A second monoclinic polymorph of methyl 4-hydroxy­benzoate

Hoong-Kun Fun; Samuel Robinson Jebas

doi:10.1107/S1600536808017327

. 2008 Jun 13;64(Pt 7):o1255. doi: 10.1107/S1600536808017327

A second monoclinic polymorph of methyl 4-hydroxybenzoate

Hoong-Kun Fun ^a,^*, Samuel Robinson Jebas ^a,^‡

PMCID: PMC2961691 PMID: 21202889

Abstract

A second monoclinic polymorph of methyl 4-hydroxybenzoate, C₈H₈O₃, is reported. The unit-cell dimensions are different from those of the previously reported monoclinic form [Vujovic & Nassimbeni (2006 ▶). Cryst. Growth Des. 6, 1595–1597]. The asymmetric unit contains three crystallographically independent molecules, as observed in the previous form. The crystal structure is stabilized by intermolecular O—H⋯O and C—H⋯O hydrogen bonds and C—H⋯π interactions, which link the molecules into a three-dimensional network.

Related literature

For the other monoclinic polymorph of methyl 4-hydroxybenzoate, see: Lin (1983 ▶); Vujovic & Nassimbeni (2006 ▶).

Experimental

Crystal data

C₈H₈O₃
M _r = 152.14
Monoclinic,
a = 12.9708 (4) Å
b = 17.2485 (7) Å
c = 10.8428 (3) Å
β = 119.260 (1)°
V = 2116.32 (12) Å³
Z = 12
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 100.0 (1) K
0.29 × 0.27 × 0.19 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.969, T _max = 0.979
25224 measured reflections
3278 independent reflections
2705 reflections with I > 2σ(I)
R _int = 0.047

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.116
S = 1.05
3278 reflections
301 parameters
2 restraints
H-atom parameters constrained
Δρ_max = 0.40 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808017327/ci2607sup1.cif

e-64-o1255-sup1.cif^{(22.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808017327/ci2607Isup2.hkl

e-64-o1255-Isup2.hkl^{(157.5KB, hkl)}

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
O1A—H1A⋯O2Aⁱ	0.82	1.96	2.770 (2)	168
O1B—H1B⋯O3Cⁱⁱ	0.82	1.93	2.729 (2)	167
O1C—H1C⋯O2B	0.82	1.92	2.729 (2)	167
C6A—H6A⋯O2C	0.93	2.58	3.343 (3)	140
C8C—H8C1⋯Cg1ⁱ	0.96	2.76	3.539 (3)	139
C8C—H8C3⋯Cg2	0.96	2.70	3.442 (3)	134
C8A—H8A1⋯Cg3ⁱⁱⁱ	0.96	2.68	3.515 (3)	145
C8B—H8B3⋯Cg3^iv	0.96	2.78	3.655 (4)	151

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) . Cg1, Cg2 and Cg3 are the centroids of the C1A–C6A, C1B–C6B and C1C–C6C rings, respectively.

Acknowledgments

FHK and SRJ thank the Malaysian Government and Universiti Sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. SRJ thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

The crystal structure of the title compound at room temperature and at 113 K has been reported previously (Lin, 1983; Vujovic & Nassimbeni, 2006). We report here the structure of a second monoclinic polymorph of the title compound which was elucidated at 100.0 (1) K.

The compound crystallizes in the space group Cc with three independent molecules in the asymmetric unit, similar to the first monoclinic polymorph (Vujovic & Nassimbeni, 2006). However, the cell parameters of the present monoclinic polymorph differ significantly from the previous polymorph [a = 13.006 (3) Å, b = 17.261 (4) Å, c = 12.209 (2) Å and β = 129.12 (3)°]. The corresponding bond lengths and angles of the three independent molecules agree with each other and also with those in the other monoclinic polymorph (Vujovic & Nassimbeni, 2006). Each of the independent molecules are planar. The dihedral angles formed by the C1A-C6A plane with the C1B-C6B and C1C-C6C planes are 2.9 (1)° and 71.2 (1)°, respectively. In the first monoclinic polymorph (Vujovic & Nassimbeni, 2006) these angles are 2.9 (1) and 1.4 (1)°.

In the asymmetric unit, the independent molecules are linked via O—H···O and C—H···O hydrogen bonds. The crystal packing is stabilized by intermolecular O—H···O and C—H···O hydrogen bonds and C—H···π interactions which link the molecules into a three-dimensional network (Fig.2).

Experimental

Methyl 4-hydroxybenzoate was purchased from Aldrich. Single crystals were obtained by slow evaporation of an ethanol solution.