1,3,5-Tris(5-iodo­thio­phen-2-yl)benzene

The mol­ecule of the title compound, C₁₈H₉I₃S₃, is nearly planar. The central benzene ring makes dihedral angles of 8.7 (1), 2.5 (6) and 11.0 (2)° with the three thio­phene rings. The I...S separations of 3.5234 (4) and 3.5874 (3) Å show the short contacts between adjacent mol­ecules.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.022 Å
• R factor = 0.054
• wR factor = 0.129
• Data-to-parameter ratio = 16.1

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT342_ALERT_3_B Low Bond Precision on C-C bonds (x 1000) Ang ...         22

Alert level C
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for        C13
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C10
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C18
PLAT322_ALERT_2_C Check Hybridisation of  S2     in Main Residue .          ?
PLAT431_ALERT_2_C Short Inter HL..A Contact  I1     ..  S2      ..       3.52 Ang.
PLAT431_ALERT_2_C Short Inter HL..A Contact  I2     ..  S3      ..       3.59 Ang.

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.00
           From the CIF: _reflns_number_total               3504
           Count of symmetry unique reflns         2025
           Completeness (_total/calc)            173.04%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1479
           Fraction of Friedel pairs measured     0.730
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   6 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   6 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Thiophene derivatives constitute a class of materials with various applications in conducting films, electrochromics and field-effect transistors (FETs) (Perepichka et al., 2005). These materials are characterized by good physical properties, such as high carrier mobility and high luminescent quantum efficiencies (Hotta et al., 2004). In this paper, the synthesis and crystal structure of the title thiophene derivative, (I), are reported.

The molecular structure of (I) is shown in Fig. 1, and the two-dimensional network of the compound is given in Fig. 2. The central benzene ring makes dihedral angles of 8.7 (1), 2.5 (6) and 11.0 (2)°, respectively, with the thiophene rings S1/C7–C10 (A), S2/C13–C16 (B) and S3/C19–C22 (C). The dihedral angles A/B, A/C and B/C are 7.8 (2), 12.3 (5) and 13.0 (1)°, respectively.

The I1···S2ⁱ separation of 3.5234 (4) Å [symmetry code: (i) x, y + 1, z] and I2···S3ⁱⁱ separation of 3.5874 (3) Å [symmetry code: (ii) x + 1, y, z] show the shorter contact between adjacent molecules.

Related literature

For general background, see: Perepichka et al. (2005); Hotta et al. (2004).

S2. Experimental

For the preparation of 1,3,5-tris(2-thienyl)benzene, a three-necked flask was charged with a mixture of 2-acetylthiophene (1 ml, 9.3 mmol) and dry ethanol (50 m) in ice–water, stirred vigorously. Tetrachlorosilane (10 ml, 88 mmol) was added to the solution. Stirring continued under nitrogen for 18 h. This mixture was poured in to water and saturated with ammonium chloride (100 ml), stirred vigorously and extracted with dichloromethane (4 × 100 ml). The organic layer was dried over anhydrous magnesium sulfate and removed under reduced pressure. The filtrate was purified by column chromatography with light

petroleum as the eluent, to give the white solid product (0.62 g, yield 61.73%). For the preparation of 1,3,5-tris(5-iodothiophen-2-yl)benzene, 1,3,5-tris(2-thienyl)benzene (0.9 g, 2.8 mmol) and benzene (15 ml) were added to a three-necked flask equipped with a magnetic stirrer, a reflux condenser and an isobaric dropping funnel. ICl (4.2 g, 25.8 mmol)/ethanol (15 ml) was added to the mixture at 353 K. The reaction mixture was refluxed for 2 h and then cooled to room temperature. The resulting grey solid was filtered off and air-dried after washing with dry ethanol three times, to give 1.68 g of the product (yield 86%). Single crystals of (I) were obtained by slow evaporation of a benzene solution at room temperature.

S3. Refinement

H atoms were placed in geometrically idealized positions, with C—H = 0.93 Å, and refined in riding mode, with U_iso(H) = 1.2U_eq(C). Due to the low quality of the crystalline sample, the precision of the determination is poor.

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

Figures

Fig. 1. The molecular structure of (I), showing 30% probability displacement ellipsoids.

1,3,5-Tris(5-iodothiophen-2-yl)benzene

Crystal data

C18H9I3S3	Dx = 2.320 Mg m^−3
Mr = 702.13	Mo Kα radiation, λ = 0.71073 Å
Trigonal, P3221	Cell parameters from 4393 reflections
Hall symbol: P 32 2"	θ = 2.6–22.7°
a = 12.969 (7) Å	µ = 4.98 mm^−1
c = 20.70 (2) Å	T = 298 K
V = 3015 (4) Å^3	Block, yellow
Z = 6	0.41 × 0.27 × 0.23 mm
F(000) = 1944

Data collection

Bruker SMART CCD area-detector diffractometer	3504 independent reflections
Radiation source: fine-focus sealed tube	2631 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.059
φ and ω scans	θmax = 25.0°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→15
Tmin = 0.188, Tmax = 0.315	k = −15→14
15743 measured reflections	l = −24→23

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.054	H-atom parameters constrained
wR(F^2) = 0.129	w = 1/[σ^2(Fo^2) + (0.0615P)^2 + 25.2524P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
3504 reflections	Δρmax = 0.68 e Å^−3
217 parameters	Δρmin = −0.70 e Å^−3
0 restraints	Absolute structure: Flack (1983), with 1477 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.02 (6)

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.

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 (Ų)

	x	y	z	Uiso*/Ueq
I1	0.19980 (12)	0.83723 (10)	0.40014 (7)	0.0808 (4)
I2	0.61606 (10)	0.15440 (10)	0.41003 (6)	0.0643 (3)
I3	−0.47717 (10)	−0.26393 (11)	0.44787 (7)	0.0858 (4)
S1	0.2048 (3)	0.5886 (3)	0.3997 (2)	0.0549 (9)
S2	0.3634 (3)	0.1496 (3)	0.41515 (18)	0.0507 (9)
S3	−0.2304 (3)	−0.0070 (3)	0.4388 (2)	0.0601 (10)
C1	0.0984 (12)	0.3438 (11)	0.4149 (7)	0.045 (3)
C2	0.2091 (11)	0.3565 (12)	0.4124 (6)	0.043 (3)
H2	0.2752	0.4327	0.4110	0.051*
C3	0.2265 (11)	0.2563 (11)	0.4118 (6)	0.040 (3)
C4	0.1253 (12)	0.1468 (12)	0.4153 (6)	0.042 (3)
H4	0.1338	0.0797	0.4148	0.050*
C5	0.0093 (13)	0.1295 (13)	0.4194 (6)	0.051 (4)
C6	0.0005 (13)	0.2307 (12)	0.4196 (7)	0.050 (4)
H6	−0.0747	0.2228	0.4230	0.060*
C7	0.0855 (12)	0.4520 (11)	0.4141 (7)	0.043 (3)
C8	−0.0123 (12)	0.4593 (12)	0.4246 (7)	0.049 (4)
H8	−0.0857	0.3930	0.4341	0.059*
C9	0.0041 (13)	0.5752 (12)	0.4201 (7)	0.054 (4)
H9	−0.0553	0.5942	0.4272	0.064*
C10	0.1159 (12)	0.6535 (12)	0.4045 (7)	0.047 (3)
C11	0.3487 (12)	0.2755 (11)	0.4132 (7)	0.042 (3)
C12	0.4549 (13)	0.3736 (13)	0.4055 (7)	0.053 (4)
H12	0.4626	0.4485	0.4008	0.063*
C13	0.5548 (16)	0.3572 (17)	0.4050 (9)	0.074 (5)
H13	0.6342	0.4168	0.4019	0.088*
C14	0.5140 (13)	0.2392 (13)	0.4098 (6)	0.049 (3)
C15	−0.0910 (15)	0.0133 (13)	0.4214 (7)	0.055 (4)
C16	−0.1060 (14)	−0.0996 (13)	0.4122 (7)	0.060 (4)
H16	−0.0421	−0.1107	0.4028	0.072*
C17	−0.2139 (13)	−0.1891 (13)	0.4175 (7)	0.052 (4)
H17	−0.2329	−0.2677	0.4114	0.063*
C18	−0.2960 (14)	−0.1576 (12)	0.4325 (6)	0.050 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.0890 (9)	0.0417 (6)	0.1176 (10)	0.0371 (6)	0.0285 (8)	0.0172 (6)
I2	0.0623 (7)	0.0708 (8)	0.0793 (7)	0.0479 (6)	0.0112 (6)	0.0136 (6)
I3	0.0496 (6)	0.0606 (7)	0.1153 (10)	0.0035 (6)	0.0048 (6)	−0.0145 (7)
S1	0.048 (2)	0.0311 (19)	0.086 (3)	0.0201 (17)	0.006 (2)	−0.0017 (19)
S2	0.045 (2)	0.0367 (18)	0.075 (3)	0.0245 (16)	0.0127 (18)	0.0110 (18)
S3	0.041 (2)	0.0383 (19)	0.096 (3)	0.0161 (16)	−0.002 (2)	−0.006 (2)
C1	0.041 (7)	0.028 (7)	0.051 (8)	0.006 (6)	0.009 (7)	−0.007 (6)
C2	0.031 (7)	0.042 (8)	0.053 (8)	0.017 (6)	0.010 (6)	−0.003 (6)
C3	0.030 (7)	0.038 (7)	0.049 (8)	0.014 (6)	0.005 (6)	−0.001 (6)
C4	0.043 (8)	0.037 (7)	0.048 (8)	0.023 (6)	0.013 (7)	0.008 (6)
C5	0.055 (9)	0.057 (9)	0.034 (7)	0.022 (8)	0.008 (6)	0.016 (7)
C6	0.051 (9)	0.037 (8)	0.060 (9)	0.020 (7)	0.006 (7)	0.023 (7)
C7	0.035 (7)	0.035 (7)	0.068 (9)	0.024 (6)	−0.022 (7)	−0.013 (6)
C8	0.038 (8)	0.032 (7)	0.073 (10)	0.015 (6)	0.010 (7)	0.006 (7)
C9	0.038 (8)	0.047 (9)	0.083 (11)	0.027 (7)	−0.010 (8)	−0.014 (8)
C10	0.037 (8)	0.038 (7)	0.074 (9)	0.024 (6)	0.009 (7)	0.008 (7)
C11	0.048 (8)	0.021 (7)	0.061 (9)	0.020 (6)	0.007 (7)	0.002 (6)
C12	0.063 (9)	0.047 (8)	0.065 (10)	0.040 (8)	−0.002 (7)	−0.014 (7)
C13	0.046 (9)	0.089 (13)	0.091 (13)	0.038 (9)	−0.012 (9)	−0.008 (10)
C14	0.071 (10)	0.039 (8)	0.051 (8)	0.038 (8)	0.006 (7)	0.008 (7)
C15	0.068 (10)	0.052 (9)	0.055 (9)	0.038 (8)	0.008 (8)	0.028 (8)
C16	0.049 (9)	0.048 (9)	0.082 (11)	0.024 (8)	−0.003 (8)	−0.029 (8)
C17	0.054 (9)	0.045 (8)	0.061 (9)	0.028 (8)	−0.011 (7)	−0.004 (7)
C18	0.065 (10)	0.037 (7)	0.037 (7)	0.017 (7)	−0.004 (7)	−0.007 (6)

Geometric parameters (Å, º)

I1—C10	2.068 (13)	C5—C6	1.37 (2)
I2—C14	2.102 (13)	C5—C15	1.42 (2)
I3—C18	2.070 (15)	C6—H6	0.9300
S1—C7	1.697 (14)	C7—C8	1.336 (18)
S1—C10	1.737 (13)	C8—C9	1.412 (18)
S2—C14	1.705 (16)	C8—H8	0.9300
S2—C11	1.736 (12)	C9—C10	1.329 (19)
S3—C18	1.701 (14)	C9—H9	0.9300
S3—C15	1.730 (17)	C11—C12	1.34 (2)
C1—C2	1.362 (18)	C12—C13	1.42 (2)
C1—C6	1.382 (18)	C12—H12	0.9300
C1—C7	1.494 (18)	C13—C14	1.35 (2)
C2—C3	1.426 (19)	C13—H13	0.9300
C2—H2	0.9300	C15—C16	1.39 (2)
C3—C4	1.372 (18)	C16—C17	1.301 (19)
C3—C11	1.476 (17)	C16—H16	0.9300
C4—C5	1.408 (19)	C17—C18	1.35 (2)
C4—H4	0.9300	C17—H17	0.9300
C7—S1—C10	90.9 (6)	C8—C9—H9	124.6
C14—S2—C11	89.1 (7)	C9—C10—S1	112.3 (10)
C18—S3—C15	92.5 (8)	C9—C10—I1	129.4 (10)
C2—C1—C6	119.0 (13)	S1—C10—I1	117.5 (7)
C2—C1—C7	119.5 (12)	C12—C11—C3	131.7 (12)
C6—C1—C7	121.5 (13)	C12—C11—S2	110.6 (10)
C1—C2—C3	121.9 (12)	C3—C11—S2	117.1 (10)
C1—C2—H2	119.1	C11—C12—C13	116.2 (14)
C3—C2—H2	119.1	C11—C12—H12	121.9
C4—C3—C2	115.9 (12)	C13—C12—H12	121.9
C4—C3—C11	124.3 (12)	C14—C13—C12	107.5 (15)
C2—C3—C11	119.5 (12)	C14—C13—H13	126.3
C3—C4—C5	124.1 (13)	C12—C13—H13	126.3
C3—C4—H4	117.9	C13—C14—S2	116.4 (11)
C5—C4—H4	117.9	C13—C14—I2	126.9 (12)
C6—C5—C4	116.2 (14)	S2—C14—I2	116.7 (7)
C6—C5—C15	123.1 (15)	C16—C15—C5	133.5 (16)
C4—C5—C15	120.7 (15)	C16—C15—S3	106.4 (12)
C5—C6—C1	122.9 (15)	C5—C15—S3	120.1 (12)
C5—C6—H6	118.6	C17—C16—C15	116.7 (15)
C1—C6—H6	118.6	C17—C16—H16	121.6
C8—C7—C1	128.3 (13)	C15—C16—H16	121.6
C8—C7—S1	111.0 (10)	C16—C17—C18	114.1 (14)
C1—C7—S1	120.7 (10)	C16—C17—H17	123.0
C7—C8—C9	114.9 (13)	C18—C17—H17	123.0
C7—C8—H8	122.5	C17—C18—S3	110.3 (11)
C9—C8—H8	122.5	C17—C18—I3	129.5 (11)
C10—C9—C8	110.8 (13)	S3—C18—I3	120.2 (9)
C10—C9—H9	124.6