Hydrothermal Synthesis, Crystal Structure, and Catalytic Potential of a One-Dimensional Molybdenum Oxide/Bipyridinedicarboxylate Hybrid

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• 作者：Tatiana R. Amarante ; Patr铆cia Neves ; Anabela A. Valente ; Filipe A. Almeida Paz ; Andrew N. Fitch ; Martyn Pillinger ; Isabel S. Gon莽alves
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：April 15, 2013
• 年：2013
• 卷：52
• 期：8
• 页码：4618-4628
• 全文大小：513K
• 年卷期：v.52,no.8(April 15, 2013)
• ISSN：1520-510X

文摘

The reaction of MoO₃, 2,2鈥?bipyridine-5,5-dicarboxylic acid (H₂bpdc), water, and dimethylformamide in the mole ratio 1:1:1730:130 at 150 掳C for 3 days in a rotating Teflon-lined digestion bomb leads to the isolation of the molybdenum oxide/bipyridinedicarboxylate hybrid material (DMA)[MoO₃(Hbpdc)]路nH₂O (1) (DMA = dimethylammonium). Compound 1 was characterized by scanning electron microscopy, FT-IR and ¹³C{¹H} CP MAS NMR spectroscopies, and elemental and thermogravimetric analyses. The solid state structure of 1 was solved and refined through Rietveld analysis of high resolution synchrotron X-ray powder diffraction data in conjunction with information derived from the above techniques. The material, crystallizing in the noncentrosymmetric monoclinic space group Pc, is composed of an anionic one-dimensional organic鈥搃norganic hybrid polymer, _{鈭?/sub>¹[MoO3(Hbpdc)]^{鈭?/sup>, formed by corner-sharing distorted {MoO4N2} octahedra, which cocrystallizes with charge-balancing DMA+ cations and one water molecule per metal center. In the crystal structure of 1, the close packing of individual anionic polymers, DMA+ cations, and water molecules is mediated by a series of supramolecular contacts, namely strong (O鈥揌路路路O, N+鈥揌路路路O鈥?/sup>) and weak (C鈥揌路路路O) hydrogen bonding interactions, and 蟺鈥撓€ contacts involving adjacent coordinated Hbpdc鈥?/sup> ligands. The catalytic potential of 1 was investigated in the epoxidation reactions of the bioderived olefins methyl oleate (Ole) and dl-limonene (Lim) using tert-butylhydroperoxide (TBHP) as the oxygen donor and 1,2-dichloroethane (DCE) or (trifluoromethyl)benzene (BTF) as cosolvent, at 55 or 75 掳C. Under these conditions, 1 acts as a source of active soluble species, leading to epoxide yields of up to 98% for methyl 9,10-epoxystearate (BTF, 75 掳C, 100% conversion of Ole) and 89% for 1,2-epoxy-p-menth-8-ene (DCE, 55 掳C, 95% conversion of Lim). Catalytic systems employing the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide as solvent could be effectively recycled.}}