Abstract
The solvent effects on the electronic spectra of two polar organic dyes: pyridinium-cyclopentadien-ylid (I) and pyridinium-N-phenol-betain (II) are predicted and shown to be in agreement with experimental results. The solvatochromic behavior of the dyes is related to a medium of dielectric constant 2 and not as it is usually done to a vacuum. This method leads to the problem of calculating the dipole moments and molecular polarizabilities of the ground state and the excited states of the dye molecules in a medium of dielectric constant 2. Procedures for calculating these molecular constants are given.