Goethe University chemists have managed to synthesise a compound featuring an Si20 dodecahedron. The Platonic solid, which was published in the "Angewandte Chemie" journal, is not just aesthetically pleasing, it also opens up new perspectives for the semiconductor industry.
The discovery of the soccer ball-shaped C60 molecule in 1985 was a milestone for the development of nanotechnology. In parallel with the fast-blooming field of research into carbon fullerenes, researchers have spent a long time trying in vain to create structurally similar silicon cages.
Goethe University chemists have now managed to synthesise a compound featuring an Si20 dodecahedron. The Platonic solid, which was published in the "Angewandte Chemie" journal, is not just aesthetically pleasing, it also opens up new perspectives for the semiconductor industry.
The Si20 dodecahedron is roughly as large as the C60 molecule. However, there are some crucial differences between the types of bonding: All of the carbon atoms in C60 have a coordination number of three and form double bonds. In the silicon dodecahedron, in contrast, all atoms have a coordination number of four and are connected through single bonds, so that the molecule is also related to dodecahedrane (C20H20).
"In its day, dodecahedrane was viewed as the 'Mount Everest' of organic chemistry, because it initially could only be synthesized through a 23- step sequence. In contrast, our Si20 cage can be created in one step starting from Si2 building blocks," explains Prof. Matthias Wagner of the Goethe University Institute of Inorganic and Analytical Chemistry.
The Si20 hollow bodies, which have been isolated by his PhD student, Jan Tillmann, are always filled with a chloride ion. The Frankfurt chemists therefore suppose that the cage forms itself around the anion, which thus has a structure-determining effect. On its surface, the cluster carries eight chlorine atoms and twelve Cl3Si groups.
These have highly symmetric arrangements in space, which is why the molecule is particularly beautiful. Quantum chemical calculations carried out by Professor Max C. Holthausen's research group at Goethe University show that the substitution pattern that was observed experimentally indeed produces a pronounced stabilisation of the Si20 structure.
In future, Tillmann and Wagner are planning to use the surface-bound Cl3Si anchor groups to produce three dimensional nanonetworks out of Si20 units. The researchers are particularly interested in the application potential of this new compound:
"Spatially strictly limited silicon nanoparticles display fundamentally different properties to conventional silicon wafers," explains Matthias Wagner. The long strived-for access to siladodecahedrane thus opens up the possibility of studying the fundamental electronic properties of cage-like Si nanoparticles compared to crystalline semiconductor silicon.
J. Tillmann et al: One-Step Synthesis of a Silafullerane with an Endohedral Chloride
Ion, in: Angew. Chem. Int. Ed. 2015, DOI: 10.1002/anie.201412050
Download an image from: http://www.muk.uni-frankfurt.de/54612947?
Information: Prof. Matthias Wagner, Institute for Anorganic and Analytic Chemistry, Campus Riedberg, phone: +49(069)798-29156, email: Matthias.Wagner@chemie.uni-frankfurt.de
Goethe University is a research-oriented university in the European financial centre Frankfurt Founded in 1914 with purely private funds by liberally-oriented Frankfurt citizens, it is dedicated to research and education under the motto "Science for Society" and to this day continues to function as a "citizens’ university". Many of the early benefactors were Jewish. Over the past 100 years, Goethe University has done pioneering work in the social and sociological sciences, chemistry, quantum physics, brain research and labour law. It gained a unique level of autonomy on 1 January 2008 by returning to its historic roots as a privately funded university. Today, it is among the top ten in external funding and among the top three largest universities in Germany, with three clusters of excellence in medicine, life sciences and the humanities.
Publisher The President of Goethe University, Marketing and Communications Department, 60629 Frankfurt am Main
Editor: Dr. Anke Sauter, Science Editor, International Communication, Tel: +49(0)69 798-12498, Fax +49(0)69 798-761 12531, firstname.lastname@example.org
Dr. Anke Sauter | idw - Informationsdienst Wissenschaft
New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy