Steady-state fluorescence was used to measure the ratio of emission intensities, denoted I-D/I-M, for excited state complexes and excited monomers of five trichromophoric compounds, 2-naphthyl-COO-(CH2)(m)-OOC-2,6-dinaphthyl-OOC-2-naphthyl, m = 2-6. The linear aliphatic alcohols H(CH2)(n)OH, n = 1-7, as well as mixtures of ethylene glycol and methanol, were used to change the viscosity of the medium, eta. The values of I-D/I-M depend on eta and m. A Rotational Isomeric State model and Molecular Dynamics simulations were used for interpretation of the experimental results.