Two aza scorpionand-like macrocycles and have been prepared. consists of a tren amine with two of its arms cyclizized with a 2,6-bis(bromomethyl)pyridine. In , the remaining pendant arm has been further functionalized with a fluorophoric naphthalene group. X-ray data on the compounds [H)]ClO4 center dot H2O and [H3H2PO4)(3)center dot H2O as well as solution studies (pH-metry, UV-vis, and fluorescence data) show the movement of the pendant arm as a result of the protonation degree of the macrocycles and of the formation of intramolecular hydrogen bonds. X-ray data on the complexes [Cu](ClO4)(2)](2)center dot H2O and [Cu](ClO4)(2) and solution studies on Cu2+ coordination show the implication of the nitrogen of the arm in the binding to the metal ion. Kinetic studies on the decomposition and formation of the Cu2+ complexes provide additional information about the pH-dependent molecular reorganizations. Moreover, the obtained information suggests that the kinetics of the tail on/off process is essentially independent of the lability of the metal center.