Hydrogen bonding in 3-methyl­enecyclo­hexane-1,1-dicarboxylic acid

In the title structure, C₉H₁₂O₄, the mol­ecules assemble into a one-dimensional hydrogen-bonded chain of carboxylic dimers of extended C₂²(12)[R₂²(8)] notation.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C)= 0.003 Å
• R factor = 0.052
• wR factor = 0.145
• Data-to-parameter ratio = 17.1

checkCIF/PLATON results

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Computing details

Data collection: COLLECT (Nonius, 2000); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: WinGX (Farrugia, 1999), PLATON and Mercury (Bruno et al., 2002).

3-methylenecyclohexane-1,1-dicarboxylic acid

Crystal data

C9H12O4	Z = 2
Mr = 184.19	F(000) = 196
Triclinic, P1	Dx = 1.296 Mg m^−3
Hall symbol: -P 1	Melting point = 426–427 K
a = 6.6486 (6) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.1156 (6) Å	Cell parameters from 2027 reflections
c = 10.9252 (11) Å	θ = 1.9–27.0°
α = 75.880 (3)°	µ = 0.10 mm^−1
β = 86.265 (3)°	T = 295 K
γ = 70.310 (4)°	Prism, colourless
V = 471.90 (8) Å^3	0.33 × 0.20 × 0.20 mm

Data collection

KappaCCD diffractometer	1692 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.049
Horizontally mounted graphite crystal monochromator	θmax = 27.0°, θmin = 1.9°
Detector resolution: 9 pixels mm^-1	h = −8→8
φ and ω scans	k = −8→9
4497 measured reflections	l = −13→13
2052 independent reflections

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)] = 0.052	Hydrogen site location: difference Fourier map
wR(F^2) = 0.145	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0615P)^2 + 0.2209P] where P = (Fo^2 + 2Fc^2)/3
2052 reflections	(Δ/σ)max = 0.001
120 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.19 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	0.7223 (2)	0.3259 (2)	0.46827 (14)	0.0565 (5)
O2	0.4108 (2)	0.4336 (3)	0.36783 (15)	0.0595 (5)
H2	0.3756	0.5065	0.4186	0.071*
O3	0.4650 (2)	0.3075 (2)	0.10563 (12)	0.0466 (4)
O4	0.7065 (2)	0.4552 (2)	0.11673 (13)	0.0483 (4)
H4	0.6535	0.5255	0.0479	0.058*
C1	0.6933 (3)	0.1872 (2)	0.29172 (15)	0.0291 (4)
C2	0.9398 (3)	0.1018 (3)	0.29678 (17)	0.0344 (4)
H2A	0.9956	0.2133	0.2628	0.041*
H2B	0.9884	0.0437	0.3840	0.041*
C3	1.0253 (3)	−0.0608 (3)	0.22255 (18)	0.0418 (5)
C4	0.9361 (3)	−0.2330 (3)	0.2593 (2)	0.0534 (6)
H4A	0.9814	−0.3093	0.3451	0.064*
H4B	0.9906	−0.3261	0.2040	0.064*
C5	0.6922 (3)	−0.1500 (3)	0.2505 (2)	0.0444 (5)
H5A	0.6472	−0.0880	0.1629	0.053*
H5B	0.6366	−0.2625	0.2804	0.053*
C6	0.6008 (3)	0.0096 (3)	0.32882 (17)	0.0362 (4)
H6A	0.6320	−0.0567	0.4175	0.043*
H6B	0.4467	0.0650	0.3173	0.043*
C7	0.6114 (3)	0.3235 (3)	0.38519 (16)	0.0336 (4)
C8	0.6098 (3)	0.3220 (2)	0.16124 (15)	0.0290 (4)
C9	1.1645 (4)	−0.0471 (5)	0.1320 (2)	0.0641 (7)
H9A	1.2155	−0.1521	0.0860	0.077*
H9B	1.2145	0.0689	0.1120	0.077*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0518 (9)	0.0656 (10)	0.0451 (8)	0.0075 (7)	−0.0160 (7)	−0.0346 (7)
O2	0.0443 (8)	0.0702 (10)	0.0559 (10)	0.0121 (7)	−0.0115 (7)	−0.0413 (8)
O3	0.0570 (9)	0.0494 (8)	0.0351 (7)	−0.0265 (7)	−0.0184 (6)	0.0043 (6)
O4	0.0605 (9)	0.0488 (8)	0.0364 (8)	−0.0290 (7)	−0.0160 (6)	0.0082 (6)
C1	0.0332 (9)	0.0285 (8)	0.0220 (8)	−0.0051 (7)	−0.0018 (6)	−0.0063 (6)
C2	0.0321 (9)	0.0400 (10)	0.0288 (9)	−0.0064 (7)	−0.0047 (7)	−0.0106 (7)
C3	0.0313 (9)	0.0502 (11)	0.0395 (10)	0.0002 (8)	−0.0059 (7)	−0.0205 (9)
C4	0.0498 (12)	0.0384 (11)	0.0654 (14)	0.0024 (9)	−0.0054 (10)	−0.0228 (10)
C5	0.0492 (11)	0.0332 (10)	0.0515 (12)	−0.0124 (8)	−0.0013 (9)	−0.0122 (8)
C6	0.0399 (9)	0.0348 (9)	0.0295 (9)	−0.0100 (8)	0.0016 (7)	−0.0032 (7)
C7	0.0407 (9)	0.0302 (9)	0.0236 (8)	−0.0026 (7)	−0.0040 (7)	−0.0067 (7)
C8	0.0349 (8)	0.0280 (8)	0.0229 (8)	−0.0084 (7)	−0.0013 (6)	−0.0065 (6)
C9	0.0445 (12)	0.0948 (19)	0.0596 (15)	−0.0159 (12)	0.0093 (11)	−0.0428 (14)

Geometric parameters (Å, º)

O1—C7	1.212 (2)	C3—C9	1.319 (3)
O2—C7	1.298 (2)	C3—C4	1.495 (3)
O2—H2	0.8200	C4—C5	1.528 (3)
O3—C8	1.217 (2)	C4—H4A	0.9700
O4—C8	1.301 (2)	C4—H4B	0.9700
O4—H4	0.8200	C5—C6	1.527 (3)
C1—C7	1.528 (2)	C5—H5A	0.9700
C1—C8	1.529 (2)	C5—H5B	0.9700
C1—C6	1.543 (3)	C6—H6A	0.9700
C1—C2	1.543 (2)	C6—H6B	0.9700
C2—C3	1.508 (2)	C9—H9A	0.9571
C2—H2A	0.9700	C9—H9B	0.9629
C2—H2B	0.9700
C7—O2—H2	109.5	H4A—C4—H4B	108.1
C8—O4—H4	109.5	C6—C5—C4	111.17 (17)
C7—C1—C8	106.52 (13)	C6—C5—H5A	109.4
C7—C1—C6	107.78 (14)	C4—C5—H5A	109.4
C8—C1—C6	110.70 (14)	C6—C5—H5B	109.4
C7—C1—C2	110.06 (14)	C4—C5—H5B	109.4
C8—C1—C2	111.32 (14)	H5A—C5—H5B	108.0
C6—C1—C2	110.31 (14)	C5—C6—C1	112.24 (15)
C3—C2—C1	111.54 (15)	C5—C6—H6A	109.2
C3—C2—H2A	109.3	C1—C6—H6A	109.2
C1—C2—H2A	109.3	C5—C6—H6B	109.2
C3—C2—H2B	109.3	C1—C6—H6B	109.2
C1—C2—H2B	109.3	H6A—C6—H6B	107.9
H2A—C2—H2B	108.0	O1—C7—O2	123.6 (2)
C9—C3—C4	123.9 (2)	O1—C7—C1	123.2 (2)
C9—C3—C2	121.8 (2)	O2—C7—C1	113.2 (2)
C4—C3—C2	114.27 (17)	O3—C8—O4	123.5 (2)
C3—C4—C5	110.46 (16)	O3—C8—C1	123.1 (2)
C3—C4—H4A	109.6	O4—C8—C1	113.4 (1)
C5—C4—H4A	109.6	C3—C9—H9A	120.1
C3—C4—H4B	109.6	C3—C9—H9B	119.9
C5—C4—H4B	109.6	H9A—C9—H9B	120.0
C2—C1—C7—O1	−14.5 (2)	C7—C1—C6—C5	−173.62 (14)
C6—C1—C8—O3	10.8 (2)	C8—C1—C6—C5	70.24 (18)
C7—C1—C2—C3	170.41 (15)	C8—C1—C7—O1	−135.34 (19)
C8—C1—C2—C3	−71.7 (2)	C6—C1—C7—O1	105.8 (2)
C6—C1—C2—C3	51.6 (2)	C8—C1—C7—O2	45.7 (2)
C1—C2—C3—C4	−54.2 (2)	C6—C1—C7—O2	−73.13 (19)
C2—C3—C4—C5	55.3 (2)	C2—C1—C7—O2	166.52 (16)
C3—C4—C5—C6	−55.0 (2)	C7—C1—C8—O3	−106.15 (19)
C4—C5—C6—C1	55.5 (2)	C2—C1—C8—O3	133.86 (18)
C2—C1—C6—C5	−53.4 (2)	C7—C1—C8—O4	72.89 (18)
C1—C2—C3—C9	124.8 (2)	C6—C1—C8—O4	−170.20 (14)
C9—C3—C4—C5	−123.7 (2)	C2—C1—C8—O4	−47.1 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1^i	0.82	1.86	2.681 (2)	176
O4—H4···O3^ii	0.82	1.85	2.667 (2)	178

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z.