Abstract
Equilibrium quotients for the 1:1 complexes of dibenzo-30-crown-10 with Na(+), K(+), Rb(+), Cs(+), NH(4) (+), and T1(+) in methanol solution have been determined spectrophotometrically. The observed selectivity pattern is discussed in terms of the hydration energy of the cations and the cation-ligand binding energy. The rate of complex formation is diffusion-controlled. Relaxation amplitude data are consistent with a mechanism that involves conformational change of the crown compound.