Systematic Molecular Design of <i>p</i>‑Phenylene Lasing Properties

In an effort to design p-phenylene laser dyes with molecular properties which allow them to work more effectively with 308 nm XeCl lasers, two new empirical theories are proposed to predict the peak lasing wavelength of terminally substituted p-phenylene laser dyes. These theories account for variable numbers of p-phenylene units, different terminal groups with a range of electronic properties, and the effects of bridging between p-phenylene units. Both empirical models predict maximum molar absorption coefficients in addition to peak lasing wavelengths with the one intuitive parameter. Possibilities for the molecular engineering of p-phenylene properties are achieved with these new models, which have also been used to forecast the properties of two further p-phenylene compounds.