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固定化磺基离子液体催化合成5-羟甲基糠醛研究 被引量:6
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作者 张元元 邓俊辉 +3 位作者 单玉华 周永生 王桂敏 李明时 《高校化学工程学报》 EI CAS CSCD 北大核心 2010年第5期824-829,共6页
对微球硅胶固定化离子液体(IL3)催化果糖脱水合成5-羟甲基糠醛(HMF)进行了研究。以微球硅胶为载体,通过γ-氯丙基三甲氧基硅烷将磺基功能化离子液体-N-磺丙基咪唑盐(IL2)化学键联到其上制得IL3。用液氮吸附、13C-NMR、元素分析及酸度测... 对微球硅胶固定化离子液体(IL3)催化果糖脱水合成5-羟甲基糠醛(HMF)进行了研究。以微球硅胶为载体,通过γ-氯丙基三甲氧基硅烷将磺基功能化离子液体-N-磺丙基咪唑盐(IL2)化学键联到其上制得IL3。用液氮吸附、13C-NMR、元素分析及酸度测定等方法对IL3进行分析与表征,并考察其在果糖脱水合成HMF反应过程中的催化性能。研究结果表明:IL3能有效催化果糖脱水生成HMF。IL2固载量越高,IL3的表面酸度越大、但比表面积和孔体积都下降。当IL2的固载量为45.4%时,所制得的催化剂(45.4-IL3)对果糖脱水生成HMF具有较好的催化性能。过高的反应温度和果糖浓度会使生焦反应加剧,导致HMF收率降低。在115℃、15%~25%(wt)果糖溶液中反应是较合适的,HMF收率维持在80%以上。IL3可方便地循环使用,但随循环使用次数增加,HMF生成速率和收率都呈下降趋势。尤其是催化剂循环使用四次后,HMF收率明显下降,是反应过程中生成的不溶性焦质在催化剂表面覆盖所致。 展开更多
关键词 5-羟甲糠醛 磺基离子液体 固定化 微球硅胶 果糖
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N-tosyl-nitropyrroles as Dienophiles in Polar Cycloaddition Reactions Developed in Protic Ionic Liquids
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作者 Carla M. Ormachea Anna Francesca Lopez Baena Claudia Della Rosa Maria N. Kneeteman Pedro M. E.Mancini 《Journal of Chemistry and Chemical Engineering》 2012年第7期661-667,共7页
N-tosyl-2-nitropirrole and N-tosyl-3-nitropirrole reacts with poorly and activated dienes using protic ionic liquids as reaction media. They exhibit a dienophilic character producing the corresponding indoles through ... N-tosyl-2-nitropirrole and N-tosyl-3-nitropirrole reacts with poorly and activated dienes using protic ionic liquids as reaction media. They exhibit a dienophilic character producing the corresponding indoles through a Diels-Alder process. In all cases the presence of protic ionic liquids as reaction media improve the yields respect to the use of molecular solvent, while the temperature and the reaction time decrease. A similar behavior was observed in disubstituted N-tosyl-pyrroles. 展开更多
关键词 Nitropyrroles INDOLE ionic liquid Siels-Alder.
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Conversion coatings of Mg-alloy AZ91D using trihexyl(tetradecyl) phosphonium bis(trifluoromethanesulfonyl)amide ionic liquid 被引量:2
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作者 HOWLETT P. C. GRAMET S. +4 位作者 LIN J. EFTHIMIADIS J. CHEN X. B. BIRBILIS N. FORSYTH M. 《Science China Chemistry》 SCIE EI CAS 2012年第8期1598-1607,共10页
This work reveals the performance of a trihexyl(tetradecyl)phosphonium bis(trifluoromethanesulfonyl)amide ([P6,6,6,14][NTf2]) ionic liquid (IL) conversion coating upon AZ91D. Such conversion coatings represent a novel... This work reveals the performance of a trihexyl(tetradecyl)phosphonium bis(trifluoromethanesulfonyl)amide ([P6,6,6,14][NTf2]) ionic liquid (IL) conversion coating upon AZ91D. Such conversion coatings represent a novel avenue for chromate replacement. An optimization of coating performance was pursued by careful alloy pretreatment to generate a surface on which the coating performs best, as the AZ91 substrate is distinctly different from pure or dilute Mg alloys. The results reveal that a functional conversion coating can be achieved, retarding anodic dissolution kinetics, causing a significant decrease in corrosion rate. The coating efficacy is closely tied to the pretreatment performed, which dictates both the microstructural and electrochemical heterogeneity of the surface. The resulting coatings were found to contain MgxFx and phosphonium cation related components, the proportions of which were dependent on the pretreatment. 展开更多
关键词 AZ91D corrosion conversion coating ionic liquid PRETREATMENT
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