A discrete, dicopper mu-alkynyl complex, [Cu-2(mu-eta(1):eta(1)-C equivalent to C(C6H4)CH3)DPFN]NTf2 (DPFN = 2,7-bis(fluoro-di(2-pyriclyl)methyl)-1,8-naphthyrldine; NTf2- = N(SO2CF3)(2)(-)), reacts with p-tolylazide to yield a dicopper complex with a symmetrically bridging 1,2,3-triazolide, [Cu-2(mu-eta(1):eta(1)-(1,4-bis(4-tolyl)-1,2,3-triazolide))DPFN]NTf2. This transformation exhibits bimolecular reaction kinetics and represents a key step in a proposed, bimetallic mechanism for copper-catalyzed azide-alkyne cycloaddition (CuAAC). The mu-alkynyl and mu-triazolide complexes undergo reversible redox events (by cyclic voltammetry), suggesting that a cycloaddition pathway involving mixed-valence dicopper species might also be possibte. Synthesis and characterization of the mixed-valence mu-alkynyl dicopper complex, [Cu-2(mu-eta(1):eta(1)-C equivalent to C(C6H4)CH3)DPFN](NTf2)(2), revealed an electronic structure with an unexpected partially delocalized spin, as evidenced by electron paramagnetic resonance spectroscopy. Studies of the mixed-valence mu-alkynyl complex's reactivity suggest that a mixed-valence pathway is less likely than one involving intermediates with only copper(I).