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Effect of alkyl nitrite decomposition on catalytic performance of CO coupling reaction over supported palladium catalyst

Zhenhua LI, Weihan WANG, Dongxue YIN, Jing LV, Xinbin MA

《化学科学与工程前沿（英文）》 2012年第6卷第4期页码 410-414 doi: 10.1007/s11705-012-1213-5

摘要： The syntheses of dimethyl oxalate (DMO) and diethyl oxalate (DEO) by CO coupling reaction in gaseous phase were investigated in a fixed bed reactor over Pd-Fe/Al O catalyst. The catalytic performance was characterized by CO conversion, space-time yield (STY) and selectivity of DMO (or DEO). The results showed that over Pd-Fe/Al O catalyst, the STY of DMO was higher than that of DEO under the same reaction conditions. The optimum reaction temperatures for synthesizing DMO and DEO were 403 K and 393 K, respectively, at the molar ratio 1 ∶ 1 of alkyl nitrite to CO. The difference in synthesizing DMO and DEO on the same catalyst was attributed to the decomposition performances of methyl nitrite (MN) and ethyl nitrite (EN), as density functional theory (DFT) calculation showed that EN decomposed more easily than MN.

关键词： palladium CO coupling dialkyl oxalate alkyl nitrite decomposition

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Synthesis and properties of water-soluble 1,9-dialkyl-substituted BF

Dan Wu, Gonzalo Durán-Sampedro, Donal F. O’Shea

《化学科学与工程前沿（英文）》 2020年第14卷第1期页码 97-104 doi: 10.1007/s11705-019-1828-x

摘要： Bis-alkylsulfonic acid and polyethylene glycol (PEG)-substituted BF azadipyrromethenes have been synthesized by an adaptable and versatile route. Only four synthetic stages were required to produce the penultimate fluorophore compounds, containing either two alcohol or two terminal alkyne substituents. The final synthetic step introduced either sulfonic acid or polyethylene glycol groups to impart aqueous solubility. Sulfonic acid groups were introduced by reaction of the bis-alcohol-substituted fluorophore with sulfur trioxide, and a double Cu(I)-catalyzed cycloaddition reaction between the bis-alkyne fluorophore and methoxypolyethylene glycol azide yielded a neutral bis-pegylated derivative. Both fluorophores exhibited excellent near-infrared (NIR) photophysical properties in methanol and aqueous solutions. Live cell microscopy imaging revealed efficient uptake and intracellular labelling of cells for both fluorophores. Their simple synthesis, with potential for last-step structural modifications, makes the present NIR-active azadipyrromethene derivatives potentially useful as NIR fluorescence imaging probes for live cells.

关键词： NIR-fluorophores live cell imaging NIR-AZA

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Pd-Fe/α-Al

Shengping WANG, Xin ZHANG, Yujun ZHAO, Yadong GE, Jing LV, Baowei WANG, Xinbin MA

《化学科学与工程前沿（英文）》 2012年第6卷第3期页码 259-269 doi: 10.1007/s11705-012-1212-6

摘要： Cordierite monoliths coated with Pd-Fe/α-Al O catalysts were prepared at various calcination temperatures and characterized by thermogravimetry, temperature-programmed reduction, transmission electron microscopy, diffuse reflectance infrared Fourier transformation spectroscopy and X-ray diffraction. The performance of the catalytic monoliths for the synthesis of dimethyl oxalate (DMO) through a CO coupling reaction was evaluated. Monolithic catalysts with calcination temperatures ranging from 473 K to 673 K exhibited excellent dispersion of Pd, good CO adsorption properties, and excellent performance for the coupling reaction. The optimized monolithic catalyst exhibited a much higher Pd efficiency (denoted as DMO (g)·Pd (g) ·h ) (733 h ) than that of the granular catalyst (60.2 h ), which can be attributed to its honeycomb structure and the large pore sizes in the α-Al O washcoat which was accompanied with an even distribution of the active component in the coating layer along the monoliths channels.

关键词： dimethyl oxalate coupling Pd cordierite monolith calcination structure