Bimetallic silver-gold clusters by matrix-assisted laser desorption/ionization

Sándor Kéki; Lajos Nagy; György Deák; Miklós Zsuga

doi:10.1016/j.jasms.2004.07.001

Bimetallic silver-gold clusters by matrix-assisted laser desorption/ionization

J Am Soc Mass Spectrom. 2004 Oct;15(10):1455-1461. doi: 10.1016/j.jasms.2004.07.001.

Authors

Sándor Kéki¹, Lajos Nagy¹, György Deák¹, Miklós Zsuga²

Affiliations

¹ Department of Applied Chemistry, University of Debrecen, Debrecen, Hungary.
² Department of Applied Chemistry, University of Debrecen, Debrecen, Hungary. zsugam@tigris.klte.hu.

PMID: 15465358
DOI: 10.1016/j.jasms.2004.07.001

Abstract

Pure gold clusters (Aun+) were produced up to the cluster size of n = 100 by matrix-assisted laser desorption/ionization (MALDI). The mass spectrum of the resulting clusters showed alteration in the ion intensity at odd-even clusters size. On the other hand, intensity drops at cluster size predicted by the jellium model theory was also observed. Positively and negatively charged bimetallic silver-gold clusters were produced under MALDI conditions from the mixture of HAuCl4/silver trifluoroacetate and the 2-(4-hydroxyphenylazo)benzoic acid (HABA) matrix. A linear correlation was found between the intensity ratio of AunAgm+ to Au(n+1)Ag(m-1)+ cluster ions and the molar ratio of the gold to silver salt. It was observed that the composition and the distribution of the clusters can be varied with the molar ratio of the silver and gold salts. It was also found that the resulting cluster sizes obey the lognormal distribution.