Theoretical Study on Interactions of β-cyclodextrin with Trans-dichloro(dipyridine) platinum(II)

To improve the bioavailability of trans-dichloro(dipyridine) platinum(II) (DDP) complexes, an inclusion technique has been developed to modify its physical and chemical properties. In this work, the geometries of the cyclodextrin inclusion complexes with DDP in gas phase are determined by DFT (B3LYP) method at standard 6-31G basis set and LanL2DZ basis set and PM6 semiempirical method. The optimized geometric structures obtained from DFT calculations are used to perform natural bond orbital (NBO) analysis. Intermolecular hydrogen bonds between DDP and β-CD are investigated. The calculated results indicate that DDP entering into the cavity of β-CD from its narrow side is energetic favorable. The calculated results are in good agreement with the experimental results.