Effect of crystallization water and nature of an aluminum alkyl on the reduction of Eu3+ to Eu2+ in interaction of EuCl3 · 6H2O with Bu 3 i Al and Et3Al

The first registration of a green liquid-phase chemiluminescence of the divalent Eu2+* ion in interaction of β-diketonate complexes Eu(acac)3·H2O, Eu(dpm)3, Eu(fod)3 and Eu(CH3COO)3·6H2O with Bui2AlH in THF with the participation of oxygen

“…6,[55][56][57][58][59] The important condition for the energy transfer is also the overlap of the luminescence spectrum of the energy donor and the absorption spectrum of the energy acceptor. 43,60 In our case, the triplet excited isobutyric aldehyde 3 R 0 C(H)]O* is an energy donor. As potential energy acceptors can be the Eu 2+ ion, in the bulk EuL 2 $(THF) 2 -Bu i 2 AlH complex and organic ligand L, coordinated with the Eu 2+ ion (Fig.…”

“…13 In the cases of hydrates Eu(acac) 3 $H 2 O and Eu(CH 3 COO) 3 $6H 2 O, as well for EuCl 3 $6H 2 O, the interaction begins with the reaction of Bu i 2 AlH with water of crystallization, which is removed from the coordination sphere of Eu 3+ with formation a mixture of products (P 1 ), consisting of aluminoxane (Bu i 2 Al) 2 O, isobutene, and hydrogen (1) according to our present GLC analysis and previous data. 4,29,43 At the same time, Bu i 2 AlH taken in a big excess reacts with Eu 3+ (1) and oxygen (2-3); as a result Eu 3+ is reduced to Eu 2+ . Ligand L, removed from the coordination sphere of europium, is attached to the aluminum atom to form Bu i 2 AlL (1, top arrow) or Bu i (H)AlL (1, lower arrow), and possibly both of these compounds.…”

“…6,[55][56][57][58][59] The important condition for the energy transfer is also the overlap of the luminescence spectrum of the energy donor and the absorption spectrum of the energy acceptor. 43 Fig. S5 (ESI †) also shows the absorption spectra of Eu 2+ (acceptor) in the yellow-green reaction solutions.…”