Excitation and Detection Energy Dependence of the Fluorescence of Polysilanes in Dilute Solutions

Excitation energy dependence of the fluorescence spectra and detection energy dependence of the fluorescence excitation spectra have been investigated for symmetrically and unsymmetrically substituted polyalkylsilanes in dilute solutions at different temperatures. The fluorescence maximum measured as a function of the excitation energy and the excitation maximum obtained at different detection energies at temperatures above the thermochromic transition temperature for the former polysilanes vary almost in the same way as those of the latter polysilanes. It is inferred from the spectroscopic data that the distribution and arrangement of the segment lengths of symmetrically substituted polysilanes above the transition temperature resemble those of unsymmetrically substituted polysilanes.