Abstract: This paper is concerned with the exciplex formation between 2,6-dimethyl naphthalene di-carboxylate and some dimethyl naphthalenes. The relationship between the exciplex formation and molecular structure was studied by steady state and transient fluorescence measurements. Although the ionization potentials of dimethyl naphthalenes used was almost the same yet the charge distribution was different due to the different positions of two methyl groups on naphthalene. Thus, it was concluded that the capability of exciplex formation was affected not only by ionization potential but also by charge distribution.

Key words: exciplex, ionization potential, molecular structure, 2,6-dimethyl naphthalene dicarboxylate, dimethyl naphthalene