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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2011-1-27
pubmed:abstractText
Lanthanide complexes based on bis(amides) of diethylenetriaminepentaacetic acid with thiol functionalities are modified with 2,2'-dipyridyl disulfide to give activated complexes that can selectively react with thiol-functionalized complexes to form heterometallic lanthanide macrocycles. The preparation and full characterization of the polyaminocarboxylate ligands N,N''-bis[p-thiophenyl(aminocarbonyl)]diethylenetriamine-N,N',N''-triacetic acid (H(3)L(x)) and the activated N,N''-bis[p-(pyridyldithio)[phenyl(aminocarbonyl)]]diethylenetriamine-N,N',N''-triacetic acid (H(3)L(y)) and the complexes LaL(x), NdL(x), SmL(x), EuL(x), GdL(x), DyL(x), TbL(x), ErL(x), and YbL(x) are reported. The luminescence properties of the LnL(x) complexes emitting in the visible (where Ln = Dy(3+), Tb(3+), Eu(3+), and Sm(3+)) are examined by steady-state and time-resolved photoluminescence, and the triplet state energy level of GdL(x) was estimated to be 24?100 cm(-1) from the 0-0 band of the 77 K phosphorescence spectrum. Near-infrared emission was detected for the NdL(x), YbL(x), and ErL(x) complexes, demonstrating the versatility of the thiophenol chromophore. The assembly of purely heterometallic EuTbL(x)(2) macrocycles by reaction of EuL(x) with TbL(y) was followed by UV-vis absorption spectroscopy, monitoring the characteristic absorption peak of pyridyl-2-thione at 353 nm. Analysis of the solution by mass spectrometry reveals the formation of purely heterometallic macrocycle EuTbL(x)(2). This is in contrast with the results obtained by dynamic self-assembly under oxidative conditions, where we observe a statistical mixture of macrocyclic complexes of Eu(2)L(x)(2), Tb(2)L(x)(2), and EuTbL(x)(2). The EuTbL(x)(2) macrocycle displays dual color emission, incorporating the characteristic f-f transitions of Eu(3+) and Tb(3+). Investigation into the time-resolved photophysical properties of EuTbL(x)(2) reveals energy transfer from Tb(3+) to Eu(3+), facilitated by the different conformations of the macrocycle in solution.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
2
pubmed:volume
133
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1033-43
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Purely heterometallic lanthanide(III) macrocycles through controlled assembly of disulfide bonds for dual color emission.
pubmed:affiliation
School of Chemistry, The University of Birmingham , Edgbaston B15 2TT, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't