[Mixed aggregation of pigments with participation of bacteriochlorophyll].

In binar mixture of solvents (dioxane--water, 1 : 4) the spectral-luminescent investigation of the regularities of mixed association and the energetic interaction between molecules of bacteriochlorophyll (BChl) and its analogs (chlorophyll a--Chl, protochlorophyll--PChl, 4-vinyl-protochlorophyll--4VPChl) under variation of donor-acceptor ratio (0,001 less than or equal to CD/CA less than or equal to 1) in the polymer complex was conducted. The essential role of the elementary cell structure of the mixed associate was discovered: the associate of individual BChl did not possess measurable fluorescence whereas the introduction of PChl, 4VPChl and Chl admixture (approximately greater than 1%) into BChl aggregate resulted in the appearance of a BChl fluorescent ability. It was suggested that admixture and BChl molecules formed dimer cells in which the excitation nonradiative deactivation probability was strongly decreased in comparison with individual BChl aggregate. These cells are the centres of mixed associates emission. It was shown that under conditions of effective energy migration in the system of nearly arranged centres with a high degree of orientation the excitation trapping probability strongly depended on the resonance conditions for transition density--transition density interaction between partners of aggregation.