Octa­decane 1,18 diol

organic papers

o136

Structure Reports Online

ISSN 1600-5368

Octadecane-1,18-diol

Naotake Nakamura* and Ryoji Watanabe

Department of Applied Chemistry, Faculty of Science and Engineering, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga 525-8577, Japan

Correspondence e-mail: [email protected]

Key indicators Single-crystal X-ray study

T= 298 K

Mean(C±C) = 0.003 AÊ

Rfactor = 0.045

wRfactor = 0.065

Data-to-parameter ratio = 10.9

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

#2001 International Union of Crystallography Printed in Great Britain ± all rights reserved

The skeleton of the title molecule, C18H38O2, is all-transand

the molecules aggregate to form a layer structure along thec

axis as in a smectic C liquid crystal. The inclination angle of the long axis of the molecule to the layer plane is the same in each layer, but the direction of the long axis is opposite in alternate layers. These features are very similar to those of the homologues with an even number of C atoms, but different from those with an odd number.

Comment

Crystal structures of long-chain compounds such asn-alkanes (MuÈller, 1928) andn-higher primary alcohols (e.g.Watanabe, 1961; Seto, 1962), have been studied by many researchers from the viewpoint of basic polymer science. According to those results, the compounds have a simple straight hydrocarbon chain as a skeleton and the molecular shape can be regarded as rod-like, which is one of the typical features of liquid crystal molecules. In addition, some long-chain compounds construct a layer structure in the crystal state, which is similar to that of a smectic phase of liquid crystals. Therefore, these compounds have been studied from a structural point of view as models for smectic liquid crystals.

We have already reported molecular and crystal structures of ,!-alkanediols containing from 10 through 17 and 21 C atoms; these were investigated by Nakamura and co-workers: 1,10-decanediol (Nakamura & Sato, 1999a), 1,11-undecane-diol (Nakamuraet al., 1999), 1,12-dodecanediol (Nakamura & Setodoi, 1997), 1,13-tridecanediol (Nakamura et al., 1997), 1,14-tetradecanediol (Nakamura & Sato, 1999b), 1,15-penta-decanediol (Nakamura et al., 2000), 1,16-hexadecanediol (Nakamura & Yamamoto, 1994), 1,17-heptadecanediol (Nakamuraet al., 2001) and 1,21-henicosanediol (Nakamuraet al., 2000). The results showed a clear distinction in structure between the compounds with an even number of C atoms and those with an odd number of C atoms. In the,!-alkanediols with even number of C atoms, the hydroxyl groups located at both ends of a hydrocarbon skeleton showed an all-trans

conformation with respect to the skeleton. These molecules were arranged making layers in a herring-bone fashion,

just like the chiral smectic C liquid crystals. On the other hand, in the,!-alkanediols with an odd number of C atoms, one hydroxyl group hadgaucheconformation with respect to the hydrocarbon skeleton, whereas another hydroxyl group had

trans conformation. In this case, molecules made a layer structure which was very similar to that of the smectic A liquid

crystals. In addition, phase transition of,!-alkanediols from C13 through C24 was studied by means of a powder X-ray diffraction method and a linear relation of the longest axis of lattice constant versus number of C atoms was reported (Ogawa & Nakamura, 1999).

In the crystal structure of 1,18-octadecanediol, (I), shown in Fig. 1, an all-transconformation was observed not only in the hydrocarbon skeleton but also in both terminal hydroxyl groups. The molecule is centrosymmetric and forms a layer structure stacked along thecaxis. The inclination angle of the long axis of the molecule to the layer plane is equal in each layer, but the direction of the long axis of the molecule is opposite in alternate layers because of the existence of a twofold screw axis parallel tob. Such herring-bone structures can be regarded as a model structure of chiral smectic C liquid crystals. These features are very similar to those of 1,10-decanediol, 1,12-do1,10-decanediol, 1,14-tetradecanediol and 1,16-hexadecanediol. The average value of inclination angles of the above compounds was about 56_{, as found in the present}

structure. These molecules form interlayer hydrogen bonds, as shown in Fig. 2, with the interlayer hydrogen-bonding distance O1 O1i_{= 2.843 (2) AÊ [symmetry code: (i) 3ÿx,}1

2+y,12ÿz].

This value is in good agreement with those of other ,! -alkanediols with an even number of C atoms.

Experimental

According to the conventional method, the title compound, (I), was synthesized from commercially available octadecanedioic acid (Tokyo Kasei Kogyo Co. Ltd) by esteri®cation and reduction with LiAlH4. The single crystal used for analysis was grown by very slow

evaporation from a solution in a mixed solvent system comprising methanol, ethyl acetate and 1,3-dimethylbenzene (1:1:3 ratio). Crystal data

C18H38O2 Mr= 286.50

Monoclinic,P21/c a= 4.998 (2) AÊ

b= 5.220 (2) AÊ

c= 34.853 (2) AÊ

= 92.04 (2)

V= 908.8 (5) AÊ3 Z= 2

Dx= 1.047 Mg mÿ3

CuKradiation Cell parameters from 24

re¯ections

= 9.3±20.1

= 0.50 mmÿ1 T= 298 K Plate, colorless 0.400.200.02 mm

Data collection

Rigaku AFC-5Rdiffractometer

!±2scans

Absorption correction: scans (Northet al., 1968)

Tmin= 0.929,Tmax= 1.000

2843 measured re¯ections 1802 independent re¯ections 991 re¯ections withI> 2(I)

Rint= 0.025

max= 70.5 h=ÿ2!6

k= 0!5

l=ÿ42!42 3 standard re¯ections

every 150 re¯ections intensity decay: 2.6%

Re®nement

Re®nement onF R= 0.045

wR= 0.065

S= 1.94 991 re¯ections 91 parameters

H-atom parameters not re®ned

w= 1/[2_(F

o) + 0.00053|Fo|2]

(/)max< 0.001

max= 0.12 e AÊÿ3

min=ÿ0.11 e AÊÿ3

Acta Cryst.(2001). E57, o136±o138 Nakamura and Watanabe C₁₈H₃₈O₂

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organic papers

Figure 1

AnORTEPII (Johnson, 1976) view of the title molecule showing the crystallographic numbering scheme. Displacement ellipsoids are shown at the 50% probability level.

Figure 2

organic papers

o138

All H atoms, including hydroxyl H atoms, were ®xed in idealized positions.

Data collection and cell re®nement: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1992); data reduction: TEXSAN (Molecular Structure Corporation, 1995); program(s) used to solve structure:SAPI91 (Fan, 1991); program(s) used to re®ne structure:TEXSAN; software used to prepare material for publication:TEXSAN.

References

Fan, H.-F. (1991).SAPI91. Rigaku Corporation, Tokyo, Japan.

Johnson, C. K. (1976).ORTEPII. Report ORNL-5138. Oak Ridge National Laboratory, Tennessee, USA.

Molecular Structure Corporation (1992).MSC/AFC Diffractometer Control Software. MSC, 3200 Research Forest Drive, The Woodlands, TX 77381, USA.

Molecular Structure Corporation (1995).TEXSAN.Version 1.7. MSC, 3200 Research Forest Drive, The Woodlands, TX 77381, USA.

MuÈller, A. (1928).Proc. R.Soc. London Ser. A,120, 437±459. Nakamura, N. & Sato, T. (1999a).Acta Cryst.C55, 1685±1687. Nakamura, N. & Sato, T. (1999b).Acta Cryst.C55, 1687±1689. Nakamura, N. & Setodoi, S. (1997).Acta Cryst.C53, 1883±1885. Nakamura, N., Setodoi, S. & Ikeya, T. (1999).Acta Cryst.C55, 789±791. Nakamura, N., Tanihara, Y. & Takayama, T. (1997).Acta Cryst. C53, 253±

255.

Nakamura, N., Uno, K. & Ogawa, Y. (2000) Acta Cryst. C56, 1389± 1370.

Nakamura, N., Uno, K. & Ogawa, Y. (2001).Acta Cryst.C57. In preparation. Nakamura, N., Uno, K., Watanabe, R., Ikeya, T. & Ogawa, Y. (2000).Acta

Cryst.C56, 903±904.

Nakamura, N. & Yamamoto, T. (1994).Acta Cryst.C50, 946±948.

North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968).Acta Cryst.A24, 351± 359.

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Acta Cryst. (2001). E57, o136–o138 [doi:10.1107/S1600536801001052]

Octadecane-1,18-diol

Naotake Nakamura and Ryoji Watanabe

S1. Comment

Crystal structures of long-chain compounds such as n-alkanes (Müller, 1928) and n-higher primary alcohols (e.g.

Watanabe, 1961; Seto, 1962), have been studied by many researchers from the viewpoint of basic polymer science.

According to those results, the compounds have a simple straight hydrocarbon chain as a skeleton and the molecular

shape can be regarded as a rod-like, which is one of the typical features of liquid crystal molecules. In addition, some

long-chain compounds construct a layer structure in the crystal state, which is similar to that of a smectic phase of liquid

crystals. Therefore, these compounds have been studied from a structural point of view as models for smectic liquid

crystals.

We have already reported molecular and crystal structure of α,ω-alkanediols containing from 10 through 17 and 21 C

atoms, these were investigated by Nakamura and co-workers: 1,10-decanediol (Nakamura & Sato, 1999a),

1,11-undecanediol (Nakamura et al., 1999), 1,12-dodecanediol (Nakamura & Setodoi, 1997), 1,13-tridecanediol (Nakamura et

al., 1997), 1,14-tetradecanediol (Nakamura & Sato, 1999b), 1,15-pentadecanediol (Nakamura et al., 2000),

1,16-hexa-decanediol (Nakamura & Yamamoto, 1994), 1,17-hepta1,16-hexa-decanediol (Nakamura et al., 2001) and 1,21-henicosanediol

(Nakamura et al., 2000a). The results showed a clear distinction in the structures between the compounds with an even

number of C atoms and those with an odd number of C atoms. In the α,ω-alkanediols with even number of C atoms, the

hydroxyl groups located at both ends of a hydrocarbon skeleton showed an all-trans conformation with respect to the

skeleton. These molecules were arranged making layers in a herring-bone fashion, just like the chiral smectic C liquid

crystals. On the other hand, in the α,ω-alkanediols with an odd number of C atoms, one hydroxyl group had gauche

conformation with respect to the hydrocarbon skeleton, whereas another hydroxyl group had trans conformation. In this

case, molecules made a layer structure which was very similar to that of the smectic A liquid crystals. In addition, phase

transition of α,ω-alkanediols from C13 through C24 was studied by means of a powder X-ray diffraction method and a

linear relation of the longest axis of lattice constant versus number of C atoms was reported (Ogawa & Nakamura, 1999).

In the crystal structure of 1,18-octadecanediol, (I), shown in Fig. 1, an all-trans conformation was observed not only in

the hydrocarbon skeleton but also in both terminal hydroxyl groups. The molecule is centrosymmetric and forms a layer

structure stacked along c axis. The inclination angle of the long axis of the molecule to the layer plane is equal in each

layer, but the direction of the long axis of the molecule is opposite in alternate layers because of an existence of a twofold

screw axis parallel to b. Such herring-bone structures can be regarded as a model structure of chiral smectic C liquid

crystals. These features are very similar to those of 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol and

1,16-hexadecanediol. Average value of inclination angles of above compounds was about 56° as found in the present structure.

These molecules form interlayer hydrogen bonds, as shown in Fig. 2, with the interlayer hydrogen-bonding distance

O1···O1i _{= 2.843 (2) Å [symmetry code: (i) 3 - x, 0.5 + y, 0.5 - z]. This value is in good agreement these of other α,ω}

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S2. Experimental

According to the conventional method, the title compound, (I), was synthesized from commercially available

octadecane-dioic acid (Tokyo Kasei Kogyo Co. Ltd) by esterification and reduction with LiAlH4. The single-crystal used for analysis

was grown by very slow evaporation from a solution in a mixed solvent system comprising methanol, ethyl acetate and

dimetylbenzene (1:1:3 ratio).

S3. Refinement

All H atoms, including hydroxyl H atoms, were fixed in idealized positions.

Figure 1

An ORTEPII (Johnson, 1976) view of the title molecule showing the crystallographic numbering scheme. Displacement

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Figure 2

The bc-projection of the crystal structure; dotted lines indicate the hydrogen bonds.

(I)

Crystal data

C18H38O2

Mr = 286.50 Monoclinic, P21/c

a = 4.998 (2) Å

b = 5.220 (2) Å

c = 34.853 (2) Å

β = 92.04 (2)°

V = 908.8 (5) Å3

Z = 2

F(000) = 324

Dx = 1.047 Mg m−3

Cu Kα radiation, λ = 1.5418 Å Cell parameters from 24 reflections

θ = 9.3–20.1°

µ = 0.50 mm−1

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Data collection

Rigaku AFC-5R diffractometer

Radiation source: Rigaku rotating anode Graphite monochromator

ω–2θ scans

Absorption correction: ψ scans (North et al., 1968)

Tmin = 0.929, Tmax = 1 2843 measured reflections

1802 independent reflections 991 reflections with I > 2σ(I)

Rint = 0.025

θmax = 70.5°, θmin = 2.5°

h = −2→6

k = 0→5

l = −42→42

3 standard reflections every 150 reflections intensity decay: 2.6%

Refinement

Refinement on F

Least-squares matrix: full

R[F2 _{> 2σ(F}2_{)] = 0.045}

wR(F2_{) = 0.065}

S = 1.67 991 reflections 91 parameters

0 restraints 0 constraints

H-atom parameters not refined

w = 1/[σ2_(F

o) + 0.00053|Fo|2] (Δ/σ)max < 0.001

Δρmax = 0.12 e Å−3 Δρmin = −0.11 e Å−3

Special details

Experimental. none Geometry. none Refinement. None

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2₎

x y z Uiso*/Ueq

O1 1.4119 (3) −0.4953 (3) 0.23943 (4) 0.0802 (5)

C1 1.2271 (4) −0.5358 (4) 0.20834 (5) 0.0599 (6)

C2 1.1288 (4) −0.2830 (4) 0.19336 (5) 0.0540 (5)

C3 0.9330 (4) −0.3089 (4) 0.15912 (5) 0.0517 (5)

C4 0.8304 (4) −0.0540 (4) 0.14358 (5) 0.0514 (5)

C5 0.6396 (4) −0.0809 (4) 0.10891 (5) 0.0513 (5)

C6 0.5365 (4) 0.1724 (4) 0.09318 (5) 0.0500 (5)

C7 0.3465 (4) 0.1468 (4) 0.05827 (5) 0.0500 (5)

C8 0.2426 (4) 0.4007 (4) 0.04263 (5) 0.0501 (5)

C9 0.0519 (4) 0.3726 (4) 0.00781 (5) 0.0496 (6)

H0 1.4782 −0.6526 0.2493 0.0916*

H1a 1.3082 −0.6345 0.1882 0.0799*

H1b 1.0770 −0.6387 0.2167 0.0799*

H2a 1.2796 −0.1823 0.1854 0.0655*

H2b 1.0437 −0.1900 0.2132 0.0655*

H3a 1.0188 −0.3972 0.1390 0.0649*

H3b 0.7832 −0.4075 0.1667 0.0649*

H4a 0.9802 0.0478 0.1364 0.0598*

H4b 0.7398 0.0337 0.1633 0.0598*

H5a 0.7313 −0.1706 0.0889 0.0631*

H5b 0.4911 −0.1860 0.1158 0.0631*

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H6b 0.4449 0.2630 0.1130 0.0601*

H7a 0.4376 0.0570 0.0384 0.0621*

H7b 0.1970 0.0410 0.0652 0.0621*

H8a 0.3905 0.5056 0.0355 0.0607*

H8b 0.1502 0.4899 0.0624 0.0607*

H9a 0.1427 0.2828 −0.0120 0.0594*

H9b −0.0979 0.2686 0.0149 0.0594*

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

O1 0.096 (1) 0.0647 (10) 0.0759 (9) −0.0011 (8) −0.0557 (8) 0.0046 (8)

C1 0.068 (1) 0.056 (1) 0.0534 (10) −0.0013 (10) −0.0282 (9) 0.0024 (9)

C2 0.059 (1) 0.056 (1) 0.0466 (9) 0.0017 (9) −0.0176 (8) −0.0008 (8)

C3 0.054 (1) 0.052 (1) 0.0479 (9) −0.0045 (9) −0.0158 (8) 0.0034 (8)

C4 0.0525 (10) 0.051 (1) 0.0490 (9) −0.0041 (9) −0.0152 (8) 0.0031 (8)

C5 0.054 (1) 0.051 (1) 0.0473 (9) −0.0007 (9) −0.0168 (8) 0.0010 (8)

C6 0.054 (1) 0.048 (1) 0.0471 (10) −0.0008 (8) −0.0163 (8) 0.0002 (8)

C7 0.054 (1) 0.049 (1) 0.0462 (9) −0.0031 (9) −0.0148 (8) 0.0011 (8)

C8 0.053 (1) 0.049 (1) 0.0475 (10) −0.0032 (8) −0.0155 (8) 0.0020 (7)

C9 0.055 (1) 0.049 (1) 0.0442 (10) −0.0019 (8) −0.0159 (8) 0.0026 (7)

Geometric parameters (Å, º)

O1—C1 1.414 (2) C5—C6 1.515 (2)

C1—C2 1.496 (3) C6—C7 1.523 (2)

C2—C3 1.522 (2) C7—C8 1.518 (3)

C3—C4 1.519 (2) C8—C9 1.523 (2)

C4—C5 1.519 (2) C9—C9i _{1.521 (4)}

O1···O1ii _{2.843 (2) O1···C1}ii _{3.477 (2)}

O1···O1iii _{2.843 (2) O1···C2}iii _{3.554 (2)}

O1—C1—C2 109.4 (1) C5—C6—C7 114.0 (1)

C1—C2—C3 112.9 (2) C6—C7—C8 114.0 (2)

C2—C3—C4 113.7 (2) C7—C8—C9 113.5 (1)

C3—C4—C5 113.4 (1) C8—C9—C9i _{113.4 (2)}

C4—C5—C6 113.8 (2)