Synthesis and Electrochemical Reactivity of sigma-Bonded and N-Substituted Cobalt Porphycenes.
The first synthesis and characterization of sigma-bonded and N-substituted cobalt porphycenes is reported. The investigated compounds are represented as (Pc)Co(R) and (N-CH(3)OEPc)CoCl, where R is CH(3) or C(6)H(5), Pc is the dianion of 2,3,6,7,12,13,16,17-octaethylporphycene (OEPc), 2,7,12,17-tetrapropylporphycene (TPrPc), or 2,7,12,17-tetraethyl-3,6,13,16-tetramethylporphycene (EtioPc), N-CH(3)OEPc is the monoanion of N-methyl-2,3,6,7,12,13,16,17-octaethylporphycene. Each sigma-bonded (Pc)Co(R) derivative can be reversibly reduced or oxidized by two electrons, but a slow migration of the sigma-bonded R group occurs following electrogeneration of [(Pc)Co(R)](+)()(*)() leading, as a final product, to an N-substituted cobalt(II) porphycene which is also electroactive and undergoes two reductions in PhCN. The singly reduced product of this reaction is formulated as a Co(II) pi-anion radical which undergoes a slow "back-migration" of the CH(3) group to regenerate (OEPc)Co(CH(3)).
Kadish
K. M.
KM
Department of Chemistry, University of Houston, Houston, Texas 77204-5641, Institut für Organische Chemie, Universität zu Köln, Greinstrasse 4, 50939 Köln, Germany, and Laboratoire d'Ingénierie Moléculaire pour la Séparation et les Applications des Gaz Associé au CNRS (LIMSAG), UMR 5633, Faculté des Sciences Gabriel, Université de Bourgogne, 6 Boulevard Gabriel, 21100 Dijon, France.
Boulas
P. L.
PL
Kisters
M.
M
Vogel
E.
E
Aukauloo
A. M.
AM
D'Souza
F.
F
Guilard
R.
R