Thermotropic phase behaviour and aggregation properties of tetraphenylporphyrins carrying oligo(ethylene oxide) alkoxy units

Abstract

The thermotropic phase behaviour and aggregation properties of some tetraphenylporphyrin derivatives containing oligo(ethylene oxide) alkoxy side chains have been examined. Differerential scanning calorimetry (DSC) measurements revealed no mesomorphic behaviour for these porphyries. It was found by means of UV–VIS absorption spectroscopy that all the investigated porphyries tend to organize into similar and highly ordered J-aggregate like structures in solution, at the air/water interface and on solid substrates directed by the mutual π–π interactions of the porphyrin rings. The complexation of the porphyries with Lil in spin-coated films was studied. The ions are indeed solubilized into the ethylene oxide units and have a strong influence on the organization of the aggregates as was observed by changes in the visible absorption spectra.