Tuning the Emission of Homometallic DyIII, TbIII, and EuIII 1-D Coordination Polymers with 2,6-Di(1H-1,2,4-triazole-1-yl-methyl)-4-R-phenoxo Ligands: Sensitization through the Singlet State.

This work reports the structural characterization and photophysical properties of DyIII, TbIII, and EuIII coordination polymers with two phenoxo-triazole-based ligands [2,6-di(1H-1,2,4-triazole-1-yl-methyl)-4-R-phenoxo, LRTr (R = CH3; Cl)]. These ligands permitted us to obtain isostructural polymers, described as a 1D double chain, with LnIII being nona-coordinated. The energies of the ligand triplet (T1) states were estimated using low-temperature time-resolved emission spectra of YIII analogues. Compounds with LClTr present higher emission intensity than those with LMeTr. The emission of TbIII compounds was not affected by the different excitation wavelengths used and was emitted in the pure green region. In contrast, DyLMeTr emits in the blue-to-white region, while the luminescence of DyLClTr remains in the white region for all excitation wavelengths. On the other hand, EuIII compounds emit in the blue (ligand) or red region (EuIII) depending on the substituent of the phenoxo moiety and excitation wavelength. Theoretical calculations were employed to determine the excited states of the ligands by using time-dependent density functional theory. These calculations aided in modeling the intramolecular energy transfer and rationalizing the optical properties and demonstrated that the sensitization of the LnIII ions is driven via S1 → LnIII, a process that is less common as compared to T1 → LnIII.

A comparative dataset: Bridging COVID-19 and other diseases through epistemonikos and CORD-19 evidence.

The COVID-19 pandemic has underlined the need for reliable information for clinical decision-making and public health policies. As such, evidence-based medicine (EBM) is essential in identifying and evaluating scientific documents pertinent to novel diseases, and the accurate classification of biomedical text is integral to this process. Given this context, we introduce a comprehensive, curated dataset composed of COVID-19-related documents. This dataset includes 20,047 labeled documents that were meticulously classified into five distinct categories: systematic reviews (SR), primary study randomized controlled trials (PS-RCT), primary study non-randomized controlled trials (PS-NRCT), broad synthesis (BS), and excluded (EXC). The documents, labeled by collaborators from the Epistemonikos Foundation, incorporate information such as document type, title, abstract, and metadata, including PubMed id, authors, journal, and publication date. Uniquely, this dataset has been curated by the Epistemonikos Foundation and is not readily accessible through conventional web-scraping methods, thereby attesting to its distinctive value in this field of research. In addition to this, the dataset also includes a vast evidence repository comprising 427,870 non-COVID-19 documents, also categorized into SR, PS-RCT, PS-NRCT, BS, and EXC. This additional collection can serve as a valuable benchmark for subsequent research. The comprehensive nature of this open-access dataset and its accompanying resources is poised to significantly advance evidence-based medicine and facilitate further research in the domain.

New Highly Charged Iron(III) Metal-Organic Cube Stabilized by a Bulky Amine.

In this work, we report a new octanuclear cluster based on FeIII and the ligand 1H-imidazole-4,5-dicarboxylic acid, [Et3NH]12[Fe8(IDC)12]·10DMF·13H2O (1), with a metal core containing eight FeIII connected by only one type of organic ligand. A peak at 573 m/z in the mass spectra of the compound suggests the adduct species {[Fe8(IDC)12]+8H}4-. By X-ray photoelectron spectroscopy, the oxidation state of the iron cation was confirmed to be 3+, also identifying the presence of a quaternary nitrogen species, which act as a countercation of the anionic metal core [Fe8(IDC)12]12-. Mössbauer spectra recorded at different temperatures show an isomer shift and quadrupole splitting parameters that confirm the existence of only FeIII-HS in the structure of 1. X-ray analysis reveals that compound 1 crystallizes in the orthorhombic system space group Ibam, confirming a molecular cluster structure with an almost regular cube as geometry, with the FeIII atoms located at the corners of the cube and connected by µ-1κ2 N,O:2κ2 N',O‴-IDC3- bridges. Additionally, the magnetic measurements reveal a weak antiferromagnetic coupling in the Fe8 III coordination cluster (J = -3.8 cm-1). To the best of our knowledge, 1 is the first member of the family of cubes assembled with 1H-imidazole-4,5-dicarboxylic acid and FeIII cation, exhibiting high pH stability over a broad pH range, making it an ideal candidate for the design of supramolecular structures and metal-organic frameworks.