A Tripodal Tris(thiophene) Derivative of Hexahydropyrimidine and its Ladder-like Extended Structure

Abstract

In the title compound, 2-(2-thienyl)-1,3-bis(2-thienylmethyl)- perhydropyrimidine, C18H20N2S3, a new hexahydropyrimidine derivative with no formal crystallographic symmetry (but approximate Cs molecular symmetry), the thiophene rings are approximately orthogonal to the mean plane of the saturated pyrimidine ‘core’ of the molecule, with the three S atoms positioned on one side of the six-atom mean plane. The S atom of the directly attached thiophene ring is involved in an unconventional (alkyl)C—H S hydrogen bond (H S = 2.87 A˚ ) with a thiophene CH group of the closest neigh- bouring molecule, leading to a ladder-like one-dimensional chain as the extended structure. The crystal specimen used for data collection was an inversion twin [twin fraction x = 0.41 (4)].