Metal complexes play important roles as catalysts or other participants in synthetic and biological reactions. Substrates and sometimes attacking reagents also are activated through coordination with metal atoms or ions. In these events the natures not only of the central metals but also of ancillary ligands exert important influences on the stability and reactivity of the coordinated substrates. A ligand in general can adopt various coordination modes depending on its chemical environment, thus functioning as a probe. The number of coordination modes increases with increasing complexity of...

Even brilliant colors are all bound to scatter, Who in our changing world can stay forever? From Iroha-uta, ancient Buddhistic poem of Japan For many years we have been engaged in the preparation and characterization of new metal complexes and chelates, and especially the interpretation of their electronic spectra in solutions. In the course of these studies, we have encountered a number of strange changes in color which occur upon heating, cooling or compressing the solutions, or changing the nature of the solvent. Similar effects of temperature and pressure on the color were often also...

The phenomenon of Extended X-Ray Absorption Fine Structure (EXAFS) has been known for some time and was first treated theoretically by Kronig in the 1930s. Recent developments, initiated by Sayers, Stern, and Lytle in the early 1970s, have led to the recognition of the structural content of this technique. At the same time, the availability of synchrotron radiation has greatly improved both the acquisition and the quality of the EXAFS data over those obtainable from conventional X-ray sources. Such developments have established EXAFS as a powerful tool for structure studies. EXAFS has been...