organic compounds
trans-1,4-Dimethylcyclohexane
aChemical Crystallography, Central Chemistry Laboratory, University of Oxford, Oxford OX1 3TA, England
*Correspondence e-mail: Richard.Bream@pmb.ox.ac.uk
trans-1,4-Dimethylcyclohexane, C8H16, was studied as part of a project to develop a computer-controlled low-temperature crystal-growing device. The liquid crystallizes with the molecule lying on a centre of symmetry, leading to Z′ = .
Comment
trans-1,4-Dimethylcyclohexane, (I) (Fig. 1), was one of eight alkylcyclohexanes whose thermodynamic properties were published in 1949 (Huffman et al., 1949). That work reported a melting point of 236.217 K and showed no evidence for phase changes in the range down to liquid-nitrogen temperatures.
The sample used for the present study was one of several sealed in 0.2 mm Lindeman tubes for preliminary work carried out in 1979. Data had been collected at that time on a Stoe Weissenberg diffractometer and the structure solved, but it was not of a publishable quality (Courseille et al., 1979).
The sample solidified spontaneously to a polycrystalline mass on flash cooling to 150 K. The temperature was then raised to 230 K and the sample zone-refined into a single-crystal using tandem computer-controlled heating elements. The temperature was then slowly reduced to 150 K for data collection.
The structure of (I) consists of molecules lying on centres of symmetry. This leads to the packing consisting of columns of molecules lying along the b axis (Fig. 2), with the mean plane of the molecule inclined at 145° to that axis (Fig. 3).
Experimental
The material was used as supplied by Aldrich Chemical Company Inc. in 1979.
Crystal data
|
Data collection
The H atoms were all located in a difference map and then repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles to regularize their geometry, with C—H distances in the range 0.93–0.98 Å, and on the displacement parameters, with Uiso(H) = 1.2–1.5 times Ueq of the parent atom, after which their positions were refined with riding constraints.
Data collection: COLLECT (Nonius, 2001).; cell DENZO/SCALEPACK; data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996); software used to prepare material for publication: CRYSTALS.
Supporting information
https://doi.org/10.1107/S1600536805042273/fl6205sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536805042273/fl6205Isup2.hkl
Data collection: COLLECT (Nonius, 2001).; cell
DENZO/SCALEPACK; data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996); software used to prepare material for publication: CRYSTALS.C8H16 | Dx = 0.978 Mg m−3 |
Mr = 112.22 | Melting point: 236.217 K |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 6.0843 (2) Å | Cell parameters from 882 reflections |
b = 5.4818 (2) Å | θ = 1–27° |
c = 11.7629 (5) Å | µ = 0.05 mm−1 |
β = 103.8918 (18)° | T = 150 K |
V = 380.85 (2) Å3 | Cylinder, colourless |
Z = 2 | 1.00 × 0.20 (radius) mm |
F(000) = 128 |
Nonius KappaCCD area-detector diffractometer | 861 reflections with I > 3σ(I) |
Graphite monochromator | Rint = 0.027 |
ω scans | θmax = 27.6°, θmin = 3.5° |
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997) | h = −7→7 |
Tmin = 0.758, Tmax = 1.000 | k = −7→6 |
4141 measured reflections | l = −15→15 |
862 independent reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.044 | H-atom parameters constrained |
wR(F2) = 0.091 | w = 1/[σ2(F2) + ( 0.03P)2 + 0.07P] where P = (max(Fo2,0) + 2Fc2)/3 |
S = 0.99 | (Δ/σ)max = 0.000356 |
861 reflections | Δρmax = 0.19 e Å−3 |
13 parameters | Δρmin = −0.17 e Å−3 |
0 restraints |
x | y | z | Uiso*/Ueq | ||
C1 | 0.22877 (14) | 0.08561 (16) | 0.56580 (7) | 0.0289 | |
C2 | 0.13233 (14) | 0.14820 (17) | 0.43681 (7) | 0.0323 | |
C3 | 0.03582 (15) | 0.04284 (17) | 0.62583 (8) | 0.0331 | |
C4 | 0.39112 (15) | 0.28192 (18) | 0.62800 (9) | 0.0389 | |
H11 | 0.3132 | −0.0696 | 0.5701 | 0.0332* | |
H21 | 0.0554 | 0.3079 | 0.4325 | 0.0369* | |
H22 | 0.2582 | 0.1675 | 0.3975 | 0.0380* | |
H31 | −0.0450 | 0.2001 | 0.6270 | 0.0402* | |
H32 | 0.0987 | −0.0087 | 0.7079 | 0.0404* | |
H41 | 0.4578 | 0.2351 | 0.7116 | 0.0558* | |
H42 | 0.3105 | 0.4379 | 0.6274 | 0.0552* | |
H43 | 0.5149 | 0.3077 | 0.5892 | 0.0549* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0289 | 0.0268 | 0.0303 | 0.0042 | 0.0054 | 0.0008 |
C2 | 0.0333 | 0.0345 | 0.0302 | 0.0002 | 0.0098 | 0.0043 |
C3 | 0.0370 | 0.0383 | 0.0243 | 0.0006 | 0.0078 | −0.0002 |
C4 | 0.0356 | 0.0360 | 0.0418 | −0.0014 | 0.0028 | −0.0019 |
C1—C2 | 1.5286 (12) | C2—H22 | 0.991 |
C1—C3 | 1.5264 (12) | C3—H31 | 0.994 |
C1—C4 | 1.5238 (12) | C3—H32 | 0.990 |
C1—H11 | 0.989 | C4—H41 | 1.003 |
C2—C3i | 1.5246 (12) | C4—H42 | 0.985 |
C2—H21 | 0.988 | C4—H43 | 0.980 |
C2—C1—C3 | 109.82 (7) | C1—C3—C2i | 112.54 (7) |
C2—C1—C4 | 111.60 (7) | C1—C3—H31 | 108.1 |
C3—C1—C4 | 111.61 (7) | C2i—C3—H31 | 109.0 |
C2—C1—H11 | 108.4 | C1—C3—H32 | 109.5 |
C3—C1—H11 | 107.0 | C2i—C3—H32 | 109.4 |
C4—C1—H11 | 108.3 | H31—C3—H32 | 108.1 |
C1—C2—C3i | 112.25 (7) | C1—C4—H41 | 110.7 |
C1—C2—H21 | 108.3 | C1—C4—H42 | 110.2 |
C3i—C2—H21 | 109.2 | H41—C4—H42 | 108.2 |
C1—C2—H22 | 109.4 | C1—C4—H43 | 111.1 |
C3i—C2—H22 | 110.6 | H41—C4—H43 | 108.6 |
H21—C2—H22 | 106.9 | H42—C4—H43 | 108.0 |
Symmetry code: (i) −x, −y, −z+1. |
References
Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435. CrossRef Web of Science IUCr Journals Google Scholar
Betteridge, P. W., Carruthers, J. R., Cooper, R. I., Prout, C. K. & Watkin, D. J. (2003). J. Appl. Cryst. 36, 1487. Web of Science CrossRef IUCr Journals Google Scholar
Courseille, D., Hospital, M., Leroy, F. & Watkin, D. (1979). 5th European Crystallographic Meeting, Copenhagen, Denmark, p. 285. Google Scholar
Huffman, H. M., Todd, S. S. & Oliver, G. D. (1949). J. Am. Chem. Soc. 71, 584–592. CrossRef CAS Web of Science Google Scholar
Nonius (2001). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Watkin, D. J., Prout, C. K. & Pearce, L. J. (1996). CAMERON. Chemical Crystallography Laboratory, University of Oxford, England. Google Scholar
© International Union of Crystallography. Prior permission is not required to reproduce short quotations, tables and figures from this article, provided the original authors and source are cited. For more information, click here.