Triple Click to Tripodal Triazole-Based Ligands - Synthesis and Characterization of Blue-Emitting Ce3+Complexes

Tris(aryltriazolylmethyl)amine compounds have been synthesized by a one-pot triple click reaction of azides from anilines with tripropargylamine. The resulting tripodal ligands have been employed to obtain six new Ce3+ complexes. The formation of the new complexes, which were obtained both as heteroleptic or homoleptic types, is influenced by the nature of the counterion (nitrate, perchlorate, or triflate) of the starting Ce3+ salts. All the new Ce3+-based complexes are highly stable both in solution and in the solid state. Their structural features have been at first studied by NMR spectroscopy. In addition, by combining experimental and DFT theoretical approaches, the X-ray structure of one heteroleptic complex has been used to simulate the structures of all the remaining complexes. Finally, both the heteroleptic and the homoleptic complexes are luminescent, and the analysis of their photophysical properties indicate that the Ce3+ center regulates the occurrence of radiative processes. A new one-pot triple click reaction leads to tripodal triazole ligands, which are able to coordinate CeIII to give luminescent complexes. Their nature, such as their NMR spectra and photophysical properties, depends on the counteranion. By combining experimental and theoretical approaches, the X-ray structure of one complex is used to simulate the structures of the remaining complexes.