Structurally Controlled Porphyrin‐Aggregation Process in Phospholipid Membranes

Structurally controlled aggregation course for five porphyrins (etioporphyrin [EP], 5‐mono‐ and 5,15‐di‐[p‐tol‐yl]etioporphyrin [TP and DTP], 5,10,15,20‐tetrakis[p‐tol‐y1]porphin [TTP], and 5,10,15,20‐tetrakis[3,5‐di‐tert‐bu‐tylphenyl]porphin [TBP]) in dipalmitoyl‐phosphatidyl‐choline liposomes has been monitored by fluorescence and absorption spectroscopy. While TBP shows no tendency to aggregate in liposomes, EP, TP, DTP and TTP form a porphyrin‐enriched domain in membrane interior with time. The further aggregation steps within porphyrin clusters resulting in formation of stacked porphyrin aggregates have been observed for EP, TP and DTP.