organic papers
o1202
Muhammed S. Kahnet al. C16H20N2SSi2 DOI: 10.1107/S1600536802017993 Acta Cryst.(2002). E58, o1202±o1203 Acta Crystallographica Section EStructure Reports Online
ISSN 1600-5368
4,7-Bis(trimethylsilylethynyl)-2,1,3-benzothiadiazole
Muhammad S. Khan,aBirte Ahrens,bMary F. Mahon,bLouise Maleb* and Paul R. Raithbyb
aDepartment of Chemistry, College of Science,
Sultan Qaboos University, PO Box 36, Al Khod 123, Sultanate of Oman, andbDepartment of
Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, England
Correspondence e-mail: chplm@bath.ac.uk
Key indicators
Single-crystal X-ray study T= 170 K
Mean(C±C) = 0.003 AÊ Disorder in main residue Rfactor = 0.045 wRfactor = 0.116
Data-to-parameter ratio = 13.6
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 title compound, C16H20N2SSi2 is a rigid-rod protected
dialkyne. It is used as a model species for platinum-containing compounds of which it is a precursor. Such compounds are of interest due to the extended-conjugation exhibited through the heteroaromatic linker unit in the backbone. The molecule is pseudo-linear, with a planar central benzothiadiazole group.
Comment
In this paper, we report the structural characterization of the title compound, (I), which is a TMS-protected rigid-rod dialkyne and a precursor of the platinum(II) di-yne species
trans-[(Et3P)2(Ph)PtÐC CÐRÐC CÐPt(Ph)(Et3P)2] (R
= 2,1,3-benzothiadiazole-4,7-diyl; Kahnet al., 2002). This type of platinum-containing species forms the building block for a rigid-rod organometallic polymer of general formula trans -[(Et2)PtÐC CÐRÐC CÐ]1 (R = aromatic or
hetero-aromatic linker unit). Such poly-ynes are of interest due to the extended-conjugation exhibited along the backbone and the resulting optical emission properties (Wittmannet al., 1994; Beljonne et al., 1996; Younus et al., 1998; Chawdhury et al., 1998, 1999; Wilson et al., 2000, 2001, 2002). The various precursors to these species are studied as models of the molecular and electronic properties and structure±property relationships in the polymers.
The central benzothiadiazole ring system of the molecule is planar and the backbone is pseudo-linear. It is assumed that close intermolecular interactions in the structure are prevented by the bulk of the trimethylsilyl groups. The mol-ecules stack along thebaxis, with a distance of 5.7385 (6) AÊ between adjacent moieties.
Experimental
4,7-Bis(trimethylsilylethynyl)-2,1,3-benzothiadiazole was synthesized by the following procedure. Catalytic amounts of CuI (10 mg, 0.05 mmol), Pd(OAc2) (10 mg, 0.04 mmol) and PPh3 (30 mg,
0.11 mmol) were added to a solution of 4,7-dibromo-2,1,3-benzo-thiadiazole (1.52 g, 5.17 mmol) in NHiPr
2/THF (50 ml, 1:4v/v) under
nitrogen. The solution was stirred for 30 min at room temperature and then trimethylsilylethyne (1.27 g, 12.93 mmol) was added at room temperature to the vigorously stirred solution; during the addition, a white precipitate formed. The reaction mixture was stirred at re¯ux for 2 h and the completion of the reaction was determined by silica
thin-layer chromatography and IR spectroscopy. After cooling to room temperature, the mixture was ®ltered to eliminate the ammo-nium salt and the solvent mixture was removed under vacuum. The residue was then puri®ed by silica-column chromatography, eluting with hexane/CH2Cl2(1:2v/v), to yield a light-yellow solid,i.e. the
target compound, in 78% yield (1.32 g).
Crystal data
C16H20N2SSi2
Mr= 328.58 Monoclinic,P21=n
a= 17.623 (3) AÊ b= 5.7385 (6) AÊ c= 20.089 (4) AÊ
= 112.061 (2)
V= 1882.9 (5) AÊ3
Z= 4
Dx= 1.159 Mg mÿ3 MoKradiation Cell parameters from 9092
re¯ections
= 2.9±25.0 = 0.30 mmÿ1
T= 170 (2) K Plate, pale yellow 0.230.180.09 mm
Data collection
Nonius KappaCCD diffractometer
'and!scans
5933 measured re¯ections 3293 independent re¯ections 2565 re¯ections withI> 2(I)
Rint= 0.026
max= 25.1
h=ÿ20!20 k=ÿ5!6 l=ÿ23!22
Re®nement
Re®nement onF2
R[F2> 2(F2)] = 0.045
wR(F2) = 0.116
S= 1.03 3293 re¯ections 243 parameters
H-atom parameters constrained
w= 1/[2(F
o2) + (0.0503P)2 + 0.8463P]
whereP= (Fo2+ 2Fc2)/3 (/)max< 0.001
max= 0.22 e AÊÿ3 min=ÿ0.31 e AÊÿ3
Table 1
Selected geometric parameters (AÊ,).
S1ÐN2 1.6141 (19)
S1ÐN1 1.6169 (19)
N1ÐC11 1.348 (3)
N2ÐC10 1.344 (3)
Si2ÐC13 1.842 (2)
Si1ÐC4 1.832 (10)
C4ÐC5 1.219 (19)
C5ÐC6 1.460 (18)
Si10ÐC40 1.855 (14)
C40ÐC50 1.17 (3)
C50ÐC6 1.42 (3)
C6ÐC7 1.369 (3)
C6ÐC11 1.428 (3)
C7ÐC8 1.413 (3)
C8ÐC9 1.371 (3)
C9ÐC10 1.428 (3)
C9ÐC12 1.440 (3)
C10ÐC11 1.432 (3)
C12ÐC13 1.203 (3)
N2ÐS1ÐN1 101.28 (9)
C5ÐC4ÐSi1 178.0 (7)
C4ÐC5ÐC6 176.7 (9)
C50ÐC40ÐSi10 169.4 (12)
C40ÐC50ÐC6 172.8 (16)
C13ÐC12ÐC9 175.4 (3)
C12ÐC13ÐSi2 175.4 (2)
N2ÐS1ÐN1ÐC11 0.35 (16)
N1ÐS1ÐN2ÐC10 ÿ0.16 (16)
C6ÐC7ÐC8ÐC9 0.7 (5)
C8ÐC9ÐC10ÐN2 ÿ177.7 (2)
C7ÐC6ÐC11ÐN1 177.6 (2)
Aromatic and methyl H atoms were constrained as riding atoms ®xed to their parent atoms at distances of 0.95 and 0.98 AÊ, respec-tively. The isotropic displacement parameters were ®xed to 1.2Ueqof
that of the parent atom for aromatic and 1.5Ueqfor methyl H atoms.
Atoms C1ÐC5 and Si1 are disordered over two sites with occu-pancies of 60% and 40%, respectively.
Data collection:COLLECT(Nonius, 1997); cell re®nement:HKL SCALEPACK(Otwinowski & Minor, 1997); data reduction: HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to re®ne structure:SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); soft-ware used to prepare material for publication: WinGX (Farrugia, 1999).
We thank the Cambridge Crystallographic Data Centre for funding.
References
Beljonne, D., Wittmann, H. F., KoÈhler, A., Graham, S., Younus, M., Lewis, J., Raithby, P. R., Kahn, M. S., Friend, R. H. & Bredas, J. L. (1996).J. Chem. Phys.105, 3868±3877.
Chawdhury, N., KoÈhler, A., Friend, R. H., Younus, M., Long, N. J., Raithby, P. R. & Lewis, J. (1998).Macromolecules,31, 722±727.
Chawdhury, N., KoÈhler, A., Friend, R. H., Wong, W.-Y., Younus, M., Raithby, P. R., Lewis, J., Corcoran, T. C., Al-Mandhary, M. R. A. & Kahn, M. S. (1999). J. Chem. Phys.110, 4963±4970.
Farrugia, L. J. (1997).J. Appl. Cryst.30, 565. Farrugia, L. J. (1999).J. Appl. Cryst.32, 837±838.
Kahn, M. S., Al-Suti, M. K., Al-Mandhary, M. R. A., Ahrens, B., Bjernemose, J. K., Mahon, M. F., Male, L., Raithby, P. R., Friend, R. H., KoÈhler, A. & Wilson, J. S. (2002). Unpublished results.
Nonius (1997).COLLECT. Nonius BV, Delft, The Netherlands.
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr and R. M. Sweet, pp. 307±326. New York: Academic Press.
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of GoÈttingen, Germany.
Wilson, J. S., KoÈhler, A., Friend, R. H., Al-Suti, M. K., Al-Mandhary, M. R. A., Kahn, M. S. & Raithby, P. R. (2000).J. Chem. Phys.113, 7627±7634. Wilson, J. S., Chawdhury, N., KoÈhler, A., Friend, R. H., Al-Mandhary, M. R. A.,
Kahn, M. S., Younus, M. & Raithby, P. R. (2001).J. Am. Chem. Soc.123, 9412±9417.
Wilson, J. S., Dhoot, A. S., Seeley, A. J. A. B., Kahn, M. S., KoÈhler, A. & Friend, R. H. (2002).Nature (London),413, 828±831.
Wittmann, H. F., Friend, R. H., Kahn, M. S. & Lewis, J. (1994).J. Chem. Phys. 101, 2693±2698.
Younus, M., KoÈhler, A., Cron, S., Chawdhury, N., Al-Mandhary, M. R. A., Kahn, M. S., Lewis, J., Long, N. J., Friend, R. H. & Raithby, P. R. (1998). Angew. Chem. Int. Ed.37, 3036±3039.
Figure 1
supporting information
sup-1 Acta Cryst. (2002). E58, o1202–o1203
supporting information
Acta Cryst. (2002). E58, o1202–o1203 [https://doi.org/10.1107/S1600536802017993]
4,7-Bis(trimethylsilylethynyl)-2,1,3-benzothiadiazole
Muhammad S. Khan, Birte Ahrens, Mary F. Mahon, Louise Male and Paul R. Raithby
(I)
Crystal data C16H20N2SSi2
Mr = 328.58 Monoclinic, P21/n
a = 17.623 (3) Å b = 5.7385 (6) Å c = 20.089 (4) Å β = 112.061 (2)° V = 1882.9 (5) Å3
Z = 4
F(000) = 696 Dx = 1.159 Mg m−3
Mo Kα radiation, λ = 0.71073 Å Cell parameters from 9092 reflections θ = 2.9–25.0°
µ = 0.30 mm−1
T = 170 K Plate, pale yellow 0.23 × 0.18 × 0.09 mm
Data collection Nonius KappaCCD
diffractometer 116 1.9° images scans 5933 measured reflections 3293 independent reflections 2565 reflections with I > 2σ(I)
Rint = 0.026
θmax = 25.1°, θmin = 3.7°
h = −20→20 k = −5→6 l = −23→22
Refinement Refinement on F2
Least-squares matrix: full R[F2 > 2σ(F2)] = 0.045
wR(F2) = 0.116
S = 1.03 3293 reflections 243 parameters
153 restraints
H-atom parameters constrained w = 1/[σ2(F
o2) + (0.0503P)2 + 0.8463P]
where P = (Fo2 + 2Fc2)/3
(Δ/σ)max < 0.001
Δρmax = 0.22 e Å−3
Δρmin = −0.31 e Å−3
Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
x y z Uiso*/Ueq Occ. (<1)
Si2 0.18511 (4) −0.59538 (11) 0.08332 (3) 0.0467 (2)
Si1 0.43559 (8) 0.4803 (2) −0.29240 (6) 0.0449 (3) 0.6 C1 0.5337 (4) 0.6211 (17) −0.2390 (4) 0.114 (4) 0.6
H1A 0.5239 0.7489 −0.2109 0.171* 0.6
H1B 0.559 0.6829 −0.2713 0.171* 0.6
H1C 0.5704 0.5065 −0.2065 0.171* 0.6
C2 0.3562 (3) 0.6993 (6) −0.3370 (2) 0.0504 (10) 0.6
H2A 0.3029 0.622 −0.3587 0.076* 0.6
H2B 0.3695 0.7787 −0.3744 0.076* 0.6
H2C 0.3539 0.8135 −0.3015 0.076* 0.6
C3 0.44912 (19) 0.2761 (5) −0.36059 (16) 0.0712 (8) 0.6
H3A 0.49 0.1575 −0.3359 0.107* 0.6
H3B 0.4675 0.3644 −0.3935 0.107* 0.6
H3C 0.3968 0.2002 −0.3878 0.107* 0.6
C4 0.4032 (4) 0.3100 (13) −0.2306 (5) 0.0431 (16) 0.6 C5 0.3837 (7) 0.192 (3) −0.1890 (9) 0.037 (2) 0.6 Si1′ 0.48653 (14) 0.3881 (3) −0.26928 (11) 0.0530 (5) 0.4 C1′ 0.4755 (12) 0.7007 (18) −0.2668 (9) 0.165 (7) 0.4
H1D 0.4921 0.7522 −0.2168 0.248* 0.4
H1E 0.4181 0.7435 −0.2934 0.248* 0.4
H1F 0.5101 0.7761 −0.2888 0.248* 0.4
C2′ 0.5949 (4) 0.3016 (17) −0.2229 (4) 0.088 (3) 0.4
H2D 0.6274 0.3628 −0.2493 0.131* 0.4
H2E 0.5989 0.1312 −0.2208 0.131* 0.4
H2F 0.6158 0.3649 −0.174 0.131* 0.4
C3′ 0.44912 (19) 0.2761 (5) −0.36059 (16) 0.0712 (8) 0.4
H3D 0.3922 0.3254 −0.3858 0.107* 0.4
H3E 0.4519 0.1055 −0.3594 0.107* 0.4
H3F 0.483 0.337 −0.3857 0.107* 0.4
C4′ 0.4291 (7) 0.2492 (17) −0.2191 (7) 0.044 (2) 0.4 C5′ 0.4048 (11) 0.157 (5) −0.1790 (14) 0.040 (3) 0.4 C6 0.36533 (14) 0.0481 (4) −0.13710 (12) 0.0453 (5)
C7 0.31601 (16) −0.1439 (5) −0.15841 (13) 0.0607 (7) H7 0.2996 −0.1948 −0.2068 0.073* C8 0.28854 (17) −0.2695 (4) −0.11123 (14) 0.0612 (7)
H8 0.2549 −0.4025 −0.129 0.073*
supporting information
sup-3 Acta Cryst. (2002). E58, o1202–o1203
H15C 0.2972 −0.6999 0.1883 0.135* C16 0.1387 (3) −0.3816 (6) 0.1249 (2) 0.1056 (13) H16A 0.1815 −0.2803 0.1572 0.158* H16B 0.1111 −0.4636 0.1523 0.158* H16C 0.0987 −0.2871 0.0874 0.158*
Atomic displacement parameters (Å2)
U11 U22 U33 U12 U13 U23
S1 0.0502 (4) 0.0626 (4) 0.0387 (3) −0.0102 (3) 0.0175 (3) −0.0031 (3) N1 0.0407 (10) 0.0507 (11) 0.0395 (10) −0.0050 (8) 0.0178 (8) 0.0026 (8) N2 0.0443 (10) 0.0540 (11) 0.0393 (11) 0.0015 (9) 0.0196 (9) 0.0058 (9) Si2 0.0546 (4) 0.0489 (4) 0.0423 (4) −0.0157 (3) 0.0248 (3) 0.0006 (3) Si1 0.0462 (7) 0.0526 (7) 0.0425 (7) −0.0010 (6) 0.0243 (5) 0.0128 (5) C1 0.076 (4) 0.186 (9) 0.070 (4) −0.075 (5) 0.016 (3) 0.030 (5) C2 0.076 (3) 0.036 (2) 0.049 (2) −0.0022 (19) 0.035 (2) 0.0023 (17) C3 0.087 (2) 0.0801 (19) 0.0645 (18) 0.0181 (16) 0.0492 (17) 0.0221 (15) C4 0.045 (4) 0.045 (4) 0.040 (4) 0.001 (3) 0.018 (3) 0.008 (3) C5 0.027 (5) 0.050 (5) 0.031 (5) −0.005 (4) 0.009 (4) 0.005 (3) Si1′ 0.0751 (14) 0.0474 (10) 0.0527 (11) −0.0081 (10) 0.0425 (11) 0.0039 (8) C1′ 0.32 (2) 0.060 (6) 0.231 (17) −0.006 (10) 0.239 (17) 0.007 (8) C2′ 0.062 (4) 0.134 (7) 0.068 (5) −0.035 (5) 0.026 (4) −0.005 (5) C3′ 0.087 (2) 0.0801 (19) 0.0645 (18) 0.0181 (16) 0.0492 (17) 0.0221 (15) C4′ 0.050 (7) 0.047 (6) 0.034 (5) −0.001 (4) 0.016 (5) 0.009 (4) C5′ 0.033 (8) 0.057 (7) 0.025 (6) 0.002 (6) 0.005 (6) 0.006 (5) C6 0.0494 (13) 0.0521 (13) 0.0393 (12) −0.0099 (10) 0.0221 (11) 0.0020 (10) C7 0.0779 (18) 0.0709 (17) 0.0401 (13) −0.0301 (14) 0.0298 (13) −0.0092 (12) C8 0.0786 (18) 0.0581 (16) 0.0545 (16) −0.0305 (13) 0.0337 (14) −0.0064 (12) C9 0.0509 (13) 0.0468 (13) 0.0458 (13) −0.0049 (10) 0.0249 (11) 0.0075 (10) C10 0.0372 (11) 0.0443 (12) 0.0365 (12) 0.0047 (9) 0.0180 (9) 0.0063 (9) C11 0.0361 (11) 0.0425 (12) 0.0375 (12) −0.0012 (9) 0.0175 (9) 0.0051 (9) C12 0.0513 (13) 0.0488 (13) 0.0461 (13) −0.0056 (11) 0.0223 (11) 0.0064 (11) C13 0.0558 (14) 0.0509 (14) 0.0476 (14) −0.0070 (11) 0.0234 (12) 0.0049 (11) C14 0.090 (2) 0.100 (2) 0.0531 (17) −0.0446 (18) 0.0208 (16) −0.0035 (16) C15 0.074 (2) 0.114 (3) 0.072 (2) −0.0226 (19) 0.0173 (17) 0.0400 (19) C16 0.153 (3) 0.065 (2) 0.156 (4) −0.025 (2) 0.124 (3) −0.016 (2)
Geometric parameters (Å, º)
S1—N2 1.6141 (19) C1′—H1E 0.9800
S1—N1 1.6169 (19) C1′—H1F 0.9800
N1—C11 1.348 (3) C2′—H2D 0.9800
N2—C10 1.344 (3) C2′—H2E 0.9800
Si2—C14 1.833 (3) C2′—H2F 0.9800
Si2—C16 1.840 (3) C4′—C5′ 1.17 (3)
Si2—C13 1.842 (2) C5′—C6 1.42 (3)
Si2—C15 1.847 (3) C6—C7 1.369 (3)
Si1—C2 1.843 (4) C7—C8 1.413 (3)
Si1—C1 1.844 (6) C7—H7 0.9500
Si1—C3 1.885 (3) C8—C9 1.371 (3)
C1—H1A 0.9800 C8—H8 0.9500
C1—H1B 0.9800 C9—C10 1.428 (3)
C1—H1C 0.9800 C9—C12 1.440 (3)
C2—H2A 0.9800 C10—C11 1.432 (3)
C2—H2B 0.9800 C12—C13 1.203 (3)
C2—H2C 0.9800 C14—H14A 0.9800
C3—H3A 0.9800 C14—H14B 0.9800
C3—H3B 0.9800 C14—H14C 0.9800
C3—H3C 0.9800 C15—H15A 0.9800
C4—C5 1.219 (19) C15—H15B 0.9800
C5—C6 1.460 (18) C15—H15C 0.9800
Si1′—C1′ 1.808 (11) C16—H16A 0.9800
Si1′—C2′ 1.851 (8) C16—H16B 0.9800
Si1′—C4′ 1.855 (14) C16—H16C 0.9800
C1′—H1D 0.9800
N2—S1—N1 101.28 (9) C7—C6—C5 121.2 (7) C11—N1—S1 105.85 (14) C11—C6—C5 121.8 (7) C10—N2—S1 106.18 (14) C6—C7—C8 122.6 (2) C14—Si2—C16 111.54 (18) C6—C7—H7 118.7 C14—Si2—C13 107.53 (12) C8—C7—H7 118.7 C16—Si2—C13 108.45 (12) C9—C8—C7 122.5 (2) C14—Si2—C15 109.06 (16) C9—C8—H8 118.8 C16—Si2—C15 110.00 (19) C7—C8—H8 118.8 C13—Si2—C15 110.24 (13) C8—C9—C10 117.03 (19) C4—Si1—C2 108.7 (2) C8—C9—C12 120.9 (2) C4—Si1—C1 107.6 (3) C10—C9—C12 122.1 (2) C2—Si1—C1 111.0 (3) N2—C10—C9 126.57 (19) C4—Si1—C3 108.5 (3) N2—C10—C11 113.28 (19) C2—Si1—C3 110.53 (16) C9—C10—C11 120.15 (19) C1—Si1—C3 110.4 (3) N1—C11—C6 125.49 (18) C5—C4—Si1 178.0 (7) N1—C11—C10 113.42 (19) C4—C5—C6 176.7 (9) C6—C11—C10 121.09 (19) C1′—Si1′—C2′ 110.7 (7) C13—C12—C9 175.4 (3) C1′—Si1′—C4′ 109.0 (5) C12—C13—Si2 175.4 (2) C2′—Si1′—C4′ 106.4 (4) Si2—C14—H14A 109.5 Si1′—C1′—H1D 109.5 Si2—C14—H14B 109.5 Si1′—C1′—H1E 109.5 H14A—C14—H14B 109.5
H1D—C1′—H1E 109.5 Si2—C14—H14C 109.5
Si1′—C1′—H1F 109.5 H14A—C14—H14C 109.5 H1D—C1′—H1F 109.5 H14B—C14—H14C 109.5
H1E—C1′—H1F 109.5 Si2—C15—H15A 109.5
Si1′—C2′—H2D 109.5 Si2—C15—H15B 109.5 Si1′—C2′—H2E 109.5 H15A—C15—H15B 109.5
supporting information
sup-5 Acta Cryst. (2002). E58, o1202–o1203
Si1′—C2′—H2F 109.5 H15A—C15—H15C 109.5 H2D—C2′—H2F 109.5 H15B—C15—H15C 109.5
H2E—C2′—H2F 109.5 Si2—C16—H16A 109.5
C5′—C4′—Si1′ 169.4 (12) Si2—C16—H16B 109.5 C4′—C5′—C6 172.8 (16) H16A—C16—H16B 109.5 C7—C6—C5′ 124.3 (12) Si2—C16—H16C 109.5 C7—C6—C11 116.6 (2) H16A—C16—H16C 109.5 C5′—C6—C11 118.0 (11) H16B—C16—H16C 109.5
