Organosilicon compounds
Organosilicon compounds (also: organosilicon compounds ) is the collective term for compounds that either have direct silicon - carbon bonds (Si – C) or in which the carbon is linked to the silicon via oxygen , nitrogen or sulfur atoms. Organosilicon compounds can be described by the general formula R n SiX 4− n (with n from 1 to 4), where R represents various organic radicals, such as B. aliphatics , aromatics , heterocycles . X stands for different groups (see table). In contrast, compounds such as monosilane (SiH 4 ), tetrachlorosilane (SiCl 4 ) etc. are not counted among the organosilicon compounds.
| X | Substance group | Remarks |
|---|---|---|
| H or R | organo silane | z. B. tetramethylsilane , which in the NMR spectroscopy as (internal) standard for the determination of the chemical shift is used |
| OH | organo silanols | z. B. trimethylsilanol , a water repellent |
| Cl | Organo chlorosilanes | will u. a. used in construction chemistry as a waterproofing agent; Organohalosilanes are of industrial importance as starting materials for silicone polymers |
| Si – O, alternately |
Siloxanes silicones |
z. B. Hexamethyldisiloxane , (H 3 C) 3 Si − O − Si (CH 3 ) 3 |
| Si – N, alternating | Polysilazanes | z. B. Hexamethyldisilazane , (H 3 C) 3 Si-NH-Si (CH 3 ) 3 |
| Si – C, alternately | Carbosilanes | z. B. (H 3 C) 3 Si-CH 2 -Si (CH 3 ) 3 |
In addition to the areas of application mentioned in the table, organosilicon compounds are used in a wide variety of areas, e.g. B.
- in the form of silicones u. a. as a lubricant for plastics processing , in toothpaste , as a sealing material,
- Silicon surfactants as foam stabilizers in plastics,
- organofunctional silanes as adhesion promoters ,
- as reactive intermediates in the synthesis of organic compounds, e.g. B. in Peterson olefination . Highly reactive silicon reagents are u. a. Trimethylsilyl iodide or cyanide.
Organosilicon compounds were already described and investigated in the middle of the 19th century.
literature
- Reinhold Tacke: Bioactive silicon compounds. In: Chemistry in Our Time . 14, No. 6, 1980, pp. 197-207, doi : 10.1002 / ciuz.19800140605 .
- Jürgen Ackermann, Volker Damrath: Chemistry and Technology of Silicones II. Production and use of silicone polymers. In: Chemistry in Our Time . 23, No. 3, 1989, pp. 86-99, doi : 10.1002 / ciuz.19890230304 .
- Franz AK, Wilson SO: Organosilicon molecules with medicinal applications . In: J. Med. Chem. . 56, No. 2, 2013, pp. 388-405. doi : 10.1021 / jm3010114 . PMID 23061607 .
Individual evidence
- ↑ Hans-Ulrich Reissig: Silicon compounds in organic synthesis, Chemistry in our time , 18th year 1984, No. 2, pp. 46–53, doi : 10.1002 / ciuz.19840180203 .
- ↑ Jacques-Joseph Ebelmen : Investigation of the compounds of boric acid and silica with ethers. In: Journal for practical chemistry . 37, No. 1, 1846, pp. 347-376.
- ↑ C. Friedel, JM Crafts: About some new organic compounds of silicon and the atomic weight of this element. In: Annals of Physics and Chemistry . 127, 1863, pp. 28-32.