The synthesis and complexation of a cobaltocenium-based redox-active cryptand containing the phenanthroline unit

The synthesis and characterization of a cobaltocenium-based redox-active cryptand 3 containing a phenanthroline unit is described. Complex formation (with Ca2+) was studied by 1H/13C-NMR, and the effects of complexation on the redox properties of 3 were monitored by cyclic voltammetry. The fluorescence spectra of the complexes of 3 and its ferrocene analogue (4) with Eu3+ are also reported, and the low intensity of the fluorescence in each case attributed to carbonyl coordination of Eu3+ rather than metallocene quenching.