Lanthanide Complexes of Polyacid Ligands derived from 2, 6-bis(pyrazol-1-yl)pyridine, pyrazine, and 6, 6′-bis(pyrazol-1-yl)-2, 2′-bipyridine: Synthesis and luminescence properties

✍ Scribed by Juan Carlos Rodriguez-Ubis; Rosa Sedano; Gemma Barroso; Olga Juanes; Ernesto Brunet

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: German
• Weight: 790 KB
• Volume: 80
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19970800108

✦ Synopsis

The synthesis of three novel pyrazole-containing complexing acids, N,N,N',N'-{ 2,6-bis[3-(aminomethyl)pyrdzol-l-yl]-4-methoxypyridine}tetrakis(acetic acid) (l), N,N,N',N'-{2,6-bis[3-(aininomethyl)pyrdzoI-1-yl]pyrazine}tetrakis(acetic acid) (2), and N,N,N',N'-{6,6'-bis[3-(aminomethyl)pyrazol-l-yl]-2,2-bipyridine)tetrakis(acetic acid) (3) is described. Ligands 1-3 formed stable complexes with Eu"', Tb"', Sm"', and Dy"' in H 2 0 whose relative luminescence yields, triplet-state energies, and emission decay lifetimes were measured. The number of H 2 0 molecules in the first coordination sphere of the lanthanide ion were also determined. Comparison of data from the Eu"' and Tb"' complexes of 1-3 and those of the parent trisheterocycle N,N,N',N'-{2,6-bis[3-(aminomethyl)pyrazol-1-yl]pyridine}tetrakis(acetic acid) showed that the modification of the pyridine ring for pyrazine or 2.2'bipyridine strongly modify the luminescence properties of the complexes. Me0 Substitution at C(4) of 1 maintain the excellent properties described for the parent compound and give an additional functional group that will serve for attaching the label to biomolecules in bioaffinity applications.