Bulletin of Japan Society of Coordination Chemistry
Online ISSN : 1883-1737
Print ISSN : 1882-6954
ISSN-L : 1882-6954
57 巻
選択された号の論文の9件中1~9を表示しています
Award Accounts
  • Andrew K Udit, Michael G Hill, Jay R Winkler, Harry B Gray
    2011 年 57 巻 p. 2-12
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    Employing laser flash-quench triggering methods, we have shown that 20-angstrom, coupling-limited Cu(I) to Ru(III) electron tunneling in Ru-modified blue copper proteins can occur on the microsecond timescale both in solutions and crystals. Redox equivalents can be transferred even longer distances by multistep tunneling, often called hopping, through intervening amino acid side chains. The lessons we have learned about the control of electron tunneling and hopping through biological molecules are now guiding the construction of wired and sensitizer-modified P450s for investigations of electrocatalysis and photocatalysis of oxygenation reactions.
  • 藤田 誠
    2011 年 57 巻 p. 13-29
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    Molecular self-assembly has recently undergone on explosive development, making possible the synthesis of many fascinating and complex structures using only relatively simple procedures. Over the last two decades, we have been showing that the simple combination of palladium's square planer geometry (a 90 degree coordination angle) with pyridine-based bridging ligands gives rise to the quantitative self-assembly of nano-sized, discrete organic frameworks. Representative and early examples in this field include square molecules (1990), linked-ring molecules (1994), cages (1995), tubes (1999), capsules (1999), and spheres (2004) that are self-assembled from simple and small components. By networking the discreet frameworks, we have also developed porous coordination networks (1994). In this article, we will disclose the structure of these self-assemblies as well as the chemistry of self-assembled “space” created in the void of the assemblies, where new chemical and physical properties of enclosed molecules are exhibited.
  • 橋本 和仁
    2011 年 57 巻 p. 30-35
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    Genus Shewanella is a gram-negative microorganism which has a unique property of utilizing solid state metal-oxide as a terminal electron acceptor. The extracellular electron transfer (ET) occurs via cytochromes located in the outer membrane (outer membrane-cytochrome, OMC). Due to the unique property, Shewanella has attracted a lot of attentions from the view point of biogeochemical cycle and microbial fuel cell. In this review, our recent results on the extracellular ET will be introduced with Shewanella loihica PV-4. We used various electrochemical techniques as well as spectroscopic ones to investigate the ET between the microbes and the (solid) electrode. Based on the various experimental results, we show evidences of the existence of direct ET path from OMC to electrode. We also show that the addition of water soluble Mn Porphyrines, semiconducting iron oxide nano colloids, etc., greatly enhances the ET efficiency. The extracellular ET process can be applied to microbial fuel cell. The power output of thin fuel cell, so far we achieved, is ca. 2 W/l, which is almost equal to one of the most efficient bio-fuel cells using isolated protein catalysts.
  • 高石 慎也
    2011 年 57 巻 p. 36-44
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    Metal complexes have originally many kinds of bistability owing to charge, spin, lattice etc. Recently, there has been much effort for controlling the macroscopic properties by the molecular bistability through cooperative phenomena. In the one-dimensional systems, especially, dynamics can be expected owing to the bistability of molecules because cooperativity is not so strong comparing to three-dimensional systems. We have studied on the charge dynamics in quasi-one-dimensional halogen-bridged metal complexes by using charge bistability of metal ions. In this review, a method for creating the charge bistability by reducing band gap energy and new method for detecting such a charge bistability by using scanning tunneling microscopy (STM) has been reported.
  • 松田 亮太郎
    2011 年 57 巻 p. 45-56
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    Nanoporous materials are ubiquitous and indispensable in daily life as adsorbents. The discovery of a new porous compound having unique properties based on intrinsic nano-sized space and surface functionalities is scientifically and technologically important. Recently, porous coordination polymers (PCPs) or metal organic frameworks (MOFs) have been extensively studied because they can provide variety of nano-sized space in their stable frameworks by taking advantage of the features of “metal complex”. Now, many unusual porous functions have been achieved in this class of compounds, which have not been found in the traditional materials. In this accounts, we focus on the synthesis and functionalization of porous coordination polymers and their unusual selective sorption properties. Here, the following topics have been reported; 1) highly controlled acetylene accommodation in one dimensional channel, 2) a molecular gate exhibiting a locking / unlocking system in the nano-channel, 3) selective sorption of O2 and NO in a TCNQ based porous coordination polymer utilizing charge transfer interaction, and 4) on-demand photochemical guest trapping and conversion by a light-responsive porous coordination polymer.
Accounts
  • 倉橋 拓也, 藤井 浩
    2011 年 57 巻 p. 57-66
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    In order to garner in-depth understanding of oxidation catalysis by salen complexes, we investigated the conformation, electronic structure and reactivity of high-valent salen complexes. We herein show that the conformation of a chiral manganese salen complex (Jacobsen's complex) is critically dependent on the oxidation state of the manganese ion and the external axial ligands that coordinate to the manganese ion, in relevance to asymmetric reactions. We also show that the reaction of a manganese(III) salen complex with m-chloroperoxybenzoic acid, an oxidant utilized for enantioselective epoxidation, generates a mixture of manganese(IV)-oxo and manganese(IV)-hydroxo species at –80°C. In contrast, the reaction of an iron(III) salen complex with m-chloroperoxybenzoic acid at –80°C generates a ligand radical complex with an iron(III) ion. The difference of electronic structures might be related to the fact that a manganese salen complex is a superior epoxidation catalyst than an iron salen complex. We also describe a model study for protocatechuate 3,4-dioxygenase using an iron(III) salen complex with sterically-hindered mesityl groups.
Review
  • 八木 政行
    2011 年 57 巻 p. 67-74
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    Artificial photosynthesis is expected as one of promising clean energy-providing systems in future. Development of an efficient catalyst for water oxidation to evolve O2 is a key task to yield a breakthrough for construction of an artificial photosynthetic device. Recently, significant progress has been reported in development of the molecular catalysts for water oxidation based on manganese, ruthenium and iridium complexes. The molecular aspects of the catalysts in chemical, electrochemical, and photo- or photoelectro-driven water oxidation were reviewed to provide hints to design an efficient catalyst. This review will mainly cover the related progress in the last 5 or 6 years.
Topics
  • 作田 絵里, 喜多村 昇
    2011 年 57 巻 p. 75-77
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    In this topics, we overview the recent research trends on the photophysical properties of ruthenium(II) and rhenium(I) complexes having arylborane charge transfer unit(s). The vacant p-orbital on the boron atom (p(B)) in a triarylborane derivative plays important roles in determining the electronic structure and the excited-state properties of the derivative. Recent studies on the spectroscopic and excited-state properties of arylborane compounds indicated that the characteristic absorption and fluorescence bands were ascribed essentially to the charge transfer (CT) transition between the π-orbital of the aryl group (π(aryl)) and p(B) : π(aryl)-p(B) CT. By utilizing such characteristics of triarylborane derivatives, new approaches toward tuning of the redox, spectroscopic, and excited-state properties of transition metal complexes have been explored through combining the π(aryl)-p(B) CT interaction in a triarylborane derivative with the metal-to-ligand charge transfer (MLCT) state of a transition metal complex.
  • 錦織 広昌
    2011 年 57 巻 p. 77-80
    発行日: 2011/05/31
    公開日: 2011/08/31
    ジャーナル フリー
    Spirooxazines (SOs) exhibit the well-known photochromic reaction of photoinduced interconversion between the original colorless form and the colored merocyanine (MC) form. The MC easily coordinates to specific metal ions (e.g., Zn2+) in solvents and forms a fluorescent chelate complex. It is difficult to dissociate the complex in solvents because it is stable to heat and visible light. The control of the interaction between the SO molecule and metal ion is required for the reversible photochromic reaction. For example, MC forms a reversible complex with metal bonding to oxide networks such as silica gel and it is dissociated by visible irradiation because the MC is weakly coordinated to the metal ion. Such photochromic reaction can be control in the sol-gel matrix by organic modification of the silicon due to increasing the pore volume changing the polarity. The elucidation of the formation and dissociation of such metal chelates leads to create novel photofunctional materials.
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