New molecular scaffolding using optically active 1,3-diethynylallenes

This proposal deals with the synthesis of new chiral diethynylallenes and their use as modules for the construction of molecular carbon scaffolds. The main focus of this project will lie on the development of new helical structures based on an all carbon back-bone made from acetylene and allene moieties. These novel helical structures will open a whole new research area in the field of material sciences and supramolecular chemistry. First, the synthetic route towards the new chiral building blocks will be perfected. The stucture and behaviour of these new class of compounds will be systematically investigated by various techniques, especially to assess their chiroptical properties. These modules will then be used to construct novel supramolecular structures. Special emphasis will be on the construction of new helical structures. Variation of substituents attached to the outer rim of the helix structure should allow functionalization and manipulation of these structures and allow their incorporation into unprecedented chiral helical supramolecular assemblies void of a chiral center. Furthermore, the synthetic possibilities will be explored to extend the allene moiety to afford chiral [4]cumulenes, a class of compounds that has remained unexplored.