Tetramerization
As tetramerization even cyclotetramerization is called the union of four molecules, the monomer to a tetramer . The resulting substances usually contain an eight-membered ring .
In chemistry, it is generally the combination of four identical molecules to form a new molecule through addition reactions . The tetramer thus has four times the molecular weight of the starting material. Tetramerization often also produces trimers and higher by-products, i.e. higher oligomers .
The cyclotetramerization of acetylene , in the presence of catalytic amounts of nickel cyanide in tetrahydrofuran, gives cycloacta-1,3,5,7-tetraene in 70% yield . This chemistry, carried out on an industrial scale, is based on the work of Walter Reppe (1892–1969).
If acetylene is oligomerized at 60-70 ° C. in the presence of catalysts such as tricarbonyl (triphenylphosphine) nickel (0) , the trimerization product benzene (88% yield) and the tetramerization product styrene (12% yield) are also formed.
In biochemistry, tetramers (e.g. tetrameric proteins ) can be composed of the same (homotetramer) or different (heterotetramer) subunits.
Individual evidence
- ^ A b Siegfried Hauptmann : Organic Chemistry , 2nd revised edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 262, ISBN 3-342-00280-8 .
- ^ Siegfried Hauptmann: Organic Chemistry , 2nd reviewed edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 255, ISBN 3-342-00280-8 .