Colorimetric analysis: A new strategy to improve ratiometric temperature sensing performance of lanthanide benzenedicarboxylates

A Highly Stable Yttrium Organic Framework as a Host for Optical Thermometry and D2O Detection

“…Lowering the Tb 3+ substitution concentration in (Y 0.9 Tb 0.10 ) 6 ‐MOF allowed for the detection of the ligand‐centered emissions bands (Figure S7). Time‐resolved phosphorescence spectra recorded at 77 K confirmed a triplet state energy (T 1 ) around 23923 cm −1 for the BDC ligand, in agreement with previously reported values [26] . Despite the efficient energy transfer from BDC to the acceptor levels of the Ln 3+ ions (Figure S8), the energy gap between the T 1 level and the 5 D 0 emitting state of Eu 3+ (6651 cm −1 ) is much bigger compared to the difference between T 1 and the 5 D 4 of Tb 3+ (3347 cm −1 ).…”

“…The BDC ligand is a known antenna chromophore for sensitising lanthanoid ions, especially Tb 3+ and Eu 3+ [24–26] . Under 325 nm excitation, the as‐prepared MOF displayed the typical green and red luminescence of Tb 3+ and Eu 3+ ions (Figure S4).…”

“…Time-resolved phosphorescence spectra recorded at 77 K confirmed a triplet state energy (T 1 ) around 23923 cm À 1 for the BDC ligand, in agreement with previously reported values. [26] Despite the efficient energy transfer from BDC to the acceptor levels of the Ln 3 + ions (Figure S8), the energy gap between the T 1 level and the 5 D 0 emitting state of Eu 3 + (6651 cm À 1 ) is much bigger compared to the difference between T 1 and the 5 D 4 of Tb 3 + (3347 cm À 1 ). Hence, thermally driven depopulation of the 5 D 4 state by back-transfer from Tb 3 + to BDC is much more likely to occur than back-transfer from the 5 D 0 level of Eu 3 + to the ligand.…”

“…The BDC ligand is a known antenna chromophore for sensitising lanthanoid ions, especially Tb 3 + and Eu 3 + . [24][25][26] Under 325 nm excitation, the as-prepared MOF displayed the typical green and red luminescence of Tb 3 + and Eu 3 + ions (Figure S4). (Y 0.9 Tb 0.10 ) 6 -MOF exhibited emissions at 486, 544, 587, 621, 650, 668, and 680 nm attributed to the 5 D 4 !…”

Photoluminescent Lanthanide Coordination Polymers for Ammonia Gas Detection at Ambient Temperature and Humidity

“…The triplet state energies of the poa − and pydc 2− could be estimated to span from 15,000 to 25,000 cm −1 from the spectrum of II (Figure 2c), as the sensitization of Gd III by any organic ligand is not attainable. 34,35 This energy range is consistent with the emissions of both 2,5-pydc 2− and poa − and the assumption of the negligible interaction between their triplet states. 36 With respect to the accepting levels of Eu III ( 5 D 0 = 17,270 cm −1 and 5 D 1 = 19,030 cm −1 ) and Tb III ( 5 D 4 = 20,470 cm −1 ), the effective sensitization of I and III can be accounted for.…”