ic402247n_si_001.pdf (1.34 MB)

The Electrode as Organolithium Reagent: Catalyst-Free Covalent Attachment of Electrochemically Active Species to an Azide-Terminated Glassy Carbon Electrode Surface

Download (1.34 MB)
journal contribution
posted on 02.12.2013, 00:00 by Atanu K. Das, Mark H. Engelhard, Fei Liu, R. Morris Bullock, John A. S. Roberts
The reaction of a lithium acetylide–ethylenediamine complex with azide-terminated glassy carbon surfaces affords 1,2,3-triazolyllithium surface groups that are active toward covalent C–C coupling reactions, including salt metathesis with an aliphatic halide and nucleophilic addition at an aldehyde. Surface ferrocenyl groups were introduced by reaction with (6-iodohexyl)­ferrocene; the voltammetry of electrode samples shows narrow, symmetric peaks indicating uniform attachment. X-ray photoelectron and reflectance infrared spectroscopic data provide further support for the surface-attached products. Formation of the 1,2,3-triazolyllithium linkage requires neither a catalyst nor a strained alkyne. Coverages obtained by this route are similar to those obtained by the more common Cu­(I)-catalyzed alkyne–azide coupling (CuAAC) of ethynylferrocene with surface azides. Preconditioning of the glassy carbon disk electrodes at ambient temperature under nitrogen affords coverages comparable to those reported with preconditioning at 1000 °C under hydrogen/nitrogen.