Preparation and physicochemical properties of tervalent cobalt complexes of porphyrins.
スポンサーリンク
概要
- 論文の詳細を見る
Tervalent cobalt complexes of octaethylporphyrin (OEP) and tetraphenylporphyrin (TPP), [Co<SUP>III</SUP>(OEP)(H<SUB>2</SUB>O)<SUB>2</SUB>]X (X=ClO<SUB>4</SUB>, BF<SUB>4</SUB>), [Co<SUP>III</SUP>(OEP)(THF)<SUB>2</SUB>]ClO<SUB>4</SUB>, [Co<SUP>III</SUP>(TPP)(H<SUB>2</SUB>O)<SUB>2</SUB>]X (X=ClO<SUB>4</SUB>), and [Co<SUP>III</SUP>(TPP)(H<SUB>2</SUB>O)Y] (Y=Cl, Br, SCN, N<SUB>3</SUB>) were synthesized. Molecular weight measurements indicate that only [Co<SUP>III</SUP>(TPP)(H<SUB>2</SUB>O)<SUB>2</SUB>]BF<SUB>4</SUB> and [Co<SUP>III</SUP>(TPP)(H<SUB>2</SUB>O)<SUB>2</SUB>]ClO<SUB>4</SUB> aggregate at higher concentrations in chloroform. In polar solvents such as methanol, all are monomeric. In nonpolar solvents, all the complexes show Soret bands at shorter wavelengths and somewhat paramagnetic <SUP>1</SUP>H NMR spectra; these anomalies are absent in polar solvents. Tetrafluoroborates and perchlorates react with ethyl vinyl ether smoothly to form 2,2-diethoxyethylcobalt(III) complexes which are easily converted to formylmethylcobalt(III) complexes. <SUP>1</SUP>H NMR and absorption spectra of the amine adducts prepared in this study, [Co<SUP>III</SUP>(OEP)(L)<SUB>2</SUB>]ClO<SUB>4</SUB> (L=pyridine, 2-methylimidazole) and [Co<SUP>III</SUP>(TPP)(L′)<SUB>2</SUB>]ClO<SUB>4</SUB> (L′=pyridine, 4-cyanopyridine, 4-methylpyridine), indicate that the two amine molecules coordinate to the central cobalt atom. As regards redox potentials for the Co(III)/Co(II) couple as measured by cyclic voltammetry, the cobalt(III) porphyrins are categorized into three groups: (i) BF<SUB>4</SUB> and ClO<SUB>4</SUB> salts with redox potentials at about 0.7 V; (ii) halides and pseudohalides with those at 0.2–0.3 V; and (iii) bis(amine) adducts with those at −0.3–+0.1 V. In polar solvents, however, the redox potentials of (i) and (ii) are very similar to one another.
- 公益社団法人 日本化学会の論文
著者
-
Sugimoto Hiroshi
Faculty Of Engineering Tokyo University Of Science
-
Mori Masayasu
Faculty of Science Osaka City University
-
Ueda Nobuhiro
Faculty of Science, Osaka City University
関連論文
- Antiadhesive Sites Present in the Fibronectin TypeIII-Like Repeats of Human Plasma Fibronectin
- The Preparation of Strictly Halide Complexes of Copper(II) and Their EPR Spectra
- Paramagnetic cobalt(III) complexes with organic ligands. VI. An X-ray photoelectron spectroscopic study.
- Preparation and physicochemical properties of tervalent cobalt complexes of porphyrins.
- The Reaction and Reaction Products of μ-O2-Dicobalt Ammine Complexes with Nitrites, Thiocyanates, etc.
- Tetravalent ruthenium porphyrin. II. The molecular and crystal structure of .MU.-oxo-bis((octaethylporphinato)ruthenium(IV) chloride) benzene solvate.
- The crystal and molecular structure of quadrivalent osmium porphyrin; .MU.-Oxo-bis(methoxo(octaethylporphinato)osmium(IV)).
- The crystal and molecular structure of diaqua(tetraphenylporphinato)-cobalt(III) perchlorate.
- The crystal and molecular structure of six-coordinate intermediate-spin porphinatoiron(III) complex. (Octaethylporphinato)bis(tetrahydrofuran)iron(III) perchlorate.
- Paramagnetic cobalt(III) complexes with organic ligands. VII. The isolation and properties of paramagnetic tetraammine-(5-nitrososalicylato)cobalt(III) complexes.
- Crystal Structure of μ-Peroxo-bis[nitrobis(ethylenediamine)cobalt(III)] Dinitrate Tetrahydrate