《Enhanced Menshutkin SN2 Reactivity in Mesoporous Silica: The Influence of Surface Catalysis and Confinement》 was written by Zheng, Weizhong; Yamada, Steven A.; Hung, Samantha T.; Sun, Weizhen; Zhao, Ling; Fayer, Michael D.. HPLC of Formula: 616-47-7 And the article was included in Journal of the American Chemical Society in 2020. The article conveys some information:
A significant enhancement in the Menshutkin SN2 reaction between 1-methylimidazole (MeIm) and Me thiocyanate (MeSCN) is observed when the reaction is confined in the nanoscale silica pores of MCM41 and SBA15. The experiments in the silica pores are conducted without the surrounding bulk reaction mixture The influences of temperature, pore radius, and surface chem. on the kinetics of the confined reaction are analyzed with time-dependent IR spectroscopy, mol. dynamics simulations, and ab initio calculations The rate constant of the pseudo-first order reaction increases with decreasing pore size, and the activation energy is found to decrease by 5.6 kJ/mol in the smallest pore studied (2.8 nm) relative to the bulk reaction. The rate constant dependence on pore size is accurately described by a two-state model in which mols. within the 4.6 Å interfacial layer experience a 2.4-fold rate constant increase relative to those reacting at the bulk rate further away from the interface. The removal of polar silanol groups from the silica surface via passivation with trimethylsilyl chloride results in bulk-like kinetics despite a reduction in the pore diameter, demonstrating the role of silanols as catalytic sites. Electronic structure calculations of the energy profile on a model silica surface confirm that silanol groups, particularly those of the vicinal type, can reduce the activation energy and reaction endothermicity through the donation of hydrogen bonds to the reactant, transition state, and product complexes. In the experiment, the researchers used 1-Methyl-1H-imidazole(cas: 616-47-7HPLC of Formula: 616-47-7)
1-Methyl-1H-imidazole(cas: 616-47-7) is actively involved in removing acid during the production of diethoxyphenylphosphine. It is used as an intermediate in organic synthesis.HPLC of Formula: 616-47-7
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem