2219-72-9Relevant articles and documents
Dendritic and Core–Shell–Corona Mesoporous Sister Nanospheres from Polymer–Surfactant–Silica Self-Entanglement
Zhang, Kun,Yang, Tai-Qun,Shan, Bing-Qian,Liu, Peng-Cheng,Peng, Bo,Xue, Qing-Song,Yuan, En-Hui,Wu, Peng,Albela, Belén,Bonneviot, Laurent
, p. 478 - 486 (2018)
Mesoporous nanospheres are highly regarded for their applications in nanomedicine, optical devices, batteries, nanofiltration, and heterogeneous catalysis. In the last field, the dendritic morphology, which favors molecular diffusion, is a very important morphology known for silica, but not yet for carbon. A one-pot, easy, and scalable co-sol–gel route by using the triphasic resol–surfactant–silica system is shown to yield the topologies of dendritic and core–shell–corona mesoporous sister nanospheres by inner radial phase speciation control on a mass-transfer-limited process, depending on the relative polycondensation rates of the resol polymer and silica phases. The trick was the use of polyolamines with different catalytic activities on each hard phase polycondensation. The self-entanglement of phases is produced at the {O?, S+, I?} organic–surfactant–inorganic interface. Mono- and biphasic mesoporous sister nanospheres of carbon and/or silica are derivatized from each mother nanospheres and called “syntaxic” because of similar sizes and mirrored morphologies. Comparing these “false twins”, or yin and yang mesoporous nanospheres, functionalized by sulfonic groups provides evidence of the superiority of the dendritic topologies and the absence of a shell on the diffusion-controlled catalytic alkylation of m-cresol.
Ab initio study of the selective alkylation of m-cresol with tert-butanol catalyzed by SO3H-functionalized ionic liquids
Zhou, Jinxia,Liu, Xiumei,Zhang, Shuguang,Mao, Jingbo,Guo, Xinwen
experimental part, p. 232 - 237 (2010/11/03)
Our previous work showed that for catalytic alkylation of m-cresol with tert-butanol (TBA) SO3H-functionalized ionic liquids exhibited several characteristic advantages over conventional catalysts. This work investigated the reaction mechanism of the alkylation of m-cresol with tert-butanol catalyzed by the SO3H-functionalized ionic liquid (IL) through quantum chemical calculation in combination with the experimental studies. The experimental results showed that 2-tert-butyl-5-methyl phenol (2-TBC), 4-tert-butyl-3-methyl phenol (4-TBC) and tert-butyl-m-cresol ether (TBMCE) products were all primary products, while 2,6-di-tert-butyl-3-methyl phenol (2,6-DTBC) was a secondary product. The calculation results indicated that the selectivities of the products depended on the fundamental natures of the reactive sites, including the orbital overlap, the Coulomb and the steric effect in the interaction between the tert-butyl ion ([t-C4H9]+) and the m-cresol; the TBMCE was dynamically favored but not thermodynamically stable, while the C-alkylated products, especially 2-TBC, were the thermodynamically preferred products; the IL played an important role in generating the [t-C4H9]+ from the TBA and the final products from the intermediates.
