Molecular motion, cyclodextrin complexes

In the supramolecular systems as the complexes of polymers and copolymers with cyclic molecules as cyclodextrins, the surface properties and the molecular motion must change when the polymer is free that when the polymer is included inside of a cyclic molecule. The polymer in the complexed form cannot have the same situation when it is in uncomplexed state. 

Savage, H. Water structure in vitamin B12 coenzyme crystals. II. Structural characteristics of the solvent networks. Biophys. J. 50, 967-980 (1986). Stezowski, J. J. Molecular motion in host-substrate complexes the / -cyclodextrin N-acetylphenylalanine methyl ester system. Trans. Amer. Cryst. Assn. 20, 73-82 (1984). 

Similar spectral changes have been observed for Fecp2 in its inclusion complexes with cyclodextrins. Of particular interest is a comparison of the motional behaviour of ferrocene included in a-, p- and y-cyclodextrins, which have 6,7, and 8 rings respectively in the cyclic structures. The spectra of the Fecp2 inclusion complexes of a- and p-cyclodextrins are closely similar, but marked differences are observed for the complex with y-cyclodextrin. These differences are broadly consistent with proposals from CD studies of the inclusion complexes in solution which indicate that in both or and p-cyclodextrins the Fecp2 molecular axis is parallel to the cavity axis, but in y-cyclodextrin it is perpendicular to it [ ]. The different motional averaging experienced in the different complexes therefore relates closely to the... 

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