THERMOTROPIC PHASE-BEHAVIOR AND AGGREGATION PROPERTIES OF TETRAPHENYLPORPHYRINS CARRYING OLIGO(ETHYLENE OXIDE) ALKOXY UNITS

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