摘要:

Recent research has uncovered a variety of compounds of palladium or platinum in formal oxidation states I and III. These are generally dimeric with some form of metal-metal interaction and many of them show unique chemical behavior.

ISSN:0260-3594    

DOI:10.1080/02603598408078129

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Starting from the well known connection between the accessibility of different oxidation states of the transition metals and the donor-acceptor characteristics of the ligands, synthesis and structural characterization of electron-rich phenyl transition metal complexes are reviewed. To explain the existence of these unusual compounds in accordance with Pauling's principle of electroneutrality, a coordinative interaction of lithium ions with the central transition metal atom has been suggested as a new principle of stabilization of low oxidation states in coordination chemistry.

ISSN:0260-3594    

DOI:10.1080/02603598408078130

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Recent research that bridges the apparently disparate disciplines of inorganic chemistry and nuclear medicine is described.

ISSN:0260-3594    

DOI:10.1080/02603598408078131

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The goal of this Comment is to propose a strategic approach to the design of ferromagnetically coupled dinuclear complexes. The theoretical aspect of the problem is discussed at two levels of approximation. At the first level only the metallic unpaired electrons are considered as active electrons; at the second the eventual spin polarization effects from the highest occupied orbitals of the bridging ligands are included. Three situations leading to ferromagnetic interaction are then presented, namely, the strict orthogonality of the magnetic orbitals, the accidental orthogonality and spin polarization effects. For each situation several examples are described. It is emphasized that the accidental orthogonality can be distroyed by a very small change of structural parameter, whereas the two other situations are less sensitive to such modifications. Finally, it is pointed out that in the case of ferromagnetic interaction there is great uncertainty in the energy gaps between low lying states deduced from the magnetic data.

ISSN:0260-3594    

DOI:10.1080/02603598408078132

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

As the role of transition metal ions in biological systems becomes better understood, it has become apparent that various biological ligands strongly modulate the oxidation-reduction behavior of metal ions. Less well studied but no less important are the effects exerted by transition metal ions on the redox behavior of biologically important molecules, particularly those which normally function as electron transfer agents. Striking examples of this have been shown for a series of MgIIand ZnIIporphyrin complexes in which substitution of the metal ion for two protons sufficiently lowers the oxidation potential of the porphyrin so that it becomes fairly oxidizable in two successive 1esteps.1Sirohemes in nitrite and sulfite reductases catalyze a remarkable 6ereduction in which the reducing ability of both the iron and the isobacteriochlorin are important.2,3Metal ions are particularly important in modifying the redox behavior of substrates which coordinate in the active sites of metalloenzymes. Examples of this are nitrogenase and the series of enzymes containing the xanthine-oxidase type of molybdenum center.4Some copper enzymes, such as ascorbate oxidase5also appear to coordinate the substrate directly in order to effect an efficient electron transfer. Oxygen coordination to copper appears to be especially useful in facilitating critical reductions of O26

ISSN:0260-3594    

DOI:10.1080/02603598408078133

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The use of a juxtaposition preequilibrium model is examined for a wide range of mechanisms. Particular attention is given to the effects of ionic strength both on equilibria and on electron transfer rates. A brief extension to gas phase reactions is noted.

ISSN:0260-3594    

DOI:10.1080/02603598408078134

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0260-3594    

DOI:10.1080/02603598408078128

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor