Characterization of New Excimer Pumped UV Laser Dyes 3. P-Quinqui-, Sexi-, Octi- and Deciphenyls

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