Ethoxysilane appended M(II) complexes and their SiO2/MCM-41 supported forms as catalysts for efficient oxidation of secondary alcohols
| Autor: | Pratap Vishnoi, Ramaswamy Murugavel, Serhan URUŞ, Rajendran Antony, Marimuthu Rajendiran |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Denticity
Schiff base 010405 organic chemistry Chemistry Inorganic chemistry 010402 general chemistry 01 natural sciences Toluene 0104 chemical sciences Catalysis law.invention Inorganic Chemistry chemistry.chemical_compound Transition metal MCM-41 law Polymer chemistry Materials Chemistry Physical and Theoretical Chemistry Electron paramagnetic resonance Single crystal |
| Zdroj: | Inorganica Chimica Acta. 469:173-182 |
| ISSN: | 0020-1693 |
| DOI: | 10.1016/j.ica.2017.09.024 |
| Popis: | Divalent transition metal complexes ML2 (M = Mn 1; Co 2; Cu 3; Zn 4), possessing an ethoxysilane group as a part of the bidentate Schiff base ((E)-1-((3-(triethoxysilyl)propylimino)methyl)naphthalen-2-ol (L)), have been synthesized. While the copper complex 3 has been isolated in an analytically pure form and characterized by spectroscopic and single crystal XRD studies, the formation of complexes 1, 2, and 4 in solution has been verified by ESI mass spectroscopy and subsequently used for further catalyst preparation without their isolation. Treatment of the in situ formed 1–4 with pre-activated silica in boiling toluene produces the catalysts 5–8, respectively. The copper complex 3 was also treated with MCM-41 in boiling toluene to obtain CuL2@MCM-41 (9). Elemental analysis (CHN), ESI MS, IR, UV–vis., 13C & 29Si NMR, EPR, P-XRD, TGA, BET, SEM and TEM have been used to characterize the compounds. Compounds 3 (homogeneous) and 5–9 (heterogeneous) have been utilized as catalysts in the oxidation of secondary alcohols to corresponding carbonyls in the presence of H2O2, t-BuOOH, and C6H5C(CH3)2OOH. 3 and 9 have shown better catalytic activity than the rest of the catalysts investigated. Combination of 9 with H2O2 is the best catalytic system due to its efficiency and reusability besides being environment friendly. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect