A polymer-anchored cobalt(II) complex as a reusable catalyst for oxidation of benzene, ethylbenzene and cyclohexane
| Autor: | K. Renuka Maldepalli, Gayathri Virupaiah |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Cyclohexane
010405 organic chemistry Metals and Alloys Cyclohexanol chemistry.chemical_element Cyclohexanone 010402 general chemistry Divinylbenzene 01 natural sciences Ethylbenzene 0104 chemical sciences Inorganic Chemistry chemistry.chemical_compound chemistry Polymer chemistry Materials Chemistry Organic chemistry Benzene Cobalt Acetophenone |
| Zdroj: | Transition Metal Chemistry. 42:25-34 |
| ISSN: | 1572-901X 0340-4285 |
| DOI: | 10.1007/s11243-016-0102-z |
| Popis: | A polymer-supported cobalt complex of 2,6-bis(benzimidazolyl)pyridine (BBP) was synthesized by immobilization of BBP on chloromethylated polystyrene cross-linked with 6.5 % divinylbenzene, followed by complexation with CoCl2 in methanol, and characterized by physico-chemical and spectroscopic methods. The polymer-bound Co(PS–BBP)Cl2 was found to be more stable compared to free Co(BBP)Cl2 as determined by TGA analyses. The catalytic activity of Co(PS–BBP)Cl2 was investigated towards oxidation of benzene, ethylbenzene and cyclohexane using tert-butylhydroperoxide as oxidant. At optimum conditions, benzene showed 72.6 % conversion with 100 % selectivity towards phenol; ethylbenzene exhibited 97.0 % conversion with 82.5 and 17.4 % selectivity towards benzaldehyde and acetophenone, respectively, whilst conversion of cyclohexane was 60.0 with 75.8 and 24.1 % selectivity towards cyclohexanol and cyclohexanone. The unsupported complex Co(BBP)Cl2 showed lower activities and selectivities compared to the polymer-supported complex. Co(PS–BBP)Cl2 was found to be very active and reusable, giving high yields of the desired products. A possible reaction mechanism is proposed for these oxidation reactions. |
| Databáze: | OpenAIRE |
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