Organophosphazenes. 25. The synthesis and electrochemistry of the dicobalt hexacarbonyl complexes of phenylethynylcyclophosphazenes

The syntheses of the dicobalt hexacarbonyl complexes, N3P3F6-n(C[Formula: see text]CPhCo2(CO)6)n (n = 1 (3), n = 2 (4)), is reported. The introduction of the organometallic fragment allows for simplification of the NMR spectra and separation of the isomers of the disubstituted (4) derivatives. Electrochemical studies show that 3 undergoes a reversible one-electron reduction. At 233 K, the geminal isomer of 4 undergoes two separate reversible one-electron reductions. The ESR spectra of the radical anions of 3 and 4 have been obtained and show the absence of delocalization of unpaired spin density from the organometallic cluster to the phosphazene.Key words: cyclophosphazenes, cobalt–alkyne clusters, electrochemistry, ESR.