Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 11, 2006
Previous Article Next Article

Determination of geometric orientation of adsorbed cinchonidine on Pt and Fe and quiphos on Pt nanoclusters viaDRIFTS

Author affiliations

Abstract

Platinum nanoclusters modified with cinchonidine have been employed as ‘quasi-homogeneous’ catalysts for the hydrogenation of ethyl pyruvate and have demonstrated exceptional activities while the ee’s of these systems are currently inferior to the traditional Pt/Al2O3 heterogeneous system. For the bulk systems it has been shown that the orientation of the modifier on the metal surface is a critical parameter influencing catalytically induced enantioselectivity. It has been speculated that the lower observed ee’s for the nanocluster systems are a result of the modifier assuming an orientation unfavorable for inducing enantioselectivity due to the lack of large numbers of planar metal atoms. Using DRIFTS (diffuse reflectance infra-red Fourier transform spectroscopy) analysis of samples together with geometry optimization and IR modelling we have studied the orientation of cinchonidine on Pt and Fe nanoclusters and additionally the man-made ligand quiphos on Pt nanoclusters. It has been determined that cinchonidine can adsorb on Pt and Fe nanoclusters in both ‘flat’ and ‘tilted’ modes, while quiphos can be adsorbed on Pt only via the ‘π-bonded’ mode. These studies thus provide an insight into modifier orientation on nanocluster surfaces that can be extended to a wide range of potential modifiers and facilitate a better understanding of the origin of enantioselectivity with these ‘quasi-homogeneous’ catalyst systems.

Graphical abstract: Determination of geometric orientation of adsorbed cinchonidine on Pt and Fe and quiphos on Pt nanoclusters via DRIFTS

Back to tab navigation

Article information


Submitted
18 Oct 2005
Accepted
06 Feb 2006
First published
17 Feb 2006

Phys. Chem. Chem. Phys., 2006,8, 1321-1328
Article type
Paper

Determination of geometric orientation of adsorbed cinchonidine on Pt and Fe and quiphos on Pt nanoclusters via DRIFTS

A. Kraynov, A. Suchopar, L. D’Souza and R. Richards, Phys. Chem. Chem. Phys., 2006, 8, 1321
DOI: 10.1039/B514750F

Social activity

Search articles by author

Spotlight

Advertisements