Issue 4, 2005

Oxoperoxo molybdenum(vi) and tungsten(vi) and oxodiperoxo molybdate(vi) and tungstate(vi) complexes with 8-quinolinol: synthesis, structure and catalytic activity

Abstract

A solution obtained by dissolving MoO3 in a moderate excess of H2O2 reacts with 8-quinolinol (QOH) to give [MoO(O2)(QO)2] (1), but, when the same reaction is conducted with a large excess of H2O2, an anionic complex is formed, which reacts with PPh4Cl to give the corresponding salt [MoO(O2)2(QO)][PPh4] (2·PPh4). Freshly prepared WO3 behaves the same way and, depending on the amount of H2O2 used, as above, produces either [WO(O2)(QO)2] (3) or [WO(O2)2(QO)][PPh4] (4·PPh4), respectively. Crystallographic analyses reveal the coordination geometries around the metal center in these complexes to be distorted pentagonal bipyramids. These compounds show interesting catalytic properties in the oxidation of alcohols using H2O2 as the terminal oxidant. In the case of aromatics, including benzylic and cinnamylic alcohols, the oxidation occurs selectively, affording aldehydes or ketones with reasonably high turnover numbers. Taking benzyl alcohol as a representative case, a probable mechanism of the alcohol-to-aldehyde conversion mediated by the prepared catalysts is suggested. The oxidation of aliphatic primary alcohols, under the same conditions, does not show the above selectivity: the reaction yields the corresponding aldehydes as well as carboxylic acids. The work was also extended to study the catalytic activity towards the oxidation of phenol and various sulfides and amines using the same oxidants.

Graphical abstract: Oxoperoxo molybdenum(vi) and tungsten(vi) and oxodiperoxo molybdate(vi) and tungstate(vi) complexes with 8-quinolinol: synthesis, structure and catalytic activity

Article information

Article type
Paper
Submitted
17 Jul 2004
Accepted
11 Nov 2004
First published
18 Feb 2005

New J. Chem., 2005,29, 554-563

Oxoperoxo molybdenum(VI) and tungsten(VI) and oxodiperoxo molybdate(VI) and tungstate(VI) complexes with 8-quinolinol: synthesis, structure and catalytic activity

S. K. Maiti, S. Banerjee, A. K. Mukherjee, K. M. Abdul Malik and R. Bhattacharyya, New J. Chem., 2005, 29, 554 DOI: 10.1039/B410984H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements