Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270107001576/fg3045sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270107001576/fg3045Isup2.hkl |
CCDC reference: 641797
For related literature, see: Batsanov (2000); DiCesare & Lakowicz (2002); Fronczek et al. (2001); Gravel et al. (2002); Miyaura & Suzuki (1995); Scouten et al. (1994); Secor & Glass (2004); Wang et al. (2002); Yang et al. (2003); Zarychta et al. (2004).
2,3-Difluoro-4-formylphenylboronic acid was received from Aldrich, crystallized from tetrahydrofuran and dried in air.
All H atoms were located geometrically and their positions were refined, while their displacement parameters were not. The refined C—H distances are in the range 0.949–1.061 (16) Å. Uiso(H) values were fixed at 0.040 (aromatic C—H) and 0.057 Å2 (hydroxy O—H).
Data collection: CrysAlis CCD (Oxford Diffraction, 2005); cell refinement: CrysAlis RED (Oxford Diffraction, 2005); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 1990).
C7H5BF2O3 | Z = 4 |
Mr = 185.92 | F(000) = 376 |
Monoclinic, P21/c | Dx = 1.618 Mg m−3 |
a = 7.9154 (12) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.8527 (15) Å | µ = 0.15 mm−1 |
c = 9.8141 (13) Å | T = 293 K |
β = 94.198 (12)° | Prismatic, colourless |
V = 763.33 (19) Å3 | 0.74 × 0.21 × 0.17 mm |
Kuma KM-4 CCD area-detector diffractometer | 1827 independent reflections |
Radiation source: fine-focus sealed tube | 1135 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.014 |
Detector resolution: 8.6479 pixels mm-1 | θmax = 28.6°, θmin = 2.9° |
ω scans | h = −9→10 |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2005) | k = −13→13 |
Tmin = 0.92, Tmax = 0.97 | l = −12→13 |
7011 measured reflections |
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)] = 0.039 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.109 | Only H-atom coordinates refined |
S = 0.90 | w = 1/[σ2(Fo2) + (0.0733P)2] where P = (Fo2 + 2Fc2)/3 |
1827 reflections | (Δ/σ)max < 0.001 |
133 parameters | Δρmax = 0.25 e Å−3 |
0 restraints | Δρmin = −0.26 e Å−3 |
C7H5BF2O3 | V = 763.33 (19) Å3 |
Mr = 185.92 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.9154 (12) Å | µ = 0.15 mm−1 |
b = 9.8527 (15) Å | T = 293 K |
c = 9.8141 (13) Å | 0.74 × 0.21 × 0.17 mm |
β = 94.198 (12)° |
Kuma KM-4 CCD area-detector diffractometer | 1827 independent reflections |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2005) | 1135 reflections with I > 2σ(I) |
Tmin = 0.92, Tmax = 0.97 | Rint = 0.014 |
7011 measured reflections |
R[F2 > 2σ(F2)] = 0.039 | 0 restraints |
wR(F2) = 0.109 | Only H-atom coordinates refined |
S = 0.90 | Δρmax = 0.25 e Å−3 |
1827 reflections | Δρmin = −0.26 e Å−3 |
133 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. 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 | ||
F1 | 0.08133 (11) | 0.44514 (8) | 0.81222 (8) | 0.0451 (3) | |
F2 | 0.08435 (11) | 0.71320 (8) | 0.81950 (9) | 0.0506 (3) | |
O1 | 0.31103 (16) | 0.20733 (10) | 1.13513 (10) | 0.0479 (3) | |
O2 | 0.22559 (18) | 0.18922 (11) | 0.90638 (12) | 0.0668 (4) | |
O3 | 0.33564 (16) | 0.92918 (9) | 1.11936 (12) | 0.0549 (3) | |
C1 | 0.25962 (17) | 0.42850 (12) | 1.01712 (14) | 0.0300 (3) | |
C2 | 0.17349 (16) | 0.50549 (13) | 0.91650 (12) | 0.0310 (3) | |
C3 | 0.17390 (16) | 0.64581 (13) | 0.91945 (13) | 0.0329 (3) | |
C4 | 0.26279 (17) | 0.71563 (13) | 1.02367 (14) | 0.0335 (3) | |
C5 | 0.35048 (18) | 0.64050 (13) | 1.12635 (14) | 0.0348 (3) | |
C6 | 0.34761 (17) | 0.50024 (13) | 1.12289 (14) | 0.0334 (3) | |
C7 | 0.2625 (2) | 0.86563 (15) | 1.02785 (17) | 0.0443 (4) | |
B2 | 0.2637 (2) | 0.26766 (15) | 1.01568 (15) | 0.0335 (4) | |
H5 | 0.4161 (18) | 0.6860 (15) | 1.1971 (15) | 0.040* | |
H6 | 0.4079 (18) | 0.4511 (15) | 1.1891 (16) | 0.040* | |
H7 | 0.1997 (18) | 0.9145 (14) | 0.9421 (16) | 0.040* | |
H1 | 0.311 (2) | 0.1237 (19) | 1.1298 (17) | 0.057* | |
H2 | 0.215 (2) | 0.2272 (17) | 0.8339 (18) | 0.057* |
U11 | U22 | U33 | U12 | U13 | U23 | |
F1 | 0.0570 (6) | 0.0356 (5) | 0.0403 (5) | −0.0017 (4) | −0.0131 (4) | −0.0057 (3) |
F2 | 0.0645 (6) | 0.0352 (5) | 0.0494 (5) | 0.0096 (4) | −0.0154 (4) | 0.0079 (4) |
O1 | 0.0870 (8) | 0.0191 (5) | 0.0360 (6) | −0.0005 (5) | −0.0066 (5) | 0.0002 (4) |
O2 | 0.1323 (12) | 0.0271 (6) | 0.0373 (7) | 0.0051 (6) | −0.0199 (7) | −0.0028 (5) |
O3 | 0.0816 (9) | 0.0250 (5) | 0.0562 (7) | −0.0026 (5) | −0.0075 (6) | −0.0034 (5) |
C1 | 0.0366 (7) | 0.0232 (6) | 0.0306 (7) | 0.0000 (5) | 0.0048 (6) | 0.0004 (5) |
C2 | 0.0355 (8) | 0.0281 (7) | 0.0291 (7) | −0.0009 (5) | 0.0003 (6) | −0.0024 (5) |
C3 | 0.0388 (8) | 0.0271 (7) | 0.0323 (7) | 0.0049 (6) | −0.0014 (6) | 0.0048 (6) |
C4 | 0.0420 (8) | 0.0231 (7) | 0.0357 (7) | 0.0009 (5) | 0.0049 (6) | 0.0001 (6) |
C5 | 0.0435 (8) | 0.0261 (7) | 0.0340 (8) | −0.0025 (6) | −0.0021 (6) | −0.0032 (6) |
C6 | 0.0430 (8) | 0.0259 (7) | 0.0304 (7) | 0.0018 (6) | −0.0025 (6) | 0.0017 (5) |
C7 | 0.0610 (10) | 0.0254 (7) | 0.0459 (9) | 0.0013 (7) | 0.0000 (8) | 0.0016 (7) |
B2 | 0.0428 (9) | 0.0241 (7) | 0.0333 (8) | −0.0007 (6) | 0.0017 (6) | −0.0011 (6) |
F1—C2 | 1.3505 (14) | C1—B2 | 1.5851 (19) |
F2—C3 | 1.3431 (15) | C2—C3 | 1.3828 (19) |
O1—B2 | 1.3430 (18) | C3—C4 | 1.3817 (19) |
O1—H1 | 0.826 (19) | C4—C5 | 1.3939 (19) |
O2—B2 | 1.3385 (18) | C4—C7 | 1.4785 (19) |
O2—H2 | 0.803 (18) | C5—C6 | 1.3825 (19) |
O3—C7 | 1.2073 (19) | C5—H5 | 0.949 (16) |
C1—C2 | 1.3845 (18) | C6—H6 | 0.916 (16) |
C1—C6 | 1.3987 (19) | C7—H7 | 1.061 (16) |
B2—O1—H1 | 112.8 (12) | C5—C4—C7 | 120.83 (13) |
B2—O2—H2 | 116.4 (12) | C6—C5—C4 | 120.44 (13) |
C2—C1—C6 | 116.42 (12) | C6—C5—H5 | 119.8 (9) |
C2—C1—B2 | 123.41 (12) | C4—C5—H5 | 119.7 (9) |
C6—C1—B2 | 120.17 (12) | C5—C6—C1 | 121.99 (13) |
F1—C2—C3 | 117.15 (11) | C5—C6—H6 | 120.3 (9) |
F1—C2—C1 | 120.65 (12) | C1—C6—H6 | 117.7 (9) |
C3—C2—C1 | 122.18 (12) | O3—C7—C4 | 122.51 (14) |
F2—C3—C4 | 120.49 (12) | O3—C7—H7 | 121.7 (8) |
F2—C3—C2 | 118.60 (11) | C4—C7—H7 | 115.7 (8) |
C4—C3—C2 | 120.90 (12) | O2—B2—O1 | 118.43 (13) |
C3—C4—C5 | 118.06 (12) | O1—B2—C1 | 116.06 (12) |
C3—C4—C7 | 121.10 (13) | O2—B2—C1 | 125.51 (13) |
C6—C1—C2—F1 | −178.26 (11) | C3—C4—C5—C6 | −0.01 (19) |
B2—C1—C2—F1 | 2.50 (19) | C7—C4—C5—C6 | 178.86 (12) |
C6—C1—C2—C3 | 0.09 (19) | C4—C5—C6—C1 | 0.7 (2) |
B2—C1—C2—C3 | −179.15 (12) | C2—C1—C6—C5 | −0.76 (19) |
F1—C2—C3—F2 | −0.25 (17) | B2—C1—C6—C5 | 178.51 (12) |
C1—C2—C3—F2 | −178.64 (11) | C3—C4—C7—O3 | 178.17 (14) |
F1—C2—C3—C4 | 179.02 (12) | C5—C4—C7—O3 | −0.7 (2) |
C1—C2—C3—C4 | 0.62 (19) | C2—C1—B2—O2 | 18.2 (2) |
F2—C3—C4—C5 | 178.60 (11) | C6—C1—B2—O2 | −160.99 (14) |
C2—C3—C4—C5 | −0.65 (19) | C2—C1—B2—O1 | −162.35 (13) |
F2—C3—C4—C7 | −0.3 (2) | C6—C1—B2—O1 | 18.4 (2) |
C2—C3—C4—C7 | −179.52 (12) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O3i | 0.826 (19) | 1.929 (19) | 2.7526 (14) | 174.3 (16) |
O2—H2···O1ii | 0.803 (18) | 2.242 (17) | 2.9744 (17) | 152.0 (16) |
O2—H2···F1 | 0.803 (18) | 2.395 (17) | 2.8917 (14) | 121.1 (14) |
Symmetry codes: (i) x, y−1, z; (ii) x, −y+1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C7H5BF2O3 |
Mr | 185.92 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 7.9154 (12), 9.8527 (15), 9.8141 (13) |
β (°) | 94.198 (12) |
V (Å3) | 763.33 (19) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.15 |
Crystal size (mm) | 0.74 × 0.21 × 0.17 |
Data collection | |
Diffractometer | Kuma KM-4 CCD area-detector diffractometer |
Absorption correction | Multi-scan (CrysAlis RED; Oxford Diffraction, 2005) |
Tmin, Tmax | 0.92, 0.97 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7011, 1827, 1135 |
Rint | 0.014 |
(sin θ/λ)max (Å−1) | 0.673 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.039, 0.109, 0.90 |
No. of reflections | 1827 |
No. of parameters | 133 |
H-atom treatment | Only H-atom coordinates refined |
Δρmax, Δρmin (e Å−3) | 0.25, −0.26 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2005), CrysAlis RED (Oxford Diffraction, 2005), CrysAlis RED, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg, 1999), SHELXTL (Sheldrick, 1990).
O1—B2 | 1.3430 (18) | C1—B2 | 1.5851 (19) |
O2—B2 | 1.3385 (18) | ||
O2—B2—O1 | 118.43 (13) | O2—B2—C1 | 125.51 (13) |
O1—B2—C1 | 116.06 (12) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O3i | 0.826 (19) | 1.929 (19) | 2.7526 (14) | 174.3 (16) |
O2—H2···O1ii | 0.803 (18) | 2.242 (17) | 2.9744 (17) | 152.0 (16) |
O2—H2···F1 | 0.803 (18) | 2.395 (17) | 2.8917 (14) | 121.1 (14) |
Symmetry codes: (i) x, y−1, z; (ii) x, −y+1/2, z−1/2. |
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Arylboronic acids containing a carbonyl group are valuable starting materials in organic synthesis. The high reactivity of this group enables modification of the structure of boronic acids to obtain a wide range of compounds possessing interesting properties. Recently, the synthesis of (N-alkyl)aminomethylphenylboronic acids via reductive amination of formylphenylboronic acids was published (Gravel et al., 2002). The formation of arylboronic acids containing a chalcone moiety in an aldol-type reaction between 4-acetylphenylboronic acids and aldehydes is also known (DiCesare & Lakowicz, 2002). The products obtained have found applications as potential saccharide (Wang et al., 2002) and hormone receptors (Secor & Glass, 2004) or as reagents in Suzuki coupling (Miyaura & Suzuki, 1995). The determination of the crystal structures of boronic acids can be helpful in the elucidation of the influence of hydrogen-bond formation on the activity of these compounds as potential pharmaceutical agents (Yang et al., 2003). Against this background, we present here the crystal structure of the title compound, (I).
The molecular structure of (I) is presented in Fig. 1, with selected geometry details in Table 1. The formyl group is essentially coplanar with the benzene ring [torsion angle C5—C4—C7—O3 - 0.7 (2)°] and the boronic acid group is twisted around the C—B bond [torsion angle C2—C1—B2—O2 18.2 (2)°], thus producing a non-planar six-membered ring. The boronic acid group has an exo–endo conformation. The endo-oriented OH group is engaged in a relatively weak intramolecular O—H···F interaction with atom F1,
The supramolecular assembly in (I) (Fig. 2) is primarily achieved due to O—H···O intermolecular hydrogen-bonding interactions (Table 2), of which there are two types. The exo-oriented OH group is the H-atom donor engaged in the nearly linear hydrogen bond with the O atom from the formyl group of an adjacent molecule. As a result, the molecules are connected in a `head-to-tail' fashion to form an infinite chain aligned along the crystallographic b axis. The exo –H group acts simultaneously as the H-atom acceptor for the endo OH group of another molecule; this hydrogen bond is weaker, but it seems to be responsible for the twisting of the boronic acid group. Thus,the hydrogen-bonded network in (I) can be described as a folded layer. It should be noted that a similar structure was reported for the related 4-formylphenylboronic acid (Fronczek et al., 2001), whereas molecules of the isomeric 3-formyl- (Zarychta et al., 2004) and 2-formylphenylboronic acids (Scouten et al., 1994) form centrosymmetric dimers via intermolecular hydrogen bonds between boronic acid groups.
Examination of the crystal packing in (I) reveals that layers are paired due to weak interactions of their `fluorinated' sides. These interactions are represented by relatively short B2···F2iii distances of 3.301 (2) Å, [symmetry code: -x, 1 - y, 2 - z], presumably the result of electrostatic attractive forces between B and F atoms, producing centrosymmetric dimeric motifs. According to Batsanov (2000), the sum of the van der Waals radii for B and F is 3.51 Å.
In conclusion, the supramolecular structure of (I) is achieved via two types of intermolecular hydrogen bonds to form a folded layer structure. In addition, the layers are paired due to B···F interactions.