
TY  - JOUR
A1  - Honan, GJ 
A1  - Lincoln, SF 
A1  - Williams, EH 
T1  - A Proton Magnetic Resonance Study of Ligand Exchange on the Pentakis (N-formylpyrrolidine)dioxouranium (VI) Ion
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1979
VL  - 32
IS  - 8
SP  - 1851
EP  - 1855
KW  - 
UR  - https://doi.org/10.1071/CH9791851 
N2  - Pentakis(N-formylpyrrolidine)dioxouranium(VI) perchlorate, [UO2(fpr)5] (ClO4)2, has been isolated from solution. In the presence of excess free fpr the greatly predominant species in CD2Cl2 solutions is [UO2(fpr)5]2+, as shown by 1H N.M.R. spectroscopy, and fpr exchange is characterized by a two term rate law:  exchange rate = 5(k1+ k2[fpr])[UO2(fpr)52+]  It is found that k1(220 K) = 42·6±0·5 s-1, &#916;H&#8225; = 30·7±1·4 kJ mol-1 and &#916;S&#8225; = -71·6±6·3 J K-1 mol-1, and k2(220 K) = 369±20 dm3 mol-1 s-1, &#916;H&#8225; = 30·5±1·0 kJ mol-1 and &#916;S&#8225; = -54·9±5·0 J K-1 mol-1. The mechanistic implications of these data are discussed. 
ER  -

