Erbium bis(pentafluorophenyl)phosphinate: a new hybrid material with unusually long-lived infrared luminescence

Abstract

There is an error in the calculation of the average luminescence lifetime, s h i, using the experimentally determined values s = 237 ls and b = 0.7 in the equation for s h i presented on page S432. The correct value is s h i = 0.30 ms. We are grateful to Professor J.-C. Bünzli for informing us of our error. Figure 3 inadvertently showed the photoluminescence emission spectrum of [(C 6 F 5 ) 2 PO 2 ] 3 Er (5). The correct version of Fig. 3, showing the spectrum of [(C 6 H 5 ) 2 PO 2 ] 3 Er (6), is given below.

Effects of Progressive Halogen Substitution on the Photoluminescence Properties of an Erbium−Porphyrin Complex

“…To this regard, it should also be noted that the NIR emission intensity in the present complexes seems to be independent of the large variation of the triplet energy levels observed in the different derivatives (see the band peak locations in Figure 4) but increases with the degree of halogen substitution. All of these findings suggest that the effective bottleneck of the overall efficiency does not lie in the intramolecular energy-transfer processes.Morereasonably,asunderlinedbyseveralauthors, 4,6,8,[11][12][13][14][15][16][17][18][19][20] a strong quenching of the NIR emission may occur through Fo ¨rster resonant transfer to the second overtone of the C-H vibration in the respective chemical groups of the porphyrinic ligand. Within this framework, the strategy of substituting all of the aromatic hydrogens with halogens, presently achieved in Er(acac)BrFTPP, seems to be a step in the right direction since it doubles the intensity of the NIR emission regardless of the fact that it gives the lowest quenching factor of the visible emission.…”

“…A stretched exponential decay function with an average lifetime of τ ) 300 µs was found in a similar erbium compound. 20 This latter result, however, was obtained upon direct optical excitation into the 2 H 11/2 level of the Er(III) ion, * To whom correspondence should be addressed. E-mail: Pizzoferrato@ uniroma2.it.…”

“…Consequently, the overall radiative efficiency is generally as low as ϕ ≈ 10 −4 . Halogenation of the hydrogen-containing ligands has been suggested as a way to overcome such effects and has been carried out in few cases – with different results. For example, a moderate increase of about 30% in the emission efficiency has been found in erbium quinolinates with a measured lifetime of τ = 1.9 μs .…”

“…On such a basis, several erbium-containing compounds have been synthesized and characterized over the past decade, – with the aim of enhancing the near-infrared (NIR) emission and improving the physical processability and compatibility of the materials. Specifically, great attention has been paid to the investigation and engineering of the intramolecular energy transfer through the choice of specific organic ligands, as well as to reducing the quenching of the radiative emission.…”

Infrared 4f-Luminescence of Erbium(III) Complexes with Tetrapyrrole Ligands

“…The main drawback of erbium-doped glass fibre amplifiers arises from the requirement in application of high power pump lasers for relatively long fibre. [2] It derives from the limited concentration of erbium ions in erbium-doped glass (10 20 ions/cm 3 ) and low extinction coefficients of f-fabsorption of lanthanides (typically less than 10 M -1 cm -1 ). Altogether it leads to very poor 4f-emission.…”