Mononuclear and Binuclear Cyclopentadienyl Oxo Molybdenum and Tungsten Complexes: Syntheses and Applications in Olefin Epoxidation Catalysis
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- 作者：Ana M. Martins ; Carlos C. Romã ; o ; Marta Abrantes ; M. Cristina Azevedo ; Jinlan Cui ; Alberto R. Dias ; M. Teresa Duarte ; M. Amé ; lia Lemos ; Tiago Lourenç ; o ; and Rinaldo Poli
- 刊名：Organometallics
- 出版年：2005
- 出版时间：May 23, 2005
- 年：2005
- 卷：24
- 期：11
- 页码：2582 - 2589
- 全文大小：156K
- 年卷期：v.24,no.11(May 23, 2005)
- ISSN：1520-6041
文摘
New half-sandwich molybdenum complexes [Mo(CpBz)Cl2(O)] (1), [{Mo(CpBz)(O)2}2(
es/entities/mgr.gif">-es/entities/Ogr.gif">)](5), and [Mo(CpBz)Cl2]2 (6) (CpBz = C5(CH2Ph)5), the tungsten derivative [W(CpBz)Cl(O)2](3), and a high yield synthesis of [Mo(CpBz)Cl(O)2] (2) are described. The molecular structuresand cyclic voltammetry measurements of 1 and 2 and a comparative study of variousmolybdenum dioxo complexes as olefin epoxidation catalyst precursors are also presented.The performance of [Mo(CpPri4)Cl(O)2] (9) as cyclooctene epoxidation catalyst using TBHPas oxidant was determined and compared with other [MoCp'Cl(O)2] complexes (Cp' = C5H5(7), C5Me5 (8), CpBz (2)) to assess the activity dependence on the ring substituents. Underthe same experimental conditions, bimetallic compounds [{MoCp'(O)2}2(es/entities/mgr.gif">-es/entities/Ogr.gif">)] (Cp' = CpBz(5), Cp* (10), CpBut3 (11), CpPri4 (12)) have been tested and [CpMoO2]2O was checked inaqueous solution, with H2O2 and TBHP as oxidant. Finally, [Mo(CpBz)(CO)3CH3] (4) wasused as a catalyst precursor for cyclooctene epoxidation in the presence of TBHP. The analogybetween the behaviors displayed by this complex and complex 2 is discussed.