ISSN:
0899-0042
Schlagwort(e):
chiral asymmetry generation
;
chiral autocatalysis
;
primary nucleation
;
secondary nucleation
;
chiral cobalt complex
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Chiral asymmetry generation, the predominant production of one enantiomer in a non-chiral environment, could occur in the production of the chiral complex cis-[CoBr(NH3)(en)2]Br2 by the reaction of [Co(H2O)2{(OH)2Co(en)2}2](SO4)2 with ammonium bromide in an aqueous medium. The main kinetic steps in the reaction system have been determined. During the reaction, the product crystallizes at an early stage. When a very small amount of crystalline enantiomer was added to the reaction system at an early stage, the same enantiomer was produced preferentially; in addition, the enantiomeric excess of the product increased with increasing the stirring rate. Thus, it seems that each enantiomer generates chiral crystals that could self-replicate through secondary nucleation when the solution is stirred; these crystals in turn enhance the production of the same enantiomer. With a computer code that simulates such a kinetic mechanism, it is shown that enantiomeric excess observed in the experiments could be reproduced. Chirality 10:343-348, 1998. © 1998 Wiley-Liss, Inc.
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
