(2,4-Dipropoxyphen­yl)boronic acid

Marek Dąbrowski; Krzysztof Durka; Sergiusz Luliński; Janusz Serwatowski

doi:10.1107/S1600536811049737

. 2011 Nov 30;67(Pt 12):o3455. doi: 10.1107/S1600536811049737

(2,4-Dipropoxyphenyl)boronic acid

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

PMCID: PMC3239085 PMID: 22199933

Abstract

In the crystal, the title compound, C₁₂H₁₉BO₄, exists as a centrosymmetric O—H⋯O hydrogen-bonded dimer. Dimers are linked via C—H⋯O hydrogen bonds, generating an infinite zigzag chain oriented parallel to [1 Inline graphic 1]. The chains are assembled, giving sheets aligned parallel to (21) and interconnected by weak C—H⋯π interactions, producing a three-dimensional network.

Related literature

For the structural characterization of related ortho-alkoxy arylboronic acids, see: Dąbrowski et al. (2008 ▶, 2009 ▶); Yang et al. (2005 ▶).

Experimental

Crystal data

C₁₂H₁₉BO₄
M _r = 238.08
Triclinic,
a = 7.9630 (9) Å
b = 8.8014 (12) Å
c = 9.3182 (13) Å
α = 101.585 (11)°
β = 91.924 (10)°
γ = 90.826 (10)°
V = 639.26 (15) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 100 K
0.15 × 0.12 × 0.10 mm

Data collection

Bruker APEXII diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1995 ▶) T _min = 0.986, T _max = 0.992
12243 measured reflections
2950 independent reflections
1981 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.081
S = 0.90
2950 reflections
154 parameters
H-atom parameters constrained
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2010 ▶); cell refinement: SAINT (Bruker, 2010 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXS97 (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/S1600536811049737/zj2041sup1.cif

e-67-o3455-sup1.cif^{(23.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811049737/zj2041Isup2.hkl

e-67-o3455-Isup2.hkl^{(169.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811049737/zj2041Isup3.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
O1—H1⋯O2ⁱ	0.84	1.96	2.794 (1)	176
O2—H2⋯O3	0.84	1.95	2.672 (1)	144
C5—H5⋯O4ⁱⁱ	0.95	2.50	3.445 (1)	175
C10—H10B⋯O1ⁱⁱⁱ	0.99	2.84	3.78 (1)	158
C8—H8B⋯Cg1^iv	0.99	2.83	3.671 (1)	143

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

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 Aldrich Chemical Co. through donation of chemicals and equipment, and by Warsaw University of Technology.

supplementary crystallographic information

Comment

The ability of arylboronic acids to form supramolecular assemblies due to intermolecular hydrogen bonding is well known. Our interest has focused on ortho-alkoxy derivatives and the influence of various factors (including the number and length of the alkoxy group) on their structural behaviour.

The molecular structure of (I) shows the boronic groups possesses an exo-endo conformation. The entire molecule including both propoxy groups remains essentially planar. The endo-oriented OH group is engaged in an intramolecular O—H···O hydrogen bond (Table 1) with the 2-propoxy O atom, resulting in the formation of a six-membered ring. This motif is generally typical for structures of all ortho-alkoxyarylboronic acids (Yang et al., 2005; Dąbrowski et al., 2008; Luliński, 2008).

Centrosymmetric O—H···O hydrogen-bonded dimers of (I) are linked by weaker C—H···O hydrogen bonds connecting the H5 atom attached to aromatic ring with the O atom of the 4-propoxy group in the adjacent molecule. Thus, another centrosymmetric dimeric motif can be distinguished. These two alternating dimeric motifs generate a zig-zag chain which runs along the [111] direction. Adjacent chains are ordered due to van der Waals interactions of propoxy groups which leads to the formation of a 2D layer aligned parallel to the (211) plane. The supramolecular architecture extends further due to weak C—H···O contacts between α-methylene units of 4-propoxy groups and one of O atoms of the boronic group. Finally, C—H···π interactions occur between the β-methylene units of the 2-propoxy group and the aromatic ring of a molecule in the adjacent layer. As a result, a three-dimensional network is formed.

Experimental

The title compound was received from Aldrich. Crystals suitable for single-crystal X-ray diffraction analysis were grown by slow evaporation of a solution of the acid (0.2 g) in acetone/water (10 ml, 1:1).