|Budget Amount *help
¥6,800,000 (Direct Cost : ¥6,800,000)
Fiscal Year 1991 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Fiscal Year 1990 : ¥5,400,000 (Direct Cost : ¥5,400,000)
1. Preparation of new dinuclear complexes :
(1) New dinuclear complexes of[Cr_2 (X)_2 (acac)_2] type (acac=acetylacetonato) with bridging ligands such as oxalato, fluoro, 4, 5-imidazoledicarboxylato, 3.5pyrazinedicarboxylato, pyrazole (hydroxo) were synthesized.
(2) A systematic synthetic route to dinuclear complexes ( (N-N)_2 Cr(OH)(RCOO)Cr(nta)]^+((N-N)=(NH_3)_2, ethylenediamine, R, R-cyclohexanediamine ; nta=nitrilotriacetato ; R=CH_<>Cl, H, C_6H_5, CH_3) was established.
(3) New dihydroxo dinuclear complex[Cr_2(OH)_2 ( (R, R)-chxn)_4]^<4+> and hydroxoaqua dinuclear complexes[Cr_2(OH)_2(H_2O)_2 ( (R, R)-chxn)_4]^<4+>, [Cr_2(OH)(H_2O) (edtrp)_2] and[Cr_2(OH)(H_2O) ( (S)-pdtrp)_2] were prepared and characterized.
2. X-ray structural analyses :
The X-ray structural analyses were performed for two isomorphous crystals[(tn)_2Cr(OH)_2M(nta)]Cl-1.5H_2O(M=Cr, Co), and their molecular structures were compared with each other with respect to the difference in bond lengths and bond angles between central metal ions.
3. NMR spectra :
For[(N-N)_2Cr(OH)_2M(nta)]^+ (M=Cr(III), Co(III)) ; ((N-N)=(NH_3)_2, ethylenediamine, R, Rcyclohexanediamine, 2, 2'-bipyridine ; nta=nitrilotriacetato), ^1H-, ^2H-NMR spectra were observed and examined in view of the influence from the paramagnetic CR (III)ion in[Cr-Cr)and[Cr-Col complexes. ^2HNMR spectra of the bridging ligands in[(N-N)_2Cr(OH) (CD_3COO)Cr (nta)]^+ were measured.
4. Magnetic susceptibility measurements :
The construction of a Faraday apparatus for automatic magnetic susceptibility measurement was completed. The temperature dependent magnetic susceptibility for new dinuclear CR (III) complexes obtained throughout the present research project term was measured and their magnetic interactions were discussed in relation with the electronic properties of the bridging ligands.