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, (1)H 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-naphthalocyanine 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.