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γ-Hydroquinone (1) and its tetrafluoro, tetrachloro and tetrabromo derivatives (2), (3) and (4) adopt crystal structures that have an almost invariant system of O—H...O hydrogen bonds. However, within this O—H...O framework, the four structures display variations that are characteristic of the C—H, C—F, C—Cl and C—Br groups. In the parent compound (1) aromatic rings are packed with a herringbone geometry, whilst in the halogenated derivatives (3) and (4), polarization-type halogen...halogen contacts are optimized. The fluoro derivative (2) is exceptional in that neither of the above possibilities is adopted, even though the O—H...O scaffolding does not per se prohibit either of them geometrically.

Supporting information

cif

Crystallographic Information File (CIF)
Contains datablocks 2, global, 4

hkl

Structure factor file (CIF format)
Contains datablock 2

hkl

Structure factor file (CIF format)
Contains datablock 4

CCDC references: 138566; 138567

Computing details top

Data collection: XSCANS V.2.10b (Siemens,1994a) for (2); SMART V.4.209 (Siemens, 1995) for (4). Cell refinement: XSCANS V.2.10b (Siemens,1994a) for (2); SAINT V.4.050 (Siemens, 1995) for (4). Data reduction: XSCANS V.2.10b (Siemens,1994a) for (2); SAINT V.4.050 (Siemens, 1995) for (4). For both compounds, program(s) used to solve structure: SHELXTL V.5.03 (Siemens, 1994b); program(s) used to refine structure: SHELXTL V.5.03 (Siemens, 1994b); molecular graphics: SHELXTL V.5.03 (Siemens, 1994b); software used to prepare material for publication: SHELXTL V.5.03 (Siemens, 1994b).

(2) 2,3,5,6-Tetrafluorohydroquinone top
Crystal data top
C6H2F4O2F(000) = 180
Mr = 182.08Dx = 1.957 Mg m3
Monoclinic, P21/nMelting point: 446 K
Hall symbol: -P 2ynMo Kα radiation, λ = 0.71073 Å
a = 6.5533 (10) ÅCell parameters from 50 reflections
b = 4.8848 (10) Åθ = 10–12.5°
c = 10.148 (2) ŵ = 0.22 mm1
β = 107.990 (11)°T = 298 K
V = 308.97 (9) Å3Block, colourless
Z = 20.25 × 0.21 × 0.13 mm
Data collection top
Siemens P4 four circle
diffractometer
Rint = 0.026
Radiation source: fine-focus sealed tubeθmax = 30.0°, θmin = 3.3°
Graphite monochromatorh = 99
adaptive ω scansk = 16
2177 measured reflectionsl = 1413
901 independent reflections3 standard reflections every 100 reflections
664 reflections with I > 2σ(I) intensity decay: No decay
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)] = 0.041All H-atom parameters refined
wR(F2) = 0.131Calculated w = 1/[σ2(Fo2) + (0.0709P)2 + 0.0239P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.001
901 reflectionsΔρmax = 0.23 e Å3
60 parametersΔρmin = 0.16 e Å3
0 restraintsExtinction correction: SHELXL93 (Sheldrick, 1993), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0252 (201)
Special details top

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. Refinement on F2 for ALL reflections except for 0 with very negative F2 or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating _R_factor_obs 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*/Ueq
O0.7357 (2)0.0043 (3)0.8162 (2)0.0636 (4)
H0.719 (4)0.158 (6)0.773 (3)0.082 (7)*
C10.6196 (3)0.0083 (3)0.9067 (2)0.0469 (4)
C20.6619 (2)0.1834 (3)1.0113 (2)0.0480 (4)
C30.5445 (2)0.1912 (3)1.10273 (15)0.0472 (4)
F10.8189 (2)0.3666 (2)1.02410 (14)0.0700 (4)
F20.5912 (2)0.3787 (2)1.20450 (12)0.0657 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O0.0844 (9)0.0547 (7)0.0725 (8)0.0039 (6)0.0547 (7)0.0017 (6)
C10.0538 (8)0.0449 (8)0.0502 (8)0.0033 (6)0.0281 (6)0.0044 (6)
C20.0496 (8)0.0440 (8)0.0561 (8)0.0039 (6)0.0244 (6)0.0020 (6)
C30.0541 (8)0.0444 (8)0.0466 (7)0.0013 (6)0.0206 (6)0.0020 (6)
F10.0656 (7)0.0608 (7)0.0953 (9)0.0206 (5)0.0422 (6)0.0121 (5)
F20.0778 (7)0.0631 (6)0.0623 (6)0.0120 (5)0.0304 (5)0.0199 (5)
Geometric parameters (Å, º) top
O—C11.362 (2)C2—C31.376 (2)
C1—C21.378 (2)C3—F21.343 (2)
C1—C3i1.379 (2)C3—C1i1.379 (2)
C2—F11.340 (2)
O—C1—C2119.27 (14)C3—C2—C1121.13 (13)
O—C1—C3i123.30 (14)F2—C3—C2119.66 (14)
C2—C1—C3i117.40 (13)F2—C3—C1i118.87 (13)
F1—C2—C3119.26 (14)C2—C3—C1i121.46 (14)
F1—C2—C1119.60 (13)
Symmetry code: (i) x+1, y, z+2.
(4) 2,3,5,6-Tetrabromohydroquinone top
Crystal data top
C6H2Br4O2F(000) = 388
Mr = 425.72Dx = 3.041 Mg m3
Monoclinic, P21/nMelting point: 517 K
Hall symbol: -P 2ynMo Kα radiation, λ = 0.71073 Å
a = 8.8907 (2) ÅCell parameters from 2859 reflections
b = 4.7316 (1) Åθ = 2.9–28.2°
c = 11.0612 (3) ŵ = 17.26 mm1
β = 92.167 (1)°T = 303 K
V = 464.98 (2) Å3Block, colourless
Z = 20.58 × 0.46 × 0.32 mm
Data collection top
Siemens SMART
diffractometer
1130 independent reflections
Radiation source: fine-focus sealed tube709 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.150
Data collection in ω at 0.3 ° scan width, four runs with 636, 465, 636 and 465 frames, Φ = 0, 88, 180, 270θmax = 28.2°, θmin = 2.9°
Absorption correction: empirical (using intensity measurements) SADABS (blessing, 1995)
Siemens SADABS program has been used for the absorption correction
h = 1111
Tmin = 0.16, Tmax = 1.00k = 66
4829 measured reflectionsl = 1414
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)] = 0.067Riding
wR(F2) = 0.146Calculated w = 1/[σ2(Fo2) + (0.0448P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.93(Δ/σ)max = 0.001
1130 reflectionsΔρmax = 2.04 e Å3
56 parametersΔρmin = 1.92 e Å3
0 restraintsExtinction correction: SHELXL93 (Sheldrick, 1993), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0017 (14)
Special details top

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. Refinement on F2 for ALL reflections except for 0 with very negative F2 or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating _R_factor_obs 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*/Ueq
O0.2092 (6)0.5559 (14)0.1783 (6)0.031 (2)
H0A0.1779 (6)0.6640 (14)0.2315 (6)0.046*
Br10.32011 (10)0.1586 (3)0.01217 (10)0.0367 (4)
Br20.07172 (10)0.0776 (2)0.22943 (9)0.0316 (4)
C10.1052 (9)0.5344 (18)0.0910 (8)0.022 (2)
C20.1356 (8)0.354 (2)0.0062 (8)0.021 (2)
C30.0310 (9)0.3210 (19)0.0963 (8)0.021 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O0.021 (4)0.050 (5)0.022 (4)0.003 (3)0.008 (3)0.006 (3)
Br10.0203 (5)0.0599 (8)0.0298 (7)0.0126 (4)0.0009 (4)0.0003 (5)
Br20.0276 (6)0.0463 (8)0.0206 (6)0.0010 (4)0.0028 (4)0.0073 (4)
C10.018 (4)0.031 (5)0.017 (5)0.001 (3)0.003 (3)0.004 (4)
C20.012 (4)0.036 (6)0.014 (5)0.000 (3)0.001 (3)0.001 (4)
C30.017 (4)0.034 (5)0.012 (5)0.002 (3)0.008 (3)0.000 (4)
Geometric parameters (Å, º) top
O—C11.366 (9)C1—C21.393 (13)
Br1—C21.881 (8)C2—C31.396 (12)
Br2—C31.893 (9)C3—C1i1.390 (11)
C1—C3i1.390 (11)
O—C1—C3i123.1 (8)C3—C2—Br1121.6 (7)
O—C1—C2118.4 (8)C1i—C3—C2121.2 (8)
C3i—C1—C2118.5 (8)C1i—C3—Br2118.2 (6)
C1—C2—C3120.2 (8)C2—C3—Br2120.6 (6)
C1—C2—Br1118.1 (6)
Symmetry code: (i) x, y+1, z.
 
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