1991 Fiscal Year Final Research Report Summary
Design and Syntheses of Paramagnetic Dinuclear Metal Complexes Inducing Significant Cooperative Effects and Their Multinuclear NMR Study
| Project/Area Number |
02453040
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
無機・錯塩・放射化学
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| Research Institution | Osaka University |
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Principal Investigator |
KAIZAKI Sumio Dept. Chem., Fac. Sci., Osaka Univ. Prof., 理学部, 教授 (20089874)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Cr (III) dinuclear omplex / Spin-forbidden d-d Transition / Circular Dichroism / Magnetic circular Dichroism / Multinuclear NMR / Magnetic Susceptibility / exchange interaction / Cooperative Effect |
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| Research Abstract |
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.
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Research Products
(2 results)
