Epoxidation and catechol oxidation catalytic processes promoted by manganese(III) complexes of salen-type ligands
IR@NISCAIR: CSIR-NISCAIR, New Delhi - ONLINE PERIODICALS REPOSITORY (NOPR)
View Archive Info| Field | Value | |
| Title |
Epoxidation and catechol oxidation catalytic processes promoted by manganese(III) complexes of salen-type ligands
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| Creator |
Guha, Averi
Zangrando, Ennio Chandra, Arpita |
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| Subject |
Mononuclear Manganese(III) complexes
Catecholase activity Epoxidation catalyst |
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| Description |
169-176
Four new mononuclear manganese(III) complexes namely <strong>1</strong>, <strong>2</strong>,<strong> 3 </strong>and <strong>4 </strong>of salen-type ligands H<sub>2</sub>L<sup>1</sup>-H<sub>2</sub>L<sup>4</sup> (ligands were obtained <em>in situ</em> via Schiff-base condensation of 2-formyl-6-hydroxymethyl-4-methylphenol and amines cyclohexane-1,2-diamine, 2-methylpropane-1,2-diamine, propane-1,2-diamine and ethane-1,2-diamine, respectively) have been synthesised and characterised by routine physicochemical techniques. <strong>1</strong> is further characterised by X-ray single crystal structure analysis. Catalytic efficiencies of the complexes as epoxidation catalysts (substrates: styrene and (<em>E</em>)-stilbene; terminal oxidants: PhIO/NaOCl; solvent: MeCN /dicholorometane) and as catalysts for oxidation of catachol (substrates: 3,5-di-<em>tert</em>-butylcatechol (3,5-DTBC); solvent: methanol) have been evaluated. In both cases the catalytic efficiency increases on going from <strong>4-1</strong> although the actual mechanisms in those two catalytic reactions are completely different. However, the observations have been rationalized on the basis of steric and electronic factors exerted by the alkyl substituents present on the imine back-bone of the salen-type ligands. This study also verifies that there is at least another active epoxidizing species, [Cl–O–Mn(III)(salen)X] in addition to the discrete Mn(V)=O(salen) species in epoxidation of olefins depending upon the terminal oxidants employed. |
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| Date |
2021-02-11T07:06:47Z
2021-02-11T07:06:47Z 2021-02 |
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| Type |
Article
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| Identifier |
0975-0975(Online); 0376-4710(Print)
http://nopr.niscair.res.in/handle/123456789/56205 |
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| Language |
en_US
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| Rights |
<img src='http://nopr.niscair.res.in/image/cc-license-sml.png'> <a href='http://creativecommons.org/licenses/by-nc-nd/2.5/in' target='_blank'>CC Attribution-Noncommercial-No Derivative Works 2.5 India</a>
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| Publisher |
NISCAIR-CSIR, India
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| Source |
IJC-A Vol.60A(02) [February 2021]
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