Download citation
Download citation
link to html
The structure of tetrakis(3,4-ethyl­ene­dioxy-2-thienyl)­silane carbon tetrachloride solvate, Si(C6H5O2S)4·CCl4, has been determined in the noncentrosymmetric space group I\overline 4. The Si and C atoms of the CCl4 are located on the fourfold inversion axes. The Si atom has a tetrahedral geometry. The thio­phene ring in the 3,4-ethyl­ene­dioxy­thio­phene group is nearly planar to within 0.005 Å, and the ethyl­ene­dioxy moiety is in a half-chair conformation.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100006740/oa1098sup1.cif
Contains datablocks Si(EDOT)4, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270100006740/oa1098Isup2.hkl
Contains datablock I

CCDC reference: 150345

Comment top

Thiophene derivatives have attracted attention in the field of materials chemistry due to their ease of derivatization and ability to polymerize by a variety of chemical and electrochemical methods (Roncali, 1997; Jestin et al., 1998; Visy et al., 1996). Polythiophene derivatives show interesting electronic, optical and electrochemical properties. One of the most interesting polythiophene derivatives is poly(3,4-ethylenedioxythiophene) (PEDOT), because it has a much lower bandgap, better environmental stability and higher conductivity than polythiophene (Sotzing et al., 1997). Recently, PEDOT has been utilized in the field of electrochromics because of its highly transmissive oxidized state, opaque deep-blue reduced state and high contrast ratio (Kumar et al., 1998; Sankaran & Reynolds, 1997). In the course of our ongoing research on electrochromic materials, we have synthesized tetrakis(3,4-ethylenedioxy-2-thienyl)silane carbon tetrachloride solvate, (I), as a novel precursor for poly(3,4-ethylenedioxythiophene) and have determined its crystal structure. \sch

The ORTEP drawing of (I) is presented in Fig. 1. Compound (I) cocrystallizes with CCl4 in a 1:1 ratio in the noncentrosymmetric space group I4. Since Z is 2, the Si atoms reside on the 4 axes at (0,1/2,1/4) and (0,1/2,3/4), as shown in Fig. 2. The asymmetric unit consists of a quarter of an Si atom, one ethylenedioxythienyl ring and a quarter of a CCl4 molecule. The C atoms of the CCl4 solvate occupy fourfold inversion axes at the special positions (0,0,0) and (1/2,1/2,1/2), and the Cl atoms are in general positions as shown in Fig. 2.

The coordination sphere around the Si atom is perfectly tetrahedral due to the symmetry definition. The Si atom lies in the thienyl ring plane and each thienyl ring is planar to within an average standard deviation from planarity of the thienyl atoms of 0.005 Å. The Si—C bond length of 1.848 (2) Å is very close to that found in phenylsilane [1.843 (5) Å; Keidel & Bauer, 1956] but shorter than those in tetra(2-thienyl)silane and tetraphenylsilane [1.888 (3) and 1.872 (7) Å, respectively; Glidewell & Sheldrick, 1971]. The average C—S distance [1.727 (6) Å] in the thienyl ring is very similar to the mean C—S distances in 1,2-bis[2-(3,4-ethylenedioxy)thienyl]vinylene and 1,4-bis[2-(3,4-ethylenedioxy)thienyl]benzene [1.725 (3) and 1.728 (2) Å, respectively; Sotzing et al., 1996]. The C—C bond lengths in the thienyl ring are very similar to those of the corresponding C—C bond distances in free thiophene (Bak et al., 1961; Harshbarger & Bauer, 1970). The C3—C4 bond length [1.426 (3) Å] in the thienyl ring is significantly longer than those of C2—C3 [1.364 (3) Å] and C4—C5 [1.354 (3) Å]; however, all three C—C bond lengths differ from normal Csp2—Csp2 single [1.48 Å] and Csp2Csp2 double [1.34 Å] bond distances. The average C—S bond distance [1.727 (6) Å] is somewhat shorter than a normal Csp2—S single-bond length [1.759 (8) Å] but is longer than the corresponding C—S distance of free thiophene [1.714 (1) Å; Angelici, 1990]. Therefore, the thienyl ring structure indicates some delocalization of the π-electrons but less than is found in free thiophene. The C2—S—C5 angle [93.4 (1) Å] is the same, to within experimental error, as those in free thiophene, in 3,4-ethylenedioxythiophyene derivatives (Sotzing et al., 1996) and in S-bound thiophene transition metal complexes (Angelici, 1990).

The six-membered dioxane ring is in a half-chair conformation. The structural features of the dioxane moiety in (I) are close to those found in 2-(1,2-dibromoethyl)-1,4-benzodioxan (Barnes & Schroth, 1988) and bis(1,4-benzodioxan)silver(I) perchlorate (Barnes & Blyth, 1985). The angle between the thienyl ring and the C6—C7 bond is 30.4 (2)°. The dihedral angles in the dioxane moiety are as follows: C2—C3—O1—C6 163.8 (2), O1—C6—C7—O2 − 65.4 (3), C4—O2—C7—C6 46.2 (3) and C6—O1—C3—C4 − 17.2 (3)°. The H atoms on the ethylene C atoms have a nearly gauche configuration.

Experimental top

To freshly distilled diethyl ether (30 ml) in a Schlenk flask was added 3,4-ethylenedioxythiophene (1.0 g, 7.0 mmol) under an Ar atmosphere. The solution was cooled to 195 K with a dry ice-acetone bath and n-butyllithium (4.4 ml, 1.6 M in n-hexane) was added slowly over 15 min using a dropping funnel. The dry ice-acetone bath was then replaced with an ice bath. After 30 min the ice bath was removed and the resulting light-yellow solution containing a white salt was stirred at room temperature for 2 h. Next, tetrachlorosilane (0.2 ml, 1.7 mmol) was dissolved in distilled diethylether (15 ml) in another Schlenk flask and added slowly via a cannula. After 10 min, the ice bath was removed and the reaction mixture was stirred at room temperature for 4 h. The reaction mixture was then added to CH2Cl2 (100 ml) and washed with water (30 ml) and brine (30 ml) twice. The organic phase was dried over MgSO4, filtered and evaporated to give a light-brown liquid. The crude product was purified by column chromatography (2 × 15 cm, silica gel, CH2Cl2 eluent). Evaporation of the eluent under vacuum gave a white solid. This was recrystallized from a saturated CH2Cl2 solution by a slow cooling method to give colourless transparent crystals of (I) (0.32 g, 0.54 mmol, 31% yield). Crystals suitable for X-ray crystallography were obtained by very slow cooling using a double Dewar technique in a saturated CCl4 solution. Spectroscopic analysis, 1H NMR, δ (acetone-d6/DMSO-d6): 6.7 (s, 4H), 4.1 (m, 16H); analysis calculated for C24H20O8S4Si: C 48.63, H 3.40%; found: C 48.48, H 3.56%.

Refinement top

H atoms were located from a difference electronic density map and refined using isotropic displacement parameters.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SMART; data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXTL (Siemens, 1994); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. The structure of (I) showing 30% probability displacement ellipsoids and the atomic numbering scheme. The carbon tetrachloride molecule and H atoms are omitted for clarity.
[Figure 2] Fig. 2. The molecular packing diagram of (I).
Tetrakis(3,4-ethylenedioxy-2-thienyl)silane carbon tetrachloride solvate top
Crystal data top
C24H20O8S4Si·CCl4Dx = 1.612 Mg m3
Mr = 746.54Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I4Cell parameters from 3266 reflections
Hall symbol: I -4θ = 4–53°
a = 13.1846 (6) ŵ = 0.74 mm1
c = 8.8493 (6) ÅT = 193 K
V = 1538.31 (14) Å3Block, colourless
Z = 20.41 × 0.18 × 0.18 mm
F(000) = 760
Data collection top
Siemens CCD area-detector
diffractometer
1557 independent reflections
Radiation source: fine-focus sealed tube1480 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.000
ϕ and ω scansθmax = 26.4°, θmin = 2.2°
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1997)
h = 1616
Tmin = 0.751, Tmax = 0.878k = 016
1557 measured reflectionsl = 011
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.028Only H-atom displacement parameters refined
wR(F2) = 0.074 w = 1/[σ2(Fo2) + (0.055P)2 + 0.401P]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max = 0.001
1557 reflectionsΔρmax = 0.21 e Å3
115 parametersΔρmin = 0.29 e Å3
0 restraintsAbsolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.08 (8)
Crystal data top
C24H20O8S4Si·CCl4Z = 2
Mr = 746.54Mo Kα radiation
Tetragonal, I4µ = 0.74 mm1
a = 13.1846 (6) ÅT = 193 K
c = 8.8493 (6) Å0.41 × 0.18 × 0.18 mm
V = 1538.31 (14) Å3
Data collection top
Siemens CCD area-detector
diffractometer
1557 independent reflections
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1997)
1480 reflections with I > 2σ(I)
Tmin = 0.751, Tmax = 0.878Rint = 0.000
1557 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.028Only H-atom displacement parameters refined
wR(F2) = 0.074Δρmax = 0.21 e Å3
S = 1.01Δρmin = 0.29 e Å3
1557 reflectionsAbsolute structure: Flack (1983)
115 parametersAbsolute structure parameter: 0.08 (8)
0 restraints
Special details top

Experimental. Data were collected over a hemisphere of reciprocal space, by combining three sets of exposures; each set had a different phi angle for the crystal and each exposure of 10 s covered 0.3 in ω. The crystal-to-detector distance was 4.5 cm. A total of 1271 frames were collected. The crystal showed no significant decay. Only reflections with 2θ less than 53° were used for the structure refinement. The structure was solved by direct methods and refined by full matrix least-squares. Anisotropic displacement parameters were used for all non-H atoms.

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.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) 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) top
xyzUiso*/Ueq
Si1/211/40.0196 (2)
S0.58643 (4)0.78829 (4)0.15379 (6)0.02697 (15)
Cl0.89071 (7)1.00101 (6)0.88706 (10)0.0604 (3)
O10.36088 (13)0.92404 (13)0.03840 (19)0.0296 (4)
O20.40498 (14)0.72941 (12)0.1798 (2)0.0318 (4)
C11110.0369 (11)
C20.49965 (16)0.88572 (15)0.1291 (2)0.0225 (4)
C30.43722 (16)0.86174 (16)0.0114 (3)0.0217 (4)
C40.45871 (17)0.76650 (17)0.0579 (3)0.0246 (5)
C50.53702 (18)0.71714 (18)0.0083 (3)0.0281 (5)
C60.29017 (18)0.8699 (2)0.1328 (3)0.0310 (5)
C70.3458 (2)0.80865 (19)0.2506 (3)0.0325 (5)
H50.569 (2)0.657 (3)0.010 (4)0.044 (9)*
H6A0.252 (2)0.827 (2)0.066 (4)0.037 (8)*
H6B0.251 (2)0.925 (2)0.181 (3)0.025 (6)*
H7A0.300 (2)0.775 (2)0.312 (3)0.033 (7)*
H7B0.392 (2)0.843 (2)0.315 (3)0.039 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Si0.0203 (3)0.0203 (3)0.0182 (6)000
S0.0295 (3)0.0255 (3)0.0259 (3)0.0068 (2)0.0034 (2)0.0005 (2)
Cl0.0668 (5)0.0497 (4)0.0648 (6)0.0069 (4)0.0336 (4)0.0064 (4)
O10.0294 (9)0.0293 (8)0.0303 (9)0.0059 (7)0.0084 (7)0.0037 (7)
O20.0384 (9)0.0282 (8)0.0288 (9)0.0017 (7)0.0059 (7)0.0068 (7)
C10.0383 (17)0.0383 (17)0.034 (3)000
C20.0246 (11)0.0196 (10)0.0234 (12)0.0027 (8)0.0002 (9)0.0002 (9)
C30.0222 (10)0.0221 (10)0.0210 (11)0.0009 (8)0.0007 (8)0.0018 (8)
C40.0285 (12)0.0239 (11)0.0215 (11)0.0027 (9)0.0025 (9)0.0003 (9)
C50.0361 (13)0.0208 (11)0.0273 (12)0.0033 (9)0.0020 (10)0.0028 (9)
C60.0286 (11)0.0384 (13)0.0261 (13)0.0028 (10)0.0032 (11)0.0034 (10)
C70.0382 (13)0.0335 (12)0.0258 (12)0.0047 (10)0.0071 (11)0.0001 (10)
Geometric parameters (Å, º) top
Si—C21.848 (2)O2—C41.380 (3)
S—C21.734 (2)O2—C71.447 (3)
S—C51.721 (3)Si—C2i1.848 (2)
C2—C31.364 (3)Si—C2ii1.848 (2)
C3—C41.426 (3)Si—C2iii1.848 (2)
C4—C51.354 (3)Cl—C11.7537 (8)
C6—C71.509 (4)C1—Cliv1.7537 (8)
O1—C31.372 (3)C1—Clv1.7537 (8)
O1—C61.441 (3)C1—Clvi1.7537 (8)
C2—S—C593.42 (11)C4—O2—C7111.08 (18)
C3—C2—S108.83 (16)C2i—Si—C2ii109.59 (7)
C3—C2—Si129.22 (17)C2i—Si—C2109.59 (7)
S—C2—Si121.95 (12)C2ii—Si—C2109.23 (13)
C2—C3—O1123.3 (2)C2i—Si—C2iii109.23 (13)
C2—C3—C4114.4 (2)C2ii—Si—C2iii109.59 (7)
O1—C3—C4122.3 (2)C2—Si—C2iii109.59 (7)
C5—C4—O2124.0 (2)Cliv—C1—Cl108.95 (3)
C5—C4—C3112.9 (2)Cliv—C1—Clv108.95 (3)
O2—C4—C3123.1 (2)Cl—C1—Clv110.51 (7)
C4—C5—S110.51 (17)Cliv—C1—Clvi110.51 (7)
O1—C6—C7110.54 (19)Cl—C1—Clvi108.95 (3)
O2—C7—C6110.4 (2)Clv—C1—Clvi108.95 (3)
C3—O1—C6111.37 (18)
C2—C3—O1—C6163.8 (2)Si—C2—C3—O10.7 (3)
O1—C6—C7—O265.4 (3)S—C2—C3—C40.0 (2)
C4—O2—C7—C646.2 (3)Si—C2—C3—C4179.82 (17)
C6—O1—C3—C417.2 (3)C7—O2—C4—C5164.3 (2)
C5—S—C2—C30.57 (18)C7—O2—C4—C315.5 (3)
C5—S—C2—Si179.62 (14)C2—C3—C4—C50.7 (3)
C2i—Si—C2—C369.01 (16)O1—C3—C4—C5179.9 (2)
C2ii—Si—C2—C351.07 (18)C2—C3—C4—O2179.10 (19)
C2iii—Si—C2—C3171.1 (2)O1—C3—C4—O20.0 (3)
C2i—Si—C2—S111.22 (19)O2—C4—C5—S178.70 (17)
C2ii—Si—C2—S128.71 (16)C3—C4—C5—S1.1 (3)
C2iii—Si—C2—S8.63 (14)C2—S—C5—C40.99 (19)
S—C2—C3—O1179.09 (17)C3—O1—C6—C748.1 (3)
Symmetry codes: (i) y1/2, x+3/2, z1/2; (ii) x+1, y+2, z; (iii) y+3/2, x+1/2, z1/2; (iv) y+2, x, z+2; (v) x+2, y+2, z; (vi) y, x+2, z+2.

Experimental details

Crystal data
Chemical formulaC24H20O8S4Si·CCl4
Mr746.54
Crystal system, space groupTetragonal, I4
Temperature (K)193
a, c (Å)13.1846 (6), 8.8493 (6)
V3)1538.31 (14)
Z2
Radiation typeMo Kα
µ (mm1)0.74
Crystal size (mm)0.41 × 0.18 × 0.18
Data collection
DiffractometerSiemens CCD area-detector
diffractometer
Absorption correctionEmpirical (using intensity measurements)
(SADABS; Sheldrick, 1997)
Tmin, Tmax0.751, 0.878
No. of measured, independent and
observed [I > 2σ(I)] reflections
1557, 1557, 1480
Rint0.000
(sin θ/λ)max1)0.625
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.028, 0.074, 1.01
No. of reflections1557
No. of parameters115
H-atom treatmentOnly H-atom displacement parameters refined
Δρmax, Δρmin (e Å3)0.21, 0.29
Absolute structureFlack (1983)
Absolute structure parameter0.08 (8)

Computer programs: SMART (Siemens, 1996), SMART, SAINT (Siemens, 1996), SHELXTL (Siemens, 1994), SHELXTL.

Selected geometric parameters (Å, º) top
Si—C21.848 (2)C6—C71.509 (4)
S—C21.734 (2)O1—C31.372 (3)
S—C51.721 (3)O1—C61.441 (3)
C2—C31.364 (3)O2—C41.380 (3)
C3—C41.426 (3)O2—C71.447 (3)
C4—C51.354 (3)
C2—S—C593.42 (11)C5—C4—C3112.9 (2)
C3—C2—S108.83 (16)O2—C4—C3123.1 (2)
C3—C2—Si129.22 (17)C4—C5—S110.51 (17)
S—C2—Si121.95 (12)O1—C6—C7110.54 (19)
C2—C3—O1123.3 (2)O2—C7—C6110.4 (2)
C2—C3—C4114.4 (2)C3—O1—C6111.37 (18)
O1—C3—C4122.3 (2)C4—O2—C7111.08 (18)
C5—C4—O2124.0 (2)
C2—C3—O1—C6163.8 (2)C4—O2—C7—C646.2 (3)
O1—C6—C7—O265.4 (3)C6—O1—C3—C417.2 (3)
 

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds