n Decane

organic papers

o196

Acta Crystallographica Section E Structure Reports Online

ISSN 1600-5368

n

-Decane

Andrew D. Bond* and John E. Davies

Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, England

Correspondence e-mail: [email protected]

Key indicators

Single-crystal X-ray study T= 150 K

Mean(C±C) = 0.002 AÊ Rfactor = 0.054 wRfactor = 0.181

Data-to-parameter ratio = 12.5

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2002 International Union of Crystallography Printed in Great Britain ± all rights reserved

The crystal structure of n-decane, C10H22, has been deter-mined at 150 (2) K followingin situ crystal growth from the liquid. In space group P1, the molecule is sited on a crystallographic centre of symmetry, and has a fully extended conformation.

Comment

It has been known for well over a century that the melting points of the straight-chain aliphatic acids display an odd-even alternation effect, the melting points of those with an even number of C atoms being high compared with those with an odd number of C atoms (Baeyer, 1877). Since the boiling points of these compounds show a monotonic increase with chain length, this phenomenon must be attributed to differ-ences in the crystal structures. A plausible explanation for the effect has been proposed only recently: from precise single-crystal X-ray diffraction data, Boeseet al. (1999) established that the melting point alternation for the short- and inter-mediate-chain n-alkanes (CnH2n+2, n = 2±10) mirrors an

alternation in crystal density. Forn-hexane ton-nonane, which crystallize in space groupP1, this density alternation may be attributed to the interaction between the terminal methyl groups. Even-numbered n-alkanes adopt optimal inter-molecular contacts at both ends of the molecules while odd-numbered n-alkanes must adopt longer intermolecular distances at one end, resulting in a lower crystal density.

The elegant study of Boeseet al. (1999) was facilitated by examination of crystals grownin situfrom the liquid (obtained where necessary by condensation of the gas), by application of a CO2 laser beam along a sealed capillary. This technique proved successful for n-propane to n-nonane. It was not possible, however, to obtain a crystal ofn-decane suitable for data collection. Recently, we have been pursuing a programme of research intended to improve techniques for determining the crystal structures of compounds that are liquid at room temperature (see, for example, Bond & Davies, 2001a,b,c), and report here the crystal structure ofn-decane at 150 (2) K. The crystal was grown in situ from the liquid using a technique described earlier (Davies & Bond, 2001). In space groupP1, the molecule is sited on a crystallographic centre of symmetry, and the unit-cell parameters are consistent with those of the rest of the series, and also with values determined previously

from powder X-ray diffraction measurements (Norman & Mathisen, 1972).

Experimental

The sample (99%) was obtained from the Aldrich Company and used without further puri®cation. The crystal was grown in a 0.3 mm glass capillary tube atca241.5 K (a temperature only slightly less than the melting point of the solid in the capillary). Once grown, the crystal was cooled to 150 (2) K for data collection. The length of the cyl-indrical crystal was not estimated, but it exceeded the diameter of the collimator (0.35 mm).

Crystal data

C10H22

Mr= 142.28 Triclinic,P1 a= 4.1741 (4) AÊ b= 4.7239 (6) AÊ c= 13.5066 (15) AÊ = 85.974 (1)

= 81.463 (7)

= 74.652 (6) V= 253.85 (5) AÊ3

Z= 1

Dx= 0.931 Mg mÿ3 MoKradiation Cell parameters from 3994

re¯ections = 1.0±27.5

= 0.05 mmÿ1

T= 150 (2) K Cylinder, colourless 0.15 mm (radius)

Data collection

Nonius KappaCCD diffractometer Thin-slice!and'scans Absorption correction: none 2851 measured re¯ections 1122 independent re¯ections 865 re¯ections withI> 2(I)

Rint= 0.069

max= 27.4

h=ÿ4!5 k=ÿ6!6 l=ÿ15!17

Re®nement

Re®nement onF2

R[F2_{> 2(F}2_{)] = 0.054}

wR(F2_{) = 0.181}

S= 1.09 1122 re¯ections 90 parameters

All H-atom parameters re®ned

w= 1/[2_(F

o2) + (0.0856P)2 + 0.0416P]

whereP= (Fo2+ 2Fc2)/3 (/)max< 0.001

max= 0.22 e AÊÿ3

min=ÿ0.18 e AÊÿ3

All H atoms were located from a difference Fourier map and re®ned freely with independent isotropic displacement parameters.

Data collection:COLLECT(Nonius, 1998); cell re®nement:HKL SCALEPACK(Otwinowski & Minor, 1997); data reduction: HKL SCALEPACK and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to re®ne structure:SHELXL97 (Sheldrick, 1997); molecular graphics:XP(Sheldrick, 1993) andCAMERON(Watkinet al., 1996); software used to prepare material for publication:

SHELXL97.

We thank the EPSRC for ®nancial assistance towards the purchase of the Nonius CCD diffractometer.

References

Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994).J. Appl. Cryst.27, 435.

Baeyer, A. (1877).Ber. Chem. Ges.10, 1286.

Boese, R., BlaÈser, D. & Weiss, H.-C. (1999).Angew. Chem. Int. Ed.38, 988± 992.

Bond, A. D. & Davies, J. E. (2001a).Acta Cryst.E57, o1039±o1040. Bond, A. D. & Davies, J. E. (2001b).Acta Cryst.E57, o1087±o1088. Bond, A. D. & Davies, J. E. (2001c).Acta Cryst.E57, o1191±o1193. Davies, J. E. & Bond, A. D. (2001).Acta Cryst.E57, o947±o949. Nonius (1998).COLLECT. Nonius BV, Delft, The Netherlands. Norman, N. & Mathisen, H. (1972).Acta Chem. Scand.26, 3913±3916. Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276,

Macromolecular Crystallography, Part A, edited by C. W. Carter and R. M. Sweet, pp. 307±326. London: Academic Press.

Sheldrick, G. M. (1993).XP. University of GoÈttingen, Germany. Sheldrick, G. M. (1997).SHELXL97. University of GoÈttingen, Germany. Watkin, D. J., Prout, C. K. & Pearce, L. J. (1996).CAMERON. Chemical

Crystallography Laboratory, University of Oxford, England. Figure 2

Projection on to (100) (CAMERON; Watkinet al., 1996).

Figure 1

supporting information

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Acta Cryst. (2002). E58, o196–o197

supporting information

Acta Cryst. (2002). E58, o196–o197 [https://doi.org/10.1107/S1600536802001332]

n

-Decane

Andrew D. Bond and John E. Davies

n-decane

Crystal data C10H22 Mr = 142.28 Triclinic, P1 a = 4.1741 (4) Å b = 4.7239 (6) Å c = 13.5066 (15) Å α = 85.974 (1)° β = 81.463 (7)° γ = 74.652 (6)° V = 253.85 (5) Å3 Z = 1

F(000) = 82 Dx = 0.931 Mg m−3 Melting point: 243 K

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 3994 reflections θ = 1.0–27.5°

µ = 0.05 mm−1 T = 150 K

Cylinder, colourless 0.15 mm (radius)

Data collection Nonius KappaCCD

diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

Thin–slice ω and φ scans 2851 measured reflections 1122 independent reflections

865 reflections with I > 2σ(I) Rint = 0.069

θmax = 27.4°, θmin = 4.6° h = −4→5

k = −6→6 l = −15→17

Refinement Refinement on F2 Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.054} wR(F2_{) = 0.181} S = 1.09 1122 reflections 90 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: difference Fourier map All H-atom parameters refined

w = 1/[σ2_(F

o2) + (0.0856P)2 + 0.0416P] where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001 Δρmax = 0.22 e Å−3 Δρmin = −0.18 e Å−3

Special details

Experimental. Crystal grown in situ in 0.3 mm glass capillary at 241.5 K

Refinement. Refinement of F2 _{against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F}2_, conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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 (Å2₎

x y z Uiso*/Ueq

C1 0.8145 (4) 0.2469 (3) 0.90220 (10) 0.0378 (5)

H1A 1.032 (5) 0.112 (4) 0.8816 (13) 0.047 (4)*

H1B 0.659 (4) 0.132 (4) 0.9203 (13) 0.048 (4)*

H1C 0.822 (5) 0.348 (4) 0.9652 (15) 0.058 (5)*

C2 0.7018 (3) 0.4660 (3) 0.81807 (9) 0.0314 (4)

H2A 0.865 (4) 0.588 (3) 0.8014 (11) 0.041 (4)*

H2B 0.485 (4) 0.594 (3) 0.8401 (11) 0.039 (4)*

C3 0.6817 (3) 0.3198 (2) 0.72290 (8) 0.0269 (4)

H3A 0.899 (4) 0.184 (3) 0.7009 (11) 0.032 (3)*

H3B 0.523 (4) 0.199 (3) 0.7389 (11) 0.031 (3)*

C4 0.5746 (3) 0.5375 (2) 0.63783 (8) 0.0269 (4)

H4A 0.737 (4) 0.654 (3) 0.6228 (11) 0.035 (4)*

H4B 0.358 (4) 0.671 (3) 0.6601 (11) 0.032 (3)*

C5 0.5523 (3) 0.3915 (2) 0.54273 (8) 0.0265 (4)

H5A 0.767 (4) 0.255 (3) 0.5210 (11) 0.031 (3)*

H5B 0.390 (4) 0.270 (3) 0.5587 (12) 0.036 (4)*

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

C1 0.0419 (8) 0.0452 (9) 0.0268 (7) −0.0105 (7) −0.0103 (5) 0.0040 (5)

C2 0.0360 (7) 0.0327 (7) 0.0253 (6) −0.0069 (5) −0.0073 (5) −0.0004 (5)

C3 0.0296 (7) 0.0270 (7) 0.0234 (7) −0.0060 (5) −0.0050 (5) 0.0012 (5)

C4 0.0304 (7) 0.0263 (7) 0.0236 (7) −0.0058 (5) −0.0056 (5) 0.0010 (5)

C5 0.0301 (7) 0.0259 (7) 0.0228 (7) −0.0058 (5) −0.0053 (5) 0.0011 (5)

Geometric parameters (Å, º)

C1—C2 1.5232 (18) C3—H3A 0.979 (16)

C1—H1A 0.976 (18) C3—H3B 0.974 (15)

C1—H1B 0.946 (18) C4—C5 1.5257 (15)

C1—H1C 1.01 (2) C4—H4A 0.972 (15)

C2—C3 1.5242 (15) C4—H4B 0.976 (16)

C2—H2A 0.994 (16) C5—C5i _{1.523 (2)}

C2—H2B 0.963 (16) C5—H5A 0.974 (16)

C3—C4 1.5233 (16) C5—H5B 0.988 (16)

C2—C1—H1A 111.5 (10) C4—C3—H3B 109.3 (9)

C2—C1—H1B 110.0 (10) C2—C3—H3B 108.4 (9)

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Acta Cryst. (2002). E58, o196–o197

C2—C1—H1C 112.0 (10) C3—C4—C5 113.56 (9)

H1A—C1—H1C 110.0 (15) C3—C4—H4A 107.9 (9)

H1B—C1—H1C 105.9 (14) C5—C4—H4A 109.1 (9)

C1—C2—C3 113.19 (11) C3—C4—H4B 109.4 (9)

C1—C2—H2A 108.7 (9) C5—C4—H4B 109.2 (9)

C3—C2—H2A 108.1 (9) H4A—C4—H4B 107.5 (13)

C1—C2—H2B 109.7 (9) C5i_{—C5—C4 113.69 (11)}

C3—C2—H2B 108.8 (9) C5i_{—C5—H5A 109.7 (9)}

H2A—C2—H2B 108.3 (13) C4—C5—H5A 109.6 (9)

C4—C3—C2 113.50 (10) C5i_{—C5—H5B 109.2 (9)}

C4—C3—H3A 109.7 (9) C4—C5—H5B 108.8 (9)

C2—C3—H3A 109.6 (8) H5A—C5—H5B 105.5 (13)

C1—C2—C3—C4 −179.04 (11) C3—C4—C5—C5i _{−179.59 (12)}

C2—C3—C4—C5 −179.63 (9)