A nonlinear waveguide material with a good transparency/efficiency trade-off is presented. The synthesis of the biaryl-based salt and its mesomorphic and nonlinear optical properties, including second harmonic generation from floating Langmuir-Blodgett layers, are described. The advantages of this new phenol/pyridinium triflate, which exhibits mesomorphic properties over a 50-degrees-C range, compared to the uncharged and zwitterionic analogues are discussed.