2-Meth­oxy-3-(tri­methyl­sil­yl)phenyl­boronic acid

Krzysztof Durka; Sergiusz Luliński; Janusz Serwatowski

doi:10.1107/S1600536813031656

. 2013 Nov 23;69(Pt 12):o1818. doi: 10.1107/S1600536813031656

2-Methoxy-3-(trimethylsilyl)phenylboronic acid

Krzysztof Durka ^a, Sergiusz Luliński ^a,^*, Janusz Serwatowski ^a

PMCID: PMC4004439 PMID: 24860295

Abstract

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,
a = 9.1832 (11) Å
b = 9.7082 (10) Å
c = 14.1415 (16) Å
β = 104.26 (1)°
V = 1221.9 (2) Å³
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[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 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

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 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813031656/tk5273sup1.cif

e-69-o1818-sup1.cif^{(19.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813031656/tk5273Isup2.hkl

e-69-o1818-Isup2.hkl^{(161.5KB, hkl)}

Click here for additional data file.^{(4.7KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813031656/tk5273Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

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⋯O2ⁱ	0.84	1.97	2.8051 (14)	175

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Symmetry code: (i) Inline graphic .

Acknowledgments

The X-ray measurements were undertaken in the Crystallographic Unit of the Physical Chemistry Laboratory at the Chemistry Department of the University of Warsaw. This work was supported by the Warsaw University of Technology. The support by Aldrich Chemical Co., Milwaukee, WI, USA, through continuous donation of chemicals and equipment is gratefully acknowledged.

supplementary crystallographic information

1. Introduction

2. Experimental

2.1. 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).

2.2. 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).

3. 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.