The specific rates of solvolysis of N, N, N', N'-tetramethyldiamidophosphorochloridate have been measured at 25.0° C in 31 solvents. Analysis with the extended Grunwald-Winstein equation leads to sensitivities toward changes in solvent nucleophilicity (l) of 1.20±0.07 and toward changes in solvent ionizing power (m) of 0.69±0.04. The correlation is improved by omission of the four data points for 2, 2, 2-trifluoroethanol-ethanol mixtures (F-test value ...