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Acta Crystallogr Sect E Struct Rep Online. Aug 1, 2008; 64(Pt 8): o1562.
Published online Jul 23, 2008. doi:  10.1107/S1600536808022381
PMCID: PMC2962184
A polymorph of terephthalaldehyde
Lei Tenga* and Zhiguo Wanga
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.
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 [triangle]).
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Object name is e-64-o1562-scheme1.jpg Object name is e-64-o1562-scheme1.jpg
Crystal data
  • C8H6O2
  • M r = 134.13
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-64-o1562-efi1.jpg
  • 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
  • Δρmax = 0.16 e Å−3
  • Δρmin = −0.10 e Å−3
Data collection: SMART (Bruker, 2001 [triangle]); cell refinement: SAINT (Bruker, 2001 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL.
Supplementary Material
Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808022381/bq2093sup1.cif
Structure factors: contains datablocks I. DOI: 10.1107/S1600536808022381/bq2093Isup2.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.
Refinement
All H atoms were initially located in a difference Fourier map and then included with constrained bond lengths and isotropic displacement parameters: C—H=0.93Å and Uiso(H)=1.2Ueq(C) for H atoms.
Figures
Fig. 1.
Fig. 1.
The molecular structure of (I) with 50% probability displacement ellipsoids (arbitrary spheres for H atoms).
Fig. 2.
Fig. 2.
The packing of the molecules, viewed down the b axis.
Crystal data
C8H6O2F000 = 280
Mr = 134.13Dx = 1.334 Mg m3
Orthorhombic, Pca21Mo Kα radiation λ = 0.71073 Å
Hall symbol: P 2c -2acCell parameters from 1070 reflections
a = 12.8811 (5) Åθ = 3.1–23.5º
b = 3.8933 (3) ŵ = 0.10 mm1
c = 13.3202 (9) ÅT = 295 (2) K
V = 668.01 (7) Å3Block, colorless
Z = 40.20 × 0.10 × 0.10 mm
Data collection
Bruker SMART 4K CCD area-detector diffractometer563 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.030
Monochromator: graphiteθmax = 25.5º
T = 295(2) Kθmin = 3.1º
[var phi] and ω scansh = −15→12
Absorption correction: nonek = −4→4
3959 measured reflectionsl = −16→15
653 independent reflections
Refinement
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.042H-atom parameters constrained
wR(F2) = 0.112  w = 1/[σ2(Fo2) + (0.0755P)2 + 0.0133P] where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max = 0.014
653 reflectionsΔρmax = 0.16 e Å3
91 parametersΔρmin = −0.10 e Å3
1 restraintExtinction 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)
xyzUiso*/Ueq
C10.8164 (2)0.3463 (7)0.2145 (2)0.0509 (7)
C20.9236 (2)0.3850 (7)0.2147 (3)0.0545 (7)
H20.95660.48470.15990.065*
C30.9315 (2)0.1279 (7)0.3776 (2)0.0515 (7)
C40.8239 (2)0.0894 (7)0.3770 (3)0.0547 (7)
H40.7907−0.01060.43160.066*
C50.7668 (2)0.1993 (6)0.2955 (3)0.0543 (7)
H50.69500.17440.29530.065*
C60.9805 (2)0.2776 (7)0.2951 (3)0.0547 (6)
H61.05230.30400.29490.066*
C70.7563 (4)0.4635 (8)0.1269 (4)0.0707 (10)
H70.79340.55470.07330.085*
C80.9916 (3)0.0084 (8)0.4657 (4)0.0627 (9)
H80.9550−0.08740.51900.075*
O10.6637 (2)0.4514 (7)0.1187 (3)0.0930 (10)
O21.0834 (2)0.0266 (7)0.4731 (4)0.0876 (9)
Atomic displacement parameters (Å2)
U11U22U33U12U13U23
C10.0535 (16)0.0494 (14)0.0498 (17)0.0041 (11)0.0057 (14)−0.0068 (13)
C20.0564 (18)0.0551 (15)0.0520 (17)0.0022 (13)0.0123 (15)0.0015 (15)
C30.0547 (16)0.0509 (14)0.0490 (17)−0.0008 (12)0.0064 (15)−0.0078 (13)
C40.0593 (19)0.0573 (14)0.0476 (17)−0.0067 (14)0.0140 (16)0.0002 (14)
C50.0463 (13)0.0570 (14)0.0595 (15)−0.0016 (12)0.0102 (17)−0.0083 (14)
C60.0448 (13)0.0582 (14)0.0610 (15)−0.0003 (12)0.0043 (18)−0.0008 (14)
C70.071 (2)0.077 (2)0.063 (3)0.0121 (16)−0.006 (2)−0.0016 (18)
C80.067 (2)0.0704 (19)0.0508 (19)0.0030 (13)0.009 (2)0.0003 (14)
O10.075 (2)0.129 (2)0.075 (2)0.0162 (14)−0.0158 (19)−0.0026 (18)
O20.0617 (17)0.125 (2)0.0761 (19)0.0064 (12)−0.0077 (16)0.0074 (15)
Geometric parameters (Å, °)
C1—C51.378 (4)C4—C51.379 (5)
C1—C21.389 (4)C4—H40.9300
C1—C71.473 (6)C5—H50.9300
C2—C61.363 (5)C6—H60.9300
C2—H20.9300C7—O11.199 (5)
C3—C41.393 (4)C7—H70.9300
C3—C61.395 (4)C8—O21.188 (4)
C3—C81.482 (6)C8—H80.9300
C5—C1—C2120.2 (3)C1—C5—C4119.9 (3)
C5—C1—C7120.4 (3)C1—C5—H5120.1
C2—C1—C7119.4 (3)C4—C5—H5120.1
C6—C2—C1120.2 (3)C2—C6—C3120.2 (2)
C6—C2—H2119.9C2—C6—H6119.9
C1—C2—H2119.9C3—C6—H6119.9
C4—C3—C6119.4 (3)O1—C7—C1125.6 (5)
C4—C3—C8119.4 (3)O1—C7—H7117.2
C6—C3—C8121.2 (3)C1—C7—H7117.2
C5—C4—C3120.1 (3)O2—C8—C3124.5 (4)
C5—C4—H4120.0O2—C8—H8117.7
C3—C4—H4120.0C3—C8—H8117.7
C5—C1—C2—C60.1 (4)C1—C2—C6—C30.0 (4)
C7—C1—C2—C6−179.9 (3)C4—C3—C6—C20.0 (4)
C6—C3—C4—C5−0.2 (4)C8—C3—C6—C2179.9 (3)
C8—C3—C4—C5180.0 (3)C5—C1—C7—O11.8 (5)
C2—C1—C5—C4−0.2 (4)C2—C1—C7—O1−178.2 (3)
C7—C1—C5—C4179.7 (3)C4—C3—C8—O2179.2 (3)
C3—C4—C5—C10.2 (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]
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