Synthesis, structural, photophysical and thermal studies of benzoate bridged Sm(III) complexes

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(H2O)(EtOH)]·0.5(18C6) 1, 1∞[Eu(PhCOO)3(H2O)2]·0.5(18C6) 2, 1∞[Nd(PhCOO)3(H2O)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 TbCl3·6H2O and EuCl3·6H2O in a molar ratio of 95 : 5. The EuIII ions have statistically substituted the TbIII ions in the host lattice The luminescence thermometry performance of the Tb0.95Eu0.05 system was investigated using pulsed excitation into TbIII absorption at 352 nm. The maximum Sr 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, Tb0.95Eu0.05, show X-ray induced luminescence.

Novel mononuclear Ln complexes with pyrazine-2-carboxylate and acetylacetonate co-ligands: remarkable single molecule magnet behavior of a Yb derivative

A series of novel mononuclear complexes were prepared, and the Yb derivative exhibits the highest Δ_eff/k_B value known for ytterbium complexes.

Tetra-kis(μ-4-tert-butyl-benzoato)-κO:O';κO,O':O';κO:O,O'-bis-[aqua-(4-tert-butyl-benzoato-κO,O')(4-tert-butyl-benzoic acid-κO)neodymium(III)]

The reaction of neodymium nitrate and 4-tert-butyl­benzoic acid (tBBAH) in aqueous solution yielded the dinuclear title complex, [Nd₂(C₁₁H₁₃O₂)₆(C₁₁H₁₄O₂)₂(H₂O)₂], which has non-crystallographic C_i symmetry. The two Nd^III ions are linked by two bridging and two bridging–chelating tBBA ligands with an Nd⋯Nd separation of 4.0624 (5) Å. Moreover, each Nd^III ion is coordinated by one chelating tBBA ion, one monodentate tBBAH ligand and one water mol­ecule. The nine-coordinated Nd^III ion is in a distorted tricapped trigonal–prismatic environment. The mol­ecules are linked into infinite chains along the c axis by inter­molecular O—H⋯O hydrogen bonds. Three of the tert-butyl groups are disordered over two sets of sites with equal occupancies.