Enhancing luminescence in lanthanide coordination polymers through dilution of emissive centers

Multifunctional Lanthanide-Based Metal–Organic Frameworks Derived from 3-Amino-4-hydroxybenzoate: Single-Molecule Magnet Behavior, Luminescent Properties for Thermometry, and CO2 Adsorptive Capacity

“… 47 , 48 Following this strategy, in compounds 16 Y-Tb-Eu10% and 17 Gd-Tb-Eu10% , Ln centers are prompted to be adequately distributed within the net avoiding nonradiative energy-transfer mechanisms derived by intermetallic energy-transfer processes, which could overall reduce luminescence efficiency. 49 …”

“…47,48 Following this strategy, in compounds 16 Y-Tb-Eu10% and 17 Gd-Tb-Eu10% , Ln centers are prompted to be adequately distributed within the net avoiding nonradiative energy-transfer mechanisms derived by intermetallic energy-transfer processes, which could overall reduce luminescence efficiency. 49 I Tb and I Eu were determined by integrating the emission spectra in the ranges of 538−552 and 609−619 nm for 16 Y-Tb-Eu10% and in the range of 536−556 and 610−618 nm for 17 Gd-Tb-Eu10% . Figure 9 presents the temperature-dependent emission spectra of the compounds 16 Y-Tb-Eu10% and 17 Gd-Tb-Eu10% in the 12−320 K range.…”

Energy Transfer in Metal–Organic Frameworks and Its Applications

“…Einkauf et al also used Gd 3+ to dilute the Eu 3+ or Tb 3+ emissive centers, further proving that adjusting the emission efficiency is possible by calculating the distance between the neighboring emissive lanthanides (Figure 8a). [ 63 ] In the ligand, [Tb/Eu x Gd y (C 6 H 8 O 4 ) 3 (H 2 O) 2 ] 4,4′‐dipy, the length of the Ln chain is 9.9 Å, which is close to the critical value of 10 Å; thus, the NR EnT mechanism can be ignored in this case. The Gd 3+ ions can act as spacers between the emissive centers within the chains, thereby reducing the probability of Tb‐to‐Tb (Eu‐to‐Eu) adverse EnT processes while enhancing the emission of Tb 3+ (Eu 3+ ).…”

“…In addition, the excited states of an optically active Ln 3+ ion can be exploited for improving the ion sensitivity in the excited states of another Ln 3+ ion due to its optimal Δ E with the T 1 of the ligands. For example, the Tb 3+ ions can sensitize Eu 3+ ions in mixed Eu 3+ /Tb 3+ frameworks thanks to phonon‐assisted FRET processes from Tb 3+ to Eu 3+ [13d,63] . This has been demonstrated using Eu 3+ : 5 D 0 secondary source feeds originated from the Tb 3+ level and temperature‐dependent f–f EnT processes.…”

Crystal structure of a one-dimensional coordination polymer of gadolinium dibromoacetate with 4,4'-bipyridine

“…4,4'-Bipyridine may be one or two donor ligand, which gives different possibilities of coordination. Two nitrogen atoms opposing themselves and two independent pyridine rings with ability to rotation along C-C bond give chance to create coordination polymers [10][11][12][13][14]. The structure will depend on the size and coordination number of metal ion as well as the presence of other ligands.…”