Luminescence thermometry based on one-dimensional benzoato-bridged coordination polymers containing lanthanide ions

Three 1D coordination polymers with benzoate bridges have been assembled in the presence of 18-crown-6-ether (18C6): 1 ∞ [Tb(PhCOO) 3 (H 2 O)(EtOH)]·0.5(18C6) 1 , 1 ∞ [Eu(PhCOO) 3 (H 2 O) 2 ]·0.5(18C6) 2 , 1 ∞ [Nd(PhCOO) 3 (H 2 O) 2 ]·0.5(18C6) 3 . Compounds 2 and 3 are isomorphous. The crown ether molecules co-crystallize with the resulting 1D coordination polymers and play an important role in the supramolecular architecture of the crystals. A molecular alloy was prepared in a similar way to compound 1 using TbCl 3 ·6H 2 O and EuCl 3 ·6H 2 O in a molar ratio of 95 : 5. The Eu III ions have statistically substituted the Tb III ions in the host lattice The luminescence thermometry performance of the Tb 0.95 Eu 0.05 system was investigated using pulsed excitation into Tb III absorption at 352 nm. The maximum S r value is 1.88% K −1 at 80 K which is slightly reduced at 1.60% K −1 at 313 K. Time-gated emission spectroscopy, employed here for the first time, allows us to reduce the spectral overlap of Tb and Eu emissions in the 610 to 625 nm range by 100% at 80 K, from 18 to 9%. Compound 1 as well as the molecular alloy, Tb 0.95 Eu 0.05 , show X-ray induced luminescence. Luminescent europium and terbium benzoato-bridged 1D coordination polymers have been characterized and employed for luminescence thermometry.