Laser Dye Synthesis; Group F Compounds

摘要

This report describes progress toward the syntheses of new potential laser dyes. It is anticipated that new substrates will allow upscaling of flashlamp-pumped dye lasers to higher energies. The criteria for assessment of these dyes include a) the extent to which they show a lower, laser action threshold, b) their operational efficiencies, and c) their photochemical stabilities compared with laser dyes previously evaluated. In principle, high optical quality and convenient cooling are obtainable using a flow system. Also, costs should be relatively small compared with those for solid state lasers if reasonably short, high yield synthetic routes can be found. Pavlopoulos has proposed that improvements in presently available laser dyes may be realized by restricting chromophores and auxochromic groups to coplanarity or near coplanarity. The desired result of imposing these structural conditions is the reduction of intersystem crossing and thus improvements in quantum fluorescence yields. The targeted compounds described were designed to meet these objectives. Keywords: 9,9-Dimethyl-fluorene derivatives, Deprotonation, Bromination. (aw)