Kinetic studies show that azamacrocycles functionalised with pendent co-ordinating 2,2'-bipyridyl-yl-methyl arms co-ordinate to labile metal ions in two stages; the first stage is rapid and second-order, and involves formation of an intermediate with rate-determining co-ordination of the pendent bipyridyl arm, and the second stage is slower and first-order, involving chelation by the macrocyclic ring.Some studies have indicated that macrocycles functionalised with pendent co-ordinating arms may allow entry of a metal ion into the macrocyclic cavity at a more rapid rate than is possible with the unfunctionalised parent macrocycles. The proposed mechanism involves initial capture of the metal ion by the pendent arms, followed by transfer to the macrocyclic cavity.'--3 This conclusion, if generally true, would be of considerable value, since not only would the pendent arms enhance the stability of the final products, but they would also be beneficial in aiding the kinetics of the overall formation process. Entry of metal ions into the cavities of unfunctionalised macrocycles is often rather slow, partly because of the ligand conformational changes (e.g. chiral N-inversions) which often occur following initial metal ion binding.4-7Recently we reported the synthesis and characterisation of the azamacrocycles L1 and L2 which contain a pendent co-ordinating 2,2'-bipypyridyl-6-yl-methyl arm. L1 forms