supplementary materials
Low-temperature redetermination of trans-cyclohexane-1,2-dicarboxylic acid
The molecule of the title compound, C8H12O4, lies on a twofold rotation axis that passes through the mid-points of two opposite C-C bonds of the ring. Carboxyl groups of adjacent molecules are linked by pairs of hydrogen bonds around a centre of inversion; this interaction gives rise to a chain that runs along [101].
The commercially available acid was recrystallized from ethanol.
Carbon-bound H-atoms were placed in calculated positions (C—H 0.99 to 1.00 Å) and were included in the refinement in the riding model approximation,
with U(H) set to 1.2 U(C).
The acid H-atom was located in a difference Fourier map, and was
isotropically refined with a
distance restraint of O–H 0.85 (1) Å.
Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2008).
trans-cyclohexane-1,2-dicarboxylic acid
top
Crystal data top
| C8H12O4 | F000 = 368 |
| Mr = 172.18 | Dx = 1.483 Mg m−3 |
| Monoclinic, C2/c | Mo Kα radiation
λ = 0.71073 Å |
| Hall symbol: -C 2yc | Cell parameters from 739 reflections |
| a = 5.585 (1) Å | θ = 3.6–28.2º |
| b = 13.840 (3) Å | µ = 0.12 mm−1 |
| c = 10.035 (2) Å | T = 100 (2) K |
| β = 96.114 (3)º | Strip, colourless |
| V = 771.3 (3) Å3 | 0.38 × 0.06 × 0.04 mm |
| Z = 4 | |
Data collection top
Bruker SMART APEX
diffractometer | 715 reflections with I > 2σ(I) |
| Radiation source: fine-focus sealed tube | Rint = 0.035 |
| Monochromator: graphite | θmax = 27.5º |
| T = 100(2) K | θmin = 2.9º |
| ω scans | h = −7→7 |
| Absorption correction: None | k = −17→17 |
| 2320 measured reflections | l = −13→8 |
| 883 independent reflections | |
Refinement top
| Refinement on F2 | Secondary atom site location: difference Fourier map |
| Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
| R[F2 > 2σ(F2)] = 0.042 | H atoms treated by a mixture of
independent and constrained refinement |
| wR(F2) = 0.115 | w = 1/[σ2(Fo2) + (0.0635P)2 + 0.2009P]
where P = (Fo2 + 2Fc2)/3 |
| S = 1.07 | (Δ/σ)max = 0.001 |
| 883 reflections | Δρmax = 0.31 e Å−3 |
| 59 parameters | Δρmin = −0.28 e Å−3 |
| 1 restraint | Extinction correction: none |
| Primary atom site location: structure-invariant direct methods | |
Crystal data top
| C8H12O4 | V = 771.3 (3) Å3 |
| Mr = 172.18 | Z = 4 |
| Monoclinic, C2/c | Mo Kα |
| a = 5.585 (1) Å | µ = 0.12 mm−1 |
| b = 13.840 (3) Å | T = 100 (2) K |
| c = 10.035 (2) Å | 0.38 × 0.06 × 0.04 mm |
| β = 96.114 (3)º | |
Data collection top
Bruker SMART APEX
diffractometer | 883 independent reflections |
| Absorption correction: None | 715 reflections with I > 2σ(I) |
| 2320 measured reflections | Rint = 0.035 |
Refinement top
| R[F2 > 2σ(F2)] = 0.042 | 1 restraint |
| wR(F2) = 0.115 | H atoms treated by a mixture of
independent and constrained refinement |
| S = 1.07 | Δρmax = 0.31 e Å−3 |
| 883 reflections | Δρmin = −0.28 e Å−3 |
| 59 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top| | x | y | z | Uiso*/Ueq | |
| O1 | 0.0840 (2) | 0.1596 (1) | 0.0902 (1) | 0.0173 (3) | |
| O2 | 0.4725 (2) | 0.1968 (1) | 0.0869 (1) | 0.0166 (3) | |
| C1 | 0.3157 (3) | 0.1471 (1) | 0.1279 (2) | 0.0122 (3) | |
| C2 | 0.3668 (2) | 0.0626 (1) | 0.2220 (2) | 0.0122 (4) | |
| C3 | 0.2893 (3) | −0.0314 (1) | 0.1475 (2) | 0.0139 (4) | |
| C4 | 0.3647 (3) | −0.1208 (1) | 0.2303 (2) | 0.0159 (4) | |
| H1o | 0.068 (4) | 0.206 (1) | 0.035 (2) | 0.036 (6)* | |
| H2 | 0.2676 | 0.0704 | 0.2986 | 0.015* | |
| H3a | 0.1121 | −0.0315 | 0.1261 | 0.017* | |
| H3b | 0.3626 | −0.0339 | 0.0620 | 0.017* | |
| H4a | 0.2799 | −0.1218 | 0.3120 | 0.019* | |
| H4b | 0.3184 | −0.1796 | 0.1776 | 0.019* | |
Atomic displacement parameters (Å2) top| | U11 | U22 | U33 | U12 | U13 | U23 |
| O1 | 0.0124 (6) | 0.0179 (6) | 0.0205 (7) | 0.0008 (4) | −0.0027 (5) | 0.0074 (5) |
| O2 | 0.0149 (6) | 0.0153 (6) | 0.0186 (6) | −0.0017 (4) | −0.0028 (4) | 0.0048 (4) |
| C1 | 0.0140 (7) | 0.0112 (7) | 0.0107 (8) | 0.0012 (5) | −0.0025 (6) | −0.0034 (6) |
| C2 | 0.0115 (7) | 0.0118 (7) | 0.0126 (8) | 0.0003 (5) | −0.0025 (6) | −0.0004 (6) |
| C3 | 0.0138 (7) | 0.0141 (7) | 0.0134 (8) | −0.0013 (5) | −0.0012 (6) | −0.0014 (6) |
| C4 | 0.0170 (8) | 0.0109 (7) | 0.0190 (9) | −0.0011 (5) | −0.0012 (6) | 0.0003 (6) |
Geometric parameters (Å, °) top
| O1—C1 | 1.321 (2) | O1—H1o | 0.85 (1) |
| O2—C1 | 1.220 (2) | C2—H2 | 1.0000 |
| C1—C2 | 1.511 (2) | C3—H3a | 0.9900 |
| C2—C2i | 1.533 (3) | C3—H3b | 0.9900 |
| C2—C3 | 1.5397 (19) | C4—H4a | 0.9900 |
| C3—C4 | 1.523 (2) | C4—H4b | 0.9900 |
| C4—C4i | 1.521 (3) | | |
| | | |
| O2—C1—O1 | 123.1 (1) | C3—C2—H2 | 108.3 |
| O2—C1—C2 | 123.6 (1) | C4—C3—H3a | 109.2 |
| O1—C1—C2 | 113.3 (1) | C2—C3—H3a | 109.2 |
| C1—C2—C2i | 109.9 (1) | C4—C3—H3b | 109.2 |
| C1—C2—C3 | 109.0 (1) | C2—C3—H3b | 109.2 |
| C2i—C2—C3 | 112.9 (1) | H3a—C3—H3b | 107.9 |
| C4—C3—C2 | 112.0 (1) | C4i—C4—H4a | 109.5 |
| C4i—C4—C3 | 110.5 (1) | C3—C4—H4a | 109.5 |
| C1—O1—H1o | 109 (1) | C4i—C4—H4b | 109.5 |
| C1—C2—H2 | 108.3 | C3—C4—H4b | 109.5 |
| C2i—C2—H2 | 108.3 | H4a—C4—H4b | 108.1 |
| | | |
| O2—C1—C2—C2i | 11.2 (2) | C1—C2—C3—C4 | 172.7 (1) |
| O1—C1—C2—C2i | −171.2 (1) | C2i—C2—C3—C4 | 50.2 (2) |
| O2—C1—C2—C3 | −113.0 (2) | C2—C3—C4—C4i | −56.6 (2) |
| O1—C1—C2—C3 | 64.6 (2) | | |
| Symmetry codes: (i) −x+1, y, −z+1/2. |
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| O1—H1o···O2ii | 0.85 (1) | 1.81 (1) | 2.662 (2) | 178 (2) |
| Symmetry codes: (ii) −x+1/2, −y+1/2, −z. |
Table 1
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| O1—H1o···O2i | 0.85 (1) | 1.81 (1) | 2.662 (2) | 178 (2) |
| Symmetry codes: (i) −x+1/2, −y+1/2, −z. |
We thank the University of Malaya for the purchase of the diffractometer.
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191.
Benedetti, E., Corradini, P., Perrone, C. & Post, B. (1969). J. Am. Chem. Soc. 91, 4072–4074.
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Koningsveld, H. van (1984). Acta Cryst. C40, 1857–1863.
Luger, P., Plieth, K. & Ruban, G. (1972). Acta Cryst. B28, 706–710.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Westrip, S. P. (2008). publCIF. In preparation.
![[Figure 1]](./cv2404fig1thm.gif)
![[Figure 2]](./cv2404fig2thm.gif)
Crystallographic studies of the metal derivatives of trans-1,2-cyclohexanedicarboxylic acid occasionally refer to the room-temperature crystal structure of the dicarboxylic acid, which was reported in 1969. The report (Benedetti et al., 1969) contains typographical errors that have since been corrected in the Cambridge Structural Database (Version 5.29, Nov. 2007). The reported monoclinic cell dimensions can be transformed to 5.65 (1), b 13.34 (3), c 10.22 (3) Å; β 97.2 (2)°.
Whereas the low-temperature unit cell has a slightly larger volume compared with the room-temperature cell, the low-temperature cell has a much longer b-axis [13.840 (3) Å]. The bond distances and angles of room-temperature structure are normal; those of the present study are not significantly different despite the longer axis. Possibly, the expansion of this axis is a genuine observation. Moreover, the present study is able to establish the hydrogen bonding scheme of the compound (Scheme I, Fig. 1). Adjacent molecules are linked by a linear O–H···O hydrogen bond [2.662 (2) Å] into a chain (Fig. 2).
The crystal structures of 1,3- and 1,4-cyclohexanedicarboxylic acids have already been reported (van Koningsveld, 1984; Luger et al., 1972).