Condensed Phenoxazine Dimer and Its Radical Cation.

A condensed phenoxazine dimer was synthesized and characterized. X-ray crystallographic analysis of the dimer shows a double-butterfly structure, in which the nitrogen atoms are located above and below the molecular plane. A radical cation salt of the dimer was obtained using tris(4-bromophenyl)aminium hexafluoroantimonate as the oxidant. The salt is air-stable in solid and solution states. The cation structure was evaluated by X-ray crystallographic analysis, showing that the phenoxazine units were converted to a planar structure upon oxidation.

(Azulene-1,3-diyl)-bis(nitronyl nitroxide) and (Azulene-1,3-diyl)-bis(iminonitroxide) and Their Copper Complexes.

In contrast to diradicals connected by alternant hydrocarbons, only a few studies on those connected by nonalternant hydrocarbons have been reported. The syntheses, structures, and magnetic properties of azulene-1,3-diyl linked bis(nitronyl nitroxide) (NN2 Az) and bis(iminonitroxide) (IN2 Az) diradicals and their Cu(hfac)2 (hfac=hexafluoroacetylacetonate) complexes were investigated. NN2 Az was shown to have an intramolecular ferromagnetic interaction with Jobs /kB =+10.0 K (H=-2JS1 ⋅S2 ) between (nitronyl nitroxide) spins, whereas IN2 Az was estimated to have a much weaker intramolecular magnetic interaction. The reactions of NN2 Az and IN2 Az with Cu(hfac)2 gave a 1:2 [{Cu(hfac)2 }2 (NN2 Az)] complex and a 1:1 [Cu(hfac)2 (IN2 Az)]⋅C6 H12 complex, respectively. [{Cu(hfac)2 }2 (NN2 Az)] showed strong intramolecular antiferromagnetic interactions (J1-Cu-R /kB ≈-800 K, J2-Cu-R /kB ≈-500 K) between the CuII spins and the coordinating NN spins, whereas [Cu(hfac)2 (IN2 Az)] exhibited a ferromagnetic exchange interaction (Jobs-Cu-R /kB =+114 K) between the CuII spin and the imino-coordinated iminonitroxide spin.

Passive-type rehabilitation system for upper limbs which can display the exact resistance force in the orientation opposite to hand motion.

In these days, there are many patients with ataxia, which is paralysis caused by a brain stroke or asynergia. Early detection of functional deterioration and sufficient rehabilitative training are necessary for these patients. Rehabilitation support systems for upper limbs using force display devices are expected to quantify the effects of rehabilitative training and enhance the motivation of patients. The application of passive-type force display devices unactuated by motors is especially desirable for its high safety. There are, however, some orientations and positions for which it is difficult to display force in an unactuated force display systems using only passive elements. To solve this problem, a method for the improvement of controllability using larger number of brakes than the degree of freedom of system had been suggested. This method made it possible to display more various force power and orientations than could be done with previous systems. However, the system with the larger number of brakes often become huge system. In this study, we have developed a rehabilitation system for the upper limbs which use only the same number of brakes as the degree of freedom but can display the resistance force in the orientation opposite to operator's motion in any orientations and link posture: "Neo-PLEMO".

Passive-type rehabilitation systems for upper limbs with MR fluid brake and its training software.

It is important to construct rehabilitation system for elderly people, people who have suffered strokes, and so on. In recent years, the need for rehabilitation support systems is increasing that using force display devices. When using force display systems, it is most important to ensure safety mechanically in order to prevent operators from hurting. Conventional force display systems are active-type devices with actuators but these devices may become dangerous when going out of control. On the other hand, passive-type force display devices with only passive elements are thought to be an effective method for assuring inherent safety. In this paper, we evaluate force display ability about a 2-D passive-type force display device with fast-response MR (Magneto-Rheological) fluid brakes to apply this device to rehabilitation training.