Related Experiment Video
Updated: May 14, 2026

Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
Published on: October 18, 2019
Density functional theory studies on hydroxylamine mechanism of cyclohexanone ammoximation on titanium silicalite-1
Chang Qing Chu1, Hai Tao Zhao, Yan Ying Qi
1Department of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Nankai District, Wei Jin Road 92, Tianjin 300072, China.
Abstract:
The hydroxylamine mechanism of cyclohexanone ammoximation on defective titanium active site of titanium silicalite-1 (TS-1) was simulated using two-layer ONIOM (M062X/6-31G**:PM6) method. A new energy favorable reaction route was found, which contained two parts: (1) the catalytic oxidation of adsorbed NH3 to form hydroxylamine using the Ti-OOH as an active oxidant formed by reacting H2O2 with the defective Ti active site; (2) the subsequent noncatalytic oximation of desorbed hydroxylamine and cyclohexanone out of TS-1 pores to form cyclohexanone oxime. In the catalytic formation of hydroxylamine on the Ti active site of TS-1, the proposed mechanism of two-step single-proton transfer aided by a lattice oxygen atom bonded to Ti atom need a lower reaction energy than the mechanism proposed before. In the subsequent noncatalytic oximation of hydroxylamine and cyclohexanone, which contained two elementary reaction steps in total, the mechanisms of one-step double-proton transfer in the first elementary reaction step and the subsequent one-step three-proton transfer for the second elementary reaction step were proposed, in which the solvent water molecules played a very important role in assisting and stabilizing the proton transfer processes.
More Related Videos
12:08Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes
Published on: June 24, 2022
08:25Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
Published on: January 17, 2020
Related Concept Videos
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Heterogeneous Catalysis
Catalysis
Cycloaddition Reactions: MO Requirements for Thermal Activation
Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.