Electronic Transitions of Tetracyanoethylene and 1,2,4,5-tetramethylbenzene in Polar and Non- Polar solvents

The interaction of molecules with a solvent has an influence on the shape and position of bands of a chromophore in electronic spectroscopy. The maximum absorption wavelength ( λmax ) was determined using the spectra obtained from the UV/Visible spectrophotometer .Considering the shape, the spectral bands of the molecule in solution were noticed to be broader than in gas phase because of the fluctuations in the solute- solvent interactions. Really, such interactions were observed to change slightly among solute molecules, and with time showed the energy differences between their electronic and vibrational levels. This can be seen as an important source of the inhomogeneous broadening, indicating that the broadening is attributed to theinhomogeneous conditions experienced by the absorbing or emitting molecules