In:
Magnetic Resonance in Chemistry, Wiley, Vol. 40, No. 1 ( 2002-01), p. 87-92
Abstract:
The introduction of a squaric acid moiety at the secondary nitrogen center of DO3A [DO3A = 1,4,7‐tris(carboxymethyl)‐1,4,7,10‐tetraazacyclododecane] yields the DO3ASQ ligand endowed with a potential octadenticity towards Ln(III) ions. On the basis of 17 O NMR investigations on [Gd(DO3ASQ)(H 2 O)], 13 C NMR observations on [Lu(DO3ASQ)(H 2 O)] and UV spectra of [Eu(DO3ASQ)(H 2 O)], it is suggested that [Ln(DO3ASQ)(H 2 O)] complexes are present in solution as a mixture of two isomers differing in the coordination number of the Ln(III) ion, being 8 and 9, respectively. Only in the latter isomer is the squaric moiety coordinated to the Ln(III) ion. Interestingly, the two isomers display different exchange rates of the coordinated water molecule. Copyright © 2001 John Wiley & Sons, Ltd.
Type of Medium:
Online Resource
ISSN:
0749-1581
,
1097-458X
Language:
English
Publisher:
Wiley
Publication Date:
2002
detail.hit.zdb_id:
1475029-6
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