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Silsesquioxanes as Ligands for Gold Clusters
Author(s) -
Schmid Günter,
Pugin Raphael,
Malm JanOlle,
Bovin JanOlov
Publication year - 1998
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(199806)1998:6<813::aid-ejic813>3.0.co;2-9
Subject(s) - chemistry , nanotechnology , combinatorial chemistry , materials science
A new type of gold cluster has been synthesized using the silsesquioxane derivative (cyclopentyl) 7 Si 8 O 12 (CH 2 ) 3 SH (T 8 ‐OSS−SH) to exchange the PPh 3 ligands in (PPh 3 ) 12 Au 55 Cl 6 by T 8 ‐OSS−SH quantitatively. This exchange causes several important changes in the physical and chemical behavior of the compound. Owing to the presence of cyclopentyl substituents, the cluster becomes soluble in non‐polar solvents such as pentane. The stability of this compound compared with that of the PPh 3 ‐protected cluster is considerably higher meaning that decomposition in solution, and even under the high‐energetic irradiation in the microscope, is not observed over longer periods of time. The increase in the total diameter from 2.1 to ca. 4.4 nm is probably responsible for these advantageous properties, supported by strong S−Au bonds. The increase in size is also expressed as an increase in the activation energy for electron‐tunneling processes through the ligand shells of neighboring clusters in a densely packed pellet. This increase is from 0.16 eV for (PPh 3 ) 12 Au 55 Cl 6 to 0.26 eV for the T 8 ‐OSS−SH‐protected cluster.