Sebacic acid

The crystal structure of octane-1,8-di­carboxyl­ic acid (sebacic acid), C₁₀H₁₈O₄, has been redetermined at 180 K. The molecular units are centrosymmetric and linked via the ubiquitous syn-syn carboxyl­ic acid dimer to form infinite chains running along the [01] vector.

Key indicators

• Single-crystal X-ray study
• T = 180 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.051
• wR factor = 0.139
• Data-to-parameter ratio = 18.2

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

Crystal data for sebacic acid have been reported on four previous occasions, by Caspari (1928), Morrison & Robertson (1949) (SEBAAC01), Housty & Hospital (1966) (SEBAAC) and Haget et al. (1980) (SEBAAC02). All four studies essentially report the same structure in space group P2₁/c with unit-cell dimensions ca a = 15.1, b = 5.0, c = 10.1 Å, β = 133.1°. [Morrison & Robertson (1949) describe the structure in the non-standard setting P2₁/a.] The most precise cell determination (SEBAAC02) to date is derived from powder X-ray diffraction data, and atomic coordinates were not determined. We have re-examined sebacic acid at 180 K and report the structure to significantly greater precision in P2₁/c with β ca 92°. The previously reported structures in P2₁/c with β ca 133.1° may be transformed to our structure by the matrix (101, 010, 001) followed by an origin shift of (1/2, 1/2, 1/2) to bring an entire molecule into the unit cell.

S2. Experimental

Sebacic acid was obtained from Aldrich and recrystallized from ethanol.

S3. Refinement

All H atoms (apart from H1) 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. H1 was refined without restraint.

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: 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 refine structure: SHELXL97 (Sheldrick 1997); molecular graphics: XP (Sheldrick, 1993) and CAMERON (Watkin et al., 1996); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular unit of the title compound showing displacement ellipsoids at the 50% probability level.
	Fig. 2. Projection onto (010) showing chains of sebacic acid running along the [\-101] vector.

octane-1,8-dicarboxylic acid

Crystal data

C10H18O4	Dx = 1.239 Mg m^−3
Mr = 202.24	Melting point = 406–408 K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71069 Å
a = 10.9197 (7) Å	Cell parameters from 2040 reflections
b = 4.9876 (6) Å	θ = 1.0–27.5°
c = 9.964 (1) Å	µ = 0.10 mm^−1
β = 92.273 (6)°	T = 180 K
V = 542.27 (9) Å^3	Plate, colourless
Z = 2	0.23 × 0.18 × 0.05 mm
F(000) = 220

Data collection

Nonius KappaCCD diffractometer	1241 independent reflections
Radiation source: fine-focus sealed tube	796 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.054
Thin–slice ω and ϕ scans	θmax = 27.5°, θmin = 3.7°
Absorption correction: multi-scan (SORTAV; Blessing, 1995)	h = −11→14
Tmin = 0.912, Tmax = 0.995	k = −5→6
3745 measured reflections	l = −12→9

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.139	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0705P)^2] where P = (Fo^2 + 2Fc^2)/3
1241 reflections	(Δ/σ)max = 0.006
68 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.18 e Å^−3

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.12859 (9)	0.4028 (2)	0.92528 (12)	0.0427 (4)
O2	0.01144 (9)	0.7593 (3)	0.88045 (12)	0.0445 (4)
H1	−0.042 (2)	0.685 (6)	0.959 (3)	0.117 (9)*
C1	0.10498 (13)	0.6043 (4)	0.85865 (16)	0.0332 (4)
C2	0.18124 (13)	0.6970 (4)	0.74613 (16)	0.0372 (5)
H2A	0.2144	0.8767	0.7691	0.045*
H2B	0.1273	0.7166	0.6645	0.045*
C3	0.28703 (13)	0.5157 (3)	0.71336 (16)	0.0365 (5)
H3A	0.2551	0.3343	0.6919	0.044*
H3B	0.3434	0.5007	0.7933	0.044*
C4	0.35752 (14)	0.6183 (4)	0.59603 (18)	0.0427 (5)
H4A	0.3005	0.6314	0.5166	0.051*
H4B	0.3870	0.8017	0.6174	0.051*
C5	0.46563 (15)	0.4497 (4)	0.55935 (18)	0.0436 (5)
H5A	0.4364	0.2655	0.5395	0.052*
H5B	0.5235	0.4395	0.6382	0.052*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0410 (7)	0.0463 (9)	0.0418 (7)	0.0036 (6)	0.0153 (5)	0.0111 (6)
O2	0.0424 (7)	0.0477 (9)	0.0449 (8)	0.0095 (6)	0.0183 (5)	0.0105 (6)
C1	0.0319 (9)	0.0361 (11)	0.0318 (9)	−0.0012 (7)	0.0053 (6)	0.0005 (8)
C2	0.0375 (8)	0.0399 (11)	0.0350 (9)	0.0000 (7)	0.0112 (7)	0.0064 (8)
C3	0.0340 (9)	0.0384 (10)	0.0377 (10)	−0.0009 (7)	0.0100 (7)	0.0048 (8)
C4	0.0415 (10)	0.0450 (12)	0.0427 (10)	0.0048 (8)	0.0157 (7)	0.0104 (9)
C5	0.0419 (9)	0.0451 (11)	0.0451 (10)	0.0049 (8)	0.0175 (8)	0.0104 (9)

Geometric parameters (Å, º)

O1—C1	1.2263 (19)	C3—H3A	0.9900
O2—C1	1.3061 (19)	C3—H3B	0.9900
O2—H1	1.06 (3)	C4—C5	1.506 (2)
C1—C2	1.496 (2)	C4—H4A	0.9900
C2—C3	1.513 (2)	C4—H4B	0.9900
C2—H2A	0.9900	C5—C5^i	1.511 (3)
C2—H2B	0.9900	C5—H5A	0.9900
C3—C4	1.514 (2)	C5—H5B	0.9900
C1—O2—H1	111.8 (14)	C4—C3—H3B	109.1
O1—C1—O2	122.96 (14)	H3A—C3—H3B	107.9
O1—C1—C2	123.21 (14)	C5—C4—C3	115.21 (15)
O2—C1—C2	113.83 (15)	C5—C4—H4A	108.5
C1—C2—C3	115.45 (14)	C3—C4—H4A	108.5
C1—C2—H2A	108.4	C5—C4—H4B	108.5
C3—C2—H2A	108.4	C3—C4—H4B	108.5
C1—C2—H2B	108.4	H4A—C4—H4B	107.5
C3—C2—H2B	108.4	C4—C5—C5^i	115.04 (19)
H2A—C2—H2B	107.5	C4—C5—H5A	108.5
C2—C3—C4	112.38 (14)	C5^i—C5—H5A	108.5
C2—C3—H3A	109.1	C4—C5—H5B	108.5
C4—C3—H3A	109.1	C5^i—C5—H5B	108.5
C2—C3—H3B	109.1	H5A—C5—H5B	107.5
O1—C1—C2—C3	3.5 (2)	C2—C3—C4—C5	179.01 (16)
O2—C1—C2—C3	−177.21 (14)	C3—C4—C5—C5^i	179.0 (2)
C1—C2—C3—C4	178.31 (15)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1···O1^ii	1.06 (3)	1.58 (3)	2.6406 (15)	175 (2)

Symmetry code: (ii) −x, −y+1, −z+2.