ISSN:
1573-1111
Keywords:
Crystal structure
;
lanthanides
;
praseodymium
;
dimer
;
macrocycle
;
(2.2.1)
;
cryptand
;
NMR
;
paramagnetic ion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract A dimeric lanthanide cryptate was obtained by the addition of an excess of cryptand (2.2.1) to a slightly hydrated solution of the monomeric praseodymium (2.2.1) perchlorate complex in acetonitrile. This new lanthanide compound is centrosymmetric and displays the space groupP21/n. The encryptated metal ions are nine-coordinated, they are bonded to all the heteroatoms of a (2.2.1) ligand and they are linked to each other by two μ-hydroxo bridges. The hydroxyl groups are relegating the cryptands to both end of the dimer and the praseodymium ions are less effectively accomodated in the macrocylic internal cavities than in the case of the monomeric Pr(2.2.1) complex. The formation of both the monomeric and the dimeric lanthanide complexes is readily observed by proton NMR.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00664109
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