- About Us
- Nano-Social Network
- Nano Consulting
- My Account
Researchers at the Department of Chemistry and Nanoscience Center (NSC) of the University of Jyväskylä (Dr Olga Lopez-Acevedo and Professor Hannu Häkkinen) have resolved the structural, electronic and optical properties of a chiral gold nanocluster that remained a mystery for ten years. The theoretical structure was confirmed via comparison to experimental results obtained by X-ray diffraction from powder samples of the pure cluster material. The theoretical work was done in collaboration with researchers at Kansas State University and the experimental part at Hokkaido University. The team is supported by the Academy of Finland and the CSC - the IT Center for Science.
The synthesis of organothiolate-protected gold clusters of 1 to 3 nm in size has been well known since the mid-1990s, but the detailed atomic structure of the most stable clusters remained a mystery until very recently. In 2007, the structure of the first cluster that contained 102 gold atoms was resolved at Stanford University using single-crystal X-ray crystallography. The cluster now resolved has exactly 38 gold atoms and 24 organothiolate molecules covering its surface and it is just about one nanometer (nanometer = one millionth of a millimeter) in size. The shape of the particle is prolate (cigar-like), and 15 out if its 38 gold atoms reside on the protective surface layer chemically bound with the thiolate molecules. The gold-thiolate layer has a chiral structure, which is responsible for the observed chiral properties. The chiral structure has two structural forms (enantiomers), the so-called right-handed and left-handed forms, in a way comparable to a twist in a DNA molecule or to a twist in the staircase structure of a block of flats.
Chirality is a very common structural property of molecules in nature. The chiral nature of gold clusters influences the way they respond to circularly polarised light. This effect was first reported in experiments by Professor Robert L. Whetten's team at Georgia Institute of Technology (Atlanta, USA) exactly ten years ago. "We observed that particularly the 38-atom cluster (for which no structural information was available) is very sensitive for the polarisation of light, and the now-resolved structure finally explains our observations," comments Professor Whetten. In the future, chiral gold nanoclusters could be used as bio-compatible, enantioselective sensors, drug carriers or catalysts.
Professor Häkkinen's team at the University of Jyväskylä has played a world-leading role in theoretical structural determination and characterisation of thiolate-protected gold nanoclusters over the last few years. The team has collaborated with researchers at Stanford University, Georgia Institute of Technology, Kansas State University, the University of North Carolina, Chalmers University of Technology and Hokkaido University.
For more information please contact Professor Hannu Häkkinen, email tel. +358 (0)14 260 4719
The study was published in the Journal of the American Chemical Society, May 25, 2010. The link to the article "Chirality and electronic structure of the thiolate-protected Au38 nanocluster", O. Lopez-Acevedo, H. Tsunoyama, T. Tsukuda, H. Häkkinen, C.M. Aikens, JACS ASAP article May 25, 2010. pubs.acs.org/doi/abs/10.1021/ja102934q
For more information, please click here
Professor Hannu Häkkinen
tel. +358 (0)14 260 4719
Academy of Finland Communications
Communications Specialist Leena Vähäkylä
tel. (09) 7748 8327
040 359 2936
Copyright © Academy of FinlandIf you have a comment, please Contact us.
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
|Related News Press|
News and information
SUNY Polytechnic Institute Announces Total of 172 Teams Selected to Compete in Solar in Your Community Challenge: Teams from 40 states, plus Washington, DC, 2 Territories, and 4 American Indian Reservations, Will Deploy Solar in Underserved Communities April 20th, 2017