SILICA SUPPORTED RHODIUM METAL NANOPARTICLES STABILIZED WITH (-)-DIOP. EFFECT OF LIGAND CONCENTRATION AND METAL LOADING ON THE ENANTIOSELECTIVE HYDROGENATION OF KETONES
作者:DORIS RUIZ、CLAUDIO MELLA、JOSÉ L.G FIERRO、PATRICIO REYES
DOI:10.4067/s0717-97072012000400013
日期:——
isotherms and XPS.This work includes the study of some variables such as metal loading and ligand concentration and their effect in metal core sizes, catalytic activity and enantioselectivity. Catalysts properties have also been evaluated in the hydrogenation of substrates: acetophenone (AP), 1-phenyl-1,2-propanedione (PPD), 3,4-hexanedione (HD), 2,3-butanedione (BD) and ethyl pyruvate (EP) as reaction
摘要合成了在手性配体(L)存在下的负载型纳米颗粒(NPs),用于其对映选择性氢化反应。在(-)-DIOP配体((4R,5R)-4,5-双(二苯基膦基甲基)-2,2-二甲基存在下,从氯化铑水合物RhCl 3×3H 2 O进行化学还原获得催化剂-1,3-二氧戊环),可控制NP的生长并获得具有手性表面的固体。使用TEM,电子衍射,EDS,氮吸附-解吸等温线和XPS等技术对SiO 2上手性稳定的铑NPs进行了表征。尺寸,催化活性和对映选择性。在底物的氢化中也评估了催化剂的性能:苯乙酮(AP),1-苯基-1,2-丙二酮(PPD),3,4-己二酮(HD),2,3-丁二酮(BD)和丙酮酸乙酯(EP)作为反应试验配体起着基本作用NPs的合成和氢化反应中的对映选择性。也就是说,由于它产生的金属粒径小于5.8 nm,而不稳定的系统产生的平均直径约为14 nm。结果表明,从NP稳定化获得的催化体系中活性增加。由