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Acta Cryst.(2001). E57, o143±o144 DOI: 101107/S1600536801000800 Bond, Edwards and Jones C9H16O4

o143

organic papers

Acta Crystallographica Section E Structure Reports Online

ISSN 1600-5368

Azelaic acid

Andrew D. Bond,* Marc R. Edwards and William Jones

Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, England

Correspondence e-mail: adb29@cam.ac.uk

Key indicators

Single-crystal X-ray study

T= 180 K

Mean(C±C) = 0.002 AÊ

Rfactor = 0.037

wRfactor = 0.096

Data-to-parameter ratio = 17.0

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2001 International Union of Crystallography Printed in Great Britain ± all rights reserved

The crystal structure of heptane-1,7-dicarboxylic acid (azelaic acid), C9H16O4, has been redetermined at 180 K. The

molecular units have twofold symmetry and are linked via

the ubiquitoussyn±syncarboxylic acid dimer to form in®nite chains running approximately along the [401] vector.

Comment

Two polymorphs of azelaic acid, (I), have been reported previously: the form crystallizes in P21/c (Caspari, 1928;

Housty & Hospital, 1967) and theform crystallizes inC2/c

(Housty & Hospital, 1967). For both polymorphs, the struc-tures present in the CSD (AZELAC10 and AZELAC01; Allen & Kennard, 1993) are derived from room-temperature

data withRfactorsca10% and ambiguities in the treatment of H atoms. We have, therefore, re-examined azelaic acid and report here the structure of theform measured at 180 K to signi®cantly greater precision.

Experimental

Azelaic acid was obtained from Aldrich and recrystallized from ethanol.

Crystal data C9H16O4

Mr= 188.22 Monoclinic,C2/c a= 22.622 (2) AÊ

b= 4.7348 (2) AÊ

c= 9.6864 (7) AÊ = 110.559 (3) V= 971.5 (1) AÊ3

Z= 4

Dx= 1.287 Mg mÿ3 MoKradiation Cell parameters from 2161

re¯ections = 1.0±27.5

= 0.10 mmÿ1

T= 180 (2) K Plate, colourless 0.250.120.06 mm

Received 12 December 2000 Accepted 9 January 2001 Online 30 January 2001

Figure 1

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Data collection

Nonius KappaCCD diffractometer Thin-slice!and'scans Absorption correction: multi-scan

(SORTAV; Blessing, 1995)

Tmin= 0.907,Tmax= 0.994

3154 measured re¯ections 1085 independent re¯ections

913 re¯ections withI> 2(I)

Rint= 0.039

max= 27.4

h= 0!28

k=ÿ6!6

l=ÿ12!11

Re®nement Re®nement onF2

R[F2> 2(F2)] = 0.037

wR(F2) = 0.096

S= 1.09 1085 re¯ections 64 parameters H atoms: see below

w= 1/[2(F

o2) + (0.0328P)2 + 0.5150P]

whereP= (Fo2+ 2Fc2)/3 (/)max= 0.010

max= 0.25 e AÊÿ3

min=ÿ0.19 e AÊÿ3

Table 1

Hydrogen-bonding geometry (AÊ,).

DÐH A DÐH H A D A DÐH A

O2ÐH1 O1i 0.96 (2) 1.70 (2) 2.6576 (12) 173.5 (17)

Symmetry code: (i)1

2ÿx;12ÿy;ÿz.

The H atom of the carboxylic acid group was located in a differ-ence Fourier map and re®ned without restraint. All other H atoms were placed geometrically and allowed to ride during subsequent

re®nement with an isotropic displacement parameter ®xed at 1.2 times that for the C atom to which they are attached.

Data collection:COLLECT(Nonius, 1998); cell re®nement:HKL SCALEPACK(Otwinowski & Minor, 1997); data reduction: HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to re®ne structure:SHELXL97 (Sheldrick, 1997); molecular graphics:XP(Sheldrick, 1993) andCAMERON(Watkinet al., 1996); software used to prepare material for publication:

SHELXL97.

We thank the EPSRC for ®nancial assistance with purchase of the CCD diffractometer.

References

Allen, F. H. & Kennard, O. (1993).Chem. Des. Autom. News,8, 1, 31±37. Blessing, R. H. (1995).Acta Cryst.A51, 33±38.

Caspari, W. A. (1928).J. Chem. Soc.pp. 3235±3241. Housty, J. & Hospital, M. (1967).Acta Cryst.22, 288±295.

Otwinowski, Z. & Minor, W. (1997).Methods Enzymol.276, 307±316. Nonius (1998).COLLECT. Nonius BV, Delft, The Netherlands. Sheldrick, G. M. (1993).XP. University of GoÈttingen, Germany.

Sheldrick, G. M. (1997). SHELXL97 and SHELXS97. University of GoÈttingen, Germany.

Watkin, D. J., Prout, C. K. & Pearce, L. J. (1996).CAMERON. Chemical Crystallography Laboratory, University of Oxford, England.

Figure 2

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supporting information

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Acta Cryst. (2001). E57, o143–o144

supporting information

Acta Cryst. (2001). E57, o143–o144 [doi:10.1107/S1600536801000800]

Azelaic acid

Andrew D. Bond, Marc R. Edwards and William Jones

S1. Comment

Two polymorphs of azelaic acid, (I), have been reported previously: the α form crystallizes in P21/c (Caspari, 1928;

Housty & Hospital, 1967) and the β form crystallizes in C2/c (Housty & Hospital, 1967). For both polymorphs, the

structures present in the CSD (AZELAC10 and AZELAC01; Allen & Kennard, 1993) are derived from room-temperature

data with R factors ca 10% and ambiguities in the treatment of H atoms. We have, therefore, re-examined azelaic acid and

report here the structure of the β form measured at 180 K to significantly greater precision.

S2. Experimental

Azelaic acid was obtained from Aldrich and recrystallized from ethanol.

S3. Refinement

The H atom of the carboxylic acid group was located in a difference Fourier map and refined without restraint. All other

H atoms were placed geometrically and allowed to ride during subsequent refinement with an isotropic displacement

parameter fixed at 1.2 times that for the C atom to which they are attached.

Figure 1

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Figure 2

Projection onto (010) showing hydrogen-bonded chains running approximately along the [401] vector.

heptane-1,7-dicarboxylic acid

Crystal data

C9H16O4

Mr = 188.22

Monoclinic, C2/c a = 22.622 (2) Å b = 4.7348 (2) Å c = 9.6864 (7) Å β = 110.559 (3)° V = 971.5 (1) Å3

Z = 4 F(000) = 408

Dx = 1.287 Mg m−3

Melting point = 382–384 K Mo Kα radiation, λ = 0.71073 Å Cell parameters from 2161 reflections θ = 1.0–27.5°

µ = 0.10 mm−1

T = 180 K Plate, colourless 0.25 × 0.12 × 0.06 mm

Data collection

Nonius KappaCCD diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

Thin–slice ω and φ scans

Absorption correction: multi-scan (SORTAV; Blessing, 1995) Tmin = 0.907, Tmax = 0.994

3154 measured reflections 1085 independent reflections 913 reflections with I > 2σ(I) Rint = 0.039

θmax = 27.4°, θmin = 3.9°

h = 0→28 k = −6→6 l = −12→11

Refinement

Refinement on F2

Least-squares matrix: full R[F2 > 2σ(F2)] = 0.037

wR(F2) = 0.096

S = 1.09 1085 reflections 64 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: inferred from neighbouring sites

H atoms treated by a mixture of independent and constrained refinement

w = 1/[σ2(F

o2) + (0.0328P)2 + 0.515P]

where P = (Fo2 + 2Fc2)/3

(Δ/σ)max = 0.010

Δρmax = 0.25 e Å−3

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supporting information

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Acta Cryst. (2001). E57, o143–o144

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 Uiso*/Ueq

O1 0.18109 (4) 0.17201 (19) 0.01920 (10) 0.0312 (3) O2 0.24341 (4) 0.54364 (19) 0.11100 (10) 0.0314 (3)

H1 0.2682 (9) 0.465 (4) 0.057 (2) 0.079 (6)*

C1 0.19218 (5) 0.3923 (3) 0.09015 (12) 0.0244 (3) C2 0.14794 (6) 0.5227 (3) 0.15576 (14) 0.0307 (3)

H2A 0.1264 0.6833 0.0927 0.037*

H2B 0.1732 0.6004 0.2536 0.037*

C3 0.09798 (5) 0.3284 (3) 0.17462 (14) 0.0282 (3)

H3A 0.1183 0.1874 0.2523 0.034*

H3B 0.0767 0.2257 0.0813 0.034*

C4 0.04919 (5) 0.4949 (3) 0.21683 (13) 0.0270 (3)

H4A 0.0715 0.6108 0.3048 0.032*

H4B 0.0272 0.6258 0.1353 0.032*

C5 0.0000 0.3150 (4) 0.2500 0.0294 (4)

H5A −0.0213 0.1920 0.1643 0.035*

Atomic displacement parameters (Å2)

U11 U22 U33 U12 U13 U23

O1 0.0272 (5) 0.0337 (5) 0.0397 (5) −0.0021 (4) 0.0205 (4) −0.0071 (4) O2 0.0262 (5) 0.0340 (5) 0.0429 (5) −0.0043 (4) 0.0235 (4) −0.0055 (4) C1 0.0213 (6) 0.0289 (6) 0.0267 (6) 0.0018 (5) 0.0132 (4) 0.0030 (5) C2 0.0269 (6) 0.0322 (7) 0.0424 (7) −0.0027 (5) 0.0240 (6) −0.0064 (5) C3 0.0244 (6) 0.0299 (7) 0.0373 (7) 0.0008 (5) 0.0196 (5) −0.0003 (5) C4 0.0222 (6) 0.0300 (7) 0.0348 (7) 0.0002 (5) 0.0175 (5) −0.0012 (5) C5 0.0251 (9) 0.0317 (9) 0.0389 (9) 0.000 0.0206 (7) 0.000

Geometric parameters (Å, º)

O1—C1 1.2255 (15) C3—H3A 0.9900

O2—C1 1.3166 (14) C3—H3B 0.9900

O2—H1 0.96 (2) C4—C5 1.5224 (14)

C1—C2 1.4944 (16) C4—H4A 0.9900

C2—C3 1.5172 (16) C4—H4B 0.9900

C2—H2A 0.9900 C5—C4i 1.5224 (14)

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C3—C4 1.5244 (15)

C1—O2—H1 110.9 (12) C2—C3—H3B 109.4

O1—C1—O2 123.02 (10) C4—C3—H3B 109.4

O1—C1—C2 123.67 (10) H3A—C3—H3B 108.0

O2—C1—C2 113.25 (10) C5—C4—C3 114.78 (11)

C1—C2—C3 116.05 (10) C5—C4—H4A 108.6

C1—C2—H2A 108.3 C3—C4—H4A 108.6

C3—C2—H2A 108.3 C5—C4—H4B 108.6

C1—C2—H2B 108.3 C3—C4—H4B 108.6

C3—C2—H2B 108.3 H4A—C4—H4B 107.5

H2A—C2—H2B 107.4 C4i—C5—C4 111.97 (14)

C2—C3—C4 111.04 (10) C4i—C5—H5A 109.2

C2—C3—H3A 109.4 C4—C5—H5A 109.2

C4—C3—H3A 109.4

O1—C1—C2—C3 19.17 (18) C2—C3—C4—C5 −175.40 (9)

O2—C1—C2—C3 −163.41 (10) C3—C4—C5—C4i −176.92 (11)

C1—C2—C3—C4 −170.14 (11)

Symmetry code: (i) −x, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A D—H H···A D···A D—H···A

O2—H1···O1ii 0.96 (2) 1.70 (2) 2.6576 (12) 173.5 (17)

Figure

Figure 1

Figure 1

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Figure 2

Figure 2

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References

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