Unsaturated 1,1´-Ferrocenylene Bisphosphanes

Polymers featuring pi-conjugation along the main chain are currently of great interest and importance. Several recent investigations have focused on the incorporation of "inorganic" elements, notably phosphorus, into oligomers and polymers. The objective of the underlying project is to combine the unique electronic properties of the ferrocene system with those of adjacent P=E (E: =C<, =P-, =N-) units. In previous work we have already explored the interaction of ferrocene with a single unsaturated phosphanyl unit. By extending this concept to bifunctional precursors we will generate compounds in which a 1,1-ferrocenediyl unit links two phosphaethene, diphosphene or iminophosphane functionalities. This novel class of compounds will allow the electronic interaction between the ferrocenylene system and unsaturated phosphane units. From phenylene analogues substantial conjugation with desirable photoelectronic properties has been reported. Replacing phenylene by ferrocenylene bridges should combine sigma- donor and pi-acceptor properties comparable to phenylene with the redoxactivity of ferrocene. The primary goal is to develop a synthetic access to molecules in which two unsaturated P=E units are linked by a 1,1-ferrocenediyl bridge. Once these compounds have been prepared, we will attempt to extend the synthetic route to oligomers and polymers with alternating P=E and ferrocenylene units. The main focus of this project is to make these novel compounds synthetically available. Besides the conventional chemical characterization of the products by NMR, MS, X-ray diffraction, etc., we will investigate their electrochemical properties and fluorescence behavior. All synthetic work and most of the analytical work will be done in the existing facilities at the Department of Chemistry of the University of Graz. Using this infrastructure, research in the area of main group chemistry has been carried out in the recent past, clearly demonstrating the methodological capabilities and the available synthetic and analytical expertise. Funding is requested for a 3 year project for two graduate students (3 years) including consumables for specialty chemicals, organometallic reagents, inorganic gases, inert solvents, special glass work and other expendable items. The incorporation of inorganic elements into the polymer backbone is synthetically challenging and often results in materials with unique properties. Therefore, the development of methods to prepare -conjugated oligomers and polymers containing heavier main group (p-p) pi bonds is of fundamental interest, and may ultimately lead to materials with novel desirable properties.