الفهرس | Only 14 pages are availabe for public view |
Abstract The solid-state thermal monomerization of 9-methylanthracene photodimer (9MeAD) together with the phase changes accompanying its thermal monomerization have been studied using differential scanning calorimetry(DSC), X-ray powder diffraction as well as molecular fluorescence spectroscopy. 9MeAD was chosen as a model compound since the melting point of 9-methylanthracene (9MeA; that is the thermal product) is lower than the phase transition temperature from one crystalline phase to another. The activation energy for the phase transformation in 9MeAD has been determined from the analysis of the exothermic calorigram peak. The DSC data for the thermal monomerization of 9MeAD give activation energies that are dependent upon the monomerization stage. This has been substantiated by carrying out the solution monomerization of 9MeAD in different solvents of different viscosities. The photochemical and/or photophysical behavior of some meso-substituted anthracenes together with a new series of anthracene laser dyes were also studied. The medium effect on the emission characteristics together with fluorescence quenching of anthracenes using organic electron-acceptors have been studied. |