ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Intramolecular Exchange of Carbonyl Group Sites in Tetracarbonyliron Complexes of Ethylene and Simple (E)-Configurated OlefinsThe activation parameters of the intramolecular exchange of carbonyl group sites in the tetracarbonyliron complexes 2-5 of ethylene, (E)-2-butene, (E)-4-octene and (E)-cyclooctene, respectively have been determined between 180 and 115 K by a complete line shape analysis of the 13C-NMR, signals of the CO-groups. The temperature dependence of the rates (k (2), k (3), k (4) and k (5), respectively) of this intramolecular exchange process can be described by the following equations (Ea in J/mol): \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} k(2) = 10^{{\rm 13}.1 \pm 0.9} {\rm exp}{\rm .(} - (31500 \pm 2500)/{\rm RT)s}^{{\rm - 1}} \\ k(3) = 10^{{\rm 11}.9 \pm 0.9} {\rm exp}{\rm .(} - (25100 \pm 2500)/{\rm RT)s}^{{\rm - 1}} \\ k(4) = 10^{{\rm 12}.1 \pm 0.7} {\rm exp}{\rm .(} - (27300 \pm 2000)/{\rm RT)s}^{{\rm - 1}} \\ k(5) = 10^{{\rm 12}.0 \pm 0.4} {\rm exp}{\rm .(} - (25100 \pm 900)/{\rm RT)s}^{{\rm - 1}} \\ \end{array} $$\end{document} Further data are given in Tables 3 and 4.Furthermore, a good linear correlation between the energies of activation of the carbonyl exchange process in 1,2-disubstituted olefins and the corresponding averaged wavenumbers ( (CO)) of the carbonyl stretching vibrations or of the corresponding chemical 13C-shifts (δ (CO)) of the carbonyl group at fast exchange in the complexes seems to exist.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19800630325
