The inclusion compound of a new ionizable derivative of beta-cyclodextrin with ferrocenium drug.

A new beta-cyclodextrin (beta-CD) derivative, mono[6-deoxy-6-(2-butenedinitrile-2,3-dimercapto sodium salt)]-beta-CD (6-mnt-beta-CD), and its inclusion compound with a ferrocenium drug, have been prepared and characterized by IR, UV, 13C-NMR spectroscopy, and mass spectrometry, elemental analysis, thermogravimetry, and cyclic voltammetry (CV). The interplay between the side-arm anion of beta-CD and the ferrocenium (guest) in the inclusion compound 6-mnt-beta-CD-/Fc+ has been investigated by 13C-NMR, UV, IR, and thermogravimetric methods. Charge transfer from the anion to the cation in 6-mnt-beta-CD-/Fc+ was then experimentally identified. The interaction between the guest and the host with side-arm in 6-mnt-beta-CD-/Fc+ resulted in smaller positive potential shifts compared to that in the inclusion compound [beta-CD/Fc+]BF4-.