Crystal structure of 3,4-bis(chloromethyl)-2,5-dimethylthiophene, C8H10Cl2S

Abstract

Source of materialAt room temperture, to as olution of 36.2 go fs -trioxane in 35.5 ml of conc. hydrochloric acid was added dropwise and with stirring 15.0 gof2,5-dimethylthiophene. The blue mixture was stirred for three hours, diluted with 100 ml of water, and extracted with 50 ml petroleume ther.T he extracts were washed successively with diluted hydrochloric acid, water, 5% sodium bisulfite, and diluted sodium hydroxide. The solid obtained by evaporation of thesolventswas recrystallized from n-hexane by coolingthe solution andyieldingcolourlessblock-shapedcrystals (14 g, 49% yield). We picked out ablock andverylucency crystalfor X-ray diffraction analysis. Elemental analysis calcd.for C 8 H 10 Cl 2 S 1 :C 45.90, H0.05%; found: C45.79, H0.05%. ExperimentaldetailsAlln on-hydrogen atoms were refined anisotropically. Theh ydrogen atomsw ere located by geometrically calculations, and theirp ositionsa nd thermal parameters were fixed during the structurerefinement. DiscussionThiophenes and their derivatives have been of interest for their useinnextgenerationelectronicmaterials owingtothe ease of production, synthetic versatility, and low cost compared to traditional inorganic materials [1][2][3]. As part of our work, we report the synthesis and crystal structure of the title compound. The asymmetric unit of the crystal structure is build up of one molecule. The C7-Cl1 and C8-Cl2 bond lengths arenearly identical at 1.808(3), 1.804(3) Å, respectively. TheC -C bonds within the thiophene are significantly shorter compared to other C-C bonds. The methyl as well as the carbon atomsofthe chloromethyl substituents C5, C6, C7 and C8 are alsonearly planar with respect to the central thiophene ring. Cl1 and Cl2 are not planar and locates above or below the thiophene ring.