|Budget Amount *help
¥13,300,000 (Direct Cost : ¥13,300,000)
Fiscal Year 2000 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1999 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1998 : ¥9,900,000 (Direct Cost : ¥9,900,000)
Electron transfer reactions of small inorganic molecules (smaller compared with biological macro molecules) have been investigated for the better understanding of the structure-reactivity relation in the biochemically important macro molecules. Regulated ET processes were observed for various Cu (II)/(I) couples in which structural change preceded ET for the reduction direction. It was clearly shown, by observing the intermediates for oxidation of dimeric Cu (I) and for reduction of monomeric Cu (II), the redox reactions of Cu (II)/Cu (I) couples actually proceed through the square scheme postulated by Rorabacher et al. Although the investigations under elevated pressure are delayed because of the rather interesting phenomena observed for the Ni (III)/(II) couple in aqueous solution, it is currently under way. The results for various Cu (II)/(I) couples have been published in the following articles and some other results will be published shortly. Inorganic Chemistry, 38, 3352-3360 (19
99), Can.J.Chem., 71, 1498-1507 (1999), Chem.Phys.Lett., 306, 291-296 (1999).
Some other reactions involving Ce (IV)/(III) couples seems to have been related to the intramolecular gated reactions which has not been clearly shown to date. We found that the activation process drastically changed by varying the driving force of the reaction (Inorg.React.Mech., 2, 19-31 (2000)). Investigations at elevated pressures are currently in progress. Electron transfer reactions of platinum (III)/(II) and related d^8 complexes were also investigated. We are currently sorting the data for the better understanding of the internal ligand substitution process to shed light on the understanding the mechanism for these reactions. Some of the results for the ET processes involving these species have been published (Can.J.Chem., 77, 1638-1647 (1999)).
Related research concerning the isomerization of small organic molecules was also carried out under supercritical conditions (elevated pressure and temperature). It was clearly shown that the unimolecular reactions in low and medium density fluids are governed essentially by the energy transfer process at very low density and the turn-over to the transition-state-theory valid region at rather lower density than has been expected. These results were published in the following journals : Chem.Lett., 1159-1160 (1998), and J.Phys.Chem.A, 103, 11250-11251 (1999).
The investigations are still continuing, and the more fruitful results are expected. Less