Heteroleptic rare earth double-decker complexes with naphthalocyaninato and phthalocyaninato ligands. General synthesis, spectroscopic, and electrochemical characteristics

A novel one-pot procedure starting from the corresponding M(acac) ₃·nH₂O, metal-free phthalocyanine H ₂Pc′, and naphthalonitrile in the presence of DBU in n-octanol has been developed to prepare heteroleptic (naphthalocyaninato)- (phthalocyaninato) rare earth double-decker complexes. A series of six sandwich compounds with different naphthalocyaninato ligands, phthalocyaninato ligands, and central rare earth metals, namely, Sm[Nc(tBu)₄](Pc) [Nc(tBu) ₄ = 3(4),12(13),21(22),30(31)-tetra(tert-butyl)naphthalocyaninato; Pc = unsubstituted phthalocyaninato] (1), Sm(Nc)(Pc′) [Pc′ - Pc(OC₅H₁₁)₄, Pc(OC₈H ₁₇)₈; Nc = 2,3-naphthalocyaninato; Pc(OC₅H ₁₁)₄ = 2(3),9(10),16(17),-24(25)-tetrakis(3-pentyloxy) phthalocyaninato; Pc(OC₈H₁₇)₈ = 2,3,9,10,16,17,24,25-octakis(octyloxy)phthalocyaninato] (2, 3), and M(Nc)[Pc(α-OC₅H₁₁)₄] [M = Sm, Eu, Y; Pc(α-OC₅H₁₁)₄ = 1,8,15,22-tetrakis(3- pentyloxy)phthalocyaninato] (4-6), have been isolated in good yields from this one-pot procedure demonstrating the generality of this synthetic pathway. In addition to spectroscopic analyses, the electrochemistry of these novel compounds has also been studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods.