Isotopic Exchange Kinetics between Dibenzoylmethane-14C and Its Tris-type Complex with Aluminium (III) in Tetrahydrofuran
- 1 September 1973
- journal article
- Published by Oxford University Press (OUP) in Bulletin of the Chemical Society of Japan
- Vol. 46 (9) , 2777-2779
- https://doi.org/10.1246/bcsj.46.2777
Abstract
Isotopic exchange kinetics between [Al(dbm)3] and Hdbm–14C (dbm−, anion of dibenzoylmethane in enol form) has been studied in tetrahydrofuran (THF) at 30 to 55°C. During several half lives the McKay plot gives straight lines, the AB spectrum remaining unchanged. The rate is very small in the absence of catalysts, and accelerated by water and trichloroacetic acid, but not by weak acids and pyridine. The rate is expressed by R = [complex](k_2[H_2O]+k_3’[acid]+k_3[acid][H_2O]) The Arrhenius plots of k2, k3′, and k3 give an equal Δ\eweq value 25.6 kcal/mol. It appears one of the ligands is present as unidentate in the intermediate state, and the break of the remaining bond is the rate-determining step.Keywords
This publication has 1 reference indexed in Scilit:
- Mechanism of Isotopic Exchange of Trisacetylacetonatoaluminum with Acetylacetone-14C in Organic SolventsBulletin of the Chemical Society of Japan, 1970