From the single-to the triple-decker sandwich. Effect of stacking on the redox and UV-visible spectroscopic properties of lutetium(III) 1,2-naphthalocyaninate complexes

(1,2-Naphthalocyaninato)lutetium(III), bis(1,2-naphthalocyaninato)lutetium(III), and tris(1,2-naphthalocyaninato)dilutetium(III) have been synthesized in good yields. These complexes were characterized by UV-visible, H-1 NMR, and mass spectroscopies and by electrochemical techniques. Bis(1,2-naphthalocyaninato)lutetium(III) is compared to bis(2,3-naphthalocyaninato)lutetium(III) : the good correspondance between the experimental data and theoretical results obtained by others is emphasized in this work. Stacking one to three-macrocyclic rings is possible in the series of the 1,2-naphthylocyanine sandwich-like complexes with lutetium(III); as shown by UV-visible spectroelectrochemistry and voltammetry, this influences greatly the pi-conjugated systems, modifying spectacularly their spectroscopic and redox properties.