2001 Fiscal Year Final Research Report Summary
Complexes having platinum to metal dative bonds
| Project/Area Number |
12640531
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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 | Tohoku University |
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Principal Investigator |
YAMAGUCHI Tadashi Tohoku Univ., Graduate school of Science, Associate Professor, 大学院・理学研究科, 助教授 (40230362)
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| Project Period (FY) |
2000 – 2001
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| Keywords | metal-metal dative bond / platinum complexes / platinum-silver bond / platinum-rhodium bond / cluster complexes |
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| Research Abstract |
It has been shown that the occupied d_<z^2> orbital of a d^8 transition metal ion with square-planar coordination geometry can act as a potential donor to another metal ion (M) resulting in a dative M(d^8)→M bond. In this study we synthesize complexes having short unsupported Pt(II)→M dative bonds by using platinum(II) complexes with carbon σ-donor ligands which exert a strong ligand field.
(1) From a mixture of [Pt(phpy)_2] (Hphpy = phenylpyridine) and AgClO_4 in acetone, a helical chain complex, [{Pt(phpy)_2}2{Ag(acetone)}2]_n(ClO_4)_<2n>・acetone_n, was obtained, which consists of alternate stacking of [Pt(phpy)_2] and Ag(acetone)^+ connected by platinum to silver dative bond and has large diameter (2.3 nm) of helix.
(2) When the silver source contains a a relatively coordinative NO_3^-, tetranuclear Pt_2Ag_2 the rhombus cluster complex [{Pt(phpy)_2}2{Ag(NO_3)}2]・CH_3CN was obtained. The cluster core has a 4-center 2-electron bond that includes not only the platinum to silver dative bonds but also a silver-silver bond.
(3) When the rhodium dimer [Rh_2(CF_3COO)_4] was used as an acceptor, the tetranuclear Pt→Rh_2←Pt complex [{Rh_2(CF_3COO)_4}{Pt(phpy)_2}2] was obtained in which the platinum complexes coordinate to axial sites of rhodium dimer. The cluster has both platinum to silver dative bonds and a rhodium-rhodium single bond.
These results show not only that platinum complexes in a strong ligand field can make a strong platinum to metal dative bond, but also that the metal-metal dative bond is useful for making large cluster complexes.
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