Synthesis and characterization of a doubly spin-labelled electrochemically driven molecular shuttle

Abstract

The EPR properties of novel nitroxide-spin-labelled rotaxanes containing a tetrathiafulvalene (TTF) unit and a cyclobis(paraquat-p-phenylene) ring are described. The rotaxanes were spin labelled both at the thread and the wheel. Single-electron oxidation of the TTF unit resulted in a significant through-space magnetic interaction between different radical units. In some cases, rotaxanation is proved to have dramatic effects on such magnetic interactions.