The magnetic susceptibility of the organic superconductors -(h8 or d8-ET) 2 X, XϭCu(NCS) 2 and Cu͓N(CN) 2 ͔Br has been studied. A metallic phase below T*ϭ37-38 K for XϭCu͓N(CN) 2 ͔Br and 46 -50 K for XϭCu(NCS) 2 has an anisotropic temperature dependence of the susceptibility and the charge transport. Partial charge-density-wave or charge fluctuation is expected to coexist with the metallic phase instead of the large antiferromagnetic fluctuation above T*. The phase diagram and the superconductivity of -(ET) 2 X are discussed in connection with this phase.

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A PCDMR (photoconductivity detected magnetic resonance) method developed recently is applied to the study of a photoinduced electron-transfer reaction. The PCDMR spectrum of the transient radical-ion pair formed by the photochemical reaction of xanthone/N,N-diethylaniline in 2-propanol is observed for the first time. A peculiar PCDMR spectrum is observed by irradiation with strong microwaves. This spectrum is tentatively explained by spin-locking at the line center and by the transition at both broadened wing portions. The lifetime of the radical-ion pair is estimated to be 2 × 10 -7 s at room temperature and is anomalously long.

Three different RYDMR (reaction-yield detected magnetic resonance) techniques, photoconductivity detected magnetic resonance (PCDMR), transient-absorption detected magnetic resonance (ADMR) and detayed fluorescente detected magnetic resonance (DFDMR), are applied to the investigation of the radical-ion pair formed in the photolysis of TMPD in mixed alcohol solution. Here, PCDMR is a newly developed RYDMR method to study the radical-ion pair. PCDMR and ADMR methods show the acceleration of the quenching reaction from the triplet manifold of the radical-ion pair by microwave radiation under electron spin resonance conditions. These spectra of the radicalion pair are significantly broadened probably because of the dynamic behavior of the radical-ion pair interacting strongly. The long lifetime of the radical-ion pair is due to the Coulomb interaction and the special role of the mixed solvent containing 2-propanol that stabilizes the radical-ion pair. Furthermore, the simultaneous observation of the PCDMR and the DFDMR shows different spectra. This indicates that the spectrum observed by the DFDMR is due to the wealdy interacting RIP formed through the pathway different from those observed by the other two methods.

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