Severe cases of silicosis can cause death from insufficient oxygen or from heart failure. A lung condition called silicotuberculosis may develop. Silicosis causes fibrosis and nodules in the lung, lowering lung capacity and making the subject more liable to pulmonary diseases, such as pneumonia. Such exposure causes a condition called silicosis, a type of pulmonary fibrosis, one of the most common disabling conditions that result from industrial exposure to hazardous substances. Because of silica's occurrence in a large number of common materials that are widely used in construction, sand blasting, refractories manufacture, and many other industrial applications, human exposure to silica dust is widespread. Silica is a hard mineral substance known as quartz in the pure form and occurring in a variety of minerals, such as sand, sandstone, and diatomaceous earth. The silicon compound that has probably caused the most illness in humans is silica, SiO2. This section covers the toxico-logical aspects of inorganic silicon compounds. Concurrent with this phenomenon has been an awareness of the toxicity of silicon compounds, many of which, fortunately, have relatively low toxicities. Filippou: Planar Tetracoordinated Silicon (ptSi): Room Temperature Stable Compounds Containing Anti-van’t Hoff/Le Bel Silicon Journal of the American Chemical Society, DOI: 10.1021/jacs.Because of its use in semiconductors, silicon has emerged as a key element in modern technology. Publication: Priyabrata Ghana, Jens Rump, Gregor Schnakenburg, Marius I. The study was funded by the University of Bonn. At any rate, for a long time it was considered completely impossible to produce such compounds.
The influence of the unusual structure on the properties of silicon, an important element for the electronics industry, is completely unclear at the moment. Producing the starting materials, on the other hand, is complex one of them was first synthesized only just over ten years ago and has already been the source for the synthesis of several novel classes of silicon compounds. Together with spectroscopic measurements, this method confirmed that ligands and silicon are indeed in the same plane in the new molecules.Īlthough the synthesis of the exotic compounds must be carried out under inert gas, it is otherwise comparatively simple. These deviations can therefore be used to calculate the spatial structure of the molecules in the crystal. The X-ray light is scattered by the atoms and changes its direction. The researchers grew crystals of the substances and then blasted them with X-rays. "Our computer calculations indicate that there is no structure for the molecules that would be more energetically favorable than the planar trapezoidal shape," emphasizes Jens Rump, a doctoral student at the Institute for Inorganic Chemistry. This appears to be so strong that it completely prevents the trapezoidal arrangement from "snapping" into a tetrahedron. In the process, they form a solid framework. The ligands also form bonds with each other. They discovered the reason by modeling the molecules on the computer. The researchers themselves were surprised by this unusual stability. Priyabrata Ghana, a former doctoral student who has since moved to RWTH Aachen University. "Despite this, the compounds are so stable that they can be filled into bottles and stored for weeks without any problems," explains Dr. They lie in one plane together with the silicon. In these, the four ligands do not form a tetrahedron, but a distorted square, a trapezoid. Filippou of the Institute for Inorganic Chemistry at the University of Bonn have now constructed silicon-containing molecules that are as unusual as a cube-shaped soap bubble. It therefore arises quasi automatically, just as a soap bubble is usually spherical. This arrangement is most favorable energetically.
The silicon atom is located in the center, its bonding partners (the so-called ligands) at the tetrahedral corners. When it does, the result is usually a tetrahedron. Like its relative carbon, silicon generally forms four bonds with other atoms.
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