Singlet and triplet energy transfer rate acceleration by additions of clusters in supramolecular pigment-organometallic cluster assemblies

摘要

Both S1 and T1 energy transfer rates (porphyrin → cluster) increase from mono- to di- to tetraearboxylateltetraphenyl-(zinc)porphyrin] adducts with [Pd3(dppm)3(CO)]2+ clusters. In past decades, tremendous efforts have been devoted to mimic natural photo-induced electron or energy transfer processes'-2 and the development of charge-separating devices.3-5 However, a large number of these models including porphyrin-based complex architectures, were based on covalent linkages.' Owing to the virtues of non-covalent systems, such as versatility, flexibility in design, and ease of synthesis, increasing attentions have recently been paid to the design and analysis of non-covalent systems, formed by hydrogen bonds,6 salt bridges,7 metal-ligand bonds8 to assemble donors and acceptors for energy transfers or charge separations. The assembling of carboxylate-porphyrins, which can bind cations, have widely been used as a convenient mean of forming noncovalent systems, including expanded porphyrins.9