26196-04-3Relevant articles and documents
Co(II) Schiff base Complexes Encapsulated in the Nanopores of Zeolite Y as Heterogeneous Catalysts for Selective Epoxidation of Alkenes with Molecular Oxygen
Banaei, A. R.,Pourali, A. R.,Rezazadeh, B.,Tabari, S.
, p. 424 - 437 (2021/07/16)
Abstract: Co(II) macrocyclic Schiff base complex nanoparticles have been encapsulated in the nanopores of zeolite Y. The new Schiff base complexes entrapped in the nanoreactor of zeolite Y were characterized by several techniques: chemical analysis and spectroscopic methods (FT-IR, XRD, and DRS). These complexes (neat and encapsulated) were used for epoxidation of alkenes with O2 as oxidant in different solvents. The catalyst demonstrated excellent activity for a variety of alkenes in a mild, inexpensive and efficient protocol. Reaction parameters including temperature, catalyst amount and solvent were screened by reaction time. The recycling experiment results indicated that the catalysts were highly stable and maintained activity and selectivity even after being used for five cycles.
Synthesis and characterization of a new poly α-amino acid Co(II)-complex supported on magnetite graphene oxide as an efficient heterogeneous magnetically recyclable catalyst for efficient free-coreductant gram-scale epoxidation of olefins with molecular oxygen
Kazemnejadi, Milad,Mahmoudi, Boshra,Sharafi, Zeinab,Nasseri, Mohammad Ali,Allahresani, Ali,Esmaeilpour, Mohsen
, p. 59 - 69 (2019/06/13)
A novel magnetic nanocomposite was prepared by immobilization of a cobalt complex of a synthetic poly α-amino acid on Fe3O4-doped graphene oxide (GO/Fe3O4@PAA Co(II)) and was demonstrated to be a highly efficient catalyst for the epoxidation of olefins in mild conditions. PAA was synthesized through a multi-step synthesis, first by a poly condensation reaction of salicylaldehyde followed by the Strecker synthesis. The synthesized nanocomposite was characterized by various analytical and spectroscopic methods including FTIR, ICP, XRD, EDX, XPS, FE-SEM, TEM, TGA, VSM and DLS analyses. A wide variety of olefins could be tolerated toward epoxidation in the presence of molecular oxygen without the need for any co-reductant. The magnetic nanocomposite could be readily separated by a magnet from the mixture and reused for several times without any significant reactivity loss, which represents its potential for practical and industrial application. Also, the scalability of the process was investigated in this work.
Schiff base complexes of Mo(VI) immobilized on functionalized graphene oxide nano-sheets for the catalytic epoxidation of alkenes
Rezazadeh, Behnam,Pourali, Ali Reza,Banaei, Alireza,Behniafar, Hossein
, p. 3401 - 3416 (2019/11/21)
Mo(VI) tetradentate Schiff base complexes were covalently immobilized onto chemically functionalized graphene oxide (GO) using 3-(tri-methoxysilyl) propylamine as a coupler. The resulting heterogeneous catalysts have been characterized by FTIR, DRS, XRD, SEM, TGA, and atomic absorption spectroscopy (AAS). These catalysts were applied in epoxidation of cyclooctene and other olefins. The catalytic procedures with all catalysts were optimized for different parameters such as oxidant, solvent and temperature. Recycling results indicated that the catalysts were highly stable and maintained activity and selectivity even after being used for five cycles.
Co(II) Schiff base complex decorated on polysalicylaldehyde as an efficient, selective, heterogeneous and reusable catalyst for epoxidation of olefins in mild and self-coreductant conditions
Kazemnejadi, Milad,Shakeri, Alireza,Nikookar, Mahsa,Mohammadi, Mohammad,Esmaeilpour, Mohsen
, p. 6889 - 6910 (2017/10/05)
Abstract: A new Co(II)-Schiff base complex was decorated on a polysalicylaldehyde (PSA) framework and used as a selective and efficient catalyst for the epoxidation of alkenes in the presence of O2 as a green source of oxygen without aco-reductant. The catalyst was characterized step by step by FTIR, UV–Vis, 1H NMR, TGA, CHN, XPS and EDX analyses. Loading an amount of Co ions in the catalyst as well as its leaching amount were studied by an ICP-OES instrument. The catalyst demonstrated excellent activity for the of a variety of alkenes in a mild, inexpensive and efficient protocol. Also, the catalyst can be simply recovered from the reaction mixture and reused for several times without any noteiceable loss in its activity. Reaction parameters including temperature, oxygen flow volume, catalyst amount and solvent were screened by reaction time. Catalytic studies including XPS spectroscopy and some blank experiments were performed to obtain an initial insight into the reaction mechanism. Also, the reactivity of the novel catalyst was evaluated as the turnover frequency. Graphical Abstract: A new and efficient protocol have been developed for the selective epoxidation of olefins using a heterogeneous recyclable Co(II)-Schiff base complex of polysalicylaldehyde in mild and self-coreductant conditions by molecular oxygen.
