Metallophthalocyanines:  Versatile Electron-Donating Building Blocks for Fullerene Dyads

Abstract

A thorough investigation on the physicochemical properties, including electrochemisty and photophysics, of a new class of donor−acceptor hybrids, namely, phthalocyanine-fullerene dyads, consisting of free base 1a and zinc and copper complexes 1b and 1c, respectively, brings new insights into the stabilization of charge-separated radical ion pairs and the impact of redoxactive transition-metal centers on the photoperformance of macrocyclic phthalocyanines. In these dyads, the role of the phthalocyanines is twofold: First, it functions as an antenna (i.e., absorbing very efficiently light in the visible region of the solar spectrum) and, second, as a donor moleculeonce photoexcited. The initial photoexcitation is succeeded by an ultrafast electron transfer largely due to the strong electronic coupling between electron donor (Pc) and electron acceptor (C60) generating surprisingly long-lived radical ion pairs Pc•+−C60 •- with lifetimes of several nanoseconds. Large driving forces for the charge recombination and small reorganization energies of the Pc−C60 ensembles corroborate slow charge recombination dynamics, which, in turn, helps to rationalize the long lifetimes of Pc•+−C60 •-.

Creation of Fullerene-Based Artificial Photosynthetic Systems

“…64,66,72,87,101 We determined various ET parameters, including V and , for porphyrin-fullerene systems from the CT absorption and emission for the first time. 64,66,72,87,101 Such CT absorption and emission were also reported for other fullerene-porphyrin-linked [102][103][104][105] and fullerene-phthalocyanine-linked 106 systems. Furthermore, the specific -interaction has been successfully used in dye-sensitized bulk heterojunction solar cells consisting of porphyrin and fullerene (vide infra).…”

Zinc Phthalocyanine–Graphene Hybrid Material for Energy Conversion: Synthesis, Characterization, Photophysics, and Photoelectrochemical Cell Preparation

“…60 Additionally, it has been reported that ZnPc •+ also shows an absorption band at 840 nm. 75,76 This band is known to be broadened by strong π--π interac--tions. 65 Therefore, no observation of the absorption band at 840 nm in Figure 6a together the red shift and broad--ening of the absorption band in Figure 4 suggests strong π--π interactions of ZnPc •+ with graphene.…”

Multichromophoric Phthalocyanine–(Perylenediimide)8 Molecules: A Photophysical Study

“…[6,38] In addition, further tuning of the energy levels of moieties might allow efficient charge generation and extraction along the stacks for use in solar cells. [39][40][41][42] …”