Electrochemical and Spectroelectrochemical Studies of Cobalt Phthalocyanine Polymers

Abstract

Spectroscopic and electrochemical properties of cobalt phthalocyanine (CoPc) polymers, which are believed to have two-and three-dimensional structures, have been studied and the results are reported. The spectral bands are shifted and a significant band broadening is observed as expected. The cyclic voltammetric results suggest that there are two energetically different Co ions in the three-dimensional polymer. The spectroscopic and electrochemical results indicate that the Co ion on the polymers appears to be in a partially reduced state in solution phases, as evidenced by the presence of the metal-ligand charge-transfer band. When adsorbed onto the carbon surface, this band becomes more prominent even in the formally unreduced state, perhaps due to the coordination of u-electron clouds of carbon into the coaxial axis of the complex, resulting in the partially reduced Co ion. As a result of this partial reduction, the electron transfer from CoPc polymers appears to be enhanced, which becomes the basis for the catalytic activities observed for this class of compounds.

Visible‐Light‐Driven CO2 Reduction by Mesoporous Carbon Nitride Modified with Polymeric Cobalt Phthalocyanine

“…Successful formation of CoPPc on mpg‐CN x was confirmed by diffuse reflectance UV/Vis spectroscopy (DRS), attenuated total reflectance infrared (ATR‐IR), Raman, and X‐ray photoelectron spectroscopy (XPS). DRS of mpg‐CN x |CoPPc shows the characteristic (S 0 →S 1 ) Q band of CoPPc at 700 nm, which is red‐shifted compared to the monomeric cobalt phthalocyanine (CoPc) (670 nm in DMF), consistent with its polymeric structure (Figure A) . Figure B shows that the Raman spectrum of mpg‐CN x is featureless, whereas that of the hybrid materials displays bands originating from CoPPc .…”

Electropreparation and characterization of polyNiTSPc films. An EQCM study

“…This porosity allows the movement of ionic species, such as hydrated cations and hydroxyl ions, within the film, as proposed by Cordoba-Torresi et al [28] for nickel hydroxide, in order to maintain film electroneutrality, thereby ensuring a low film resistance towards ion migration and diffusion. Perhaps there is also an enhanced charge delocalization in the polymeric films, which may increase not only the electron density at the central metal ion, but also the electronic conductivity of the film [29].…”

Studies on Synthesis and Spectral Characterization of Some Transition Metal Complexes of Azo-Azomethine Derivative of Diaminomaleonitrile

“…Schiff base ligands derived from the condensation of salicylaldehyde with diamines and their complexes [1,2] played an important part in the development of inorganic chemistry, as widely studied coordination compounds are increasingly important as biochemical, analytical, and antimicrobial reagents [3,4]. Also they have been used as antibacterial, antifungal, anticancer, antitubercular, hypertensive, and hypothermic reagents [5,6].…”