Preorganized macrocyclic receptors featuring endo-carboxylic acid groups. Host synthesis and inclusion compounds with alcohol and amine guests

The synthesis and characterization of four new macrocyclic host compounds 1 -4 having modified diphenylmethane units as bridging elements and two endo- orientated carboxylic acid groups attached to aromatic building blocks are described. The complexation properties of the macrocycles towards amines an d alcohols are reported, showing that the ability to form convergent inclus ion compounds depends on the type of the spacer element. For the dicarboxyl ic hosts 1 and 2 endo-complexation of guest molecules based on hydrogen ben ding to the acid functions is proved using H-1 NMR investigation and X-ray crystal structure analysis.