Bis-porphyrin arrays. Part 3.† The synthesis of model bis-porphyrin dimers and an electrochemical study
作者:Richard Beavington、Paul L. Burn
DOI:10.1039/a910323f
日期:——
We have successfully synthesised exo and endo diphenylacetylene linked bis-porphyrin dimers. We found that the exo-bis-porphyrin dimer could be easily prepared in good yield whilst the endo-dimer was harder to form due to the steric constraints of the meso-substituents. Electrochemical studies indicated that the porphyrin centred reductions of the bis-porphyrin dimers were dominated by the bis-porphyrin moieties. We found that the first four one-electron reductions of the exo- and endo-bis-porphyrin dimers occurred at similar potentials. Finally, at more negative potentials the bis-porphyrin dimers were reduced further which significantly changed the subsequent oxidation processes. This is thought to be due to a conformational change in the molecule which causes a change in orbital density in the “excited state”.
Porphyrins with appended phenanthroline units: a means by which porphyrin π-systems can be connected to an external redox centre
作者:Maxwell J. Crossley、Paul L. Burn、Steven J. Langford、Jognandan K. Prashar
DOI:10.1039/c39950001921
日期:——
Sequential condensation of a variety of porphyrin-2,3-diones with 1,2,4,5-benzenetetramine and 1,10-phenanthroline-5,6-dione generate conjugated phenanthroline-appended porphyrin systems; this chemistry provides a means by which porphyrin Ï-systems can be connected to external redox centres.