Self‐Assembling Depsipeptide Dendrimers and Dendritic Fullerenes with New <i>cis</i>‐ and <i>trans</i>‐Symmetric Hamilton Receptor Functionalized Zn–Porphyrins: Synthesis, Photophysical Properties and Cooperativity Phenomena

Katja Maurer, Bruno Grimm, Florian Wessendorf, Kristine Hartnagel, Dirk M. Guldi, Andreas Hirsch

European Journal of Organic Chemistry · 2010 · 17 citations · 64 references

Concepts

Abstract

Abstract Two novel supramolecular building blocks, namely cis ‐ and trans ‐symmetric zinc–porphyrins bearing Hamilton receptors as their focal points ( 10 and 15 ), were self‐assembled with (i) first‐, second‐ and third‐generation depsipeptide cyanurates ( 21 – 23 ); (ii) second‐generation dendrofullerene ( 24 ), and (iii) cyanuric acid substituted fullerene ( 20 ), and probed in a series of photophysical investigations. Importantly, an overall 1:2 stoichiometry was confirmed with binding constants K n , and Hill coefficients n H that indicate remarkable cooperativities. As a general feature, stronger binding evolves from the trans ‐symmetric porphyrin isomer, although the increased steric demand of the depsipeptide ligandsmeans that the binding constants decrease with each generation. The self‐assembly of 10 or 15 with 20 affords novel electron donor–acceptor hybrids that reveal, upon excitation,intra‐hybrid charge‐transfer events.

References

64