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Published on: August 13, 2020
Conformational isomers of linear rotaxanes
Edith M Sevick1, David R M Williams2
1Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia.
Abstract:
We examine a simple model of rotaxane structure, with 3 asymmetric rings interacting via repulsive power-law forces. This interlocked molecule exhibits conformational isomerisation which is different from that of molecules whose connectedness is through covalent bonds. The rings are free to translate along and rotate around the axle, and hence weak interaction forces between the rings can lead to distinct rotamer states. We use energy minimisation to determine these states exactly, and show that there can be transitions from asymmetric to symmetric states by varying the bond lengths. We also use classical statistical mechanics to show the effect of thermal noise.
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