2002 Fiscal Year Final Research Report Summary
Property and structure of aqueous solutions of optically active hydrophobic metal complexes, revealing specific liquid^liquid phase separation
| Project/Area Number |
13640563
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic chemistry
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| Research Institution | Yokohama City University |
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Principal Investigator |
HARUHIKO Yokoyama Yokohama City University, Graduate School of Integrated Science, Professor, 総合理学研究科, 教授 (10094319)
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| Project Period (FY) |
2001 – 2002
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| Keywords | phase separation / critical solution termperature / hydrophobic / rhodium complex / bipyridine / naphthalenesulfonate / optically active / self assembly |
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| Research Abstract |
Tris(2,2'-bipyridine)rhodium(III) complex, [Rh(bpy)_3]^<3+>, has been optically resolved by using (+)_<589>tris-[L-cysteinesulphinato(2-)-SN]cobaltate(III) complex to obtain the optically active Λ(+)_<405>[Rh(bpy)_3] ^<3+> and its 1-naplithalenesulfonate, Λ-[Rh(bpy)_3(1-NS)_3, was prepared by the double decomposition of Λ-[Rh(bpy)_3]Cl_3 and silver 1-naplitalenesulfonate (Ag1-NS). Aqueous solution of Λ-[Rh(bpy)_3](1-NS)_3 was revealed to be separated into two liquid phases of dilute and concentrated solutions in analogy with the racemic complex salt. The phase diagram of phase separation was made up by measuring the cloud point. It was proved that the critical solution temperature (T_c) existed at 67℃ where the composition of anhydrous salt was about 29 wt%. This temperature was by 7℃ lower than T_c observed for the racemic complex salt and the solubility of water in the concentrated phase was increased, suggesting that the complex-complex interactions inducing the self assembly through the formation of 1:3 aggregates of complex and 1-NS^-ions were concerned in the phase separation and that the ability of self assembly of A-complex was somewhat weaker than that of the racemic complex. T_c observed for Λ-[Rh(bpy)_3](1-NS)_3 was by 4℃ higher than that for rac-[Rh(bpy)_3](2-NS)_3, but the solubility of water in the concentrated phase of the former salt was equivalent or somewhat larger. This result can be explained by considering that the hydrophobicity of 1-NS^-may be stronger than that of 2-NS^-and the ability of self assembly of A-complex is weaker.
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Research Products
(10 results)
