20-and 40-membered macrocyclic mono and dinuclear uranyl complexes 11–13 incorporating salen and (R)-BINOL units have been designed and synthesized starting from 4-tert-butylphenol in eight steps. NMR measurements (COSY, NOESY/EXSY) indicate that such complexes in solution are involved in conformational equilibria, which for the 20- membered derivatives are observable already at room temperature (k1= 300s− 1 at 300K) ...