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Inclusion of bidentate phosphine molecules in the supercage of FAU zeolite
Microporous and Mesoporous Materials ( IF 4.8 ) Pub Date : 2021-08-26 , DOI: 10.1016/j.micromeso.2021.111387
Kazu Okumura 1 , Sachiko Morita 1 , Akimichi Ohtsuki 1 , Hiromitsu Takaba 2
Affiliation  

Bidentate phosphines (Ph2P(CH2)nPPh2) with different alkyl chain lengths (n = 1–10) were included in the supercage (SC) of FAU-zeolite. Thermal treatment of the mixture of a bidentate phosphines and FAU-zeolite at 443 K resulted in the inclusion of the former into the SC, with up to 0.75 molecules per SC. The included molecules were strongly bound by FAU-zeolite, with desorption observed at higher temperatures compared to those of unloaded ones. The specific surface area of the FAU-zeolite decreased linearly with an increase in the number of phosphines included. This tendency was more emphasized in phosphines with n = 6–10 compared with those with n = 1–5. A characteristic shift in the C–C stretching band of the benzene ring was observed in the Fourier-transform infrared spectroscopy (FT-IR) spectrum, due to the strong interaction between bidentate phosphines and FAU-zeolite; the extent was more when using *BEA-loaded ones. Formation of the inclusion compounds between bidentate phosphines and FAU zeolites was observed with the molecular dynamics (MD) calculations. The bidentate phosphines included in the SC of the FAU-zeolite were reacted with PdCl2 to form Pd complexes. The detailed analysis of the Pd complexes with Pd K-edge EXAFS revealed a characteristic decrease in the Pd–Cl bond distance with the use of complexes with n = 3 and 4, suggesting that the local structure around Pd was distorted through the interaction of the Pd complexes with the pores of the FAU-zeolite. The Pd complexes included in the SC were active for allylic alkylation between allyl methyl carbonate and ethyl acetoacetate.



中文翻译:

在 FAU 沸石的超笼中包含双齿膦分子

双齿膦 (Ph 2 P(CH 2 ) n PPh 2) 具有不同的烷基链长度 (n = 1-10) 被包含在 FAU 沸石的超级笼 (SC) 中。在 443 K 下对双齿膦和 FAU-沸石的混合物进行热处理,导致前者包含在 SC 中,每个 SC 含有多达 0.75 个分子。所包含的分子被 FAU 沸石强烈结合,与未加载的分子相比,在更高的温度下观察到解吸。FAU-沸石的比表面积随着所含膦数量的增加而线性降低。与 n = 1-5 的膦相比,这种趋势在 n = 6-10 的膦中更为突出。由于双齿膦和 FAU 沸石之间的强相互作用,在傅里叶变换红外光谱 (FT-IR) 光谱中观察到苯环的 C-C 伸缩带的特征位移;使用 *BEA 加载的范围更大。通过分子动力学 (MD) 计算观察到双齿膦和 FAU 沸石之间包合物的形成。FAU-沸石SC中包含的双齿膦与PdCl反应2形成钯配合物。对 Pd 配合物与 Pd K-edge EXAFS 的详细分析揭示了使用 n = 3 和 4 的配合物时 Pd-Cl 键距的特征性减小,表明 Pd 周围的局部结构通过与 Pd 的相互作用而扭曲。 Pd 与 FAU-沸石的孔络合。SC中包含的Pd配合物对于烯丙基甲基碳酸酯和乙酰乙酸乙酯之间的烯丙基烷基化具有活性。

更新日期:2021-09-07
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