Faster Synthesis of Beta-Diketonate Ternary Europium Complexes: Elapsed Times & Reaction Yields.

ABSTRACT: ?-diketonates are customary bidentate ligands in highly luminescent ternary europium complexes, such as Eu(?-diketonate)3(L)2, where L stands for a nonionic ligand. Usually, the syntheses of these complexes start by adding, to an europium salt such as EuCl3(H2O)6, three equivalents of ?-diketonate ligands to form the complexes Eu(?-diketonate)3(H2O)2. The nonionic ligands are subsequently added to form the target complexes Eu(?-diketonate)3(L)2. However, the Eu(?-diketonate)3(H2O)2 intermediates are frequently both difficult and slow to purify by recrystallization, a step which usually takes a long time, varying from days to several weeks, depending on the chosen ?-diketonate. In this article, we advance a novel synthetic technique which does not use Eu(?-diketonate)3(H2O)2 as an intermediate. Instead, we start by adding 4 equivalents of a monodentate nonionic ligand L straight to EuCl3(H2O)6 to form a new intermediate: EuCl3(L)4(H2O)n, with n being either 3 or 4. The advantage is that these intermediates can now be easily, quickly, and efficiently purified. The ?-diketonates are then carefully added to this intermediate to form the target complexes Eu(?-diketonate)3(L)2. For the cases studied, the 20-day average elapsed time reduced to 10 days for the faster synthesis, together with an improvement in the overall yield from 42% to 69%.

SUBMITTER: Lima NB 

PROVIDER: S-EPMC4692388 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature