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Synthesis and Characterization of Au 55 Clusters within Mesoporous Silica
Author(s) -
Lotz Andreas R.,
Fröba Michael
Publication year - 2005
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200500150
Subject(s) - mesoporous material , physisorption , mesoporous silica , triphenylphosphine , dichloromethane , metal , materials science , chemical engineering , matrix (chemical analysis) , cluster (spacecraft) , chemistry , inorganic chemistry , crystallography , adsorption , organic chemistry , catalysis , solvent , metallurgy , engineering , composite material , computer science , programming language
The cluster compound Au 55 (PPh 3 ) 12 Cl 6 was synthesized via the reduction of (triphenylphosphine)gold chloride with diborane and incorporated into the mesopores of SBA‐15 silica. As alternative pathway, the synthesis of Au 55 clusters directly within the silica matrix was investigated. Remarkably, the comparison of the two different methods shows that incorporation of the preformed clusters and intra‐pore synthesis give nearly identical products. Powder X‐ray diffractometry and nitrogen physisorption clearly prove the preservation of the mesoporous host matrix and the filling of the pores. Transmission electron microscopy studies reveal that the individual clusters are preferentially located inside the pore system, bulk formation on the outer surface is not observed. The guest species can partially be dissolved out of the host matrix by dichloromethane. Annealing of the host/guest compound leads to decomposition of Au 55 (PPh 3 ) 12 Cl 6 to metallic gold within the pores, whereas the particle size increases with rising temperature.