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(E)-4-(4-Methoxyphenoxy)-4-oxobut-2-enoic acid and its Ce(IV), Th(IV), and UO2(II) complexes were synthesized and characterized by MS, elemental analysis, IR, UV, TG-DTA, and NMR. The complexes have composition [CeL2(OH)2 · 2H2O] · H2O, [ThL2(OH)2 · 2H2O] · H2O, and [UO2L2 · 2H2O] · H2O. Molar conductance data confirm that the three complexes are nonelectrolytes. The IR and NMR results show that the carboxylates coordinate to the metal ions bidentate, and the ester carboxylic groups do not take part in coordination. Luminescence spectra of the ligand and complexes in DMSO at room temperature were also studied showing strong luminescence of the metal ions. [ABSTRACT FROM AUTHOR]

Polymethyl acrylic acid (PMAAc) with lower molecular weight was prepared by solution polymerization in water. A series of macromolecular rare earth complexes of PMAAc (RE-PMAAc, RE=La,Sm,Eu,Tb,Dy) have been synthesized and well characterized by means of elemental analysis, IR, TG-DTA analyses and fluorescence determination. Chemical analysis indicated that the molar ratio of -COO- and RE3+ in the complex was closely dependent on the pH of the solution. Spectroscopic studies suggested that the carboxylate was bonded to the central metal ions in bidentate form and these macromolecular complexes were cross-linked with high-temperature resistance. Among these complexes, Eu-PMAAc, Tb-PMAAc and Dy-PMAAc solid complexes are excellent photoluminescence materials, which can emit high intensity and good monochromatic characteristic fluorescence due to an effective energy transfer between the lowest excited triplet state energy level of ligand PMAAc and the excited state energy level of the corresponding rare earth ion. [ABSTRACT FROM AUTHOR]