Crystal and molecular structure of methylsulphinyl derivatives of furan and thiophene by X-ray diffraction

Abstract

An investigation of the solid-state conformational properties of 3-methylsulphinyl derivatives of furan and 2- and 3-methylsulphinyl derivatives of thiophene, which also contain halogen atoms in the heterocyclic ring, is reported. For 3-iodo-2-(methylsulphinyl)thiophene compound 1, two crystallographically independent molecules were found in the unit cell, and in 2-bromo-4-iodo-3- (methylsulphinyl)thiophene, compound 5, a high degree of disorder is present. The sulphur atom of the methylsulphinyl group has a pyramidal structure. The methyl group is highly twisted with respect to the ring plane and the SO bond adopts different orientations in the molecules exam- ined. When only one halogen atom is present in the ring the SO bond is directed to the opposite side of the ring with respect to this atom, yet the relative position of the substituents determines a different twist of this bond with respect to the heterocyclic plane.