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Updated: Jul 19, 2026
Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Controlling the supramolecular assembly of redox-active dendrimers at molecular printboards by scanning
Christian A Nijhuis1, Jatin K Sinha, Gunther Wittstock
1Laboratories of Supramolecular Chemistry and Technology and Molecular Nanofabrication, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Abstract:
Redox-active ferrocenyl (Fc)-functionalized poly(propylenimine) (PPI) dendrimers solubilized in aqueous media by complexation of the Fc end groups with beta-cyclodextrin (betaCD) were immobilized at monolayers of betaCD on glass ("molecular printboards") via multiple host-guest interactions. The directed immobilization of the third-generation dendrimer-betaCD assembly G3-PPI-(Fc)16-(betaCD)16 at the printboard was achieved by supramolecular microcontact printing. The redox activity of the patterned dendrimers was mapped by scanning electrochemical microscopy (SECM) in the positive feedback mode using [IrCl(6)](3-) as a mediator. Local oxidation of the Fc-dendrimers by the microelectrode-generated [IrCl(6)](2-) resulted in an effective removal of the Fc-dendrimers from the host surface since the oxidation of Fc to the oxidized form (Fc+) leads to a concomitant loss of affinity for betaCD. Thus, SECM provided a way not only to image the surface, but also to control the binding of the Fc-terminated dendrimers at the molecular printboard. Additionally, the electrochemical desorption process could be monitored in time as the dendrimer patterns were gradually erased upon multiple scans.
