Decomposition of A-Type Sandwiches. Synthesis and Characterization of New Polyoxometalates Incorporating Multiple d-Electron-Centered Units
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- 作者：Michelle D. Ritorto ; Travis M. Anderson ; Wade A. Neiwert ; and Craig L. Hill
- 刊名：Inorganic Chemistry
- 出版年：2004
- 出版时间：January 12, 2004
- 年：2004
- 卷：43
- 期：1
- 页码：44 - 49
- 全文大小：184K
- 年卷期：v.43,no.1(January 12, 2004)
- ISSN：1520-510X
文摘
The controlled decomposition of the sandwich-type polyoxometalates K12[(M(OH2)2)3(A-
-PW9O34)2] (where M =Mn(II) or Co(II)) in 0.5 M NaCl yields a new family of transition metal substituted POMs of the general formula[((MOH2)M2PW9O34)2(PW6O26)]17- (where M = Mn(II) (1Mn) or Co(II) (1Co)). The structure of 1Mn, determined bysingle-crystal X-ray diffraction (a = 17.4682(10) Å, b = 22.3071(12) Å, c = 35.1195(18) Å, 
= 95.898(1)
,monoclinic, P21/c, Z = 4, R1 = 6.19%, based on 50264 independent reflections), consists of two B--(MnIIOH2)MnII2PW9O343- units joined by a B-type hexavacant PW6O2611- fragment to form a C-shaped polyoxometalate. Alow resolution X-ray structure of the Co(II) analogue, 1Co, was also obtained. The UV-visible spectrum of 1Coshows the characteristic charge-transfer bands of polyoxometalates as well as a new Co-centered peak (560 nm,
= 416 M-1 cm-1) which appears at a higher wavelength relative to that exhibited by the parent A-type sandwich,K12[(Co(OH2)2)3(A--PW9O34)2]. The methyltricaprylammonium salt of 1Mn is an effective catalyst for the H2O2-based epoxidation of cis-cyclooctene, cyclohexene, and 1-hexene.
-PW9O34)2] (where M =Mn(II) or Co(II)) in 0.5 M NaCl yields a new family of transition metal substituted POMs of the general formula[((MOH2)M2PW9O34)2(PW6O26)]17- (where M = Mn(II) (1Mn) or Co(II) (1Co)). The structure of 1Mn, determined bysingle-crystal X-ray diffraction (a = 17.4682(10) Å, b = 22.3071(12) Å, c = 35.1195(18) Å, = 95.898(1),monoclinic, P21/c, Z = 4, R1 = 6.19%, based on 50264 independent reflections), consists of two B--(MnIIOH2)MnII2PW9O343- units joined by a B-type hexavacant PW6O2611- fragment to form a C-shaped polyoxometalate. Alow resolution X-ray structure of the Co(II) analogue, 1Co, was also obtained. The UV-visible spectrum of 1Coshows the characteristic charge-transfer bands of polyoxometalates as well as a new Co-centered peak (560 nm, = 416 M-1 cm-1) which appears at a higher wavelength relative to that exhibited by the parent A-type sandwich,K12[(Co(OH2)2)3(A--PW9O34)2]. The methyltricaprylammonium salt of 1Mn is an effective catalyst for the H2O2-based epoxidation of cis-cyclooctene, cyclohexene, and 1-hexene.