EXCITATION-ENERGY TRANSFER BETWEEN J-AGGREGATES OF CYANINE DYES IN LANGMUIR-BLODGETT-FILMS AND LIPOSOMES

LB films and liposomes incorporating J-aggregates of two kinds of cyanine dyes at the same membrane surface have been prepared. Four cyanine dyes, 1,1'-diethyl-2,2'-cyanine chloride or iodide (dye-I). 5,6,5',6'-dibenzo-1,1'-diethyl-2,2'-cyanine chloride (dye-II). 5.5'-dichloro-3.3'-diethyl-9-phenylthiacarbocyanine chloride (dye-III), 3,3'-dimethyl-9-phenyl-4,5,4',5'-naphtho-thiacarbocyanine chloride (dye-IV) were employed. In the case of a couple of dye-II : dye-III aggregates, quenching of resonance fluorescence of dye-II aggregate and sensitization of resonance fluoresence of dye-III aggregate, due to excitation energy transfer, were observed. The energy transfer also occurs in the dye-I : dye-III. dye-I : dye-IV, dye-II : dye-IV aggregates. In these cases, quinocyanine dye (dye-I, dye-II) aggregates and thiacarbocyanine dye (dye-III. dye-IV) aggregates act as the energy donor and acceptor, respectively.