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Spring open two-plus-two electron storage in a disulfide-strapped methyl viologen derivative
Andrew C Benniston1, Jerry Hagon, Xiaoyan He
1Molecular Photonics Laboratory, School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. a.c.benniston@ncl.ac.uk
Abstract:
The synthesis of a disulfide-strapped viologen derivative is described starting from 4,4'-bipyridinyl-3,3'-diol. The first two one-electron reduction potentials, as determined by cyclic voltammetry, occur at E(1/2) = -0.03 V and E(1/2) = -0.16 V vs Ag/AgCl. This is accompanied by two more well separated one-electron reductions at E(1/2) = -1.26 V and E(1/2) = -1.54 V vs Ag/AgCl and the breaking of the disulfide bridge. To alleviate electrostatic repulsion between the two thiolate ions the molecular system must twist or "spring open" to accommodate the final two electrons.
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