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The sensor applications of MPc derivatives on carbon-type electrodes are briefly reviewed. The electrochemical properties of metallophthalocyanines in solution and on a surface are reviewed with emphasis on predicting redox potentials using Hammett substituent constants and using ligand electrochemical parameters. Design requirements for a two-electron redox process at a metallophthalocyanine center are discussed. A two-dimensional approach using both Hammett parameters and ligand electrochemical parameters is introduced. Some preliminary test examples are presented.

The oxidation of naphthalene was investigated in a biomimetic catalytic system using KHSO₅ and iron(III) tetrakis(p-sulfonatophenyl)porphyrin (FeTPPS) in order to elucidate the influence of solution forms, such as buffer pH and co-solvent types, on the reaction. 1,4-naphthoquinone was the main byproduct and the efficiency of oxidation, particularly 1,4-naphthoquinone formation, was influenced by pH and the type of co-solvent used. The most efficient conversion of 1,4-naphthoquinone was observed at an acidic pH (= 3). At higher pH, the formation of μ-oxo species (OFe₂(TPPS)₂) leads to a decrease of the percentage of naphthalene oxidized. In addition, the organic co-solvents (methanol, ethanol, 2-propanol and acetonitrile) influenced the amounts of naphthalene conversion. The amounts of 1,4-naphthoquinone formed were related to the electron donating character of the organic co-solvents.

The complex N,N',N″,N‴-tetramethyl-tetra-3,4-pyridinoporphyrazinocobalt(II) ([Co^IITMPz[4+])⁴⁺ adsorbed on a graphite electrode undergoes spontaneous reduction, forming a surface containing Co^I. Five reversible surface peaks are observed at low pH, two of which are two-electron concerted processes. At high pH, one of these two-electron processes splits into two one-electron waves. Both oxidation and reduction of the central metal can be observed, along with successive reduction steps involving the porphyrazine ligand. Notable is the marked shift to positive potentials of these processes, relative to unsubstituted cobalt phthalocyanine, due to the positive charge localized on the porphyrazine. The electrocatalytic activity of this complex modified electrode toward the reduction of hydrogen peroxide is also reported. We demonstrate that a series of different surfaces exist which are obtained by variation of pH and polarization potential and that these surfaces possess differing electrocatalytic activity. Surfaces inactive to hydrogen peroxide can exist at potentials more negative than active surfaces even though the driving force for peroxide reduction will be greater for the former.

Single-wall carbon nanotubes (SWNTs) can be well-dispersed in water by wrapping with short segments of natural DNA from salmon sperm. We report here the isolated DNA-wrapped SWNT hybrids. Measurements were carried out using UV-vis-NIR, near-infrared photoluminescence (PL) spectrum and atomic force microscopy (AFM). A possible charge transport between SWNTs and salmon-DNA is discussed in terms of observed spectral shifts in the photoluminescence spectra.

In the present work, the hydrotalcite-like compound [Mg₆Al₂(OH)${}_{16}$]CO${}_3\cdot$$n$H₂O (shorted as MgAl–CO${}_3)$ is synthesized and the adsorption of phosphorous anions, their adsorption performance on the surface of hydrotalcites, and its mechanism are analyzed. To theoretically clarify the adsorption mechanism and adsorption structures, we perform quantum chemistry calculations of reactants, locally stable states, transition states, and products among phosphorous anion, water, and hydrotalcite in a variety of pH ranges. The experimental result shows that the efficiency of phosphate removal does not depend on pH of the solution, with which the numerical results are consistent. In particular, we identify the factors of influencing the adsorption ratio in different pH ranges from the quantum chemistry calculations: the stability of locally stable states, and the energies and locations of potential barriers along the reaction pathway relative to those of the locally stable states. The results suggest that hydrotalcites synthesized in this work are suitable as sorbent materials for the adsorption and removal of phosphorous anions from aqueous solutions.