Coordination complex [Eu(μ2-OC2H5)(btfa)(NO3) (phen)]2·phen with high luminescent efficiency

Abstract

Experimental results on the bis[(μ 2 -etoxi)(benzoyl trifluoroacetonato)(nitrato)(1,10- phenantroline)europium(III)]1,10-phenantroline europium(III) coordination complex (hereafter, [Eu(μ 2 -OC 2 H 5 )(btfa)(NO 3 )(phen)] 2 ·phen) are described. The complex is characterized by photoluminescence (PL) and infrared spectroscopy. Photoluminescence spectra of the complex exhibit strong emission with specific narrow emission bands associated with the 5 D 0 → 7 F j (j = 0–4) transitions. The pattern of emission band splitting and the luminescence time decay suggest the presence of at least two different sites of the Eu 3+ ion in a low-symmetry environment. The absolute PL quantum yield of the complex is determined to be 49.2%.

Photoluminescence properties of new dinuclear [Eu(μ2-OC2H5)(btfa)(NO3)(phen)]2phen and mononuclear Eu(TTA)3(Ph3PO)2 complexes

“…Ligands and host matrices act as an "antenna" to absorb the external excitation light and transfer this excitation energy to the Eu 3+ ion levels, from which the radiating excited levels can be populated [3]. In the present work we extend our previous study on the complexes Eu(TTA) 3 (Ph 3 PO) 2 [5,6] and [Eu(µ 2 -OC 2 H 5 )(btfa)(NO 3 )(phen)] 2 •phen) [7,8] by extending the temperature range of PL measurements to 10.7-300 K. The main attention is focused on the influence of temperature on the PL intensity and on the characteristic quantum parameters of PL: the integral intensity of PL, the emission probability, the position of the center of gravity of the radiative transition, the PL efficiency, etc. The most pronounced is the analysis of these parameters and their comparison in the mononuclear compound with the corresponding parameters in the dinuclear compound to highlight and optimize the coordinating compounds based on the Eu 3+ ion.…”