STRUCTURAL TRANSFORMATIONS OF IMPURITY CENTERS IN NAPHTHALENE CRYSTALS

A new kind of structural transformation of impurity centers in molecular crystals was found. Light irradiation and annealing of naphthalene crystals, doped with some aniline derivatives, results in sharp changes of the optical spectra of impurity and local (X trap) states. Calculations of aniline sites in naphthalene crystals using the method of atom-atom potentials have been carried out. Sets of impurity sites, with and without hydrogen bond between impurity and host molecules, were obtained. Infrared-spectra investigations confirm results of the calculations. Possible mechanisms of the observed transformations are also discussed. © 1995 American Institute of Physics.