2,5-Di-2-thienylthiazolo[4,5-d]-thiazole

Article abstract of DOI:10.1107/S0108270103001069

The molecules of the title compound, C₁₂H₆N₂S₄, lie on centres of symmetry. The thiophene and thiazole rings are almost planar and their planes make a dihedral angle of 1.68 (8)°. In the crystal structure, there is a relatively short intermolecular S...S contact distance of 3.5786 (9) A.

Full text of DOI:10.1107/S0108270103001069

organic compounds
Acta Crystallographica Section C
Crystal Structure
The molecule of (I) lies on the centre of symmetry in the
space group P2 /n. Crystals of all three thiazolo[4,5-d]thia-
1
Communications
zoles found in the CSD belong to crystal class C2h and contain
two molecules per unit cell. All of these molecules lie on
centres of symmetry in their crystals (Bossio et al., 1987;
Bolognesi et al., 1987).
ISSN 0108-2701
2
,5-Di-2-thienylthiazolo[4,5-d]-
Both symmetry-independent rings in (I) are almost planar
Ê
the maximum deviation is 0.0044 (8) A for the thiophene ring
[
thiazole
Ê
and 0.0008 (7) A for the thiazole ring], and the dihedral angle
ꢀ
between the least-squares planes of these rings is 1.68 (8) .
a
b
Paweø Wagner ² and Maciej Kubicki *
The bond lengths and angles (Table 1) in the thiazole ring are
similar to those found in thiazolo[5,4-d]thiazole (Bolognesi et
al., 1987). The asymmetry of the SÐC bond lengths observed
in the thiazole ring in (I) is also observed in other thiazole
derivatives, especially in cases where there is another ring
a
Institute of Organic Chemistry and Technology, Silesian University of Technology,
b
Krzywoustego 4, 44-100 Gliwice, Poland, and Department of Chemistry, Adam
Mickiewicz University, Grunwaldzka 6, 60-780 Pozna n , Poland
Correspondence e-mail: mkubicki@amu.edu.pl
0
0
condensed at the C4 C5 double bond. The S1 ÐC2 bond
Received 3 December 2002
Accepted 10 January 2003
Online 31 January 2003
Ê
length of 1.7605 (14) A is typical of a single SÐC bond, while
0
0
the S1 ÐC4 (1 � x, 1 � y, � z) bond has considerable double-
bond character and may therefore be involved in resonance
(cf. Smith, 1969; Ekstrand & van der Helm, 1977; Bolognesi et
al., 1987).
The molecules of the title compound, C H N S , lie on
2 4
1
2
6
centres of symmetry. The thiophene and thiazole rings are
almost planar and their planes make a dihedral angle of
In the crystal structure of (I), relatively short intermolecular
0
ꢀ
0
Ê
1
.68 (8) . In the crystal structure, there is a relatively short
S1 Á Á ÁS1 (� x, 1 � y, � z) contacts [3.5786 (9) A] are observed
intermolecular SÁ Á ÁS contact distance of 3.5786 (9) AÊ .
and these link the molecules into in®nite chains along the
[100] direction. The angle between a vector connecting the S
atoms and a normal to the plane of the thiazole ring is
35.8 (2) . Such short contacts are quite common in divalent
sulfur compounds. However, they are less frequently observed
ꢀ
Comment
The strong need for new ecological energy sources has
resulted in a growing interest in new organic semiconducting
materials, for example, those based on thiophene derivatives
(for a review, see Nalva, 1997). Electrical conductivity and the
band-gap (E ) are strongly dependent on some structural
in thiazole derivatives. For all divalent sulfur compounds,
Ê
intermolecular SÁ Á ÁS contacts shorter than 3.6 A are observed
g
parameters, including the geometry of a monomer molecule.
Therefore, a detailed knowledge of the geometrical para-
meters (such as the planarity of the molecules, their mutual
arrangenment, and any intra- and intermolecular interactions)
and electronic properties (e.g. the charge±density distribution)
is crucial for the rational design of new materials. We
performed an X-ray structural analysis of 2,5-di-2-thienyl-
thiazolo[4,5-d]thiazole, (I) (Fig. 1), a simple model compound
that could be used in electro-optically active materials. The
X-ray data could then be used as the starting model for semi-
empirical or ab initio calculations in molecular engineering.
There is a surprisingly small number of similar compounds
in the Cambridge Structural Database (CSD; Allen, 2002); in
the May 2002 release, we found only three thiazolo[4,5-d]-
thiazoles and just one compound containing the thieno±thia-
zole moiety. These ®ndings further emphasize the need for
more detailed structural data.
Figure 1
View (Siemens, 1989) of the chain of molecules of (I) connected by SÁ Á ÁS
contacts (dashed lines), showing the atomic numbering. Displacement
ellipsoids are drawn at the 50% probability level and H atoms are
depicted as spheres of arbitrary radii. [Symmetry codes: (i) 1 � x, 1 � y,
� z; (ii) � 1 + x, y, z; (iii) � x, 1 � y, � z.]
² Present address: Nanomaterial Research Centre, Massey University, Private
Bag 11 222, Palmerston North, New Zealand.
Acta Cryst. (2003). C59, o91±o92
DOI: 10.1107/S0108270103001069
# 2003 International Union of Crystallography o91

organic compounds
Ê
Ê
in 11.4% of cases, contacts shorter than 3.65 A are observed in
1
1
Table 1
Selected geometric parameters (A, ).
Ê
ꢀ
3.4% of cases and contacts shorter than 3.7 A are observed in
6.4% of cases. For compounds with sulfur in a cyclic envir-
0
0
0
0
i
S1ÐC5
S1ÐC2
1.7187 (15)
1.7287 (14)
S1 ÐC4
S1 ÐC2
1.7324 (14)
1.7605 (14)
onment, these values are even higher, the respective values
being 12.2, 15.3 and 18.3%. For thiazole derivatives, the
fraction of compounds possessing short SÁ Á ÁS contacts is much
0
0
0
C5ÐS1ÐC2
91.70 (7)
88.38 (7)
C2 ÐN3 ÐC4
108.40 (12)
0
i
C4 ÐS1 ÐC2
0
0
Ê
Ê
smaller, viz. 4.2% for a 3.6 A separation, 5.9% for a 3.65 A
Ê
separation and 8.2% for a 3.7 A separation. Such short
Symmetry code: (i) 1 � x; 1 � y; � z.
contacts are not found in any of the three thiazolo[4,5-d]-
thiazole derivatives for which the crystal structures have been
reported.
The crystal packing is determined by the partial overlap of
planar molecules (the distance between the mean planes of
Ê
two molecules related by the center of symmetry is ca 3.6 A)
and, to some extent, by SÁ Á ÁS contacts and weak CÐHÁ Á ÁS
interactions (cf. Table 2).
Table 2
Hydrogen-bonding geometry (A, ).
Ê
ꢀ
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
ii
C3ÐH3Á Á ÁS1
C4ÐH4Á Á ÁS1
C4ÐH4Á Á ÁS1
C5ÐH5Á Á ÁS1
0.94 (2)
0.97 (2)
0.97 (2)
0.94 (2)
3.14 (2)
3.15 (2)
3.18 (2)
3.10 (2)
3.7298 (17)
3.8523 (17)
4.0704 (17)
3.9434 (17)
122.9 (15)
130.7 (15)
153.4 (16)
148.9 (16)
0
iii
iv
v
1
1
1
Symmetry codes: (ii) x � 1; y; z; (iii) � x; � y; � z; (iv) � x; y � 2; � z; (v)
2
2
3
2
1 1
2 2
Experimental
� x; y � ; � z.
The title compound was synthesized according to the procedure of
Thomas (1970) by condensation of dithiooxodiamide with 2-formyl-
thiophene. Colourless prismatic crystals were grown from a methanol
solution by slow evaporation.
Data collection: CrysAlisCCD (Kuma, 1999); cell re®nement:
CrysAlisCCD; data reduction: CrysAlisRed (Kuma, 1999);
program(s) used to solve structure: SHELXS97 (Sheldrick, 1997);
program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997);
molecular graphics: Stereochemical Workstation Operation Manual
Crystal data
�
3
C
12 6
H N
S
2 4
D
x
= 1.655 Mg m
(
Siemens, 1989).
M
Monoclinic, P2
r
= 306.47
Mo Kꢁ radiation
1
/n
Cell parameters from 4325
re¯ections
Ê
a = 6.0040 (12) A
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: AV1128). Services for accessing these data are
described at the back of the journal.
Ê
b = 8.3580 (17) A
ꢀ
ꢂ = 4±22
Ê
c = 12.270 (3) A
� 1
ꢃ = 0.75 mm
T = 100 (1) K
ꢀ
ꢀ
= 92.72 (3)
Ê
3
V = 615.0 (2) A
Z = 2
Prism, yellow
0.3 Â 0.2 Â 0.2 mm
References
Data collection
Allen, F. H. (2002). Acta Cryst. B58, 380±388.
Bolognesi, A., Catellani, M., Destri, S. & Porzio, W. (1987). Acta Cryst. C43,
Kuma KM-4 CCD four-circle
diffractometer
Rint = 0.024
ꢀ
ꢂ
max = 29.0
2106±2108.
!
scans
h = � 8 ! 6
Bossio, R., Marcaccini, S., Pepino, R., Torroba, T. & Valle, G. (1987). Synthesis,
pp. 1138±1139.
Ekstrand, J. D. & van der Helm, D. (1977). Acta Cryst. B33, 1012±1016.
Kuma (1999). CrysAlisCCD (Version 168) and CrysAlisRed. Kuma Diffrac-
tion, Wrocøaw, Poland.
Nalva, H. S. (1997). Handbook of Organic Conductive Molecules and
Polymers, Vols. 1±4. Chichester: Wiley and Sons.
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of
G oÈ ttingen, Germany.
5
1
1
376 measured re¯ections
574 independent re¯ections
475 re¯ections with I > 2ꢄ(I)
k = � 11 ! 11
l = � 16 ! 13
Re®nement
2
2
2
2
Re®nement on F
2
o
w = 1/[ꢄ (F ) + (0.0305P)
2
R[F > 2ꢄ(F )] = 0.028
wR(F ) = 0.068
S = 1.10
+ 0.3939P]
where P = (F
(Á/ꢄ)max < 0.001
Áꢅmax = 0.37 e A
Áꢅmin = � 0.29 e AÊ
2
2
2
c
o
+ 2F
)/3
Siemens (1989). Stereochemical Workstation Operation Manual. Release 3.4.
Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.
Smith, D. L. (1969). Acta Cryst. B25, 625±632.
Ê
� 3
1
9
574 re¯ections
4 parameters
� 3
All H-atom parameters re®ned
Thomas, D. A. (1970). J. Heterocycl. Chem. 7, 457±462.
ꢁ
o92 Wagner and Kubicki
C H N
12 6 2
S
4
Acta Cryst. (2003). C59, o91±o92