Post-Functionalization of Pyridine-Modified Electrodes via Anodic C–N Coupling

The oxidation of 2,7,12,17-tetra-tert-butylporphyrin
Zn(II) (Zn-1) on a phenyl-pyridinyl-modified glassy carbon
(GC) or Indium Tin Oxide (ITO) electrode resulted in the formation
of a new C–N bond linking the porphyrin and pyridine units.
This innovative post-functionalization grafting strategy was investigated
using electrochemical, photophysical, structural, and surface characterizations,
validating the expected structure and the involved mechanism. Additionally,
a reference pyridinium-porphyrin compound was electrosynthesized by
oxidizing Zn-1 in the presence of a slight excess of
the corresponding phenyl-4-pyridinyl nucleophile. The physicochemical
properties of this reference compound matched those of the functionalized
porphyrin material.