Featured Research

from universities, journals, and other organizations

Fingerprints of a gold cluster revealed

Date:
February 25, 2011
Source:
Academy of Finland
Summary:
Nanometer-scale gold particles are currently intensively investigated for possible applications in catalysis, sensing, photonics, biolabeling, drug carriers and molecular electronics.

An atomistic model of the Au102(p-MBA)44 particle. Gold: yellow, sulfur: orange, carbon: green, oxygen: red, hydrogen: white
Credit: Image courtesy of Academy of Finland

Nanometre-scale gold particles are currently intensively investigated for possible applications in catalysis, sensing, photonics, biolabelling, drug carriers and molecular electronics. The particles are prepared in a solution from gold salts and their reactive gold cores can be stabilised with various organic ligands. Particularly stable particles can be synthesised by using organothiolate ligands that have a strong chemical interaction to gold. The chemical process of preparing such particles has been known since the mid-1990s and many different stable sizes and compositions are known.

However, the first definite information of their atomic structure became available only in 2007 when the group of Roger Kornberg (Chemistry Nobel Laureate 2006) at Stanford University succeeded in making single crystals for X-ray diffractometry containing only one type of a particle having 102 gold atoms and 44 thiolate ligands, the so called Au102(p-MBA)44 particle. The structure was reported in Science in late 2007 [1]. The theoretical analysis of this and other thiolate-protected gold clusters, led by Professor Hannu Häkkinen at the University of Jyväskylä in Finland, resulted in a theoretical framework that can be used to understand the stability and electronic structure of these particles. This work was reported in the Proceedings of the National Academy of Sciences in 2008 [2].

Now, researchers in the Department of Chemistry and the Nanoscience Center (NSC) at the University of Jyväskylä, in collaboration with the Kornberg group, report the first full spectroscopic characterisation of the absorption of electromagnetic radiation by the Au102(p-MBA)44 particle in solution and solid phases. The study was published in the Journal of the American Chemical Society on 24 February 2011 [3]. The spectroscopic study was performed in a large range of electromagnetic spectrum from mid-infrared ("heat absorption") to ultraviolet light.

"The study was technically demanding and could only be made now when the Stanford group has succeeded in refining the synthesis to produce pure Au102(p-MBA)44 product in large quantities," explains Adjunct Professor Mika Pettersson, who led the experimental work at the NSC. "We document clear "fingerprint" features in the absorbance spectrum that can be used in the future to benchmark chemical modifications of this particle for various applications. The work also establishes the molecular nature of the clusters by the observation of a band gap of 0.45 eV, in excellent agreement with theory. We were able to analyse these features from large-scale computations using the known structure of Au102(p-MBA)44 and thus fully understand the absorption characteristics of this particle," says Professor Häkkinen.

The other researchers involved in the work are Eero Hulkko, Jaakko Koivisto and Olga Lopez-Acevedo from the University of Jyväskylä. The pure samples of the Au102(p-MBA)44 particle were made by Yael Levi-Kalisman in the Kornberg group. The work at the NSC and the Department of Chemistry at the University of Jyväskylä is funded by the Academy of Finland. The massively parallel computations, using up to 2048 processor cores, were made in the Louhi supercomputer at CSC -- the IT Center for Science.


Story Source:

The above story is based on materials provided by Academy of Finland. Note: Materials may be edited for content and length.


Journal References:

  1. Eero Hulkko, Olga Lopez-Acevedo, Jaakko Koivisto, Yael Levi-Kalisman, Roger D. Kornberg, Mika Pettersson, Hannu Häkkinen. Electronic and Vibrational Signatures of the Au102(p-MBA)44Cluster. Journal of the American Chemical Society, 2011; 110224153619025 DOI: 10.1021/ja111077e
  2. M. Walter, J. Akola, O. Lopez-Acevedo, P. D. Jadzinsky, G. Calero, C. J. Ackerson, R. L. Whetten, H. Gronbeck, H. Hakkinen. A unified view of ligand-protected gold clusters as superatom complexes. Proceedings of the National Academy of Sciences, 2008; 105 (27): 9157 DOI: 10.1073/pnas.0801001105
  3. P.D. Jadzinsky, G. Calero, C.J. Ackerson, D.A. Bushnell and R.D. Kornberg. Structure of a thiol monolayer-protected gold nanoparticle at 1.1. Ångstrom resolution. Science, 318, 430 (2007) DOI: 10.1126/science.1148624

Cite This Page:

Academy of Finland. "Fingerprints of a gold cluster revealed." ScienceDaily. ScienceDaily, 25 February 2011. <www.sciencedaily.com/releases/2011/02/110225093915.htm>.
Academy of Finland. (2011, February 25). Fingerprints of a gold cluster revealed. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2011/02/110225093915.htm
Academy of Finland. "Fingerprints of a gold cluster revealed." ScienceDaily. www.sciencedaily.com/releases/2011/02/110225093915.htm (accessed July 30, 2014).

Share This




More Matter & Energy News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) — British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
China's Drone King Says the Revolution Depends on Regulators

China's Drone King Says the Revolution Depends on Regulators

Reuters - Business Video Online (July 30, 2014) — Comparing his current crop of drones to early personal computers, DJI founder Frank Wang says the industry is poised for a growth surge - assuming regulators in more markets clear it for takeoff. Jon Gordon reports. Video provided by Reuters
Powered by NewsLook.com
3Doodler Bring 3-D Printing to Your Hand

3Doodler Bring 3-D Printing to Your Hand

AP (July 30, 2014) — 3-D printing is a cool technology, but it's not exactly a hands-on way to make things. Enter the 3Doodler: the pen that turns you into the 3-D printer. AP technology writer Peter Svensson takes a closer look. (July 30) Video provided by AP
Powered by NewsLook.com
Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) — A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:  

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile iPhone Android Web
      Follow Facebook Twitter Google+
      Subscribe RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins