A new series of neutral protomesogenic EuIII tris(β‐diketonate) adducts with different Lewis bases have been synthesized. Only one of the complexes is liquid‐crystalline and displays smectic A and ...nematic mesomorphism over a broad temperature range. Quantum‐chemistry and small‐angle X‐ray scattering methods have permitted the evaluation of the influence of the structure of the Lewis base on the anisometry of EuIII adduct molecules and their subsequent supramolecular organization. The structural features of the presented compounds allow the creation of vitrified optically isotropic and self‐organized films with effective red luminescence. The luminescence spectra of aligned thin films of a liquid‐crystalline EuIII complex are also described.
Homogeneous films of luminescent europium(III) β‐diketonate complexes with different Lewis bases are prepared. The structure of the Lewis base and the geometric anisotropy of the complex influence the optical characteristics of the films. One of the complexes is liquid‐crystalline and displays smectic A and nematic mesomorphism over a broad temperature range.
We report rare-earth-containing metallomesogens with newly synthesized ligands represented by the β-diketone 1-(4-(4-propylcyclohexyl)phenyl)octane-1,3-dione (CPDk 3‑5) and the Lewis base ...5,5′-bis(heptadecyl)-2,2′-bipyridine (bpy17‑17). The stoichiometry of the complexes is Ln(CPDk 3‑5)3bpy17‑17, where Ln is a trivalent rare-earth ion (La, Sm, Eu, Gd, Tb, Dy, Ho, Tm, and Yb). Although the ligands themselves do not form any mesophase, the respective metal complexes produce nematic and smectic A phases. The mesogenic rare-earth complexes were characterized by NMR, MS, POM, DSC, X-ray diffraction, magnetic susceptibility measurements, and dielectric spectroscopy. The metal complexes display a remarkably large magnetic anisotropy in the mesophase. These nematic liquid crystals can, therefore, be easily aligned by an external low-threshold magnetic field.
Adducts of Eu(III), Tb(III), Gd(III) and La(III) tris(β-diketonate) forming mesophases in close temperature ranges were synthesized. The near structural features of these lanthanidomesogens render ...them suitable for obtaining homogeneous binary mixtures that vitrified on cooling into optically isotropic, self-organizing smectic films over a wide range ratio of the lanthanide complexes. The distribution of the components in the obtained films and their supramolecular organization were studied by polarizing optical microscopy, differential scanning calorimetry, and small-angle X-ray scattering. The mixtures behave as their homologous single components and exhibit smectic A and nematic phases above room temperature, and form anisotropic glasses at room temperature. The dependence of the luminescence on the ratio of each component in the mixtures under investigation has been established and a photoexcitation mechanism proposed. It was shown that the luminescence intensity per mole of the emitting substance in films obtained from mixtures of Eu(III) and Tb(III) complexes increases about three fold when compared with the individual Eu(III) complex. This enhancement of the luminescence was interpreted as the consequence of the very effective intermolecular energy transfer from Tb(III) to Eu(III) complexes, templated by the frozen smectic A supramolecular organization. We thus present here an efficient and facile approach for the creation of novel heteroionic lanthanide-containing high uniaxial materials with effective luminescence and controlled spectral properties.
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•Synthesis of Eu(III), Tb(III) and La(III) tris(β-diketonate) lanthanidomesogens.•Homogeneous smectic films of binary mixtures of Eu(III) and Tb(III) complexes.•Enhancement of the luminescence by effective intermolecular energy transfer from Tb(III) to Eu(III) complexes.
The spin-coating technique was used to produce composite films consisting of PMMA polymer doped with anisometric complexes of Eu(III) and Tb(III). It was found that an increase in the content of Tb3+ ...complexes intensifies emission of both ions due to the intermolecular energy transfer from the Tb(III) complex to the Eu(III) complex, which results in the increase in the relative luminescence quantum yield of Eu(III) ion by 36%. The temperature sensitivity of the film luminescence intensity and lifetime in the range of 296–363 K was investigated. The maximum relative sensitivity of the films reaches 5.44% × K−1 and exceeds that of all known lanthanide-containing thermal sensors designed for measuring physiological temperatures. In combination with changing luminescence color, such a sensitivity makes these films promising colorimetric thermal sensors for in situ temperature measurements.
A new series of europium adducts with the general formula Eu(CPDk3-CnH2n+1)3Phen, where CPDk3-CnH2n+1 denotes β-diketones and Phen is 1,10-phenanthroline, was synthesized. The obtained mesogenic ...complexes were heated to the temperatures of the isotropic liquid state and then cooled. The complexes having short CH3 and C2H5 substituents crystallized upon cooling, and the complexes with longer substituents from C3H7 to C6H13 underwent a glass transition with the formation of optically transparent amorphous films. Inside the series the complexes with C7H15 and C8H17 substituents exhibited a unusual smectic C mesomorphism for lanthanidomesogens. On the basis of quantum-chemical simulations and the results of small-angle X-ray scattering the dependence between the anisotropy of Eu(III) complexes with various ligand environments and their supramolecular organization was found. The synthesized Eu(III) complexes in the solid state show intense red photoluminescence upon irradiation by ultraviolet light (λmax − 337 nm).
This work reports fabrication of polylactide (PLA) films doped with various additives of an amorphous Eu(III) complex. We study the temperature behavior of the luminescence intensity and lifetime of ...the PLA-Eu(III) composites in the range of 298–353 K and investigate the mechanism of luminescence temperature quenching. The peak relative sensitivity of the films reaches 20.1 %×K−1 and exceeds the respective characteristics of all known lanthanide-containing thermosensors designed for the range of physiological temperatures. The produced films can be potential novel materials for luminescent thermosensors.
The possibilities and future perspectives of electrochemical deposition of bimetallic compositions and alloys containing Fe, Co, Ni, Cr, W, and Mo are reviewed. The synthesis of two- and ...three-component materials, as well as compositionally more complex alloys, is considered. The method of synthesizing of materials via electrodeposition from solutions containing metal ions and metalloids is one of the most promising approaches because it is fast, cheap, and it is possible to control the composition of the final product with good precision. Corrosion, catalytic and magnetic properties should be distinguished. Due to these properties, the range of applications for these alloys is very wide. The idea of a correlation between the magnetic and catalytic properties of the iron-triad metal alloys is considered. This should lead to a deeper understanding of the interplay of the properties of electrodeposited alloys. In addition to deposition from aqueous (classical) solvents, the advantages and perspectives of electrochemical deposition from ionic liquids (ILs) and deep eutectic solvents (DES) are briefly discussed. The successful use and development of this method of electrodeposition of alloys, which are quite difficult or impossible to synthesize in classical solvents, has been demonstrated and confirmed.
Europium(III) complexes that are the anisometric analogues of a well-known Eu(DBM)3Phen (DBM = dibenzoylmethane; Phen = 1,10-phenanthroline) complex were synthesized. Quantum-chemical calculations ...of the excited states of new Eu(III) complexes and some conjugated polymers showed that poly(N-vinylcarbazole) provides the most efficient energy transfer in polymer films doped with synthesized Eu(III) complexes. These new composite films were prepared, and their luminescence properties were studied. The results of experimental data confirmed theoretical prediction about significant influence introduced in molecular structure long terminal alkyl chains and cyclohexane on the luminescence efficiency of “Ln(III)–polymer” composite. As the result a substantial contribution of complex anisometry to the luminescence efficiency of composite was revealed due to the increase of the complex limit concentration before self-quenching more than twofold.
Small open reading frames (<100 codons) that are located on long noncoding RNAs (lncRNAs) can encode functional microproteins. These microproteins are shown to play important roles in different ...cellular processes, such as cell proliferation, development and disease response 1–6. However, there are only a few known lncRNA-encoded functional microproteins in plants. One such microprotein that was named PSEP3, was identified in the moss Physcomitrium patens by mass-spectrometry analysis. 57-aa PSEP3 contains Low Complexity Region (LCR) enriched with proline. We have previously shown that PSEP3 is translated in protonemata and gametophores of P. patens, and its knockout (KO line) or overexpression (OE line) affects protonemata growth 7. We performed a quantitative proteomic analysis of the mutant lines with PSEP3 knockout and overexpression. 7-days old protonemata of wild type (WT line) and both mutant lines (KO and OE) were collected and used for iTRAQ-based proteomic experiments. LC-MS/MS data were processed using PEAKS Studio v.8 software with protein identification based on a Phytozome protein database. More analysis of PSEP3 effects on plant growth can be obtained in the paper published in Nucleic Acid Research 8.
A novel temperature probe with −1.0% K
−1
mean relative and −5.4 μs K
−1
mean absolute sensitivity of the luminescence decay time in the range of 270-370 K is presented. The probe is a 20 μm thick ...vitrified film (sandwiched between two quartz plates) fabricated from an amorphous powder of an anisometric europium(
iii
) β-diketonate complex through a melt-processing technique. It is established that the film exhibits bright Eu
3+
ion luminescence with the most intense peak at 611 nm caused by efficient ligand-to-metal energy transfer. The observed thermal luminescence sensitivity we associate with a well-known non-radiative relaxation mechanism of the Eu
3+
ions through the low-lying ligand-to-metal charge transfer state. The experiments also showed that (i) the luminescence of the film is insensitive to oxygen, (ii) the film is completely resistant to UV-vis light, (iii) there is full reversibility of the temperature dependent luminescence decay time, and (iv) the strong luminescence of the film can be efficiently excited by irradiation in the wavelength range of 280-425 nm (including inexpensive and portable blue-violet light sources). The listed facts allow us to consider the film as a promising probe for reusable luminescent thermometers, suitable for long-term temperature monitoring.
Vitrified film of europium(
iii
) β-diketonate complex as reusable highly sensitive luminescent temperature probe suitable for long-term monitoring in range of 270-370 K.
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