Polynucleating systems with space-separated metal-binding sites

4 Polynucleating systems with space-separated metal-binding sites 

In this section the discussion is limited to polynucleating systems containing several substrate- or metal-binding sites which do not reside within the same macrocyclic framework. 

The ligands L1783 and L1784 were synthesised by a metal-directed condensation, around two copper(II) centres, of LI 781 and L1782 with nitroethane and formaldehyde (Eq. 8.52) [128, 129]. 

The ligands L1785 and LI786, half macrocyclic and half acyclic, are the byproducts of this synthesis. The dicopper(II) complexes of L1785 and L1786 (Eq. 8.53) possess three distinctly different electroactive groups when the pendant nitro group is considered in addition to the two non-equivalent metal centres [128]. 

Selectivity in reduction with the hydrated electron and oxidation with the hydroxyl radical have been shown to occur in redox reactions of dicopper(II) complexes with different ligand fields. The stronger field tetraazacomplexes exhibit and Cu / couples at significantly more negative potentials 

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