A triclinic polymorph of hexa-nedioic acid.

Hexane-dioic acid (or adipic acid), C(6)H(10)O(4), crystallizes with two crystallographically independent half-mol-ecules in the asymmetric unit of the triclinic unit cell, space group P, as each mol-ecule lies across a crystallographic inversion centre. A monoclinic polymorph has been reported previously, most recently by Ranganathan, Kulkarni & Rao [J. Phys. Chem. A, (2003), 107, 6073-6081]. The mol-ecules adopt the expected zigzag structure and are linked via centrosymmetric pairs of O-H⋯O hydrogen bonds, forming infinite one-dimensional chains along [011]. These chains are stacked along the a axis. The crystal is further stabilized by weak C-H⋯O inter-actions.

Related literature

For bond-length data, see Allen et al. (1987 ▶). For related structures, see, for example: Ranganathan et al. (2003 ▶); Srinivasa Gopalan et al. (1999 ▶, 2000 ▶). For general background to the influence of hydrogen bonding on phase transitions, see, for example: Chantrapromma et al. (2006 ▶); Dunitz (1991 ▶); Fun et al. (2003 ▶, 2006 ▶); How et al. (2005 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C6H10O4

M = 146.14

Triclinic,

a = 6.7666 (5) Å

b = 6.9992 (5) Å

c = 7.7180 (5) Å

α = 93.794 (4)°

β = 104.321 (4)°

γ = 102.689 (4)°

V = 342.70 (4) Å3

Z = 2

Mo Kα radiation

μ = 0.12 mm−1

T = 100 K

0.55 × 0.11 × 0.06 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.847, T max = 0.993

7773 measured reflections

1553 independent reflections

1419 reflections with I > 2σ(I)

R int = 0.027

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.094

S = 1.09

1553 reflections

91 parameters

H-atom parameters constrained

Δρmax = 0.32 e Å−3

Δρmin = −0.20 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, 2009 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809006448/sj2583sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809006448/sj2583Isup2.hkl

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

C6H10O4	Z = 2
Mr = 146.14	F(000) = 156
Triclinic, P1	Dx = 1.416 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.7666 (5) Å	Cell parameters from 1553 reflections
b = 6.9992 (5) Å	θ = 2.8–27.5°
c = 7.7180 (5) Å	µ = 0.12 mm−1
α = 93.794 (4)°	T = 100 K
β = 104.321 (4)°	Needle, colorless
γ = 102.689 (4)°	0.55 × 0.11 × 0.06 mm
V = 342.70 (4) Å3

Bruker APEXII CCD area-detector diffractometer	1553 independent reflections
Radiation source: sealed tube	1419 reflections with I > 2σ(I)
graphite	Rint = 0.027
φ and ω scans	θmax = 27.5°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −8→8
Tmin = 0.847, Tmax = 0.993	k = −9→9
7773 measured reflections	l = −10→10

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.094	H-atom parameters constrained
S = 1.09	w = 1/[σ2(Fo2) + (0.0402P)2 + 0.1411P] where P = (Fo2 + 2Fc2)/3
1553 reflections	(Δ/σ)max = 0.001
91 parameters	Δρmax = 0.32 e Å−3
0 restraints	Δρmin = −0.20 e Å−3

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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.

	x	y	z	Uiso*/Ueq
O1A	0.07345 (14)	0.10624 (13)	0.21778 (12)	0.0182 (2)
O2A	−0.11534 (14)	0.20271 (13)	−0.02751 (12)	0.0198 (2)
H2OA	−0.0961	0.1042	−0.0779	0.030*
C1A	−0.02548 (19)	0.22010 (17)	0.14771 (16)	0.0156 (3)
C2A	−0.0623 (2)	0.39330 (18)	0.24950 (16)	0.0174 (3)
H2AA	−0.2127	0.3787	0.2269	0.021*
H2AB	−0.0057	0.5124	0.2026	0.021*
C3A	0.03484 (19)	0.41932 (17)	0.45233 (16)	0.0167 (3)
H3AA	0.1794	0.4448	0.4777	0.020*
H3AB	−0.0108	0.3012	0.4996	0.020*
O1B	0.45905 (14)	0.56597 (12)	0.19844 (12)	0.0189 (2)
O2B	0.61849 (14)	0.75868 (13)	0.02759 (12)	0.0204 (2)
H2OB	0.5906	0.6539	−0.0380	0.031*
C1B	0.54652 (19)	0.72852 (18)	0.17064 (16)	0.0159 (3)
C2B	0.5885 (2)	0.91565 (18)	0.29479 (16)	0.0173 (3)
H2BA	0.5457	1.0160	0.2236	0.021*
H2BB	0.7389	0.9603	0.3491	0.021*
C3B	0.47841 (19)	0.89970 (17)	0.44459 (16)	0.0161 (3)
H3BA	0.5266	0.8106	0.5238	0.019*
H3BB	0.3356	0.8519	0.3947	0.019*

	U11	U22	U33	U12	U13	U23
O1A	0.0225 (5)	0.0180 (4)	0.0144 (4)	0.0084 (4)	0.0033 (3)	−0.0012 (3)
O2A	0.0287 (5)	0.0185 (4)	0.0129 (4)	0.0113 (4)	0.0033 (4)	−0.0023 (3)
C1A	0.0165 (6)	0.0157 (6)	0.0135 (6)	0.0019 (4)	0.0049 (4)	−0.0014 (4)
C2A	0.0218 (6)	0.0156 (6)	0.0151 (6)	0.0066 (5)	0.0044 (5)	−0.0013 (5)
C3A	0.0192 (6)	0.0155 (6)	0.0149 (6)	0.0050 (5)	0.0039 (5)	−0.0021 (5)
O1B	0.0248 (5)	0.0160 (4)	0.0166 (4)	0.0050 (4)	0.0078 (4)	−0.0008 (3)
O2B	0.0278 (5)	0.0164 (4)	0.0173 (5)	0.0022 (4)	0.0111 (4)	−0.0034 (3)
C1B	0.0157 (6)	0.0177 (6)	0.0140 (6)	0.0056 (5)	0.0028 (4)	−0.0009 (5)
C2B	0.0204 (6)	0.0149 (6)	0.0156 (6)	0.0029 (5)	0.0055 (5)	−0.0028 (5)
C3B	0.0185 (6)	0.0150 (6)	0.0138 (6)	0.0034 (5)	0.0039 (5)	−0.0019 (5)

O1A—C1A	1.2199 (15)	O1B—C1B	1.2207 (15)
O2A—C1A	1.3237 (14)	O2B—C1B	1.3238 (15)
O2A—H2OA	0.8200	O2B—H2OB	0.8200
C1A—C2A	1.5007 (16)	C1B—C2B	1.5001 (16)
C2A—C3A	1.5220 (16)	C2B—C3B	1.5201 (17)
C2A—H2AA	0.9700	C2B—H2BA	0.9700
C2A—H2AB	0.9700	C2B—H2BB	0.9700
C3A—C3Ai	1.528 (2)	C3B—C3Bii	1.525 (2)
C3A—H3AA	0.9222	C3B—H3BA	0.9537
C3A—H3AB	0.9462	C3B—H3BB	0.9224
C1A—O2A—H2OA	109.5	C1B—O2B—H2OB	109.5
O1A—C1A—O2A	123.52 (11)	O1B—C1B—O2B	123.41 (11)
O1A—C1A—C2A	124.18 (11)	O1B—C1B—C2B	124.33 (11)
O2A—C1A—C2A	112.29 (10)	O2B—C1B—C2B	112.25 (10)
C1A—C2A—C3A	114.73 (10)	C1B—C2B—C3B	115.27 (10)
C1A—C2A—H2AA	108.6	C1B—C2B—H2BA	108.5
C3A—C2A—H2AA	108.6	C3B—C2B—H2BA	108.5
C1A—C2A—H2AB	108.6	C1B—C2B—H2BB	108.5
C3A—C2A—H2AB	108.6	C3B—C2B—H2BB	108.5
H2AA—C2A—H2AB	107.6	H2BA—C2B—H2BB	107.5
C2A—C3A—C3Ai	111.19 (13)	C2B—C3B—C3Bii	110.83 (12)
C2A—C3A—H3AA	110.2	C2B—C3B—H3BA	110.6
C3Ai—C3A—H3AA	111.6	C3Bii—C3B—H3BA	108.1
C2A—C3A—H3AB	109.9	C2B—C3B—H3BB	109.3
C3Ai—C3A—H3AB	106.7	C3Bii—C3B—H3BB	109.7
H3AA—C3A—H3AB	107.0	H3BA—C3B—H3BB	108.3
O1A—C1A—C2A—C3A	0.07 (17)	O1B—C1B—C2B—C3B	−11.15 (18)
O2A—C1A—C2A—C3A	179.19 (10)	O2B—C1B—C2B—C3B	169.89 (10)
C1A—C2A—C3A—C3Ai	−172.28 (12)	C1B—C2B—C3B—C3Bii	−176.67 (13)

D—H···A	D—H	H···A	D···A	D—H···A
O2A—H2OA···O1Aiii	0.82	1.82	2.6397 (13)	172
O2B—H2OB···O1Biv	0.82	1.82	2.6421 (13)	174
C2A—H2AB···O2Av	0.97	2.58	3.5415 (16)	171

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2A—H2OA⋯O1Ai	0.82	1.82	2.6397 (13)	172
O2B—H2OB⋯O1Bii	0.82	1.82	2.6421 (13)	174
C2A—H2AB⋯O2Aiii	0.97	2.58	3.5415 (16)	171

Symmetry codes: (i) ; (ii) ; (iii) .