
%0 Journal Article
%A Lincoln, SF 
%A Hounslow, AM 
%A Jones, AJ 
%T Nuclear magnetic resonance study of ligand exchange on Hexakis(1,1,3,3-tetramethylurea)lutetium(III)
%J Australian Journal of Chemistry
%D 1982/12/01
%V 35
%N 12
%P 2393-2398
%K 
%R https://doi.org/10.1071/CH9822393
%U https://www.publish.csiro.au/paper/CH9822393 
%X A 270-MHz lH n.m.r. study shows the rate of 1,1,3,3-tetramethylurea exchange on [Lu{OC(NMe2)2}6]2+ in CD3CN solution to be independent of [OC(NMe2)2]free consistent with the operation of either a dissociative mechanism or an interchange mechanism characterized by an encounter complex stability constant &#8805; 400. For this study  ligand exchange rate = 6kex[Lu{OC(NMe2)2}63+] with kex(298.2 K) = 41.9 ± 2.7 s-l, &#916;H&#8225; = 41.7 ± -0.6 kJmol-1 and &#916;S&#8225; = -74 ± JK-1 mol-l. These data are compared with those for the analogous scandium(III) and yttrium(III) systems and also those for some eight-coordinate trivalent lanthanide systems. The preparations of [LuL6] (ClO4)3, where L = OC(NMe2)2, OCMe(NMe2) and OCMe(Net2), are reported. 
