-detector
diffractometer
1674 independent reflections
Absorption correction: multi-scan
SADABS; Sheldrick, 1996; Blessing, 1995
1434 reflections with I > 2σ(I)
Tmin = 0.81, Tmax = 0.88Rint = 0.039
6382 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.034H-atom parameters constrained
wR(F2) = 0.080Δρmax = 0.17 e Å3
S = 1.03Δρmin = 0.14 e Å3
1674 reflectionsAbsolute structure: Flack (1983)
91 parametersAbsolute structure parameter: 0.11 (8)
0 restraints
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cl10.66962 (14)0.52846 (6)0.44469 (3)0.04525 (17)
O10.1053 (4)0.36413 (15)0.75213 (8)0.0476 (4)
C10.3741 (4)0.48590 (19)0.66333 (9)0.0287 (4)
C20.2919 (5)0.38008 (18)0.61662 (9)0.0318 (4)
H20.17410.29760.63120.038*
C30.3790 (5)0.39346 (19)0.54971 (10)0.0337 (4)
H30.32050.32130.51810.040*
C40.5526 (4)0.5132 (2)0.52905 (10)0.0311 (4)
C50.6366 (5)0.62079 (19)0.57378 (10)0.0349 (4)
H50.75310.70320.55870.042*
C60.5475 (5)0.60607 (19)0.64111 (10)0.0325 (4)
H60.60520.67880.67250.039*
C70.2738 (4)0.4665 (2)0.73563 (9)0.0320 (4)
C80.3818 (5)0.5757 (2)0.78664 (10)0.0414 (5)
H8A0.29980.54820.83150.062*
H8B0.29010.66910.77430.062*
H8C0.62590.58100.78740.062*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0507 (3)0.0523 (3)0.0327 (3)0.0026 (2)0.0045 (2)0.0016 (2)
O10.0578 (10)0.0389 (8)0.0461 (9)0.0046 (8)0.0061 (8)0.0089 (7)
C10.0246 (9)0.0271 (9)0.0344 (10)0.0047 (7)0.0040 (7)0.0006 (7)
C20.0319 (9)0.0229 (9)0.0405 (11)0.0010 (7)0.0016 (9)0.0006 (8)
C30.0331 (10)0.0307 (9)0.0373 (11)0.0028 (8)0.0044 (9)0.0073 (8)
C40.0290 (8)0.0335 (10)0.0309 (9)0.0058 (8)0.0013 (7)0.0017 (8)
C50.0378 (11)0.0279 (9)0.0390 (11)0.0016 (9)0.0003 (9)0.0009 (8)
C60.0356 (10)0.0247 (9)0.0371 (11)0.0009 (8)0.0032 (8)0.0039 (8)
C70.0298 (9)0.0322 (9)0.0340 (10)0.0074 (9)0.0021 (7)0.0041 (8)
C80.0401 (12)0.0528 (12)0.0312 (10)0.0041 (10)0.0001 (9)0.0051 (9)
Geometric parameters (Å, º) top
Cl1—C41.740 (2)C4—C51.383 (3)
O1—C71.217 (2)C5—C61.386 (3)
C1—C61.394 (3)C5—H50.9500
C1—C21.395 (3)C6—H60.9500
C1—C71.497 (3)C7—C81.500 (3)
C2—C31.375 (3)C8—H8A0.9800
C2—H20.9500C8—H8B0.9800
C3—C41.382 (3)C8—H8C0.9800
C3—H30.9500
C6—C1—C2118.86 (17)C6—C5—H5120.7
C6—C1—C7122.22 (17)C5—C6—C1120.79 (17)
C2—C1—C7118.93 (16)C5—C6—H6119.6
C3—C2—C1120.89 (17)C1—C6—H6119.6
C3—C2—H2119.6O1—C7—C1120.05 (17)
C1—C2—H2119.6O1—C7—C8121.07 (18)
C2—C3—C4119.13 (17)C1—C7—C8118.87 (17)
C2—C3—H3120.4C7—C8—H8A109.5
C4—C3—H3120.4C7—C8—H8B109.5
C3—C4—C5121.65 (18)H8A—C8—H8B109.5
C3—C4—Cl1119.12 (15)C7—C8—H8C109.5
C5—C4—Cl1119.24 (15)H8A—C8—H8C109.5
C4—C5—C6118.67 (17)H8B—C8—H8C109.5
C4—C5—H5120.7
(BrM) 4-bromoacetophenone top
Crystal data top
C8H7BrOF(000) = 392
Mr = 199.05Dx = 1.739 Mg m3
Monoclinic, CcMo Kα radiation, λ = 0.71073 Å
Hall symbol: C -2ycCell parameters from 2078 reflections
a = 18.635 (5) Åθ = 2.2–25.7°
b = 6.9554 (17) ŵ = 5.33 mm1
c = 5.9035 (15) ÅT = 173 K
β = 96.36 (1)°Plate, colorless
V = 760.5 (3) Å30.45 × 0.15 × 0.03 mm
Z = 4
Data collection top
Siemens SMART area-detector
diffractometer
1691 independent reflections
Radiation source: fine-focus sealed tube1569 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.038
ω scansθmax = 27.5°, θmin = 3.1°
Absorption correction: multi-scan
(SADABS including thin plate correction; Sheldrick, 1996; Blessing, 1995)
h = 2323
Tmin = 0.39, Tmax = 0.85k = 89
3840 measured reflectionsl = 77
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.032H-atom parameters constrained
wR(F2) = 0.077 w = 1/[σ2(Fo2) + (0.036P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.001
1691 reflectionsΔρmax = 0.75 e Å3
91 parametersΔρmin = 0.27 e Å3
2 restraintsAbsolute structure: Flack(1983), 849 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.004 (14)
Crystal data top
C8H7BrOV = 760.5 (3) Å3
Mr = 199.05Z = 4
Monoclinic, CcMo Kα radiation
a = 18.635 (5) ŵ = 5.33 mm1
b = 6.9554 (17) ÅT = 173 K
c = 5.9035 (15) Å0.45 × 0.15 × 0.03 mm
β = 96.36 (1)°
Data collection top
Siemens SMART area-detector
diffractometer
1691 independent reflections
Absorption correction: multi-scan
(SADABS including thin plate correction; Sheldrick, 1996; Blessing, 1995)
1569 reflections with I > 2σ(I)
Tmin = 0.39, Tmax = 0.85Rint = 0.038
3840 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.032H-atom parameters constrained
wR(F2) = 0.077Δρmax = 0.75 e Å3
S = 1.05Δρmin = 0.27 e Å3
1691 reflectionsAbsolute structure: Flack(1983), 849 Friedel pairs
91 parametersAbsolute structure parameter: 0.004 (14)
2 restraints
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.50000.27942 (5)0.50000.04028 (13)
O10.8276 (2)0.1930 (5)0.0907 (6)0.0486 (8)
C10.7401 (2)0.2382 (4)0.3424 (7)0.0266 (7)
C20.6834 (2)0.1785 (6)0.1811 (7)0.0284 (9)
H20.69410.12970.03840.034*
C30.6124 (2)0.1895 (5)0.2261 (6)0.0292 (8)
H30.57460.14800.11570.035*
C40.5969 (2)0.2617 (5)0.4340 (7)0.0282 (8)
C50.6516 (2)0.3221 (5)0.5979 (6)0.0271 (7)
H50.64020.37280.73900.033*
C60.7226 (2)0.3078 (5)0.5534 (6)0.0282 (8)
H60.76020.34540.66680.034*
C70.8153 (3)0.2291 (7)0.2851 (8)0.0341 (9)
C80.8756 (3)0.2688 (6)0.4701 (9)0.0439 (10)
H8A0.92210.25740.40790.066*
H8B0.87370.17570.59380.066*
H8C0.87050.39920.52910.066*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.03165 (19)0.0465 (2)0.0438 (2)0.0034 (4)0.00901 (13)0.0015 (5)
O10.0398 (19)0.071 (2)0.0368 (16)0.0005 (16)0.0133 (14)0.0054 (14)
C10.036 (2)0.0173 (16)0.0269 (16)0.0001 (12)0.0042 (15)0.0007 (12)
C20.040 (2)0.023 (2)0.0228 (18)0.0000 (17)0.0047 (14)0.0003 (15)
C30.035 (2)0.026 (2)0.0261 (17)0.0029 (14)0.0015 (14)0.0036 (12)
C40.0271 (19)0.0241 (18)0.0342 (19)0.0020 (13)0.0074 (15)0.0050 (13)
C50.037 (2)0.0214 (18)0.0234 (16)0.0033 (13)0.0041 (14)0.0021 (12)
C60.037 (2)0.0221 (19)0.0257 (18)0.0018 (13)0.0031 (15)0.0010 (12)
C70.038 (2)0.030 (2)0.035 (2)0.002 (2)0.0076 (18)0.0011 (19)
C80.031 (2)0.056 (3)0.046 (3)0.0022 (18)0.0067 (19)0.0032 (18)
Geometric parameters (Å, º) top
Br1—C41.892 (4)C4—C51.390 (6)
O1—C71.221 (6)C5—C61.382 (5)
C1—C21.405 (6)C5—H50.9500
C1—C61.408 (5)C6—H60.9500
C1—C71.478 (7)C7—C81.504 (7)
C2—C31.379 (6)C8—H8A0.9800
C2—H20.9500C8—H8B0.9800
C3—C41.386 (6)C8—H8C0.9800
C3—H30.9500
C2—C1—C6118.1 (4)C4—C5—H5120.3
C2—C1—C7119.6 (4)C5—C6—C1120.9 (4)
C6—C1—C7122.4 (4)C5—C6—H6119.5
C3—C2—C1121.3 (4)C1—C6—H6119.5
C3—C2—H2119.4O1—C7—C1120.4 (4)
C1—C2—H2119.4O1—C7—C8121.1 (5)
C4—C3—C2119.3 (4)C1—C7—C8118.5 (4)
C4—C3—H3120.3C7—C8—H8A109.5
C2—C3—H3120.3C7—C8—H8B109.5
C3—C4—C5121.1 (4)H8A—C8—H8B109.5
C3—C4—Br1120.3 (3)C7—C8—H8C109.5
C5—C4—Br1118.7 (3)H8A—C8—H8C109.5
C6—C5—C4119.4 (3)H8B—C8—H8C109.5
C6—C5—H5120.3
(IM-A) p-iodoacetophenone polymorph A top
Crystal data top
C8H7IOF(000) = 464
Mr = 246.04Dx = 2.037 Mg m3
Monoclinic, CcMelting point: 358-359 K K
Hall symbol: C -2ycMo Kα radiation, λ = 0.71073 Å
a = 19.425 (5) ÅCell parameters from 3302 reflections
b = 7.049 (2) Åθ = 3.1–27.5°
c = 5.8769 (15) ŵ = 3.92 mm1
β = 94.41 (1)°T = 173 K
V = 802.3 (4) Å3Plate, pale yellow
Z = 40.25 × 0.20 × 0.10 mm
Data collection top
Siemens SMART area-detector
diffractometer
1821 independent reflections
Radiation source: fine-focus sealed tube1768 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.031
ω scansθmax = 27.5°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996; Blessing, 1995)
h = 2525
Tmin = 0.38, Tmax = 0.68k = 99
4483 measured reflectionsl = 77
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.023H-atom parameters constrained
wR(F2) = 0.060 w = 1/[σ2(Fo2) + (0.032P)2 + 0.031P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.001
1821 reflectionsΔρmax = 0.63 e Å3
91 parametersΔρmin = 0.31 e Å3
2 restraintsAbsolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.01 (3)
Crystal data top
C8H7IOV = 802.3 (4) Å3
Mr = 246.04Z = 4
Monoclinic, CcMo Kα radiation
a = 19.425 (5) ŵ = 3.92 mm1
b = 7.049 (2) ÅT = 173 K
c = 5.8769 (15) Å0.25 × 0.20 × 0.10 mm
β = 94.41 (1)°
Data collection top
Siemens SMART area-detector
diffractometer
1821 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996; Blessing, 1995)
1768 reflections with I > 2σ(I)
Tmin = 0.38, Tmax = 0.68Rint = 0.031
4483 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.023H-atom parameters constrained
wR(F2) = 0.060Δρmax = 0.63 e Å3
S = 1.05Δρmin = 0.31 e Å3
1821 reflectionsAbsolute structure: Flack (1983)
91 parametersAbsolute structure parameter: 0.01 (3)
2 restraints
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
I10.50000.26811 (3)0.50000.03998 (9)
O10.8311 (2)0.2031 (5)0.0940 (7)0.0532 (8)
C10.7426 (2)0.2402 (4)0.3415 (7)0.0278 (7)
C20.6910 (2)0.1829 (6)0.1788 (7)0.0297 (8)
H20.70340.13830.03510.036*
C30.6220 (2)0.1895 (5)0.2210 (6)0.0307 (6)
H30.58760.14750.10880.037*
C40.6037 (2)0.2580 (4)0.4291 (7)0.0285 (8)
C50.6537 (2)0.3188 (5)0.5961 (6)0.0300 (6)
H50.64050.36640.73760.036*
C60.7228 (2)0.3088 (5)0.5534 (6)0.0303 (6)
H60.75720.34840.66730.036*
C70.8164 (3)0.2347 (6)0.2888 (9)0.0337 (9)
C80.8714 (3)0.2684 (6)0.4777 (10)0.0475 (11)
H8A0.91690.26130.41690.071*
H8B0.86810.17160.59600.071*
H8C0.86510.39440.54360.071*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.03069 (13)0.04697 (13)0.04280 (14)0.0027 (3)0.00627 (9)0.0040 (3)
O10.0398 (19)0.083 (2)0.0382 (16)0.0006 (17)0.0135 (14)0.0091 (16)
C10.032 (2)0.0273 (15)0.0250 (16)0.0004 (11)0.0064 (14)0.0007 (10)
C20.0402 (19)0.0263 (18)0.0228 (16)0.0007 (16)0.0034 (13)0.0010 (14)
C30.0349 (18)0.0292 (15)0.0272 (15)0.0011 (14)0.0025 (13)0.0034 (12)
C40.030 (2)0.0259 (15)0.0300 (19)0.0006 (11)0.0023 (16)0.0040 (10)
C50.0403 (18)0.0267 (14)0.0230 (14)0.0008 (13)0.0030 (12)0.0007 (11)
C60.0367 (17)0.0278 (15)0.0261 (15)0.0025 (13)0.0013 (12)0.0033 (12)
C70.034 (2)0.029 (2)0.038 (2)0.0011 (16)0.0074 (18)0.0002 (15)
C80.033 (2)0.068 (3)0.042 (3)0.0055 (17)0.0051 (19)0.0008 (17)
Geometric parameters (Å, º) top
I1—C42.090 (5)C4—C51.393 (6)
O1—C71.221 (7)C5—C61.387 (5)
C1—C21.391 (6)C5—H50.9500
C1—C61.416 (5)C6—H60.9500
C1—C71.491 (7)C7—C81.499 (8)
C2—C31.381 (6)C8—H8A0.9800
C2—H20.9500C8—H8B0.9800
C3—C41.387 (6)C8—H8C0.9800
C3—H30.9500
C2—C1—C6118.3 (4)C4—C5—H5120.4
C2—C1—C7120.2 (4)C5—C6—C1120.5 (3)
C6—C1—C7121.5 (4)C5—C6—H6119.7
C3—C2—C1121.6 (4)C1—C6—H6119.7
C3—C2—H2119.2O1—C7—C1119.8 (5)
C1—C2—H2119.2O1—C7—C8121.2 (5)
C4—C3—C2119.2 (4)C1—C7—C8118.9 (5)
C4—C3—H3120.4C7—C8—H8A109.5
C2—C3—H3120.4C7—C8—H8B109.5
C3—C4—C5121.1 (4)H8A—C8—H8B109.5
C3—C4—I1120.3 (3)C7—C8—H8C109.5
C5—C4—I1118.6 (3)H8A—C8—H8C109.5
C6—C5—C4119.3 (3)H8B—C8—H8C109.5
C6—C5—H5120.4
(IM-B) p-iodoacetophenone polymorph B top
Crystal data top
C8H7IODx = 2.021 Mg m3
Mr = 246.04Melting point: 357-359 K K
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 2276 reflections
a = 9.777 (2) Åθ = 2.9–27.4°
b = 8.232 (2) ŵ = 3.89 mm1
c = 20.089 (5) ÅT = 173 K
V = 1616.8 (7) Å3Plate, colorless
Z = 80.25 × 0.20 × 0.01 mm
F(000) = 928
Data collection top
Siemans SMART area-detector
diffractometer
1855 independent reflections
Radiation source: fine-focus sealed tube1236 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.052
ω scansθmax = 27.5°, θmin = 2.9°
Absorption correction: multi-scan
SADABS; Sheldrick, 1996; Blessing, 1995
h = 1212
Tmin = 0.41, Tmax = 0.96k = 1010
15576 measured reflectionsl = 2626
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)] = 0.026Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.070H-atom parameters constrained
S = 1.09 w = 1/[σ2(Fo2) + (0.019P)2 + 2.68P]
where P = (Fo2 + 2Fc2)/3
1855 reflections(Δ/σ)max = 0.002
91 parametersΔρmax = 0.56 e Å3
0 restraintsΔρmin = 0.45 e Å3
Crystal data top
C8H7IOV = 1616.8 (7) Å3
Mr = 246.04Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 9.777 (2) ŵ = 3.89 mm1
b = 8.232 (2) ÅT = 173 K
c = 20.089 (5) Å0.25 × 0.20 × 0.01 mm
Data collection top
Siemans SMART area-detector
diffractometer
1855 independent reflections
Absorption correction: multi-scan
SADABS; Sheldrick, 1996; Blessing, 1995
1236 reflections with I > 2σ(I)
Tmin = 0.41, Tmax = 0.96Rint = 0.052
15576 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0260 restraints
wR(F2) = 0.070H-atom parameters constrained
S = 1.09Δρmax = 0.56 e Å3
1855 reflectionsΔρmin = 0.45 e Å3
91 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
I10.58879 (2)0.25265 (3)0.657830 (12)0.03254 (10)
O10.5437 (3)0.1968 (4)1.00741 (14)0.0375 (6)
C10.6182 (4)0.1533 (4)0.89715 (18)0.0258 (8)
C20.5141 (4)0.2487 (4)0.87084 (19)0.0299 (7)
H20.44790.29490.89980.036*
C30.5053 (4)0.2772 (4)0.8031 (2)0.0307 (9)
H30.43430.34360.78560.037*
C40.6014 (4)0.2080 (4)0.76080 (19)0.0278 (8)
C50.7058 (4)0.1120 (4)0.78602 (19)0.0294 (8)
H50.77150.06500.75700.035*
C60.7133 (4)0.0854 (5)0.85411 (19)0.0297 (8)
H60.78470.01960.87150.036*
C70.6249 (4)0.1289 (4)0.97091 (19)0.0291 (8)
C80.7347 (4)0.0212 (5)0.9984 (2)0.0427 (10)
H8A0.72720.01741.04700.064*
H8B0.82450.06430.98590.064*
H8C0.72410.08860.98030.064*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.03458 (15)0.03895 (16)0.02411 (15)0.00124 (12)0.00010 (9)0.00237 (12)
O10.0456 (16)0.0407 (14)0.0263 (15)0.0027 (13)0.0019 (13)0.0030 (12)
C10.0259 (18)0.0242 (18)0.027 (2)0.0038 (14)0.0000 (15)0.0006 (15)
C20.0316 (18)0.0314 (18)0.0268 (19)0.0031 (18)0.0001 (15)0.0043 (18)
C30.0293 (18)0.032 (2)0.031 (2)0.0069 (15)0.0040 (15)0.0007 (16)
C40.0325 (19)0.0270 (18)0.024 (2)0.0057 (15)0.0025 (15)0.0017 (14)
C50.0236 (18)0.0341 (19)0.030 (2)0.0018 (15)0.0058 (15)0.0007 (17)
C60.0282 (19)0.032 (2)0.029 (2)0.0031 (16)0.0015 (15)0.0040 (16)
C70.0344 (19)0.0275 (18)0.025 (2)0.0066 (15)0.0029 (17)0.0009 (16)
C80.046 (3)0.048 (3)0.034 (2)0.007 (2)0.002 (2)0.0043 (19)
Geometric parameters (Å, º) top
I1—C42.105 (4)C4—C51.387 (5)
O1—C71.217 (5)C5—C61.387 (5)
C1—C61.387 (5)C5—H50.9500
C1—C21.390 (5)C6—H60.9500
C1—C71.497 (5)C7—C81.497 (5)
C2—C31.384 (6)C8—H8A0.9800
C2—H20.9500C8—H8B0.9800
C3—C41.389 (5)C8—H8C0.9800
C3—H30.9500
C6—C1—C2118.8 (3)C4—C5—H5120.4
C6—C1—C7122.2 (3)C5—C6—C1121.0 (3)
C2—C1—C7119.0 (3)C5—C6—H6119.5
C3—C2—C1121.0 (3)C1—C6—H6119.5
C3—C2—H2119.5O1—C7—C1120.4 (3)
C1—C2—H2119.5O1—C7—C8121.1 (4)
C2—C3—C4119.3 (3)C1—C7—C8118.4 (3)
C2—C3—H3120.3C7—C8—H8A109.5
C4—C3—H3120.3C7—C8—H8B109.5
C5—C4—C3120.6 (4)H8A—C8—H8B109.5
C5—C4—I1120.1 (3)C7—C8—H8C109.5
C3—C4—I1119.3 (3)H8A—C8—H8C109.5
C6—C5—C4119.3 (3)H8B—C8—H8C109.5
C6—C5—H5120.4

Experimental details

(ClM)(BrM)(IM-A)(IM-B)
Crystal data
Chemical formulaC8H7ClOC8H7BrOC8H7IOC8H7IO
Mr154.59199.05246.04246.04
Crystal system, space groupOrthorhombic, P212121Monoclinic, CcMonoclinic, CcOrthorhombic, Pbca
Temperature (K)173173173173
a, b, c (Å)4.0079 (10), 9.366 (2), 19.787 (5)18.635 (5), 6.9554 (17), 5.9035 (15)19.425 (5), 7.049 (2), 5.8769 (15)9.777 (2), 8.232 (2), 20.089 (5)
α, β, γ (°)90, 90, 9090, 96.36 (1), 9090, 94.41 (1), 9090, 90, 90
V3)742.8 (3)760.5 (3)802.3 (4)1616.8 (7)
Z4448
Radiation typeMo KαMo KαMo KαMo Kα
µ (mm1)0.445.333.923.89
Crystal size (mm)0.50 × 0.40 × 0.300.45 × 0.15 × 0.030.25 × 0.20 × 0.100.25 × 0.20 × 0.01
Data collection
DiffractometerSiemens SMART area-detector
diffractometer
Siemens SMART area-detector
diffractometer
Siemens SMART area-detector
diffractometer
Siemans SMART area-detector
diffractometer
Absorption correctionMulti-scan
SADABS; Sheldrick, 1996; Blessing, 1995
Multi-scan
(SADABS including thin plate correction; Sheldrick, 1996; Blessing, 1995)
Multi-scan
(SADABS; Sheldrick, 1996; Blessing, 1995)
Multi-scan
SADABS; Sheldrick, 1996; Blessing, 1995
Tmin, Tmax0.81, 0.880.39, 0.850.38, 0.680.41, 0.96
No. of measured, independent and
observed [I > 2σ(I)] reflections
6382, 1674, 1434 3840, 1691, 1569 4483, 1821, 1768 15576, 1855, 1236
Rint0.0390.0380.0310.052
(sin θ/λ)max1)0.6510.6500.6500.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.080, 1.03 0.032, 0.077, 1.05 0.023, 0.060, 1.05 0.026, 0.070, 1.09
No. of reflections1674169118211855
No. of parameters91919191
No. of restraints0220
H-atom treatmentH-atom parameters constrainedH-atom parameters constrainedH-atom parameters constrainedH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.17, 0.140.75, 0.270.63, 0.310.56, 0.45
Absolute structureFlack (1983)Flack(1983), 849 Friedel pairsFlack (1983)?
Absolute structure parameter0.11 (8)0.004 (14)0.01 (3)?

Computer programs: SMART (Siemens, 1995), SAINT (Siemens, 1995), SAINT, SHELXTL (Sheldrick, 1997), SHELXTL.

Table 2. Distances and angles(Å, °) in the C-H···X contacts.a top
HXbC-HC-H···XH···XH···X-CC···X
Cl-C6H4COCH3
*H2O10.95982.49832.788 (2)
*H8AO10.98732.46562.370 (2)
H6O1i0.951672.571163.499 (3)
H8BO1ii0.951662.461513.421 (3)
*H3Cl10.95742.80462.697 (2)
*H5Cl10.95742.81462.700 (2)
H5Cl1iii0.951633.02873.936 (3)
H8ACl1iv0.951583.031213.951 (3)
H8ACl1v0.981213.131483.736 (3)
Br-C6H4COCH3
*H2O10.95982.51822.799 (6)
*H8AO10.98732.47562.377 (6)
H8BO1vi0.981312.701063.430 (6)
*H3Br10.95762.94442.854 (4)
*H5Br10.95772.90452.835 (4)
H3Br1vii0.951333.32664.024 (4)
H8ABr1viii0.981482.961373.822 (4)
H8BBr1ix0.981143.181203.697 (4)
H2πvii0.951252.8182c3.437 (4)
H5πx0.951252.8082c3.436 (4)
I-C6H4COCH3 polymorph A
*H2O10.95982.52822.809 (7)
*H8AO10.98732.46562.374 (7)
H8AO1vi0.981351.741053.494 (7)
*H3I10.95783.08413.035 (5)
*H5I10.95793.05423.016 (5)
H3I1vii0.951353.42624.152 (5)
H8AI1viii0.981483.041383.907 (5)
H8BI1ix0.981083.381243.814 (5)
H2πvii0.951212.9283c3.504 (5)
H5πx0.951222.9080c3.494 (5)
I-C6H4COCH3 polymorph B
*H2O10.95982.49832.792 (5)
*H8AO10.98732.46562.368 (5)
H8CO1xi0.981112.781213.262 (5)
*H3I10.95793.07413.036 (4)
*H5I10.95793.09413.047 (4)
H5I1xii0.951553.53634.406 (4)
H8AI1xiii0.981353.221393.969 (4)
H3C5i0.951612.9766c3.880 (5)
H6C2xii0.951562.9782c3.860 (5)
a. The entries preceded by * are intramolecular distances for comparison. b. π refers to the center of the C6 ring. c. This angle is the angle between the H···X bond and the plane of the C6 ring. Symmetry codes: (i) 1 − x, 1/2 + y, 3/2 − z; (ii) −x, 1/2 + y, 3/2 − z; (iii) 1/2 + x, 3/2 − y. 1 − z; (iv) 1/2 − x, 1 − y, 1/2 + z; (v) 3/2 − x, 1 − y, 1/2 + z; (vi) x, −y, 1/2 + z; (vii) x, −y, −1/2 + z; (viii) 1/2 + x, 1/2 − y, −1/2 + z; (ix) 1/2 + x, 1/2 − y, 1/2 + z; (x) x, 1 − y, −1/2 + z; (xi) 1 − x, −y, 2 − z; (xii) 3/2 − x, −1/2 + y, z; (xiii) (xiii) x, 1/2 − y, 1/2 + z.
Table 2. Distances and angles(Å, °) in the C-X···O=C contacts. top
compoundXOC-X···OX···OX···O=Cref.
BrMBr1O1i177.4 (4)3.320 (4)115.2 (3)a
IM-AI1O1i177.5 (4)3.374 (5)116.3 (3)a
IM-BI1O1ii174.7 (4)3.082 (4)124.0 (3)a
IC6H4CHOI2O1174.5 (4)3.068 (4)119.2 (3)b
IC6H4CHOI2O2174.0 (3)3.074 (4)118.5 (3)b
C13H14INO3I1O4170.9 (4)2.987 (4)119.5 (3)c
C13H14INO3I2O1166.4 (4)3.110 (4)120.8 (3)c
C13H13I3O4I1O5159.8 (7)3.229 (7)143.3 (6)d
C13H13I3O4I2O4176.1 (7)3.092 (7)113.1 (6)d
C13H13I3O4I4O1158.2 (7)3.347 (7)143.6 (6)d
C13H13I3O4I5O7146.4 (7)3.507 (7)106.8 (6)d
a. this work. b. Britton & Young, 1997; refcode RIWTOG. c. Horne et al., 1991; refcode KOLWIR. d. Franssen et al., 1996; refcode TATDEX. Symmetry codes: (i) −1/2 + x, 1/2 − y, 1/2 + z; (ii) x, 1/2 − y, −1/2 + z.
 

Subscribe to Acta Crystallographica Section C: Structural Chemistry

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds