Heterometallic Molecular Architectures Based on Fluorinated β-Diketone Ligands

Potassium and Cesium Fluorinated β-Diketonates: Effect of a Cation and Terminal Substituent on Structural and Thermal Properties

As potential precursors for the synthesis of fluoroperovskites, a family of heavy alkali metal (MI = K, Cs) fluorinated β-diketonates were prepared and characterized by elemental analysis, IR, and powder-XRD. The crystal structures of the new six complexes, MI(β-dikF)(H2O)X, X = 0 or 1, were also determined. The structural diversity of this poorly explored class of complexes was discussed, including the preferred types of cation polyhedra and the ligand coordination modes, and the thermal properties of the metal β-diketonates were studied by TG-DTA in an inert (He) atmosphere. The data obtained allowed us to reveal the effect of the metal cation and the terminal substituent on the structural and thermal features of this family of complexes.

Exploring Ln(III)-Ion-Based Luminescent Species as Down-Shifters for Photovoltaic Solar Cells

In this work, we have compiled our research on lanthanide-based luminescent materials for use as down-shifter layers in photovoltaic (PV) mini-modules. The complexes we have prepared (C1-17), with formulas [Eu₂(phen)₂(bz)₆] (C1), [Eu₂(bphen)₂(bz)₆] (C2), [Eu(tta)₃bphen] (C3), [Eu(bta)₃pyz-phen] (C4), [Eu(tta)₃pyz-phen] (C5), [Eu(bta)₃me-phen] (C6), [Er(bta)₃me-phen] (C7), [Yb(bta)₃me-phen] (C8), [Gd(bta)₃me-phen] (C9), [Yb(bta)₃pyz-phen] (C10), [Er(tta)₃pyz-phen] (C11), [Eu₂(bz)₄(tta)₂(phen)₂] (C12), [Gd₂(bz)₄(tta)₂(phen)₂] (C13), [EuTb(bz)₄(tta)₂(phen)₂] (C14), [EuGd(bz)₄(tta)₂(phen)₂] (C15), [Eu_1.2Gd_0.8(bz)₄(tta)₂(phen)₂] (C16), and [Eu_1.6Gd_0.4(bz)₄(tta)₂(phen)₂] (C17), can be grouped into three families based on their composition: Complexes C1-6 were synthesized using Eu³⁺ ions and phenanthroline derivatives as the neutral ligands and fluorinated β-diketonates as the anionic ligands. Complexes C7-11 were prepared with ligands similar to those of complexes C1-6 but were synthesized with Er³⁺, Yb³⁺, or Gd³⁺ ions. Complexes C12-17 have the general formula [M1M2(bz)₄(tta)₂(phen)₂], where M1 and M2 can be Eu³⁺, Gd³⁺, or Tb³⁺ ions, and the ligands were benzoate (bz^-), 2-thenoyltrifluoroacetone (tta^-), and 1,10-phenanthroline (phen). Most of the complexes were characterized using X-ray techniques, and their photoluminescent properties were studied. We then assessed the impact of complexes in the C1-6 and C12-17 series on the EQE of PV mini-modules and examined the durability of one of the complexes (C6) in a climate chamber when embedded in PMMA and EVA films. This study emphasizes the methodology employed and the key findings, including enhanced mini-module efficiency. Additionally, we present promising results on the application of complex C6 in a bifacial solar cell.

Perfluoroalkyl Chain Length Effect on Crystal Packing and [LnO8] Coordination Geometry in Lanthanide-Lithium β-Diketonates: Luminescence and Single-Ion Magnet Behavior

Functionalized perfluoroalkyl lithium β-diketonates (LiL) react with lanthanide(III) salts (Ln = Eu, Gd, Tb, Dy) in methanol to give heterobimetallic Ln-Li complexes of general formula [(LnL₃)(LiL)(MeOH)]. The length of fluoroalkyl substituent in ligand was found to affect the crystal packing of complexes. Photoluminescent and magnetic properties of heterobimetallic β-diketonates in the solid state are reported. The effect of the geometry of the [LnO₈] coordination environment of heterometallic β-diketonates on the luminescent properties (quantum yields, phosphorescence lifetimes for Eu, Tb, Dy complexes) and single-ion magnet behavior (U_eff for Dy complexes) is revealed.

Highly Luminescent Europium(III) Complexes in Solution and PMMA-Doped Films for Bright Red Electroluminescent Devices

This paper reports the synthesis, structure, photophysical, and optoelectronic properties of five eight-coordinate Europium(III) ternary complexes, namely, [Eu(hth)₃(L)₂], bearing 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)-1,3-hexanedione (hth) as a sensitizer and L = H₂O (1), dpso (diphenyl sulphoxide, 2), dpsoCH₃ (4,4'-dimethyl diphenyl sulfoxide, 3), dpsoCl (bis(4-chlorophenyl)sulphoxide, 4), and tppo (triphenylphosphine oxide, 5) as co-ligands. The NMR and the crystal structure analysis confirmed the eight-coordinate structures of the complexes in solution and in a solid state. Upon UV-excitation on the absorption band of the β-diketonate ligand hth, all complexes showed the characteristic bright red luminescence of the Europium ion. The tppo derivative (5) displayed the highest quantum yield (up to 66%). As a result, an organic light-emitting device, OLED, was fabricated with a multi-layered structure-ITO/MoO₃/mCP/SF3PO:[complex 5] (10%)/TPBi:[complex 5] (10%)/TmPyPB/LiF/Al-using complex 5 as the emitting component.

Novel Biologically Active N-Substituted Benzimidazole Derived Schiff Bases: Design, Synthesis, and Biological Evaluation

Herein, we present the design and synthesis of novel N-substituted benzimidazole-derived Schiff bases, and the evaluation of their antiviral, antibacterial, and antiproliferative activity. The impact on the biological activity of substituents placed at the N atom of the benzimidazole nuclei and the type of substituents attached at the phenyl ring were examined. All of the synthesized Schiff bases were evaluated in vitro for their antiviral activity against different viruses, antibacterial activity against a panel of bacterial strains, and antiproliferative activity on several human cancer cell lines, thus enabling the study of the structure-activity relationships. Some mild antiviral effects were noted, although at higher concentrations in comparison with the included reference drugs. Additionally, some derivatives showed a moderate antibacterial activity, with precursor 23 being broadly active against most of the tested bacterial strains. Lastly, Schiff base 40, a 4-N,N-diethylamino-2-hydroxy-substituted derivative bearing a phenyl ring at the N atom on the benzimidazole nuclei, displayed a strong antiproliferative activity against several cancer cell lines (IC₅₀ 1.1-4.4 μM). The strongest antitumoral effect was observed towards acute myeloid leukemia (HL-60).

3-Methyl-1-phenyl-4-thioacetylpyrazol-5-one

The novel compound 3-methyl-1-phenyl-4-thioacetylpyrazol-5-one is obtained in excellent yield via a thionation of the corresponding oxygen analogue. The product is isolated in pure form using column chromatography and is characterised using 1D and 2D NMR experiments, ATR IR and HRMS spectra, and single-crystal XRD.

[Hexaamminecobalt(III)] Dichloride Permanganate—Structural Features and Heat-Induced Transformations into (CoII,MnII)(CoIII,MnIII)2O4 Spinels

We synthesized and characterized (IR, Raman, UV, SXRD) hexaamminecobalt(III) dichloride permanganate, [Co(NH3)6]Cl2(MnO4) (compound 1) as the precursor of Co–Mn–spinel composites with atomic ratios of Co:Mn = 1:1 and 1:3. The 3D−hydrogen bond network includes N–HO–Mn and N–HCl interactions responsible for solid-phase redox reactions between the permanganate anions and ammonia ligands. The temperature-limited thermal decomposition of compound 1 under the temperature of boiling toluene (110 ∘C) resulted in the formation of (NH4)4Co2Mn6O12. which contains a todorokite-like manganese oxide network (MnII4MnIII2O1210−). The heat treatment products of compounds 1 and [Co(NH3)5Cl](MnO4)2 (2) synthesized previously at 500 ∘C were a cubic and a tetragonal spinel with Co1.5Mn1.5O4 and CoMn2O4 composition, respectively. The heating of the decomposition product of compounds 1 and 2 that formed under refluxing toluene (a mixture with an atomic ratio of Co:Mn = 1:1 and 1:2) and after aqueous leaching ((NH4)4Co2Mn6O12, 1:3 Co:Mn atomic ratio in both cases) at 500 ∘C resulted in tetragonal Co0.75Mn2.25O4 spinels. The Co1.5Mn1.5O4 prepared from compound 1 at 500 ∘C during the solid-phase decomposition catalyzes the degradation of Congo red with UV light. The decomposition rate of the dye was found to be nine times faster than in the presence of the tetragonal CoMn2O4 spinel prepared in the solid-phase decomposition of compound 2. The todorokite-like intermediate prepared from compound 1 under N2 at 115 ∘C resulted in a 54 times faster degradation of Congo red, which is a great deal faster than the same todorokite-like phase that formed from compound 2 under N2.