DSpace
 

DSpace at IIT Bombay >
IITB Publications >
Article >

Please use this identifier to cite or link to this item: http://dspace.library.iitb.ac.in/jspui/handle/10054/856

Title: Kinetic investigations of the mechanism of dihydrogen driven catalytic reduction of methylene blue, safranine O, methyl viologen and ferricyanide using platinum carbonyl cluster anions (Chini-clusters) as catalyst
Authors: SEN GUPTA, NALINAVA
MATHUR, PRADEEP
DOBLE, MUKESH
BHADURI, SUMIT
Keywords: clusters
kinetics
catalysis
spectra
Issue Date: 2006
Publisher: Elsevier
Citation: Inorganica Chimica Acta 359(12), 3895-3902
Abstract: [Bu4N]2[Pt12(CO)24] (1) catalyses the selective reduction of electron acceptors (S), methylene blue (MB+), safranine O (Saf+), methyl viologen (MV2+) and ferricyanide by dihydrogen. Macroscopic rate investigations for the cationic substrates in DMF, and for ferricyanide in DMSO have been carried out. In all cases, kobs is given by k1 [S] + k2, indicating that there are two catalytic cycles. In one of them, the formation of a complex between S and [Pt12(CO)24]2− in the rate determining step (rate constant k1) is followed by electron transfer and/or other fast steps. In the other catalytic cycle, the rate determining step (rate constant k2) involves formation of the solvated cluster anion [Pt12(CO)24]2−. The solvated cluster then undergoes fast reduction by dihydrogen and other reactions. The relative contributions of these two cycles depend on the substrate, and for MB+, Saf+, MV2+ and [Fe(CN)6]3− the contribution of the second cycle is about 99%, 55%, 77% and 97%, respectively. Both k1 and k2 of ferricyanide are about three orders of magnitude smaller than those of the cationic electron acceptors. The rates of reduction of MB+ and Saf+ have also been studied in the presence of added water. Rates increase as the presence of water provides an additional pathway for the reduction of [Pt12(CO)24]2− to [Pt9(CO)18]2−.
URI: http://dx.doi.org/10.1016/S0009-2614(99)01064-7
http://hdl.handle.net/10054/856
http://dspace.library.iitb.ac.in/xmlui/handle/10054/856
ISSN: 0009-2614
Appears in Collections:Article

Files in This Item:

File Description SizeFormat
5245.pdf400 kBAdobe PDFView/Open
View Statistics

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback