2-Meth­­oxy-3-(tri­methyl­sil­yl)phenyl­boronic acid

The mol­ecular structure of the title compound, C₁₀H₁₇BO₃Si, features an intra­molecular O—H⋯O hydrogen bond; the boronic group group has an exo–endo conformation. In the crystal, the mol­ecules inter­act with each other by O—H⋯O hydrogen bonds, producing centrosymmetric dimers that are linked by weak π–π stacking inter­actions featuring specific short B⋯C contacts [e.g. 3.372 (2) Å], forming an infinite columnar structure aligned along the a-axis direction.

Related literature

For structures of related ortho-alk­oxy aryl­boronic acids, see: Cyrański et al. (2012). For binding energies of other boronic acid dimers, see: Cyrański et al. (2008); Durka et al. (2012). For the PIXEL program, see Gavezzotti (2003). For the synthesis, see: Durka et al. (2010).

Experimental

Crystal data

• C₁₀H₁₇BO₃Si

• M_r = 224.14

• Monoclinic, P 2₁ /n

• a = 9.1832 (11) Å

• b = 9.7082 (10) Å

• c = 14.1415 (16) Å

• β = 104.26 (1)°

• V = 1221.9 (2) ų

• Z = 4

• Mo Kα radiation

• μ = 0.18 mm⁻¹

• T = 100 K

• 0.16 × 0.12 × 0.10 mm

Data collection

• Bruker APEXII diffractometer

• Absorption correction: multi-scan (Blessing, 1995) T_min = 0.744, T_max = 0.780

• 11175 measured reflections

• 2939 independent reflections

• 2154 reflections with I > 2σ(I)

• R_int = 0.029

Refinement

• R[F² > 2σ(F²)] = 0.034

• wR(F²) = 0.097

• S = 1.02

• 2939 reflections

• 136 parameters

• 1 restraint

• H-atom parameters constrained

• Δρ_max = 0.36 e Å⁻³

• Δρ_min = −0.30 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1	0.84	2.04	2.7532 (14)	142
O3—H3⋯O2^i	0.84	1.97	2.8051 (14)	175
Symmetry code: (i) -x+2, -y+2, -z.

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT and SORTAV (Blessing, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: PLATON (Spek, 2009).

Supporting information

S1. Experimental

S1.1. Synthesis and crystallization

The preparation of the title compound (I) was described previously (Durka et al., 2010). Crystals suitable for single-crystal X-ray diffraction analysis were grown by slow evaporation of an acetone solution of (I).

S1.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. All hydrogen atoms were placed in calculated positions with C—H distances of 0.95 Å (phenyl) and 0.98 Å (methyl), and an O—H distance of 0.84 Å, and with U_iso(phenyl-H) = 1.2U_eq(C), U_iso(methyl-H) = 1.5U_eq(C) and U_iso(hydroxyl-H)=1.5U_eq(O).

S2. Results and discussion

The ability of aryl­boronic acids to form supra­molecular structures via hydrogen-bonding inter­actions of B(OH)₂ groups is well known. The molecular structure of (I) is shown in Fig. 1. The boronic group is only slightly twisted with respect to the benzene ring whereas the meth­oxy group is twisted almost perpendicularly. The tri­methyl­silyl group is slightly bent with respect to the aromatic ring. The boronic group has an exo-endo conformation. The endo-oriented OH group is engaged into the intra­molecular O—H···O bond with the meth­oxy O atom to form a six-membered ring typical of structures of related ortho-alk­oxy­aryl­boronic acids (Cyrański et al., 2012). The molecules of (I) are linked via almost linear O—H···O bridges to give centrosymmetric dimers. The periodic calculations performed in PIXEL programme (Gavezzotti, 2003) show that the dimer inter­action energy is equal to -58.5 kJ/mol, which is comparable to the binding energies of other boronic acids dimers reported in the literature (Cyrański et al., 2008; Durka et al., 2012). The supra­molecular architecture in (I) extends through π—π stacking inter­actions of aromatic rings in the parallel-displaced fashion. The boron atoms are also engaged in these mutual inter­actions, which is manifested by a relatively short B1···C2 contact of 3.372 (2) Å. Short B1···C2 inter­actions were described in more detail for the structures of fluorinated 1,4-phenyl­enediboronic acids (Durka et al., 2012). Thus, another centrosymmetric motif can be distinguished. The inter­action energy of such dimers amounts to -33.5 kJ/mol. As a result of H-bonding and π—π inter­actions, a specific columnar network is formed in the a axis direction (Figs 2 & 3). The total cohesive energy calculated for asymmetric unit equals to -111.7 kJ/mol. In conclusion, hydrogen-bonding inter­actions of boronic groups are operative to form centrosymmetric dimeric structure of (I). The extended supra­molecular assembly is due to π—π stacking inter­actions of aromatic rings additionally involving the boron atoms.

Related literature

For structures of related ortho-alkoxy arylboronic acids, see: Cyrański et al. (2012). For the PIXEL program, see Gavezzotti (2003). For the synthesis, see: Durka et al. (2010).

Computing details

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT (Bruker, 2010) and SORTAV (Blessing, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: PLATON (Spek, 2009).

Figures

	Fig. 1. View of the title compound (I) with the atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level.
	Fig. 2. Part of the crystal structure of (I) showing formation of a column along the [100] direction. The O–H···O, C–H···O and C(π)···B interactions are depicted as red and blue dashed lines, respectively.
	Fig. 3. Packing diagram viewed along the a axis, indicating the columns of O—H···O and C(π)···B interacting molecules of (I).

2-Methoxy-3-(trimethylsilyl)phenylboronic acid

Crystal data

C10H17BO3Si	Dx = 1.218 Mg m^−3
Mr = 224.14	Melting point: 353 K
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 9.1832 (11) Å	Cell parameters from 1540 reflections
b = 9.7082 (10) Å	θ = 2.7–28.7°
c = 14.1415 (16) Å	µ = 0.18 mm^−1
β = 104.26 (1)°	T = 100 K
V = 1221.9 (2) Å^3	Unshaped, colourless
Z = 4	0.16 × 0.12 × 0.10 mm
F(000) = 480

Data collection

Bruker APEXII diffractometer	2939 independent reflections
Radiation source: TXS rotating anode	2154 reflections with I > 2σ(I)
Multi-layer optics monochromator	Rint = 0.029
ω scans	θmax = 28.6°, θmin = 3.0°
Absorption correction: multi-scan (Blessing, 1995)	h = −11→10
Tmin = 0.744, Tmax = 0.780	k = −13→12
11175 measured reflections	l = −18→18

Refinement

Refinement on F^2	1 restraint
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.097	w = 1/[σ^2(Fo^2) + (0.0567P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max < 0.001
2939 reflections	Δρmax = 0.36 e Å^−3
136 parameters	Δρmin = −0.30 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Si1	0.39406 (5)	0.65611 (4)	0.15682 (3)	0.01408 (12)
O1	0.70378 (11)	0.73383 (10)	0.12400 (7)	0.0157 (2)
O3	0.81381 (12)	0.97690 (11)	−0.10209 (7)	0.0183 (2)
H3	0.9024	1.0067	−0.0879	0.027*
O2	0.89567 (11)	0.91160 (11)	0.06290 (8)	0.0181 (2)
H2	0.8636	0.8703	0.1059	0.027*
C5	0.62375 (16)	0.85346 (14)	−0.02981 (11)	0.0135 (3)
C1	0.44068 (16)	0.73526 (14)	0.04527 (11)	0.0137 (3)
C9	0.47875 (18)	0.48146 (15)	0.18637 (11)	0.0178 (3)
H9A	0.5884	0.4884	0.2002	0.027*
H9B	0.4423	0.4198	0.1307	0.027*
H9C	0.4499	0.4447	0.2437	0.027*
C3	0.35918 (16)	0.84434 (16)	−0.11483 (11)	0.0156 (3)
H3A	0.2810	0.8643	−0.1710	0.019*
C6	0.58695 (16)	0.77454 (15)	0.04402 (11)	0.0129 (3)
C4	0.50551 (17)	0.88657 (15)	−0.11005 (11)	0.0152 (3)
H4	0.5257	0.9389	−0.1622	0.018*
C2	0.32783 (16)	0.77273 (15)	−0.03699 (11)	0.0153 (3)
H2A	0.2267	0.7484	−0.0396	0.018*
C7	0.77696 (18)	0.60998 (17)	0.10250 (12)	0.0212 (4)
H7A	0.8574	0.5845	0.1593	0.032*
H7B	0.8197	0.6265	0.0465	0.032*
H7C	0.7034	0.5350	0.0871	0.032*
C8	0.45625 (19)	0.77761 (16)	0.26146 (12)	0.0201 (3)
H8A	0.4101	0.8680	0.2437	0.030*
H8B	0.5659	0.7866	0.2773	0.030*
H8C	0.4254	0.7419	0.3184	0.030*
C10	0.18585 (17)	0.63586 (17)	0.13142 (13)	0.0212 (4)
H10A	0.1377	0.7259	0.1156	0.032*
H10B	0.1592	0.5980	0.1892	0.032*
H10C	0.1514	0.5731	0.0762	0.032*
B1	0.78433 (19)	0.91554 (17)	−0.02287 (13)	0.0147 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.0142 (2)	0.0130 (2)	0.0156 (2)	−0.00051 (17)	0.00465 (16)	0.00139 (17)
O1	0.0130 (5)	0.0178 (5)	0.0149 (5)	0.0014 (4)	0.0006 (4)	0.0013 (4)
O3	0.0152 (5)	0.0225 (6)	0.0175 (6)	−0.0043 (4)	0.0045 (4)	0.0013 (5)
O2	0.0151 (5)	0.0229 (6)	0.0163 (5)	−0.0054 (5)	0.0036 (4)	0.0018 (5)
C5	0.0145 (7)	0.0115 (7)	0.0148 (7)	−0.0002 (6)	0.0044 (6)	−0.0022 (6)
C1	0.0144 (7)	0.0112 (7)	0.0158 (7)	−0.0001 (6)	0.0045 (6)	−0.0018 (6)
C9	0.0205 (8)	0.0158 (7)	0.0172 (8)	−0.0011 (6)	0.0046 (6)	0.0007 (6)
C3	0.0138 (7)	0.0159 (7)	0.0152 (7)	0.0009 (6)	−0.0001 (6)	0.0010 (6)
C6	0.0129 (7)	0.0120 (7)	0.0127 (7)	0.0009 (6)	0.0010 (6)	−0.0019 (6)
C4	0.0189 (8)	0.0134 (7)	0.0137 (7)	−0.0008 (6)	0.0048 (6)	0.0009 (6)
C2	0.0120 (7)	0.0146 (7)	0.0189 (8)	−0.0007 (6)	0.0032 (6)	−0.0018 (6)
C7	0.0189 (8)	0.0213 (8)	0.0235 (9)	0.0057 (6)	0.0054 (7)	0.0040 (7)
C8	0.0259 (9)	0.0175 (8)	0.0182 (8)	−0.0007 (7)	0.0080 (7)	0.0000 (7)
C10	0.0174 (8)	0.0217 (8)	0.0262 (9)	−0.0011 (6)	0.0084 (7)	0.0035 (7)
B1	0.0154 (8)	0.0128 (8)	0.0168 (9)	0.0006 (7)	0.0055 (7)	−0.0025 (7)

Geometric parameters (Å, º)

Si1—C10	1.8668 (16)	C9—H9B	0.9800
Si1—C8	1.8684 (16)	C9—H9C	0.9800
Si1—C9	1.8693 (16)	C3—C2	1.391 (2)
Si1—C1	1.8960 (15)	C3—C4	1.390 (2)
O1—C6	1.4103 (17)	C3—H3A	0.9500
O1—C7	1.4458 (18)	C4—H4	0.9500
O3—B1	1.354 (2)	C2—H2A	0.9500
O3—H3	0.8400	C7—H7A	0.9800
O2—B1	1.381 (2)	C7—H7B	0.9800
O2—H2	0.8400	C7—H7C	0.9800
C5—C6	1.402 (2)	C8—H8A	0.9800
C5—C4	1.401 (2)	C8—H8B	0.9800
C5—B1	1.574 (2)	C8—H8C	0.9800
C1—C2	1.402 (2)	C10—H10A	0.9800
C1—C6	1.401 (2)	C10—H10B	0.9800
C9—H9A	0.9800	C10—H10C	0.9800
C10—Si1—C8	108.52 (8)	C3—C4—C5	121.24 (14)
C10—Si1—C9	107.31 (7)	C3—C4—H4	119.4
C8—Si1—C9	111.49 (7)	C5—C4—H4	119.4
C10—Si1—C1	108.24 (7)	C3—C2—C1	122.12 (14)
C8—Si1—C1	108.39 (7)	C3—C2—H2A	118.9
C9—Si1—C1	112.76 (7)	C1—C2—H2A	118.9
C6—O1—C7	111.44 (11)	O1—C7—H7A	109.5
B1—O3—H3	109.5	O1—C7—H7B	109.5
B1—O2—H2	109.5	H7A—C7—H7B	109.5
C6—C5—C4	116.59 (13)	O1—C7—H7C	109.5
C6—C5—B1	123.85 (13)	H7A—C7—H7C	109.5
C4—C5—B1	119.35 (13)	H7B—C7—H7C	109.5
C2—C1—C6	115.73 (13)	Si1—C8—H8A	109.5
C2—C1—Si1	121.55 (11)	Si1—C8—H8B	109.5
C6—C1—Si1	122.32 (11)	H8A—C8—H8B	109.5
Si1—C9—H9A	109.5	Si1—C8—H8C	109.5
Si1—C9—H9B	109.5	H8A—C8—H8C	109.5
H9A—C9—H9B	109.5	H8B—C8—H8C	109.5
Si1—C9—H9C	109.5	Si1—C10—H10A	109.5
H9A—C9—H9C	109.5	Si1—C10—H10B	109.5
H9B—C9—H9C	109.5	H10A—C10—H10B	109.5
C2—C3—C4	119.67 (14)	Si1—C10—H10C	109.5
C2—C3—H3A	120.2	H10A—C10—H10C	109.5
C4—C3—H3A	120.2	H10B—C10—H10C	109.5
C5—C6—C1	124.48 (14)	O3—B1—O2	118.90 (14)
C5—C6—O1	118.37 (12)	O3—B1—C5	119.49 (14)
C1—C6—O1	117.14 (13)	O2—B1—C5	121.60 (14)
C10—Si1—C1—C2	2.07 (14)	Si1—C1—C6—O1	9.56 (18)
C8—Si1—C1—C2	−115.45 (13)	C7—O1—C6—C5	−83.99 (16)
C9—Si1—C1—C2	120.62 (12)	C7—O1—C6—C1	97.38 (15)
C10—Si1—C1—C6	174.45 (12)	C2—C3—C4—C5	2.7 (2)
C8—Si1—C1—C6	56.93 (14)	C6—C5—C4—C3	0.8 (2)
C9—Si1—C1—C6	−67.00 (14)	B1—C5—C4—C3	−174.09 (14)
C4—C5—C6—C1	−4.2 (2)	C4—C3—C2—C1	−3.1 (2)
B1—C5—C6—C1	170.43 (14)	C6—C1—C2—C3	0.0 (2)
C4—C5—C6—O1	177.24 (12)	Si1—C1—C2—C3	172.85 (11)
B1—C5—C6—O1	−8.1 (2)	C6—C5—B1—O3	172.48 (14)
C2—C1—C6—C5	3.8 (2)	C4—C5—B1—O3	−13.0 (2)
Si1—C1—C6—C5	−168.98 (11)	C6—C5—B1—O2	−8.9 (2)
C2—C1—C6—O1	−177.64 (12)	C4—C5—B1—O2	165.67 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1	0.84	2.04	2.7532 (14)	142
O3—H3···O2^i	0.84	1.97	2.8051 (14)	175

Symmetry code: (i) −x+2, −y+2, −z.