Fig.8 Fluorescence spectrums of TPPS4 in: a) ethanol [dot] {l ex=420 nm} and aqueous solution at pH=7.5 (concentration 10-6M [dash] and 10-3M [solid] {l ex=413 nm}; b) aqueous solution at pH=4 (c=5*10-6M) [dot] {l ex=420 nm} and aqueous solution at pH=2 (c=7.5*10-6M) {l ex=420 nm} [solid] ir {l ex=488 nm} [dash].