New C-functionalized syn- and anti-dioxocyclam and cyclam derivatives with 1,2,3-triazole units attached to carbon atoms within the skeleton were designed as valuable bifunctional chelating agents for applications in nuclear medicine. These macrocyclic chelators were prepared via a multi-step sequence involving alpha- and beta-amino acids, and their copper(II) complexation properties were evaluated. A solution structure in which the triazoles are in axially coordinating positions was proposed for the [Cu(anti-27)](2+) complex. Promising results have been obtained regarding the complexation kinetics (<10 s) and the pseudo-first order half-life for acid-assisted dissociation (t(1/2) = 3.21 d, 5 M HCl, 50 degrees C).