Cyclic thiatetraynes: syntheses and structural properties

Abstract

The syntheses of three cyclic dithiatetraynes 4–6 with the sulfur atoms in propargylic positions are reported. Their structural features have been studied by means of X-ray analysis on single crystals. Additionally, six cyclic octathiatetraynes 15–20 with sulfur atoms in α,α′-positions to the triple bond have been prepared. The structures of 15 and 17 have been elucidated by means of X-ray analysis. These macrocycles exhibit an ellipsoidal geometry dominated by the stiff triple bond moieties. In the case of 4 a three-dimensional columnar structure is found, demonstrating the unique features of the potential cavities.