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Electrochemically triggered iron translocation between two coordination sites

Electrochemically triggered iron translocation between two coordination sites. Shanzer et al. Nature , 1995. Redox-Driven Anion Translocation between Metal Centers.

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Electrochemically triggered iron translocation between two coordination sites

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  1. Electrochemically triggered iron translocation between two coordination sites Shanzer et al. Nature, 1995

  2. Redox-Driven Anion Translocation between Metal Centers Controlled motion can be generated at the molecular level by making a particle translocate between fixed positions, following a prescribed pathway. The particle can be an anion, X-, and can be made to move between two transition metal centers, M1 and M2, taking advantage of the redox activity of one of them.

  3. square scheme illustrating the redox-driven translocation of an X- anion from Cu(II) to Ni(III) and vice versa. As the transient species b has too short a lifetime, the oxidation step, OX, and the direct translocation step, Tdir, cannot be distinguished and are perceived as simultaneous. The same happens for the reduction (RED) and reverse translocation (Trev) steps.

  4. Electrochemically triggered anion (Cl-) translocation in a multicentric supramolecular coordination compound.

  5. Transition metal ions can be moved reversibly between the two coordinatively unequivalent compartments A and B of a ditopic ligand, using as an input the variation of a bulk solution parameter, either pH or redox potential. In a redox-driven translocation, the metal moves reversibly from A to B on cycling between two consecutive oxidation states (e.g., Cu(II)/Cu(I); Fe(III)/Fe(II)) by means of auxiliary oxidation and reduction reactions. In a pH-driven process, one compartment displays also acid-base properties.

  6. Redox-driven translocation of a metal ion. The oxidized cation,M( n+1)+ (smaller sphere), has a hard nature and likes staying in the hard compartment A. The reduced cation,Mn+ (larger sphere), of soft characteristics, prefers to reside in the soft compartment B. The metal center can be reversibly translocated between A and B, through the M( n+1)+/Mn+ redox cycle, coupled to an auxiliary oxidation-reduction process.

  7. Redox-driven translocation of a copper center, based on the Cu(II)/Cu(I) change. The Cu(II) ion stays in the tetraamine compartment of the ditopic ligand, whereas the Cu(I) ion prefers to occupy the bis(2,2¢-bipyridine) compartment. The fast and reversible translocation of the metal between the two compartments can be carried out through auxiliary redox processes (reduction of Cu(I)I with ascorbic acid; oxidation of Cu(I) with H2O2).

  8. Cd(II) and Pb(II) Complexation by Dipyridine-Containing Macrocycles with Different Molecular Architecture. Effect of Complex Protonation on Metal Coordination Environment Paloma Arranz,† Carla Bazzicalupi,‡ Andrea Bencini,*,‡ Antonio Bianchi,*,‡ Samuele Ciattini,‡ Patrizia Fornasari,‡ Claudia Giorgi,‡ and Barbara Valtancoli‡ Inorg. Chem. 2001, 40, 6383-6389

  9. redox-driven translocation of the copper cation Shanzer, Albrecht-Gary and coworkers (Chem. Comm. 2002)

  10. + e- CuIIL(N2O2) *CuIL(N2O2) fast kII kI - e- *CuIIL(N4) CuIL(N4) fast kII = 9 x 10-4 s-1 kI = 2 x 10-2 s-1

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