Acta Cryst.(2001). E57, o505±o507 DOI: 101107/S1600536801007188 Nakamura, Uno and Ogawa C20H42S2
o505
organic papers
Acta Crystallographica Section E Structure Reports Online
ISSN 1600-5368
Icosane-1,20-dithiol
Naotake Nakamura,a* Kenjiro Unoaand Yoshihiro Ogawab
aDepartment of Applied Chemistry, Faculty of
Science and Engineering, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga 525-8577, Japan, andbDepartment of Chemistry, Faculty of Science, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555, Japan
Correspondence e-mail: [email protected]
Key indicators
Single-crystal X-ray study
T= 296 K
Mean(C±C) = 0.003 AÊ
Rfactor = 0.057
wRfactor = 0.159
Data-to-parameter ratio = 19.1
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
In the molecular structure of the title compound, C20H42S2,
(I), the skeleton of the hydrocarbon has an all-trans
conformation. The terminal SÐH bond is in a gauche
conformation with respect to the skeleton. In the crystal structure, the molecules are arranged along the c axis, the longest axis, forming layers in which the long axis of the molecule is inclined to the layer plane. This packing is very similar to that of the smectic C structure of liquid crystals. Except for the length of the c axis, no big difference was observed between the crystal data obtained here and those of homologues with even numbers of C atoms already reported.
Comment
As is well known, the mercapto group plays an important role in maintaining the structure of a protein or hormone, for example, making a disul®de bond in a living body.
,!-dithiols have the mercapto groups at both ends of the hydrocarbon skeleton, and the melting-point alternation in alkane-,!-dithiols containing less than 10 C atoms was investigated (Thalladi et al., 2000). In the study, the crystal structures of nine members of the alkane-,!-dithiol family were analyzed by single-crystal X-ray diffraction. Alkane-,! -dithiols containing more than four C atoms haveP1 as a space
group for an even number of C atoms and P2/c for an odd
number of C atoms. Crystallographic data for alkane-,! -di-thiols containing more than 11 C atoms have not yet been reported to our knowledge. In this paper, the crystal structure of icosane-1,20-dithiol, (I), is reported.
Fig. 1 shows the molecular structure of (I). The skeleton of the hydrocarbon has an all-transconformation. The molecule is centrosymmetric. The CÐC distances are in the range 1.509 (3)±1.518 (3) AÊ and the CÐCÐC angles are in the range 112.8 (2)±114.6 (2). The terminal S1ÐH1sbond has agauche
conformation with respect to the skeleton [C2ÐC1ÐS1ÐH1s
torsion angle 67 (1)]. This is one of the characteristic points in
this compound, because no such conformation has been observed in alkane-,!-diols. In the crystal structure of (I), the
molecules are arranged along the c axis forming layers in
which the long axis of the molecule is inclined to the layer plane, as is shown in Fig. 2. This packing is very similar to that of the smectic C structure of liquid crystals. The interlayer S1 S1 distance is 3.551 (1) AÊ. This value is too long to make
a hydrogen bond. Except for the length of the c axis, the
organic papers
o506
Nakamura, Uno and Ogawa C20H42S2 Acta Cryst.(2001). E57, o505±o507longest axis, no major difference was observed between the crystal data obtained here and those of homologues with an even number of C atoms already reported by Thalladiet al.
(2000).
The molecular and crystal structures of ten alkane-,!-diols containing 10±18 and 21 C atoms have been analyzed by single-crystal X-ray diffraction. The structural differences between the compounds with an even number of C atoms and those with an odd number of C atoms were determined and were studied from a structural point of view as a model of polymers and/or smectic liquid crystals by Nakamura and his co-workers. In the alkane-,!-diols with an even number of C atoms, the hydroxyl groups located at both ends of the
hydrocarbon skeleton showed a trans conformation. As a
result, the molecule is constructed by an all-trans conforma-tion. In this case, these molecules form layers in a herring-bone fashion, just like the chiral smectic C of liquid crystals (Nakamura & Sato, 1999a,b; Nakamura & Setodoi, 1997; Nakamura & Yamamoto, 1994; Nakamura & Watanabe, 2001). On the other hand, for the alkane-,!-diols with an odd
number of C atoms, one hydroxyl group had a gauche
conformation with respect to the all-trans hydrocarbon
skeleton, whereas the other hydroxyl group had a trans
conformation. The molecules formed a layer structure which was very similar to that of the smectic A in liquid crystals (Nakamuraet al., 1997, 1999, 2001; Nakamura, Uno, Watanabe
et al., 2000; Nakamura, Uno & Ogawa, 2000).
Consequently, alkane-,!-diols with an even number of C atoms, those with an odd number of C atoms, and alkane-,! -dithiols with an even number of C atoms could be regarded as model compounds for chiral smectic C, smectic A and smectic C liquid crystals, respectively.
Figure 2
The projection of the crystal structure of (I) along theaaxis.
Figure 1
Experimental
Icosane-1,20-dioic acid (Tokyo Kasei Co.) was converted to its methyl ester, which was further reduced to the alcohol with LiAlH4. The
alcohol was heated with aqueous 48% hydrobromic acid and converted to the corresponding bromide. Icosane-1,20-dithiol was synthesized from the bromide according to reported procedures (Urquhartet al., 1955). The single crystal used for analysis was grown by slow evaporation from a solution containing a mixture of toluene and ethanol (1:3).
Crystal data
C20H42S2 Mr= 346.67
Triclinic,P1
a= 4.2261 (6) AÊ
b= 5.4283 (6) AÊ
c= 23.819 (3) AÊ
= 87.43 (1)
= 86.56 (1)
= 83.37 (1) V= 541.4 (1) AÊ3
Z= 1
Dx= 1.063 Mg mÿ3
CuKradiation Cell parameters from 24
re¯ections
= 9.8±17.5
= 2.17 mmÿ1 T= 296.2 K Plate, colorless 0.700.150.01 mm
Data collection
Rigaku AFC-5Rdiffractometer
!scans
Absorption correction: scan (Northet al., 1968)
Tmin= 0.767,Tmax= 0.996
3008 measured re¯ections 1967 independent re¯ections 1453 re¯ections withF2> 2(F2)
Rint= 0.045 max= 70.5 h=ÿ4!5
k=ÿ6!2
l=ÿ29!29 2 standard re¯ections
every 150 re¯ections intensity decay: 11.8%
Re®nement
Re®nement onF2 R[F2> 2(F2)] = 0.057 wR(F2) = 0.159 S= 1.77 1966 re¯ections 103 parameters
H atoms treated by a mixture of independent and constrained re®nement
w= 1/[2(F
o2) + {0.05[Max(Fo2,0) +
2Fc2]/3}2]
(/)max= 0.001
max= 0.15 e AÊÿ3
min=ÿ0.35 e AÊÿ3
The methylene H atoms were located at idealized positions and were allowed to ride on the parent C atoms. The mercapto H atom was located on difference syntheses and the positional parameters were allowed to re®ne for the ®nal re®nements. All H-atom isotropic displacement parameters were set to be 1.2Ueqof the parent atom.
Data collection: MSC/AFC Diffractometer Control Software
(Molecular Structure Corporation, 1992); cell re®nement:MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Mole-cular Structure Corporation, 2000); program(s) used to solve struc-ture:MULTAN88 (Debaerdemaekeret al., 1988); program(s) used to re®ne structure: TEXSAN; software used to prepare material for publication:TEXSAN.
References
Debaerdemaeker, T., Germain, G., Main, P., Refaat, L. S., Tate, C. & Woolfson, M. M. (1988).MULTAN88. Universities of York, England, and Louvain, Belgium.
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 (2000).TEXSAN.Version 1.11. MSC, 9009 New Trails Drive, The Woodlands, TX 77381±5209, USA.
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±1390. Nakamura, N., Uno, K. & Ogawa, Y. (2001).Acta Cryst.C57, 585±586. Nakamura, N., Uno, K., Watanabe, R., Ikeya, T. & Ogawa, Y. (2000).Acta
Cryst.C56, 903±904.
Nakamura, N. & Watanabe, R. (2001).Acta Cryst.E57, o136-138. 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.
Thalladi, V. R., Boese, R. & Weiss, H. C. (2000).J. Am. Chem. Soc.122, 1186± 1190.
Urquhart, G. G., Gates, J. W. & Connor, R. (1955).Org. Synth.III, pp. 363±365.
supporting information
sup-1 Acta Cryst. (2001). E57, o505–o507
supporting information
Acta Cryst. (2001). E57, o505–o507 [https://doi.org/10.1107/S1600536801007188]
Icosane-1,20-dithiol
Naotake Nakamura, Kenjiro Uno and Yoshihiro Ogawa
(I)
Crystal data C20H42S2 Mr = 346.67 Triclinic, P1 a = 4.2261 (6) Å b = 5.4283 (6) Å c = 23.819 (3) Å α = 87.43 (1)° β = 86.56 (1)° γ = 83.37 (1)° V = 541.4 (1) Å3
Z = 1
Dx = 1.063 Mg m−3
Cu Kα radiation, λ = 1.5418 Å Cell parameters from 24 reflections θ = 9.8–17.5°
µ = 2.17 mm−1 T = 296 K Plate, colorless 0.7 × 0.15 × 0.01 mm
Data collection Rigaku AFC-5R
diffractometer ω scans
Absorption correction: ψ (North et al., 1968) Tmin = 0.767, Tmax = 0.996 3008 measured reflections 1967 independent reflections
1453 reflections with F2 > 2σ(F2) Rint = 0.045
θmax = 70.5° h = −4→5 k = −6→2 l = −29→29
2 standard reflections every 150 reflections intensity decay: 11.8%
Refinement Refinement on F2 R[F2 > 2σ(F2)] = 0.057 wR(F2) = 0.159 S = 1.77 1966 reflections 103 parameters
H atoms treated by a mixture of independent and constrained refinement
w = 1/[σ2(Fo2) + {0.05[Max(Fo2,0) + 2Fc2]/3}2] (Δ/σ)max = 0.001
Δρmax = 0.15 e Å−3 Δρmin = −0.35 e Å−3
Special details
Geometry. none
Refinement. Refinement using reflections with F2 > -3.0 σ(F2). The weighted R-factor (wR) and goodness of fit (S) are based on F2. R-factor (gt) are based on F. The threshold expression of F2 > 2.0 σ(F2) is used only for calculating R-factor (gt).
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
x y z Uiso*/Ueq
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sup-2 Acta Cryst. (2001). E57, o505–o507
C1 1.1699 (6) 0.0041 (5) 0.08170 (10) 0.0626 (7) C2 1.0508 (6) −0.0239 (5) 0.14241 (9) 0.0563 (7) C3 0.9202 (6) 0.2219 (4) 0.16753 (9) 0.0534 (6) C4 0.7989 (6) 0.1982 (4) 0.22849 (9) 0.0546 (7) C5 0.6752 (6) 0.4440 (4) 0.25398 (9) 0.0530 (6) C6 0.5533 (6) 0.4242 (4) 0.31487 (9) 0.0531 (6) C7 0.4287 (6) 0.6702 (4) 0.34032 (9) 0.0524 (6) C8 0.3073 (6) 0.6504 (4) 0.40118 (9) 0.0520 (6) C9 0.1840 (6) 0.8966 (4) 0.42645 (9) 0.0523 (6) C10 0.0616 (6) 0.8770 (4) 0.48742 (9) 0.0519 (6) H1a 1.3258 0.1176 0.0796 0.0752* H1b 0.9946 0.0700 0.0604 0.0752* H1s 1.122 (8) −0.393 (6) 0.050 (1) 0.0942* H2a 0.8860 −0.1296 0.1445 0.0675* H2b 1.2226 −0.0971 0.1637 0.0675* H3a 1.0856 0.3272 0.1653 0.0641* H3b 0.7490 0.2948 0.1460 0.0641* H4a 0.6305 0.0959 0.2306 0.0655* H4b 0.9689 0.1220 0.2498 0.0655* H5a 0.8440 0.5462 0.2517 0.0636* H5b 0.5054 0.5199 0.2325 0.0636* H6a 0.3849 0.3218 0.3172 0.0638* H6b 0.7232 0.3488 0.3363 0.0638* H7a 0.5970 0.7728 0.3379 0.0630* H7b 0.2586 0.7455 0.3189 0.0630* H8a 0.1386 0.5483 0.4036 0.0624* H8b 0.4772 0.5748 0.4226 0.0624* H9a 0.3529 0.9986 0.4241 0.0628* H9b 0.0144 0.9724 0.4049 0.0628* H10a −0.1111 0.7787 0.4905 0.0624* H10b 0.2284 0.8018 0.5097 0.0624*
Atomic displacement parameters (Å2)
U11 U22 U33 U12 U13 U23
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sup-3 Acta Cryst. (2001). E57, o505–o507
Geometric parameters (Å, º)
S1—C1 1.806 (3) C6—C7 1.516 (3) C1—C2 1.509 (3) C7—C8 1.512 (3) C2—C3 1.518 (3) C8—C9 1.514 (3) C3—C4 1.515 (3) C9—C10 1.515 (3) C4—C5 1.515 (3) C10—C10i 1.512 (4) C5—C6 1.513 (3)
S1—C1—C2 114.8 (2) C5—C6—C7 114.6 (2) C1—C2—C3 112.8 (2) C6—C7—C8 114.6 (2) C2—C3—C4 113.8 (2) C7—C8—C9 114.4 (2) C3—C4—C5 113.8 (2) C8—C9—C10 114.4 (2) C4—C5—C6 114.6 (2) C9—C10—C10i 114.3 (2)
C2—C1—S1—H1s 67 (1)
