The electrode as organolithium reagent: catalyst-free covalent attachment of electrochemically active species to an azide-terminated glassy carbon electrode surface.
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.
Center for Molecular Electrocatalysis, Chemical and Materials Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, K2-57, Richland, Washington 99352, United States.
Atanu K
AK
Das
Mark H
MH
Engelhard
Fei
F
Liu
R Morris
RM
Bullock
John A S
JA
Roberts
D000447:Aldehydes / Q000737:chemistry; D001386:Azides / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D004566:Electrodes; D005029:Ethylenediamines / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry; D007202:Indicators and Reagents; D008094:Lithium / Q000737:chemistry*; D000075163:Metallocenes; D009942:Organometallic Compounds / Q000737:chemistry*; D014230:Triazoles / Q000737:chemistry
D000447:Aldehydes; D001386:Azides; D005029:Ethylenediamines; D005296:Ferrous Compounds; D007202:Indicators and Reagents; D000075163:Metallocenes; D009942:Organometallic Compounds; D014230:Triazoles; C031234:ethylenediamine; D002244:Carbon; D008094:Lithium; C004998:ferrocene