A molecular dynamics study of the inclusion complexes of C60 with some cyclodextrins.

The strongly hydrophobic C(60) fullerene is a carbon allotrope of huge interest in materials science and in pharmaceutical chemistry that can be solubilized in water either by extensive chemical functionalization or by inclusion in appropriate carriers such as the cyclodextrins with formation of host-guest complexes. Here we report a molecular dynamics study of the complexes formed in solution by C(60) with gamma- and delta-cyclodextrins. The most stable host-guest complex stoichiometry is determined to be 2:1 through simulations in vacuo and in explicit water by the stepwise addition of the cyclodextrins to C(60). No a priori assumption about the inclusion stoichiometry and geometry is made. The equilibrium fluctuations of the complexes that can affect the system stability are also investigated within the molecular dynamics runs.