Z. Kristallogr. NCS 224 (2009) 691-692 / DOI 10.1524/ncrs.2009.0304 691 © by Oldenbourg Wissenschaftsverlag, München

Crystal structureof2,3-bis(5-bromo-3-methylthiophen-2- yl)benzo[b]thiophene, C18H12Br2S3

Xiaochuan Li*,I,Bingcai WangI,Young-A Son*,II,Jiange WangIII and Sheng WangIV

I Normal University, College of Chemistry and Environmental Science, , Henan, 453007, P. R. II Chungnam National University, Department of Advanced Organic Materials and Textile System Engineering, Daejeon 305-764, South Korea III Normal University, College of Chemistry and Chemical Engineering, Luoyang, Henan, 471022, P. R. China IV Zhanjiang Normal University, School of Chemistry Science &Technology, Zhanjiang, Guangdong, 524048, P. R. China

Received September 28, 2009, accepted and available on-line October 5, 2009; CCDC no. 1267/2787

thiophen-2-yl)benzo[b]thiophene (90 mg, 0.276 mmol) in acetic acid (20.mL) and chloroform (20 mL) at 0°C, N-bromo- succinimide (NBS) (117.6 mg, 0.662 mol) was slowly added. The reaction mixture was stirred for 3hat0°Cinthe dark. After fil- tered, the filtrate was neutralized and extracted with ether. The ether extract was washed with water, saturated NaCl, dried over Mg2SO4,filtered and concentrated. Column chromatography on silica gel with petroleum ether afforded 123 mg of the target com- pound in 92 %yield. Colorless block-shaped single crystals suit- able for X-ray diffraction was obtained by slow evaporation of its solution in hexane. NMR data are available in the CIF.

Experimental details All Hatoms attached to Cwere fixed geometrically and treated as riding with d(C—H) =0.96 Å (methyl) or 0.93 Å (aromatic) with Uiso(H) =1.5 Ueq(methyl) or Uiso(H) =1.2 Ueq(aromatic).

Discussion The title crystal structure is built up from C18H12Br2S3 molecule (figure, top). The crystal packing is generated only one kind of hydroen bond (C6–H6···Br2i,symmetry code i: 2–x,0.5+y,1.5–z). The donor-acceptor distance is 3.193(1) Å with the bond angle 149.4(3)°.The prevalent interactions observed in the crystal are C–H···p interactions including intra- and intermolecular interac- tions. The intramolecular C–H···p interactions are C13– H13C···pii (C2/C3/C8/C7/S1, symmetry code ii: x,y,z), C18– H18C···pii (C2/C3/C8/C7/S1), and C13–H13A···pii (C14/C15/ C16/C17/S3). The local configurations correspond to type Vin- teractions [2]. The typical parallel conformation of the packed molecules in the crystals is stabilized by the intra- molecular C–H···p interactions. The parallel conformation of the two thiophene rings leads to the lost of the photochromic reactivity of the crystals [3]. Four kinds of intermolecular C–H···p interactions are observed (figure, bottom): C18–H18C···piii (C2/C3/C8/ C7/S1, symmetry code iii: x,1.5–y,0.5+z), C18–H18B···piii (C1- Abstract C6), C4–H4···pii (C1-C6), and C5–H5···pii (C2/C3/C8/C7/S1). C18H12Br2S3,monoclinic, P121/c1(no. 14), a =11.948(2) Å, The first one is atypical C–H···p interaction observed in the crys- b =7.985(1) Å, c =19.863(3) Å, b =105.998(2)°, 3 2 tal. The hydrogen atom is directly above the center of the V =1821.6 Å , Z =4,Rgt(F) =0.037, wRref(F ) =0.100, heterocycle, which indicates that the hydrogen atom is being at- T =296 K. tracted in the direction of the ring centre. The C18···centroid dis- tance is 3.638(5) Å and the bond angle is 122.3(1)°.This Source of material corresponds to atype-I interaction [2]. The other three 2,3-Bis(5-bromo-3-methylthiophen-2-yl)benzo[b]thiophene intermolecular C–H···p interactions belong to the type II. There- was synthesized by bromination of 2,3-bis(3-methylthiophen-2- fore, the molecules are packed together mainly by the stronger yl)benzo[b]thiophene, which was obtained according to our early intermolecular C–H···p interactions and the molecular structure published method [1]. To astirred solution of 2,3- bis(3-methyl- are further stabilized by intramolecular C–H···p interactions. ______*Correspondence authors (e-mail: [email protected], [email protected]) 692 C18H12Br2S3

Table 1. Data collection and handling. Table 2. Atomic coordinates and displacement parameters (in Å2).

Crystal: colorless block, size 0.18 × 0.29 × 0.40 mm Atom Site xyzUiso Wavelength: Mo Ka radiation (0.71073 Å) m:47.89 cm–1 H(1) 4e 0.2363 0.2688 0.8019 0.069 Diffractometer, scan mode: Bruker SMART CCD, j/w H(4) 4e 0.5490 0.0005 0.7502 0.061 2qmax:51° H(5) 4e 0.3684 0.0072 0.6696 0.077 N(hkl)measured, N(hkl)unique:13439, 3398 H(6) 4e 0.2137 0.1398 0.6962 0.084 Criterion for Iobs, N(hkl)gt: Iobs >2s(Iobs),2378 H(11) 4e 0.9533 −0.1407 0.9372 0.062 N(param)refined:210 H(13A) 4e 0.8067 −0.0453 1.0329 0.102 Programs: SHELX-90 [4], SHELXS-97 [5], H(13B) 4e 0.7799 −0.2186 0.9948 0.102 SHELXL-97 [6], SHELXTL [7], H(13C) 4e 0.6806 −0.0854 0.9865 0.102 DIAMOND [8] H(16) 4e 0.7934 0.3875 1.1609 0.057 H(18A) 4e 0.5276 0.2920 1.0982 0.104 H(18B) 4e 0.6207 0.1672 1.1423 0.104 H(18C) 4e 0.5513 0.1217 1.0653 0.104

Table 3. Atomic coordinates and displacement parameters (in Å2).

Atom Site xyzU11 U22 U33 U12 U13 U23

Br(1) 4e 1.02388(5) −0.01222(8) 0.80860(3) 0.0631(3) 0.1110(5) 0.0896(4) 0.0191(3) 0.0379(3) −0.0108(3) Br(2) 4e 0.98723(4) 0.55944(7) 1.11091(3) 0.0542(3) 0.0872(4) 0.0691(3) −0.0154(3) 0.0023(2) −0.0096(3) C(1) 4e 0.2990(4) 0.2169(6) 0.7914(3) 0.040(2) 0.048(3) 0.077(3) −0.003(2) 0.006(2) 0.000(2) C(2) 4e 0.4095(3) 0.2166(5) 0.8394(2) 0.037(2) 0.035(2) 0.059(3) −0.004(2) 0.010(2) 0.006(2) C(3) 4e 0.5048(3) 0.1375(5) 0.8246(2) 0.034(2) 0.032(2) 0.044(2) −0.003(2) 0.005(2) 0.003(2) C(4) 4e 0.4876(4) 0.0565(5) 0.7607(2) 0.048(2) 0.045(2) 0.054(3) −0.002(2) 0.005(2) −0.005(2) C(5) 4e 0.3794(4) 0.0591(6) 0.7129(3) 0.065(3) 0.058(3) 0.057(3) −0.011(3) −0.006(2) −0.010(2) C(6) 4e 0.2863(4) 0.1395(6) 0.7290(3) 0.049(3) 0.060(3) 0.082(4) −0.009(2) −0.014(3) 0.003(3) C(7) 4e 0.5916(3) 0.2397(5) 0.9372(2) 0.038(2) 0.033(2) 0.046(2) −0.000(2) 0.011(2) 0.002(2) C(8) 4e 0.6094(3) 0.1515(5) 0.8821(2) 0.037(2) 0.032(2) 0.043(2) −0.002(2) 0.010(2) 0.001(2) C(9) 4e 0.7228(3) 0.0786(5) 0.8814(2) 0.036(2) 0.037(2) 0.044(2) 0.000(2) 0.006(2) −0.006(2) C(10) 4e 0.7921(4) −0.0293(5) 0.9285(2) 0.046(2) 0.037(2) 0.050(2) −0.000(2) 0.007(2) −0.003(2) C(11) 4e 0.8966(4) −0.0687(5) 0.9111(2) 0.044(2) 0.046(2) 0.060(3) 0.008(2) 0.005(2) −0.006(2) C(12) 4e 0.9047(4) 0.0086(6) 0.8530(2) 0.039(2) 0.057(3) 0.057(3) 0.004(2) 0.011(2) −0.012(2) C(13) 4e 0.7621(4) −0.1012(6) 0.9914(3) 0.065(3) 0.064(3) 0.074(3) 0.011(2) 0.017(3) 0.026(3) C(14) 4e 0.6785(3) 0.2991(5) 1.0002(2) 0.039(2) 0.035(2) 0.046(2) 0.000(2) 0.012(2) −0.004(2) C(15) 4e 0.6793(4) 0.2949(5) 1.0692(2) 0.057(3) 0.037(2) 0.047(2) 0.002(2) 0.022(2) 0.002(2) C(16) 4e 0.7786(4) 0.3781(5) 1.1126(2) 0.057(3) 0.047(2) 0.036(2) −0.001(2) 0.009(2) −0.003(2) C(17) 4e 0.8482(4) 0.4414(5) 1.0764(2) 0.043(2) 0.047(2) 0.043(2) −0.000(2) 0.004(2) −0.004(2) C(18) 4e 0.5862(5) 0.2113(6) 1.0962(2) 0.097(4) 0.067(3) 0.056(3) −0.020(3) 0.040(3) 0.003(3) S(1) 4e 0.44831(9) 0.3073(1) 0.92213(6) 0.0397(6) 0.0522(6) 0.0612(7) 0.0043(5) 0.0168(5) −0.0031(5) S(2) 4e 0.78717(9) 0.1334(1) 0.81636(5) 0.0447(6) 0.0574(6) 0.0450(6) 0.0058(5) 0.0132(5) −0.0005(5) S(3) 4e 0.79913(9) 0.4028(2) 0.98858(6) 0.0455(6) 0.0637(7) 0.0435(6) −0.0123(5) 0.0133(5) −0.0045(5)

Acknowledgments. This work was supported by the National Natural Science Foundation of China for the Youth (grant nos. 20702011 and 20802065), the Startup Fund of Henan Normal University (grant no. 051004), the Science Foundation for the Youth of Henan Normal University (grant no. 2006033), and the Natural Science Foundation of Henan Provincial Education Office (grant no. 2007150022).

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