Spacer-Extended Bis-Ene-Yne Compounds: Scope, Limitations, and Properties

Abstract

The paper outlines a synthetic approach towards novel spacer-extended bis-ene-yne structures via a tandem thiophene ring-opening reaction to selectively obtain the Z,Z-isomers. Various unsaturated spacer moieties are matter of interest in these investigations owing to potential applications in organic electronics. As a result, the successful application of the tandem ring-opening process on a representative set of spacer-extended substrates is demonstrated and the limitations regarding substrate and product scope are revealed in terms of ring-opening ability and stability. Additionally, a general oxidation protocol for ene-yne compounds capable of accessing double-sided sulfone species is developed. The comparison of the photophysical and electronic properties before and after oxidation reveals significant effects of the chemical modification on the intrinsic characteristics of the materials and thus a wide variability of the developed molecular building blocks.