|Budget Amount *help
¥7,300,000 (Direct Cost : ¥7,300,000)
Fiscal Year 1994 : ¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1993 : ¥5,400,000 (Direct Cost : ¥5,400,000)
Magnetic interaction within or between molecules are typically antiferromagnetic. If two magnetic orbials, each having one electron, are sufficiently close to interact, they can overlap to from antibonding and bonding orbitals. Both electrons locate on the bonding orbital with anti-parallel spin alignment. This situation can be regarded as a very weak chemical bond. However, ferromagnetic interactions can arise in several ways. For example, Orthogonal arrangement of the magnetic orbitals can lead to stabilization of the high-spin state, sucsituation being observed for metal complexes and metal-redical complexes. On the other hand, magnetic interactions between paramagnetic centers through diamagnetic metal ions are negligibly small or weakly antiferromagnetic.
Some diamagnetic metal ios are known to favor a tetrahedral coordination geometry which is suitable for the orthogonal arrangement of two bidentate ligands. Thus, it is anticipated that coordination of two bidentate radical ligands would lead to a ferromagnetic interaction between the radicals, In this work, we studied magneism of organic radical complexes whose central metal ions are diamagnetic. We have found that tetrahedral coordination geometries of copper (I) and silver (I) ions lead to the ferromagnetic interaction between coordinating radicals, especially the copper (I) ion propagate the fairly strong ferromagnetic intcraction (103 cm^<-1>).