Heterobimetallic complexes of polypyridyl ligands containing paramagnetic centers: synthesis and characterization by...

Ligands containing linked dipicolylamine (dpa) and bipyridine sites have been explored as platforms for the synthesis of heterometallic complexes containing the paramagnetic metals Cu(2+) and Co(2+). IR and EPR studies on the bimetallic complexes and simplified model compounds support dpa-selective binding by both of these metals. The IR spectra have also been compared to those of diamagnetic Rh(+), Zn(2+), and Pd(2+) complexes whose metal binding sites had been independently determined through NMR techniques. The binding preferences have been used to control selective metalation in the synthesis of heterometallic Pt/Cu, Pd/Cu, and Rh/Cu complexes.