MOLECULAR ENCAPSULATION OF TRANSITION-METAL COMPLEXES IN CYCLODEXTRINS .3. STRUCTURAL CONSEQUENCES OF VARYING THE GUEST GEOMETRY IN CHANNEL-TYPE INCLUSION-COMPOUNDS

Inclusion compounds of a range of cyclopentadienyl(arene)iron(II) sandwich complexes, structurally related ferrocenes and (tetramethylcyclobutadiene)cobalt complexes with alpha-, beta- or gamma-cyclodextrin (alpha-, beta-, gamma-cd) have been prepared. Complexes bearing sterically demanding ring ligands were selectively included in beta- or gamma-cd. X-Ray crystallographic studies of seven new alpha-cd adducts demonstrate that the molecular packing of the alpha-cd macrocycles in channel-type structures depends on the size and shape of the guest complexes. Crystal structure determinations of two of the beta-cd adducts reveal a channel-type structure similar to that of the corresponding alpha-cd adducts, although in these cases the exact orientation of the guest molecules could not be determined due to disorder.