Persilastaffanes are an unusual new class of compounds that are introduced in the journal Angewandte Chemie by Japanese researchers led by Takeaki Iwamoto at Tohoku University.
They are rod-shaped molecules with a core consisting of one or more tiny “cages” made of silicon atoms. Even more unusual than the name and structure of these materials are the properties of their electrons, which make the materials intriguing candidates as building blocks to make new materials for electronic applications.
Where does the name persilastaffane come from? Persila indicates an organic molecule in which all (“per”) carbon atoms are replaced by silicon atoms (“sila”). A staffane is a special arrangement of five carbon atoms: two “bridgeheads” are bound to each other by way of three “bridges”, each of which has a carbon atom at its center. This results in a cage-like spatial structure. Alternatively, the structure of the cage can be viewed as a wavy ring made of four carbon atoms in which two opposite sides are additionally bridged by another carbon atom. A persilastaffane is a molecule that contains this type of cage made out of silicon atoms.
The Japanese team has developed a synthetic technique to make molecules containing one, two, or three such cages. What is so fascinating about these rod-shaped molecules? To date, there have been few studies of linear chains of silicon-containing ring systems; however theory suggests that there should be significant interactions between the cages. In these cases, the bonding electrons (sigma electrons) in the silicon–silicon bonds should not be localized between the two bonding partners as is usual in chemical bonds; instead, they should be able to move freely (delocalized) over the entire three-dimensional framework of silicon atoms, as in solid silicon.
This property is very interesting because silicon compounds with delocalized sigma electrons absorb light in the UV range, as well as being light-sensitive or conducting. They can also become conducting under light. Iwamoto and his colleagues examined the tiny rods by spectroscopic methods. They were able to confirm considerable delocalization of the sigma electrons over the silicon cages. Iwamoto remarks: “Persilstaffanes are fascinating rod-shaped silicon molecules that could serve as linear connectors for novel silicon-based finely defined materials, such as conductive molecular wires.”About the Author
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201106422
Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover
First transcription atlas of all wheat genes expands prospects for research and cultivation
17.08.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
17.08.2018 | Physics and Astronomy
17.08.2018 | Information Technology
17.08.2018 | Life Sciences