Imprinted polymers were synthesized using the surface-grafting technique with [Co(III)1(vpy)(dmap)]PF6 {1, bis[2-hydroxy-4-(4-vinylbenzyloxy)benzaldehyde] ethylene-diimine; vpy: 4 -vinylpyridine; dmap : N,N'-dimethyl-4-aminopyridine} as the template. The metallated sites were probed using spectroscopic techniques including UV-vis, Fourier transform infrared, and electron paramagnetic resonance (EPR) spectroscopies to investigate the site architecture and isolation of the immobilized sites in the surface-grafted polymers. EPR studies showed a distribution of four and five coordinated sites similar to the bulk copolymers, and the surface-grafted polymer showed reversible binding to dioxygen in multiple cycles. Both results indicated site isolation in the surface-grafted polymers analogous to the bulk polymers. Although the dioxygen binding in surface-grafted polymers is reversible, the spin density decreases to 50% in the third cycle as opposed to bulk copolymers. This indicates that the sites are more heterogeneous and more exposed to the environment than the analogous sites in bulk copolymers. (C) 2001 John Wiley & Sons, Inc.