Highly Efficient and Thermally Durable Luminescence of 1D Eu3+ Coordination Polymers with Arsenic Bridging Ligands

In this work, bisarsine oxides were evaluated as novel bridging ligands, aiming to develop practical and efficient luminescent lanthanide coordination polymers. We have synthesized one-dimensional (1D) Eu3+ coordination polymers that incorporate bisarsine oxide bridging ligands and hexafluoroacetylacetonate anions. These polymers exhibited a denser packing of chains compared to analogous polymers bridged with bisphosphine oxides. The coordination polymers demonstrated exceptional thermal stability and substantial emission quantum yields. Additionally, the bisarsine oxides induced a pronounced polarization effect, facilitating a sensitive electric dipole transition that yields considerably narrow band red emission. Remarkably, the Eu3+ coordination polymers with bisarsine oxides maintained intense emission even at 550 K. A distinctive feature of these polymers is their heating-induced emission enhancement observed when the temperature was increased from 300 K to 400 K.

Unprecedented toughness in transparent, luminescent, self-healing polymers enabled via hierarchical rigid domain design

The preparation of luminescent self-healing materials simultaneously featuring superior integrated mechanical properties is still a great challenge because the relationship between self-healing ability and mechanical capacities is conflicted. Here, transparent luminescent materials with balanced self-healing behavior, extreme toughness, and fast elastic recovery are prepared via hierarchical rigid domain design by coordinating lanthanide (Ln³⁺) to terpyridine (TPy) moieties linked to the polymer chains formed through polymerization of tolylene-2,4-diisocyanate-terminated polypropylene glycol (PPG-NCO) and 1,6-hexanediamine (HDA). The hierarchical rigid domain containing lanthanide-terpyridine (Ln³⁺-TPy) coordination interactions and H-bonds formed by urea and urethane leads to a tough network that features unprecedented toughness of 133.35 MJ m^-3, which reaches 83% of that of typical spider silk (≈ 160 MJ m^-3) and is also dynamic for fast self-healing at ambient temperature. Besides, the multi-color emission, ranging from red through orange and yellow to green, can be achieved via adjusting the molar ratio of Eu³⁺/Tb³⁺. We believe that the strategy applied in this work provides some insights for the preparation of high mechanical strength luminescence materials with self-healing properties.

The crystal structure of poly[μ2-aqua- aqua-(μ3-(E)-2-(4-((2-carbamothioylhydrazineylidene)methyl)phenoxy)acetato-κ3 O:S:S)sodium(I)], C10H14N3O5SNa

C10H14N3O5SNa, triclinic, P 1 ‾ $P\overline{1}$ (no. 2), a = 6.7015(5) Å, b = 7.5656(5) Å, c = 14.1332(8) Å, β = 93.159(5)°, V = 654.71(8) Å3, Z = 2, R gt (F) = 0.0357, wR ref (F 2) = 0.0872, T = 273 K.