Functionalisation of terpyridine complexes containing the Re(CO)(3)(+) moiety

The investigation into the substitution and addition chemistry of Re(sigma(2)-terpy)(CO)(3)Cl shows that the chloride in Re(sigma(2)-terpy)(CO)(3)Cl (1) may be substituted for acetonitrile to give [Re(sigma(2)-terpy)(CO)(3)(CH3CN)][PF6] (2), but in the cationic complex [Re(sigma(2)-terpyMe)(CO)(3)Cl][PF6] (4), where the pendant pyridine has been methylated, substitution of the chloride could not be achieved using standard conditions. However, use of [Re(sigma(2)-terpyMe)(CO)(3)I][PF6] (3) results in the formation of [Re(sigma(2)-terpyMe)(CO)(3)(CH3CN)][PF6](2) (5). The acetonitrile ligand in complex 2 was found to be labile and could be substituted by pyridine donors.