Exploring physical and chemical properties in new multifunctional indium-, bismuth-, and zinc-based 1D and 2D coordination polymers.

Main group element coordination polymers (MGE-CPs) are important compounds for the development of multifunctional materials. However, there has been a shortage of studies regarding their structural, optical, catalytic, mechanical, and antibacterial properties. This work presents an exhaustive study of a set of crystalline MGE-CPs obtained from bismuth and indium metals and iminodiacetate, 1,2,4,5-benzenetetracarboxylate, and 2,2'-bipyridine as building blocks. An in-depth topological analysis of the networks was carried out. Additionally, nanoindentation studies were performed on two representative low-dimensional compounds in order to find the relationships between their structural features and their intrinsic mechanical properties (hardness and elasticity). The solid-state photoluminescence (SSPL) properties were also studied in terms of excitation, emission, lifetimes values, and CIE chromaticites. Moreover, the heterogeneous catalytic activities of the compounds were evaluated with the cyanosilylation reaction using a set of carbonylic substrates under solvent-free conditions. Finally, the inhibitory effect of the Bi-CPs on the growth of microorganisms such as Escherichia coli, Salmonella enterica serovar Typhimurium, and Pseudomonas aeruginosa, which are associated with relevant infectious diseases, is reported.

Cryogenic luminescent thermometers based on multinuclear Eu3+/Tb3+ mixed lanthanide polyoxometalates.

Here, the excellent thermal sensing capability of a multinuclear lanthanide polyoxometalate in the cryogenic region (<100 K) is presented for the first time. Up till now, no lanthanide polyoxometalates have been studied for their use as ratiometric luminescent thermometers. The investigated Tb3+ polyoxometalate cluster is doped with 1.6% (P1) and 8.4% (P2) of Eu3+ ions. When excited into the Mo-O charge transfer bands, at room temperature only the emission of the Eu3+ ions is observed suggesting a very efficient energy transfer between Mo-O→Tb3+→Eu3+. Only in the cryogenic region the emission of Tb3+ is also witnessed.

Multidoped Ln3+ gadolinium dioxycarbonates as tunable white light emitting phosphors.

Gadolinium dioxycarbonates co-doped with different visible emitting lanthanides were synthesized via a co-precipitation method using oxalic acid as a precipitating agent. Through XRD and DTA/TG investigations, the type-II hexagonal phase of the lanthanide dioxycarbonates was confirmed for all of the samples. The materials constitute of big agglomerates formed by submicrometrical particles. By varying the Ln3+ doping percentages and ratios and by changing the excitation wavelength the gadolinium dioxycarbonates activated with Sm3+, Eu3+, Tb3+, Dy3+ and Tm3+ showed tunable emission colors. Luminescence measurements were performed in order to determine: the luminescence behavior of the ions, the CIE coordinates, the CCT values and potential energy transfer. Interesting results were achieved upon exciting the samples at 351 nm and 365 nm demonstrating the possibility to obtain white emission in the dioxycarbonate matrix.

Layered exfoliable crystalline materials based on Sm-, Eu- and Eu/Gd-2-phenylsuccinate frameworks. Crystal structure, topology and luminescence properties.

Three new layered metal-organic frameworks (MOFs) based on 2-phenylsuccinic acid (H2psa) and lanthanide ions with the formula [Ln2(C10H8O4)3(H2O)] (Ln = Eu, Sm and Eu-Gd) have been synthesized under solvothermal conditions and fully characterized by single-crystal X-ray diffraction, thermal and vibrational analyses. The compounds are isostructural featuring 2D frameworks that consist of infinite zigzag chains composed of [LnO8] and [LnO8(H2O)] edge-sharing polyhedra linked by psa ligands leading to layers further connected by weak π-π interactions in an edge orientation. Moreover, a topological study was carried out to obtain the simplified net for better comparison with structurally related compounds. The crystals were exfoliated into nanolayers after miniaturization by addition of sodium acetate as a capping agent in the reaction medium. Scanning electron microscopy was applied to characterize the miniaturized samples whereas the exfoliated hybrid nanosheets were studied by atomic force microscopy. The photoluminescence (PL) properties of the bulk compounds as well as the miniaturized and exfoliated materials were investigated and compared with other related ones. An exhaustive study of the Eu(iii)-based MOFs was performed on the basis of the obtained PL parameters (excitation and emission spectra, kr, knr, intrinsic quantum yields and lifetimes) to explore the underlying structure-property relationships.