Twelve novel phosphazene bases (X-C6H4-NN-C6H4-NPR3) with an unusual combination of properties – high lipophilicity of both neutral and charged forms, lack of localized charges in the cations, and strong spectral changes upon protonation/deprotonation – were synthesized using the Staudinger reaction and characterized by UV–Vis spectra, pKa values and lipophilicities (logP values). The bases could potentially be useful as working agents in optical sensors and acid-base indicators for lipophilic membranes.