The question concerns organic reactions catalyzed by transition metal clusters. What is a definition of cluster in this regard? I see many controversial descriptions in the literature. It should be somewhere between mononuclear metal complex and nanoparticle. Metal cluster should contain a minimum of three (or two?) metal atoms. However, what is the upper size limit of cluster? (i.e. the border between cluster and nanoparticle). I would very much appreciate the references, where a clear definition of metal cluster is given. Thanks!
There is still no sharp discrimination between the terms ‘cluster’ and ‘nanoparticle’ in the literature. Clusters are mostly considered as species, exactly defined in chemical composition and structure, whereas the expression ‘nanoparticle’ usually means particles of less precise characterization, often linked with a certain size distribution and so to some extent substitutes the historical expression ‘colloid’. Examples for typical and long-known clusters are Co4(CO)12 or Rh6(CO)16, exhibiting bridging and terminal CO groups as well as direct metal–metal bonds. (http://rsta.royalsocietypublishing.org/content/368/1915/1207.full)
Here is another reference which could be helpful to you.
http://www.annualreviews.org/doi/pdf/10.1146/annurev.pc.42.100191.002341
http://pubs.acs.org/doi/pdf/10.1021/cr00076a005
Thanks! The reference on Phil. Trans. R. Soc. is very useful (special issue on clusters).
Cluster catalysis can act as individual active sites, and minor changes in size and composition such as the addition or removal of a single atom having substantial influence on the activity and selectivity of a reaction.
- Badges
- Science topic
- Similar topics
- Methodology
- Research Methodology
- Research Papers