Equilibrium lithium ion pair acidities at 25° C have been determined in THF for the following acetamides: N, N-dimethyl-(4-biphenylyl) acetamide (1)(19.69), N, N-diethyl-(4-biphenylyl) acetamide (2)(20.30), N, N-dimethyl-diphenylacetamide (3)(20.76), N, N-diethyl- diphenylacetamide (4)(21.99), and 1-(diphenylmethylcarbonyl) pyrrolidine (5)(21.08). These acidity data compare well with those previously reported for the corresponding cesium ...