9412387 Tessier University of Akron Dr. Claire Tessier, Chemistry Department, University of Akron, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program for the preparation of main group and transition metal heterocyclynes. Cyclyne ligands are cyclic polyalkynes. The first goal of the research is the synthesis of cyclynes with three alkynes, two phenyl groups and a heteroatom in an 11 membered ring. The heteroatoms to be included in the ring include main and transition metals. The interaction of these heterocyclynes with further transition metals will be investigated, particularly in regard to the formation of complexes in which a transition metal is complexed within the cavity of the ligand. The geometric constraints of the cavity and ring may force a metal-metal bonding interaction between metals in the ring and those in the cavity. Unsymmetrical compounds which contain two metals are being exploited to activate small molecules like carbon monoxide and as non-linear optical materials. This study will form a new class of such complexes by forming a metal containing ring of atoms which contains a cavity which a second metal may enter. The two metals will be close enough to interact with each other, and this may yield new systems capable of activating small molecules and give rise to unique optical properties.