The alkaline hydrolytic stability of quaternary ammonium-functionalized organosiliconate has been studied using C-13 NMR. The half-life of (CH3O)(3)Si(CH2)(3)N(CH3)(3)Cl was determined under conditions in which base-catalyzed SI-R bond cleavage occurs. At 200 degrees C, t(1/2) decreased by three orders of magnitude from pH 5 to pH 13. The formation of propyltrimethyl ammonium, and its subsequent further hydrolysis to propanol and trimethylamine, was verified by deuterium labeling experiments. The relevance of these findings to the possible use of these reagents in novel materials synthesis is discussed.