Download citation
Download citation
link to html
The mol­ecule of the title compound, C7H7BO3, is planar, and the bond lengths and angles are typical. The formyl group is essentially coplanar with the benzene ring but does not influence significantly the distortion of the ring, although the formyl group does have a strong influence on the crystal packing. The geometry of the boronic acid group is typical. In the crystal structure, the mol­ecules are linked by O—H...O hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104006493/dn1046sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104006493/dn1046Isup2.hkl
Contains datablock I

CCDC reference: 241233

Comment top

Arylboronic acids, known for more than a hundred years, are now again the object of interest because of new applications. The most important synthetic application is Suzuki coupling, i.e. the palladium-catalyzed reaction of aryl halides with arylboronic acids to form biphenyls (Miyaura & Suzuki, 1995). Another rapidly increasing field is the biological application of these compounds. They are used in boron neutron capture therapy (BNCT; Soloway et al., 1998), as enzyme inhibitors (Myung et al., 2001) and as saccharide sensors (Wang et al., 2002). Recent developments in the use of boronic acids as potential pharmaceutical agents were reviewed by Yang et al. (2003).

The crystal structures of several arylboronic acids have been reported. The sructure of benzeneboronic acid was investigated by Rettig & Trotter (1977). Two independent molecules are linked by two intermolecular hydrogen bonds, forming a nearly planar dimeric molecule. This type of planar hydrogen-bonded dimeric structure is characteristic of many other substituted benzeneboronic acids. However, the presence of substituents on the phenyl ring can change the geometry of the molecule. For example, the formation of intramolecular hydrogen bonds is observed in 2-formylbenzeneboronic acid (Scouten et al., 1994), but the presence of a nitro group in an ortho position makes the B(OH)2 group perpendicular to the phenyl ring (Soundararayan et al., 1993). The aim of the present work is to investigate the influence of a formyl group in a meta position on the structure.

The molecular structure of the title compound, (I), is presented in Fig. 1. The molecule is planar. In most cases (of what?), the B(OH)2 group is twisted around the C—B bond (Gainsford et al., 1995; Fronczek et al., 2001; Ganguly et al., 2003). The bond lengths and valence angles of the phenyl ring in (I) are typical and in good agreement with the mean values found in other boron compounds (Rettig & Trotter, 1977; Shull et al., 2000). It seems that the boronic group, as a result of its electron properties and characteristic hydrogen-bond shell, has a strong influence on the phenyl ring distortion (Fronczek et al., 2001).

It is worth comparing the molecular structure of the title compound with its ortho and para isomers. Fronczek et al. (2001) reported a revised structure of 4-formylphenylboronic acid and Scouten et al. (1994) reported that of 2-formylphenylboronic acid. In these two compounds, the formyl group is essentially coplanar with the phenyl ring, as it is in (I). The bond lengths of the formyl groups in these three molecules are in good agreement. The C7—C3—C4 angles for the ortho, metha and para isomers are 128.14, 121.4 (1) and 123.21 (19)°, respectively. The differences are caused by the dissimilarity of the hydrogen-bonding shell around the formyl O atom and the different steric environment (steric interactions between the formyl and boronic acid group in the ortho isomer). The position of the formyl group does not influence significantly the distortion of the phenyl ring, although it has a strong influence on the crystal packing.

The region of most interest is that of the boronic acid group. The geometry of this group is typical; in all of the aforementioned structures, the boronic acid group is effectively planar. The B—O bond lengths are slightly different [0.020 (2) Å]; their values? seem to be a characteristic property of this group of compounds. The geometry of the angles around the B atom was also found to be typical?. The angle that deviates most from 120° is that related to the O atom with a hydroxy H atom in the syn position relative to the phenyl group [123.1 (1)°]. Similar effects have been reported for 2-acetylphenylboronic acid monohydrate [123.35 (14)°; Ganguly et al., 2003], L-p-boronophenylalanine (122.73°; Shull et al., 2000) and phenylboronic acid (124.02°; Rettig & Trotter, 1977).

In the crystal structure of (I), the molecules are linked by O—H···O hydrogen bonds (Fig. 2). There are two types of these bonds, one of them being formed between two boronic acid groups, causing dimeryzation, and the other being formed between formyl and boronic acid group, linking the dimers to one another.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2002); cell refinement: CrysAlis RED (Oxford Diffraction, 2002); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 1990); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. The molecular structure of (I). Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. The crystal packing and hydrogen-bonding scheme of (I). Displacement ellipsoids are drawn at the 50% probability level.
(3-Formylphenyl)boronic acid top
Crystal data top
C7H7BO3F(000) = 624
Mr = 149.94Dx = 1.407 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 5047 reflections
a = 22.635 (2) Åθ = 3.7–29.8°
b = 3.7330 (3) ŵ = 0.11 mm1
c = 17.126 (2) ÅT = 100 K
β = 102.054 (8)°Irregular, colourless
V = 1415.2 (2) Å30.16 × 0.15 × 0.15 mm
Z = 8
Data collection top
Xcalibur
diffractometer
1369 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.019
Graphite monochromatorθmax = 28.7°, θmin = 3.7°
Detector resolution: 8.4175 pixels mm-1h = 3019
ω–scank = 55
4975 measured reflectionsl = 2323
1795 independent reflections
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)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.099All H-atom parameters refined
S = 0.97 w = 1/[σ2(Fo2) + (0.0642P)2]
where P = (Fo2 + 2Fc2)/3
1795 reflections(Δ/σ)max < 0.001
128 parametersΔρmax = 0.37 e Å3
0 restraintsΔρmin = 0.22 e Å3
Crystal data top
C7H7BO3V = 1415.2 (2) Å3
Mr = 149.94Z = 8
Monoclinic, C2/cMo Kα radiation
a = 22.635 (2) ŵ = 0.11 mm1
b = 3.7330 (3) ÅT = 100 K
c = 17.126 (2) Å0.16 × 0.15 × 0.15 mm
β = 102.054 (8)°
Data collection top
Xcalibur
diffractometer
1369 reflections with I > 2σ(I)
4975 measured reflectionsRint = 0.019
1795 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0360 restraints
wR(F2) = 0.099All H-atom parameters refined
S = 0.97Δρmax = 0.37 e Å3
1795 reflectionsΔρmin = 0.22 e Å3
128 parameters
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 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*/Ueq
B10.43692 (6)0.1788 (3)0.56306 (7)0.0161 (3)
O10.42748 (4)0.1204 (2)0.48244 (5)0.0210 (2)
O20.49159 (4)0.0972 (2)0.60823 (5)0.0214 (2)
O30.34076 (4)0.6998 (3)0.85463 (5)0.0254 (2)
C10.38715 (5)0.3342 (3)0.60517 (6)0.0144 (2)
C20.39983 (5)0.3834 (3)0.68785 (7)0.0158 (2)
C30.35668 (5)0.5205 (3)0.72718 (6)0.0154 (2)
C40.29917 (5)0.6106 (3)0.68411 (7)0.0156 (2)
C50.28570 (5)0.5623 (3)0.60239 (7)0.0170 (2)
C60.32934 (5)0.4267 (3)0.56367 (6)0.0160 (3)
C70.37367 (5)0.5744 (3)0.81350 (7)0.0193 (3)
H20.4393 (6)0.316 (4)0.7195 (8)0.022 (3)*
H40.2703 (6)0.703 (3)0.7129 (7)0.015 (3)*
H50.2456 (6)0.625 (4)0.5711 (8)0.025 (4)*
H60.3176 (6)0.396 (3)0.5052 (8)0.022 (3)*
H70.4151 (6)0.505 (4)0.8388 (8)0.021 (3)*
H110.3931 (8)0.186 (4)0.4505 (10)0.048 (5)*
H210.5160 (8)0.019 (5)0.5771 (11)0.053 (5)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
B10.0169 (6)0.0171 (6)0.0152 (6)0.0009 (5)0.0058 (5)0.0005 (5)
O10.0159 (4)0.0336 (5)0.0140 (4)0.0056 (3)0.0042 (3)0.0007 (3)
O20.0156 (4)0.0325 (5)0.0167 (4)0.0051 (4)0.0048 (3)0.0034 (4)
O30.0203 (4)0.0408 (6)0.0161 (4)0.0031 (4)0.0063 (3)0.0050 (4)
C10.0152 (5)0.0132 (5)0.0160 (5)0.0007 (4)0.0056 (4)0.0003 (4)
C20.0133 (5)0.0176 (6)0.0166 (5)0.0006 (4)0.0033 (4)0.0001 (4)
C30.0167 (5)0.0162 (6)0.0140 (5)0.0012 (4)0.0047 (4)0.0006 (4)
C40.0143 (5)0.0158 (6)0.0181 (5)0.0002 (4)0.0067 (4)0.0001 (4)
C50.0134 (5)0.0193 (6)0.0180 (5)0.0011 (4)0.0028 (4)0.0013 (4)
C60.0177 (5)0.0172 (6)0.0134 (5)0.0004 (4)0.0037 (4)0.0003 (4)
C70.0164 (5)0.0249 (6)0.0165 (5)0.0011 (5)0.0035 (4)0.0008 (5)
Geometric parameters (Å, º) top
B1—O21.350 (2)C2—H20.976 (14)
B1—O11.370 (1)C3—C41.3967 (15)
B1—C11.5701 (16)C3—C71.4615 (15)
O1—H110.887 (18)C4—C51.3807 (15)
O2—H210.894 (19)C4—H40.962 (13)
O3—C71.2205 (14)C5—C61.3947 (15)
C1—C61.3959 (15)C5—H50.980 (15)
C1—C21.3970 (14)C6—H60.987 (13)
C2—C31.3943 (15)C7—H70.983 (13)
O2—B1—O1118.2 (1)C4—C3—C7121.4 (1)
O2—B1—C1118.7 (1)C5—C4—C3119.2 (1)
O1—B1—C1123.1 (1)C5—C4—H4122.5 (7)
B1—O1—H11120.6 (11)C3—C4—H4118.3 (7)
B1—O2—H21109.8 (11)C4—C5—C6120.1 (1)
C6—C1—C2117.1 (1)C4—C5—H5120.4 (8)
C6—C1—B1122.9 (1)C6—C5—H5119.5 (8)
C2—C1—B1119.9 (1)C5—C6—C1122.0 (1)
C3—C2—C1121.4 (1)C5—C6—H6117.2 (8)
C3—C2—H2118.5 (8)C1—C6—H6120.9 (8)
C1—C2—H2120.0 (8)O3—C7—C3125.0 (1)
C2—C3—C4120.2 (1)O3—C7—H7119.3 (8)
C2—C3—C7118.4 (1)C3—C7—H7115.7 (8)
O2—B1—C1—C6180.0 (1)C2—C3—C4—C50.05 (17)
O1—B1—C1—C60.3 (2)C7—C3—C4—C5178.53 (11)
O2—B1—C1—C20.4 (2)C3—C4—C5—C60.29 (17)
O1—B1—C1—C2179.4 (1)C4—C5—C6—C10.35 (18)
C6—C1—C2—C30.29 (17)C2—C1—C6—C50.05 (17)
B1—C1—C2—C3179.95 (10)B1—C1—C6—C5179.59 (11)
C1—C2—C3—C40.35 (17)C2—C3—C7—O3178.2 (1)
C1—C2—C3—C7178.27 (11)C4—C3—C7—O30.4 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H11···O3i0.89 (2)1.86 (2)2.702 (1)157 (2)
O2—H21···O1ii0.89 (2)1.87 (2)2.760 (1)175 (2)
Symmetry codes: (i) x, y+1, z1/2; (ii) x+1, y, z+1.

Experimental details

Crystal data
Chemical formulaC7H7BO3
Mr149.94
Crystal system, space groupMonoclinic, C2/c
Temperature (K)100
a, b, c (Å)22.635 (2), 3.7330 (3), 17.126 (2)
β (°) 102.054 (8)
V3)1415.2 (2)
Z8
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.16 × 0.15 × 0.15
Data collection
DiffractometerXcalibur
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
4975, 1795, 1369
Rint0.019
(sin θ/λ)max1)0.676
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.036, 0.099, 0.97
No. of reflections1795
No. of parameters128
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.37, 0.22

Computer programs: CrysAlis CCD (Oxford Diffraction, 2002), CrysAlis RED (Oxford Diffraction, 2002), CrysAlis RED, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL (Sheldrick, 1990), SHELXL97.

Selected geometric parameters (Å, º) top
B1—O21.350 (2)B1—O11.370 (1)
O2—B1—O1118.2 (1)C6—C1—B1122.9 (1)
O2—B1—C1118.7 (1)C2—C3—C7118.4 (1)
O1—B1—C1123.1 (1)C4—C3—C7121.4 (1)
C6—C1—C2117.1 (1)O3—C7—C3125.0 (1)
O2—B1—C1—C6180.0 (1)O1—B1—C1—C2179.4 (1)
O1—B1—C1—C60.3 (2)C2—C3—C7—O3178.2 (1)
O2—B1—C1—C20.4 (2)C4—C3—C7—O30.4 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H11···O3i0.89 (2)1.86 (2)2.702 (1)157 (2)
O2—H21···O1ii0.89 (2)1.87 (2)2.760 (1)175 (2)
Symmetry codes: (i) x, y+1, z1/2; (ii) x+1, y, z+1.
 

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