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An Electrochemical Investigation into a Series of Tricyanovinylated Pyrrole Moieties
Author(s) -
McCormac Timothy,
Farrell David,
Browne Wesley,
Vos Johannes G.
Publication year - 2004
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200303014
Subject(s) - chemistry , electrochemistry , acetonitrile , redox , pyrrole , cyclic voltammetry , supporting electrolyte , electrolyte , platinum , inorganic chemistry , monomer , glassy carbon , electrode , voltammetry , organic chemistry , catalysis , polymer
The electrochemical behavior of three tri‐cyanovinylated pyrrole species namely, 2‐tricyanovinyl‐pyrrole (C 4 H 4 NC 5 N 3 ), 2‐tricyanovinyl‐ N ‐methylpyrrole (C 5 H 6 NC 5 N 3 ) and 2‐tricyanovinyl‐ N ‐phenylpyrrole (C 10 H 8 NC 5 N 3 ), has been studied. All compounds were found to exhibit both an irreversible oxidation at more positive potentials compared to the unsubstituted monomer species and a reversible reduction redox couple associated with reduction of the co‐ordinated cyano ligands. The latter reductions of the tricyanovinylated compounds to their radical anions at platinum, carbon and gold electrodes in acetonitrile solution have been studied by cyclic voltammetry, using a variety of supporting electrolytes. The half‐wave potentials for each compound were found to be dependent upon the supporting electrolyte but independent of the nature of the electrode surface. This is attributed to ion‐pairing between the anions and the alkali metal cations. The reduction based redox processes of C 10 H 8 NC 5 N 3 and C 5 H 6 NC 5 N 3 were found to be facile in nature and independent of both the nature of the electrolyte and electrode surface. However, the reduction of C 4 H 4 NC 5 N 3 was found to be irreversible in nature. Attempts were made to elucidate, by both electrochemical and spectroscopic means, the structure of the products obtained upon oxidation of the tricyanovinylated compounds.