Preparation and Properties of Inclusion Compounds of Cyclodextrins with Organotransition Metal Complexes

Abstract

Inclusion compounds of transition metal complexes of cycloocta-1,5-diene (cod) and norbornadiene (nbd) with cyclodextrins were prepared. Two-to-one (cyclodextrin:guest) inclusion compounds were obtained in high yields by the treatment of β-cyclodextrin (β-CD) with [(L)RhCl]₂ (L = nbd or cod) and 1:1 inclusion compounds were obtained by the reaction of β-CD with (cod)PtX₂ (X = Cl, Br, or I) in high yields, while γ-CD formed 1:1 inclusion compounds with (cod)PtX₂ (X = Br or I). The formation of inclusion compounds is selective. α-CD did not form inclusion compounds with any transition-metal complexes with cycloocta-1,5-diene. Thermogravimetric measurements show that the complexes are stabilized by inclusion in cyclodextrin cavities. The inclusion compounds were characterized by ¹ H-NMR, IR, UV, and circular dichroism spectra.