Structures are calculated for magnesium phthalocyanine (MgPc) and its radical anion doublet (MgPc-), using both ab-initio (6-31G**) and semiempirical (INDO/1) self-consistent field approaches. The anion is first-order Jahn-Teller distorted, and the various distortions that are possible are examined. The electronic absorption spectra of both molecular species and the effect that varying the degree of distortion has on the computed anion spectrum are discussed. These results suggest that the four-orbital model often applied to porphyrin systems in interpreting the low-energy spectrum is incomplete for the anion case. We further conclude that the Jahn-Teller distortions calculated by either ab-initio or semiempirical models may be too great.

The effect of the mobility of ligands (maltose groups) in the polyrotaxanes (pRXs) on the structure of the surrounding water molecules was investigated. Raman spectra of collective OH stretching vibration of water molecules in aqueous solutions of maltose-pRX conjugates with different alpha-cyclodextrin (alpha-CD) threading on a poly(ethylene glycol) (PEG) chain was measured. The mobility of maltose groups was estimated by measuring the relaxation time T2 of the C1 protons in maltose groups bound on alpha-CD by NMR experiment. A positive correlation between the Raman intensity of the collective band and the relaxation time T2 was obtained. This result indicates that the degree of order of the water clusters is higher as the mobility of maltose groups increases in these conjugate solutions. It is suggested that rapid motion of maltose groups in the pRX conjugate can contribute to preserving ordered structure of the bulk water clusters.

The effect of surface treatment of titanium on hydrogen absorption was investigated.Surface treated titanium specimens prepared by polishing, anodizing and air oxidizing were immersed in 0.5-6%HCl solutions at the temperature range of 70C to 250C. After immersion, the weight loss, hydrogen content and oxide film thickness of three specimens were measured. As a result, it became clear that anodizing did not reduce hydrogen absorption of titanium because titanium oxide film formed by anodizing had dissolved away in dilute HCl solutions for short time but air oxidizing specimen was stable in this solution for long time and so prevented to hydrogen absorption of titanium.These results of laboratory tests corresponded to the results of field tests conducted in hot molten urea and reducing acid solution at high temperature.

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