Synthesis, characterization, and surface properties of new bis-quaternary pyrimidinium surfactants

New bis-quaternary pyrimidinium surfactants were synthesized by reacting 4- amino-5-phenyl-pyrimidine with alkylene dibromides (C-8-C-12). Structural a ssignments of the new compounds were made on the basis of elemental analysi s, infrared, and H-1 nuclear magnetic resonance spectroscopy. Critical mice lle concentrations, as determined by tensiometry, were lower than those of previously studied corresponding monoquats. The rate of drop coalescence in an oil (heptane)/water emulsion of a bis-quat was lower than that of the c orresponding monoquat, showing a higher emulsification efficiency for the f ormer.