当前位置: X-MOL 学术Mol. Catal. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Heterogeneous acid catalysts prepared by immobilization of H3PW12O40 on silica through impregnation and inclusion, applied to the synthesis of 3H-1,5-benzodiazepines
Molecular Catalysis ( IF 3.9 ) Pub Date : 2020-02-20 , DOI: 10.1016/j.mcat.2020.110842
M. Dolores Morales , Antonia Infantes-Molina , J.M. Lázaro-Martínez , Gustavo P. Romanelli , Luis R. Pizzio , Enrique Rodríguez-Castellón

Solid acid catalysts were successfully prepared using mesoporous silica (MESOSI) as support and tungstophosphoric acid (KTPA) as active phase, which was incorporated by impregnation (MESOSI#KTPA) and inclusion ([email protected]). TEM (transmission electron microscopy) images of MESOSI samples revealed the presence of mesopores (worm-like structured) and well-defined pore channels. XRD patterns of MESOSI#KTPA samples showed small crystals of H3PW12O40·6H2O that were not present in the [email protected] materials. The specific surface area of the MESOSI modified with KTPA decreases with the increment of the heteropolyacid content. 31P NMR and FT-IR characterizations confirmed the existence of undegraded [H3-XPW12O40]X− and [PW12O40]3− anions interacting with the SiOH2+ groups of MESOSI. Potentiometric titration results showed that both acid strength and number of acid sites increased with the KTPA loading in [email protected] and [email protected] samples. Moreover, the acidic properties of MESOSI#KTPA materials were remarkably higher than those of [email protected] The catalysts prepared were highly active, selective and reusable in the solvent-free synthesis of 3H-1,5-benzodiazepine from 1,2-phenylenediamine and 1,3-diphenyl-1,3-propanedione.



中文翻译:

通过将H 3 PW 12 O 40通过浸渍和包合固定在二氧化硅上而制备的多相酸催化剂,用于合成3H-1,5-苯并二氮杂pine

使用介孔二氧化硅(MESOSI)作为载体和钨磷酸(KTPA)作为活性相,成功制备了固体酸催化剂,并通过浸渍(MESOSI#KTPA)和包合物掺入([电子邮件保护])。MESOSI样品的TEM(透射电子显微镜)图像显示存在中孔(蠕虫状结构)和定义明确的孔道。MESOSI#KTPA样品的XRD图谱显示H 3 PW 12 O 40 ·6H 2 O的小晶体,这些晶体不存在于[电子邮件保护的]材料中。KTPA改性的MESOSI的比表面积随杂多酸含量的增加而降低。31 P NMR和FT-IR表征证实存在未降解的[H3-X PW 12 ö 40 ] X-和[PW 12 ø 40 ] 3-的阴离子与所述相互作用的OH 2 +基团MESOSI的。电位滴定结果表明,在[受电子邮件保护的]和[受电子邮件保护的]样品中,酸强度和酸性位点的数量均随KTPA含量的增加而增加。而且,MESOSI#KTPA材料的酸性比[email protected]的要高得多。所制备的催化剂具有很高的活性,选择性和可重用性,可以无溶剂地由1,2-苯二胺合成3H-1,5-苯并二氮杂pine和1,3-二苯基-1,3-丙二酮。

更新日期:2020-02-20
down
wechat
bug