Tendency of the Nephelauxetic Effect to Vary in a Series of Lanthanide Complexes with Allyl Acetoacetate

• DOI: 10.1007/s10812-015-0027-x
• Publication Date: 2015-01-12T18:48:03Z
• Authors: A. M. Mishchenko; E. K. Trunova; A. S. Berezhnytskaya; A. A. Rogovtsov
• Keywords: Ethyl acetoacetate

The complexation of allyl acetoacetate with Pr3+, Nd3+, Ho3+, Er3+, and Tm3+ in aqueous solution was studied by electronic absorption spectroscopy. It was shown that allyl acetoacetate at pH 5.50 formed 1:1 and 1:2 complexes with the lanthanide ions depending on the reagent ratio. Intensity parameters Ωλ in addition to bond parameters using the free ions as comparative standards were calculated for the 1:2 complexes. It was established that the nephelauxetic ratio β increased smoothly and approached unity in the order Pr3+ < Nd3+ < Ho3+ < Er3+ < Tm3+. Such variation was explained in the framework of covalent and polarization models.