Metal鈥揗etal Quadruple Bonds (M = Mo or W) Supported by 4-[2-(4-Pyridinyl)ethenyl] Benzoates and their Complexes with Tris(pentafluorophenyl)boron
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- 作者：Malcolm H. Chisholm ; Christopher J. Ziehm
- 刊名：Inorganic Chemistry
- 出版年：2015
- 出版时间：December 7, 2015
- 年：2015
- 卷：54
- 期：23
- 页码：11168-11173
- 全文大小：447K
- ISSN：1520-510X
文摘
From the reactions between M2(TiPB)4 and two equivalents of the acids LH, the compounds trans-M2(TiPB)2L2 were isolated where M = Mo, compound I, and M = W, II, TiPB = 2,4,6-triisopropylbenzoate, and LH = 4-[2-(4-Pyridinyl)ethenyl]benzoic acid. In related reactions when tris(pentafluorophenyl)boron, A, was added, the Lewis acid鈥揕ewis base complexes Mo2(TiPB)2(LA)2, IB, and W2(TiPB)2(LA)2, IIB, were isolated. Compounds I and IB are red and purple, respectively, while II and IIB are green. The new compounds have been characterized by 1H NMR, UV鈥搗isible-NIR absorption spectroscopy, and electrochemical studies, which are tied together with density functional theory, DFT, and time-dependent DFT calculations. Chemical reduction of IB and IIB yields anions where the single electron occupies a ligand-based orbital as indicated by EPR spectroscopy. The LUMO and LUMO+1 are ligand-based, and are close in energy, and upon reduction, no IVCT is observed.