Synthesis of architecturally novel calix4arene phthalocyanines
O'Malley, Shane (2006) Synthesis of architecturally novel calix4arene phthalocyanines. PhD thesis, Dublin City University.
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One of the major problems associated with phthalocyanines is their strong tendency to aggregate in both solution and the solid state. As a consequence, their application as sensors, optical filters and as photosensitisers in polar media can be limited. It is the target of this work to prepare a new series of phthalocyanines which possess an isolated core, by isolating the core aggregation between phthalocyanine rings will be eliminated.
The strategy employed involved the preparation of a 3 and 4 calixarene substituted phthalonitrile. This was achieved in three steps and interestingly we were able to prepare a partial cone derivative for the 3-calixarene phthalonitrile where the phthalonitrile is within the upper rim of the calixarene. Such an arrangement places two of the t-butyl groups of the calixarene above and below the phthalonitrile ring. Furthermore, this conformation was found to be stable at temperatures in excess of 120°C. On the other-hand the 4-calixarene phthalonitrile gave both a partial cone and cone conformation.
We found that the 4-calixarene phthalonitrile could be readily self-condensed to the tertacalixarenephthalocyanine in good yields, on the other hand the 3- calixarene phthalonitrile only yielded traces o f the phthalocyanine on selfcondensation, and this is due to steric congestion. The 3-calixarene phthalonitrile was then cross-condensed with phthalonitrile to give the unsymmetrical monocalixarenephthalocyanine, with the phthalocyanine perched into the upper rim of the calixarene.
All calixarene phthalocyanines were studied for aggregational behaviour in both polar solution and the solid state. It was found that the tetracalixarene phthalocyanine does not show any aggregation either in the solid state or solution. The unsymmetricaPperched’ phthalocyanine does not aggregate in polar solution but forms dimers in the solid state.
Also reported within the thesis are the synthesis o f a series o f new novel calixarene bridged binuclear phthalocyanines. Their synthesis and properties are discussed.
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