THE PHOSPHA-2-ALLYL-SYSTEM - ELECTROCHEMICAL AND QUANTUM-CHEMICAL INVESTIGATIONS

Electrochemical investigations on some substituted phospha-2-allyl cat ions are performed. The phospha-2-allyl cation prefers a bent rather t han a linear allene-type structure. According to quantum chemical calc ulations, in the lowest energy doublet state the single electron resid es in the non-bonding orbital of the pi-system. The electrochemical in vestigations on some substituted substrates indicate irreversible oxid ation to the radical dication as well as one-electron and two-electron reduction to the radical and anion. The various substituent effects a s well as the electronic properties of the parent cation, radical and anion and its valence isomers are rationalized by quantum chemical cal culations.