Synthesis and Photophysical Properties of Conjugated and Nonconjugated Phthalocyanine-Perylenediimide Systems

The synthesis and characterization of different conjugated phthalocyanine perylenemonoimidebenzimidazole [ZnPc-PBIm(OR)(4)] and nonconjugated phthalocyanine perylenediimide [ZnPc-PDI(OR)(4)] dyads are carried out. UV-vis, H-1 NMR, and electrochemistry measurements reveal the interaction between perylene and phthalocyanine moieties in the ground state in the conjugated hybrid and the lack of interaction in the nonconjugated one. Ultrafast transient absorption measurements show that a state with substantial charge-transfer character is formed in both compounds, but the rates for the formation and recombination from this state are much faster for the conjugated compound.