A study of the fluorescence of some newly synthesized europium complexes with pyrazolone derivatives.
Some europium complexes with pyrazolone derivatives and 1,10-phenanthroline were synthesized and characterized. The europium ion was found to coordinate to O atoms of the pyrazolone derivatives and to N atoms of 1,10-phenanthroline. A strongly ligand-localized UV absorption leads to the europium-centered emissions between 580 and 750 nm which were assigned as the 5D0-->7F0,1,2,3,4 and 5D1-->7F3,4 transitions. A low site symmetry for the Eu3+ ion was confirmed from the observation of 5D0-->7F0 emission and from the splitting of the other bands. In contrast to many Eu complexes that have been investigated a rather weak emission was measured by introduction of a Schiff base to form a ternary complex with the pyrazolone derivative. The long fluorescence lifetimes of these complexes suggest an energy transfer process from ligands to Eu3+ ion through the triplet state of the ligands.
Qian
D J
DJ
Institute of Colloid and Interface Chemistry, Shandong University, Jinan, PR China.
Leng
W N
WN
Zhang
Y
Y
Chen
Z
Z
Van Houten
J
J
D005063:Europium / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D047069:Pyrazolones; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet
D011720:Pyrazoles; D047069:Pyrazolones; C038362:pyrazolone; D005063:Europium