A polymorph of terephthalaldehyde

doi:10.1107/S1600536808022381

Acta Crystallogr Sect E Struct Rep Online. 2008 August 1; 64(Pt 8): o1562.

Published online 2008 July 23. doi: 10.1107/S1600536808022381

PMCID: PMC2962184

A polymorph of terephthalaldehyde

Lei Teng^a^* and Zhiguo Wang^a

^aSchool of Chemical and Materials Engineering, Huangshi Institute of Technology, Huangshi 435003, People’s Republic of China

Correspondence e-mail: chwangzg/at/yahoo.com.cn

Received July 15, 2008; Accepted July 17, 2008.

This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Abstract

A new orthorhombic polymorph of terephthalaldehyde, C₈H₆O₂, with a melting point of 372 K, has been obtained by recrystallization from ethanol. At room temperature, the crystals transform into the well known monoclinic form, with a melting point of 389 K. The crystal structure of the monoclinic form involves C—H (...)

O hydrogen bonds, but no such bonds are observed in the orthorhombic form. The molecule is planar.

Related literature

For the structure of the monoclinic polymorph, see: Britton (1998

An external file that holds a picture, illustration, etc.
Object name is e-64-o1562-scheme1.jpg Object name is e-64-o1562-scheme1.jpg

Experimental

Crystal data

C₈H₆O₂
M _r = 134.13
Orthorhombic,
a = 12.8811 (5) Å
b = 3.8933 (3) Å
c = 13.3202 (9) Å
V = 668.01 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 295 (2) K
0.20 × 0.10 × 0.10 mm

Data collection

Bruker SMART 4K CCD area-detector diffractometer
Absorption correction: none
3959 measured reflections
653 independent reflections
563 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.112
S = 1.04
653 reflections
91 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.10 e Å⁻³

Data collection: SMART (Bruker, 2001

); cell refinement: SAINT (Bruker, 2001

); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008

); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008

); molecular graphics: SHELXTL (Sheldrick, 2008

); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808022381/bq2093sup1.cif

Click here to view.^{(13K, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808022381/bq2093Isup2.hkl

Click here to view.^{(33K, hkl)}

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

Acknowledgments

This study was financially supported by a Key Project (No. Z2006zd02) of Huangshi Institute of Technology. The authors thank Dr Xiang-Gao Meng for the crystallographic data collection.

supplementary crystallographic information

Comment

Terephthalaldehyde, (I), is a simple aromatic compound used in organic synthesis. It is known as a white substance, slightly soluble in water, with a melting point of 389 K. To the best of our knowledge, the only packing information of (I) in the solid state comes from the work of Britton (Britton, 1998), who investigated the intermolecular C—H···O arrangement in the structure of terephthalaldehyde and the crystals suitable for diffraction were obtained by recrystallization from an acetone/ethyl ether mixture.

A new polymorphic form of (I) has been obtained serendipitously during cocrystallization of pyridine and terephthalaldehyde from ethanol (Fig. 1). Flat needles which precipitated first from the solution had a melting point of 372 K and were identified as a new polymorphic form of (I) by X-ray crystallography. At room temperature, the crystals transform into the well known monoclinic form, with a melting point of 389 K. The crystal structure of the monoclinic form involves C—H···O hydrogen bonds but no such bonds are observed in the orthorhombic form (Fig. 2).

Experimental

The title compound was purchased from Aldrich.

Figures

Fig. 1.

The molecular structure of (I) with 50% probability displacement ellipsoids (arbitrary spheres for H atoms).

Fig. 2.

The packing of the molecules, viewed down the b axis.

Crystal data

C₈H₆O₂	F₀₀₀ = 280
M_r = 134.13	D_x = 1.334 Mg m⁻³
Orthorhombic, Pca2₁	Mo Kα radiation λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 1070 reflections
a = 12.8811 (5) Å	θ = 3.1–23.5º
b = 3.8933 (3) Å	µ = 0.10 mm⁻¹
c = 13.3202 (9) Å	T = 295 (2) K
V = 668.01 (7) Å³	Block, colorless
Z = 4	0.20 × 0.10 × 0.10 mm

Data collection

Bruker SMART 4K CCD area-detector diffractometer	563 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.030
Monochromator: graphite	θ_max = 25.5º
T = 295(2) K	θ_min = 3.1º
and ω scans	h = −15→12
Absorption correction: none	k = −4→4
3959 measured reflections	l = −16→15
653 independent reflections

Refinement

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.042	H-atom parameters constrained
wR(F²) = 0.112	w = 1/[σ²(F_o²) + (0.0755P)² + 0.0133P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max = 0.014
653 reflections	Δρ_max = 0.16 e Å⁻³
91 parameters	Δρ_min = −0.10 e Å⁻³
1 restraint	Extinction correction: none
Primary atom site location: structure-invariant direct methods

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.

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)

	x	y	z	U_iso*/U_eq
C1	0.8164 (2)	0.3463 (7)	0.2145 (2)	0.0509 (7)
C2	0.9236 (2)	0.3850 (7)	0.2147 (3)	0.0545 (7)
H2	0.9566	0.4847	0.1599	0.065*
C3	0.9315 (2)	0.1279 (7)	0.3776 (2)	0.0515 (7)
C4	0.8239 (2)	0.0894 (7)	0.3770 (3)	0.0547 (7)
H4	0.7907	−0.0106	0.4316	0.066*
C5	0.7668 (2)	0.1993 (6)	0.2955 (3)	0.0543 (7)
H5	0.6950	0.1744	0.2953	0.065*
C6	0.9805 (2)	0.2776 (7)	0.2951 (3)	0.0547 (6)
H6	1.0523	0.3040	0.2949	0.066*
C7	0.7563 (4)	0.4635 (8)	0.1269 (4)	0.0707 (10)
H7	0.7934	0.5547	0.0733	0.085*
C8	0.9916 (3)	0.0084 (8)	0.4657 (4)	0.0627 (9)
H8	0.9550	−0.0874	0.5190	0.075*
O1	0.6637 (2)	0.4514 (7)	0.1187 (3)	0.0930 (10)
O2	1.0834 (2)	0.0266 (7)	0.4731 (4)	0.0876 (9)

Atomic displacement parameters (Å²)

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0535 (16)	0.0494 (14)	0.0498 (17)	0.0041 (11)	0.0057 (14)	−0.0068 (13)
C2	0.0564 (18)	0.0551 (15)	0.0520 (17)	0.0022 (13)	0.0123 (15)	0.0015 (15)
C3	0.0547 (16)	0.0509 (14)	0.0490 (17)	−0.0008 (12)	0.0064 (15)	−0.0078 (13)
C4	0.0593 (19)	0.0573 (14)	0.0476 (17)	−0.0067 (14)	0.0140 (16)	0.0002 (14)
C5	0.0463 (13)	0.0570 (14)	0.0595 (15)	−0.0016 (12)	0.0102 (17)	−0.0083 (14)
C6	0.0448 (13)	0.0582 (14)	0.0610 (15)	−0.0003 (12)	0.0043 (18)	−0.0008 (14)
C7	0.071 (2)	0.077 (2)	0.063 (3)	0.0121 (16)	−0.006 (2)	−0.0016 (18)
C8	0.067 (2)	0.0704 (19)	0.0508 (19)	0.0030 (13)	0.009 (2)	0.0003 (14)
O1	0.075 (2)	0.129 (2)	0.075 (2)	0.0162 (14)	−0.0158 (19)	−0.0026 (18)
O2	0.0617 (17)	0.125 (2)	0.0761 (19)	0.0064 (12)	−0.0077 (16)	0.0074 (15)

Geometric parameters (Å, °)

C1—C5	1.378 (4)	C4—C5	1.379 (5)
C1—C2	1.389 (4)	C4—H4	0.9300
C1—C7	1.473 (6)	C5—H5	0.9300
C2—C6	1.363 (5)	C6—H6	0.9300
C2—H2	0.9300	C7—O1	1.199 (5)
C3—C4	1.393 (4)	C7—H7	0.9300
C3—C6	1.395 (4)	C8—O2	1.188 (4)
C3—C8	1.482 (6)	C8—H8	0.9300

C5—C1—C2	120.2 (3)	C1—C5—C4	119.9 (3)
C5—C1—C7	120.4 (3)	C1—C5—H5	120.1
C2—C1—C7	119.4 (3)	C4—C5—H5	120.1
C6—C2—C1	120.2 (3)	C2—C6—C3	120.2 (2)
C6—C2—H2	119.9	C2—C6—H6	119.9
C1—C2—H2	119.9	C3—C6—H6	119.9
C4—C3—C6	119.4 (3)	O1—C7—C1	125.6 (5)
C4—C3—C8	119.4 (3)	O1—C7—H7	117.2
C6—C3—C8	121.2 (3)	C1—C7—H7	117.2
C5—C4—C3	120.1 (3)	O2—C8—C3	124.5 (4)
C5—C4—H4	120.0	O2—C8—H8	117.7
C3—C4—H4	120.0	C3—C8—H8	117.7

C5—C1—C2—C6	0.1 (4)	C1—C2—C6—C3	0.0 (4)
C7—C1—C2—C6	−179.9 (3)	C4—C3—C6—C2	0.0 (4)
C6—C3—C4—C5	−0.2 (4)	C8—C3—C6—C2	179.9 (3)
C8—C3—C4—C5	180.0 (3)	C5—C1—C7—O1	1.8 (5)
C2—C1—C5—C4	−0.2 (4)	C2—C1—C7—O1	−178.2 (3)
C7—C1—C5—C4	179.7 (3)	C4—C3—C8—O2	179.2 (3)
C3—C4—C5—C1	0.2 (4)	C6—C3—C8—O2	−0.6 (5)

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BQ2093).

References

Britton, D. (1998). J. Chem. Crystallogr.28, 601–604.
Bruker (2001). SMART and SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of
International Union of Crystallography