CHARACTERIZATION OF NEW EXCIMER PUMPED UV LASER-DYES .3. P-QUINQUIPHENYLS, SEXIPHENYLS, OCTIPHENYLS AND DECIPHENYLS

The spectroscopic and lasing characteristics of a series of 308 nm pumped p-oligophenylenes with five or more phenyl rings have been studied. Quantitative comparisons of the absorption spectra of these dyes with numerous other dyes in this class of compounds can be made by defining a parameter, theta, as the sum of the number of phenyl rings and the number of ring-bridges. Statistically good linear regressions result from the correlations of molar extinction with theta and from wavelength of absorbance with the reciprocal of theta. We find that these correlations provide good predictive information in deciding which dyes to attempt to synthesize for testing. The lasing characteristics of the dyes studied show that these dyes are amongst the best dyes in this class of dyes. Some of these dyes have exceptionally long lifetimes coupled with acceptable conversion efficiencies.