Functional Pentelidene Complexes of the heavier Group 15 Elements

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The project bases on the exploration of the reaction behavior and subsequent chemistry of a special class of compounds of bridged pentelidene complexes of the type [Cp*E{M(CO)5}2] (Cp* = eta1-C5Me5; E = P, As; M = Cr, W). In these pentelidene complexes the specific properties of the sigma-bound Cp*-substituent are linked with the electrophilic character of the bridged pentel atoms, leading to a unique combination of differentiable and therefore controllable reactivity of these complexes. The focus of the investigations is on the one hand directed to the selective photolytic generation of pentel atom radicals and their selective subsequent reactions with different compounds to yield stable radicals as three- and four-membered ring derivatives, respectively, for which also corresponding dimers with novel electron deficient bonding pattern are possible to be formed. Selected products are transferred in unprecedented cationic and anionic derivatives, respectively. On the other hand the main reactions channel to be investigated bases on the nucleophilic attack at the pentel atom of these starting materials. By systematic investigations of the reactivity towards functional nucleophiles, possessing in alpha- and beta-position reactive functions for a subsequent chemistry, the targeted formation of novel complexed heterocycles will be possible, which features a large number of different heteroatom sequences. By decomplexation reactions, for the first time, free heterocycles are obtained, which easy accessibility makes the pentelidene complexes to unique starting materials. In dependency on temperature and concentration a selective addressing of the reactivity towards multifunctional substrates is studied to achieve selective and switchable subsequent reactions. By this way new oligomers and polymers are obtained featuring heterocycles as linking units. Moreover, the reaction behavior of bridged aminopentelidene and halogenopentelidene complexes is studied and the differences to Cp* substituted derivatives are determined.