Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801001295/ob6023sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536801001295/ob6023Isup2.hkl |
CCDC reference: 159769
The synthesis of 2',6'-dimethoxyflavone has been previously reported (Wallet et al., 1989). Bromoacetic acid was from Aldrich. Crystals of (I) were obtained by slow evaporation of an ethanol solution of the stoichiometric mixture.
The positional parameters of the hydroxyl H121 atom were refined. All the other H atoms were introduced in calculated positions and constrained to ride on their bonded atom.
Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLUTON93 (Spek, 1993).
Fig. 1. View of the title complex showing the labelling of the non-H atoms. Displacement ellipsoids are shown at the 50% probability level. |
C17H14O4·C2H3BrO2 | Z = 2 |
Mr = 421.24 | F(000) = 428 |
Triclinic, P1 | Dx = 1.536 Mg m−3 |
a = 7.663 (1) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.693 (1) Å | Cell parameters from 25 reflections |
c = 12.877 (1) Å | θ = 8.5–12.5° |
α = 86.56 (1)° | µ = 2.29 mm−1 |
β = 78.56 (1)° | T = 293 K |
γ = 76.30 (2)° | Prism, pale yellow |
V = 910.71 (17) Å3 | 0.66 × 0.30 × 0.04 mm |
Enraf Nonius CAD4 diffractometer | 1072 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.065 |
Graphite monochromator | θmax = 23.7°, θmin = 2.9° |
non–profiled ω/2θ scans | h = 0→8 |
Absorption correction: ψ scan (North et al., 1968) | k = −10→10 |
Tmin = 0.440, Tmax = 0.913 | l = −14→14 |
2993 measured reflections | 3 standard reflections every 60 min |
2760 independent reflections | intensity decay: none |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.075 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.249 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.96 | w = 1/[σ2(Fo2) + (0.1319P)2] where P = (Fo2 + 2Fc2)/3 |
2760 reflections | (Δ/σ)max = 0.006 |
240 parameters | Δρmax = 0.65 e Å−3 |
0 restraints | Δρmin = −0.66 e Å−3 |
C17H14O4·C2H3BrO2 | γ = 76.30 (2)° |
Mr = 421.24 | V = 910.71 (17) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.663 (1) Å | Mo Kα radiation |
b = 9.693 (1) Å | µ = 2.29 mm−1 |
c = 12.877 (1) Å | T = 293 K |
α = 86.56 (1)° | 0.66 × 0.30 × 0.04 mm |
β = 78.56 (1)° |
Enraf Nonius CAD4 diffractometer | 1072 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.065 |
Tmin = 0.440, Tmax = 0.913 | θmax = 23.7° |
2993 measured reflections | 3 standard reflections every 60 min |
2760 independent reflections | intensity decay: none |
R[F2 > 2σ(F2)] = 0.075 | 0 restraints |
wR(F2) = 0.249 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.96 | Δρmax = 0.65 e Å−3 |
2760 reflections | Δρmin = −0.66 e Å−3 |
240 parameters |
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 presence of acid and the stoichiometry in the crystal were preliminary confirmed by CH microanalysis. Calcd for C19H17BrO6: C, 54.15; H, 4.03. Found: C, 54.43; H, 3.96. Number of psi-scan sets used was 4 Theta correction was applied. Averaged transmission function was used. No Fourier smoothing was applied. 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. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.9559 (3) | 0.26096 (14) | 0.36870 (11) | 0.1161 (9) | |
O1 | 0.4596 (8) | 0.8299 (6) | 0.9302 (5) | 0.0437 (18) | |
O4 | 0.7735 (10) | 0.4825 (6) | 0.7659 (5) | 0.064 (2) | |
O2' | 0.6078 (11) | 0.9965 (7) | 0.6770 (6) | 0.067 (2) | |
O6' | 0.0975 (10) | 0.8764 (7) | 0.8903 (6) | 0.061 (2) | |
O121 | 0.8240 (12) | 0.4156 (8) | 0.5732 (6) | 0.081 (3) | |
H121 | 0.844 (16) | 0.439 (13) | 0.652 (11) | 0.122* | |
O122 | 0.6331 (11) | 0.6031 (8) | 0.5214 (6) | 0.082 (3) | |
C2 | 0.4654 (12) | 0.8183 (9) | 0.8257 (7) | 0.037 (2) | |
C3 | 0.5688 (12) | 0.7072 (9) | 0.7686 (7) | 0.042 (3) | |
H3 | 0.5710 | 0.7073 | 0.6962 | 0.051* | |
C4 | 0.6758 (13) | 0.5885 (9) | 0.8162 (7) | 0.040 (3) | |
C5 | 0.7635 (13) | 0.4939 (10) | 0.9879 (8) | 0.047 (3) | |
H5 | 0.8357 | 0.4116 | 0.9546 | 0.057* | |
C6 | 0.7540 (15) | 0.5101 (11) | 1.0935 (8) | 0.062 (3) | |
H6 | 0.8214 | 0.4399 | 1.1316 | 0.075* | |
C7 | 0.6440 (15) | 0.6308 (11) | 1.1439 (8) | 0.066 (3) | |
H7 | 0.6353 | 0.6394 | 1.2164 | 0.079* | |
C8 | 0.5480 (15) | 0.7375 (11) | 1.0897 (8) | 0.059 (3) | |
H8 | 0.4768 | 0.8196 | 1.1238 | 0.070* | |
C9 | 0.5596 (14) | 0.7204 (9) | 0.9810 (7) | 0.045 (3) | |
C10 | 0.6667 (13) | 0.5989 (10) | 0.9299 (7) | 0.043 (3) | |
C11 | 0.7951 (16) | 0.4398 (12) | 0.3927 (9) | 0.080 (4) | |
H11A | 0.8501 | 0.5085 | 0.3482 | 0.119* | |
H11B | 0.6839 | 0.4370 | 0.3685 | 0.119* | |
C12 | 0.7427 (15) | 0.4937 (12) | 0.5016 (8) | 0.055 (3) | |
C21 | 0.6876 (16) | 1.0748 (13) | 0.5943 (10) | 0.086 (4) | |
H21A | 0.6490 | 1.0598 | 0.5302 | 0.130* | |
H21B | 0.8184 | 1.0446 | 0.5847 | 0.130* | |
H21C | 0.6504 | 1.1739 | 0.6111 | 0.130* | |
C61 | −0.0955 (14) | 0.8867 (13) | 0.9198 (9) | 0.077 (4) | |
H61A | −0.1545 | 0.9781 | 0.9499 | 0.115* | |
H61B | −0.1179 | 0.8138 | 0.9710 | 0.115* | |
H61C | −0.1434 | 0.8753 | 0.8582 | 0.115* | |
C1' | 0.3504 (14) | 0.9426 (9) | 0.7804 (8) | 0.042 (3) | |
C2' | 0.4210 (16) | 1.0271 (10) | 0.7014 (8) | 0.047 (3) | |
C3' | 0.311 (2) | 1.1358 (11) | 0.6567 (9) | 0.067 (3) | |
H3' | 0.3611 | 1.1940 | 0.6050 | 0.080* | |
C4' | 0.131 (2) | 1.1573 (11) | 0.6883 (11) | 0.080 (4) | |
H4' | 0.0565 | 1.2289 | 0.6551 | 0.097* | |
C5' | 0.0500 (16) | 1.0789 (12) | 0.7675 (10) | 0.070 (3) | |
H5' | −0.0764 | 1.1005 | 0.7893 | 0.084* | |
C6' | 0.1587 (15) | 0.9663 (10) | 0.8153 (8) | 0.051 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.1754 (19) | 0.0781 (10) | 0.0628 (9) | 0.0120 (9) | 0.0079 (10) | −0.0172 (7) |
O1 | 0.047 (5) | 0.048 (4) | 0.031 (4) | 0.005 (3) | −0.014 (3) | −0.004 (3) |
O4 | 0.086 (6) | 0.052 (4) | 0.034 (4) | 0.023 (4) | −0.010 (4) | −0.005 (3) |
O2' | 0.067 (6) | 0.064 (5) | 0.065 (5) | −0.019 (4) | −0.003 (4) | 0.031 (4) |
O6' | 0.047 (5) | 0.068 (5) | 0.063 (5) | −0.003 (4) | −0.010 (4) | 0.000 (4) |
O121 | 0.110 (7) | 0.072 (5) | 0.038 (4) | 0.040 (5) | −0.030 (5) | −0.009 (4) |
O122 | 0.096 (6) | 0.065 (5) | 0.064 (5) | 0.028 (5) | −0.021 (5) | −0.003 (4) |
C2 | 0.039 (6) | 0.038 (5) | 0.038 (6) | −0.006 (5) | −0.020 (5) | 0.002 (4) |
C3 | 0.051 (7) | 0.040 (5) | 0.027 (5) | 0.009 (5) | −0.011 (5) | 0.004 (4) |
C4 | 0.044 (6) | 0.040 (5) | 0.029 (5) | 0.000 (5) | −0.005 (5) | 0.006 (4) |
C5 | 0.045 (7) | 0.048 (5) | 0.044 (7) | 0.003 (5) | −0.015 (5) | 0.012 (5) |
C6 | 0.068 (8) | 0.071 (7) | 0.049 (7) | −0.006 (6) | −0.030 (6) | 0.019 (6) |
C7 | 0.082 (9) | 0.074 (8) | 0.036 (6) | 0.000 (7) | −0.023 (6) | 0.008 (6) |
C8 | 0.075 (9) | 0.062 (7) | 0.040 (6) | −0.013 (6) | −0.014 (6) | −0.010 (5) |
C9 | 0.055 (7) | 0.045 (6) | 0.031 (6) | −0.001 (5) | −0.011 (5) | 0.002 (5) |
C10 | 0.032 (6) | 0.065 (6) | 0.030 (5) | 0.001 (5) | −0.015 (5) | 0.001 (5) |
C11 | 0.083 (9) | 0.085 (8) | 0.056 (7) | 0.031 (7) | −0.032 (7) | −0.019 (6) |
C12 | 0.048 (7) | 0.067 (7) | 0.046 (7) | −0.006 (6) | −0.012 (6) | −0.004 (6) |
C21 | 0.072 (9) | 0.093 (9) | 0.096 (11) | −0.031 (8) | −0.015 (8) | 0.018 (8) |
C61 | 0.025 (7) | 0.123 (10) | 0.078 (9) | −0.015 (7) | 0.007 (6) | −0.031 (8) |
C1' | 0.042 (7) | 0.038 (5) | 0.043 (6) | 0.006 (5) | −0.015 (5) | −0.007 (5) |
C2' | 0.052 (8) | 0.045 (6) | 0.044 (6) | −0.005 (6) | −0.019 (6) | 0.005 (5) |
C3' | 0.082 (10) | 0.052 (7) | 0.063 (8) | −0.001 (7) | −0.028 (8) | 0.013 (6) |
C4' | 0.101 (12) | 0.046 (7) | 0.092 (10) | 0.014 (8) | −0.057 (10) | 0.014 (7) |
C5' | 0.047 (8) | 0.075 (8) | 0.083 (9) | 0.011 (7) | −0.026 (7) | −0.008 (7) |
C6' | 0.051 (8) | 0.050 (6) | 0.050 (7) | 0.005 (6) | −0.022 (6) | −0.013 (5) |
Br1—C11 | 1.876 (10) | C5—C6 | 1.364 (14) |
O1—C2 | 1.348 (10) | C5—C10 | 1.384 (12) |
O1—C9 | 1.369 (10) | C6—C7 | 1.381 (14) |
O4—C4 | 1.249 (10) | C7—C8 | 1.362 (14) |
O2'—C2' | 1.367 (11) | C8—C9 | 1.402 (13) |
O2'—C21 | 1.396 (12) | C9—C10 | 1.383 (12) |
O6'—C6' | 1.351 (12) | C11—C12 | 1.472 (14) |
O6'—C61 | 1.433 (11) | C1'—C2' | 1.375 (13) |
O121—C12 | 1.316 (12) | C1'—C6' | 1.415 (13) |
O122—C12 | 1.192 (11) | C2'—C3' | 1.360 (14) |
C2—C3 | 1.337 (11) | C3'—C4' | 1.327 (16) |
C2—C1' | 1.478 (12) | C4'—C5' | 1.373 (17) |
C3—C4 | 1.428 (12) | C5'—C6' | 1.398 (15) |
C4—C10 | 1.461 (13) | ||
C2—O1—C9 | 118.3 (6) | C9—C10—C4 | 118.4 (8) |
C2'—O2'—C21 | 117.0 (9) | C5—C10—C4 | 122.8 (8) |
C6'—O6'—C61 | 118.9 (9) | C12—C11—Br1 | 118.2 (8) |
C3—C2—O1 | 123.2 (8) | O122—C12—O121 | 123.2 (10) |
C3—C2—C1' | 123.6 (8) | O122—C12—C11 | 120.3 (11) |
O1—C2—C1' | 113.1 (7) | O121—C12—C11 | 116.4 (9) |
C2—C3—C4 | 121.7 (8) | C2'—C1'—C6' | 119.7 (9) |
O4—C4—C3 | 123.7 (8) | C2'—C1'—C2 | 122.8 (10) |
O4—C4—C10 | 120.9 (8) | C6'—C1'—C2 | 117.3 (9) |
C3—C4—C10 | 115.4 (8) | C3'—C2'—O2' | 124.0 (11) |
C6—C5—C10 | 120.6 (9) | C3'—C2'—C1' | 121.6 (11) |
C5—C6—C7 | 119.9 (9) | O2'—C2'—C1' | 114.2 (9) |
C8—C7—C6 | 121.4 (10) | C4'—C3'—C2' | 118.8 (12) |
C7—C8—C9 | 118.2 (9) | C3'—C4'—C5' | 123.2 (11) |
O1—C9—C10 | 123.0 (8) | C4'—C5'—C6' | 119.6 (12) |
O1—C9—C8 | 116.0 (8) | O6'—C6'—C5' | 126.0 (11) |
C10—C9—C8 | 121.0 (9) | O6'—C6'—C1' | 117.0 (9) |
C9—C10—C5 | 118.8 (9) | C5'—C6'—C1' | 117.0 (11) |
C9—O1—C2—C3 | −2.4 (14) | Br1—C11—C12—O121 | 4.7 (16) |
C9—O1—C2—C1' | 179.4 (9) | C3—C2—C1'—C2' | −59.5 (14) |
O1—C2—C3—C4 | 2.8 (15) | O1—C2—C1'—C2' | 118.7 (10) |
C1'—C2—C3—C4 | −179.1 (9) | C3—C2—C1'—C6' | 115.3 (11) |
C2—C3—C4—O4 | 179.7 (9) | O1—C2—C1'—C6' | −66.5 (11) |
C2—C3—C4—C10 | −1.2 (15) | C21—O2'—C2'—C3' | −5.9 (15) |
C10—C5—C6—C7 | 1.3 (17) | C21—O2'—C2'—C1' | 177.5 (9) |
C5—C6—C7—C8 | −2.1 (19) | C6'—C1'—C2'—C3' | 1.4 (15) |
C6—C7—C8—C9 | 1.7 (18) | C2—C1'—C2'—C3' | 176.0 (9) |
C2—O1—C9—C10 | 0.3 (14) | C6'—C1'—C2'—O2' | 178.1 (8) |
C2—O1—C9—C8 | −179.7 (9) | C2—C1'—C2'—O2' | −7.2 (13) |
C7—C8—C9—O1 | 179.5 (10) | O2'—C2'—C3'—C4' | −178.6 (11) |
C7—C8—C9—C10 | −0.5 (17) | C1'—C2'—C3'—C4' | −2.2 (17) |
O1—C9—C10—C5 | 179.8 (9) | C2'—C3'—C4'—C5' | 3 (2) |
C8—C9—C10—C5 | −0.2 (16) | C3'—C4'—C5'—C6' | −3.0 (19) |
O1—C9—C10—C4 | 1.1 (16) | C61—O6'—C6'—C5' | 5.3 (14) |
C8—C9—C10—C4 | −178.8 (9) | C61—O6'—C6'—C1' | −173.4 (8) |
C6—C5—C10—C9 | −0.2 (16) | C4'—C5'—C6'—O6' | −176.7 (10) |
C6—C5—C10—C4 | 178.4 (10) | C4'—C5'—C6'—C1' | 2.0 (16) |
O4—C4—C10—C9 | 178.5 (9) | C2'—C1'—C6'—O6' | 177.5 (9) |
C3—C4—C10—C9 | −0.7 (14) | C2—C1'—C6'—O6' | 2.6 (12) |
O4—C4—C10—C5 | −0.1 (16) | C2'—C1'—C6'—C5' | −1.3 (14) |
C3—C4—C10—C5 | −179.3 (9) | C2—C1'—C6'—C5' | −176.2 (9) |
Br1—C11—C12—O122 | −175.8 (9) |
D—H···A | D—H | H···A | D···A | D—H···A |
O121—H121···O4 | 1.09 (14) | 1.51 (14) | 2.534 (9) | 152 (11) |
C3—H3···O122 | 0.93 | 2.44 | 3.305 (12) | 156 |
Experimental details
Crystal data | |
Chemical formula | C17H14O4·C2H3BrO2 |
Mr | 421.24 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 7.663 (1), 9.693 (1), 12.877 (1) |
α, β, γ (°) | 86.56 (1), 78.56 (1), 76.30 (2) |
V (Å3) | 910.71 (17) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 2.29 |
Crystal size (mm) | 0.66 × 0.30 × 0.04 |
Data collection | |
Diffractometer | Enraf Nonius CAD4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.440, 0.913 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2993, 2760, 1072 |
Rint | 0.065 |
θmax (°) | 23.7 |
(sin θ/λ)max (Å−1) | 0.566 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.075, 0.249, 0.96 |
No. of reflections | 2760 |
No. of parameters | 240 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.65, −0.66 |
Computer programs: CAD-4 EXPRESS (Enraf-Nonius, 1994), CAD-4 EXPRESS, XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLUTON93 (Spek, 1993).
D—H···A | D—H | H···A | D···A | D—H···A |
O121—H121···O4 | 1.09 (14) | 1.51 (14) | 2.534 (9) | 152 (11) |
C3—H3···O122 | 0.93 | 2.44 | 3.305 (12) | 156 |
2',6'-Dimethoxyflavone is a synthetic flavone which gives inclusion compounds with alkyl carboxylic acids: acetic (Wallet et al., 1989), propionic (Tinant et al., 1991) which crystallize in space group P1, and chloroacetic and trichloroacetic acids (Espinosa et al., 1999) which crystallize in non-centrosymmetric space groups. We were interested in knowing whether the presence of a haloacetic acid would favour the crystallization in a non-centrosymmetric space group. The substitution of one halogen by another had been reported as not altering the existing packing of crystals (Kálmán et al., 1993; Wallet et al., 2000). The space group is of prime importance for the phenomenon of second harmonic generation. 2',6'-Dimethoxyflavone–acid complexes may provide the possibility to get acid molecules in different conformations of those given by pure acid crystals. Earlier examples are given by complexes with formic acid (Tinant et al., 1991) and 2,6-dimethoxybenzoic acid (Wallet et al., 1998). However, the control of the structure of solids via hydrogen-bonding interactions is known to be difficult (Desiraju, 1989).
The molecule structure of the title compound, (I), is shown in Fig. 1. The torsion angle O1—C2—C1'—C6' in the flavone is -66.5 (11)°. The backbone of the bromoacetic acid is almost planar, Br1—C11—C12—O122 = -175.8 (9)°. Two forms of crystal structure have been reported for bromoacetic acid (Vor der Bruck & Leiserowitz, 1975). In (I), the acid molecule shows the same conformation as in the pure acid crystals (synplanar). The difference is that the bromoacetic acid is in the anti Br—C—C═O conformation (syn in the two forms of the pure acid). In addition to the O121—H121···O4 hydrogen bond (Table 1) there is a short contact C3—H3···O122, which exists in the complexes with acetic and propionic acids (space group P1) but does not exist in the complexes with chloroacetic and trichloroacetic acids which crystallize in non-centrosymmetric space groups. Thus, a skewed non-planar arrangement of the carboxyl group to the benzopyrone moiety of flavone seems to be a driving force leading to non-centrosymmetric structure.