Coordination Compounds of Lanthanides as Materials for Luminescent Turn Off Sensors

This review aims at describing the possible use of lanthanide coordination compounds as materials for luminescent sensors now more necessary due to the continuous requirements from the society of electroluminescent and lighting devices, for example analytical sensors and imaging instruments. This is the first part of a work describing the photophysical foundations of the luminescence of complex compounds of lanthanides in the context of design materials with a sensory response, and also considers in detail materials with the most common type of response - turn off sensors

Luminescent Materials with <em>Turn-on</em> and <em>Ratiometric</em> Sensory Response Based on Coordination Compounds of Lanthanides

Luminescent lanthanide complexes serve as a unique set of tools for creating sensory materials. The most significant types of sensory response in such materials are the turn-on/off response, when the analyte causes an increase or decrease in the emission intensity, respectively, as well as the ratiometric response, which manifests itself as a change in the ratio of luminescence intensities at different wavelengths. In this paper, we consider two of the most technologically advanced types of luminescent sensor materials based on lanthanide compounds—“turn on” and ratiometric sensors. The production of such materials is not only of importance per their possible application but is especially interesting from a fundamental point of view, since their design requires the implementation of non-trivial solutions

Исследование влияния степени соприкосновения поверхностей качения на контактные напряжения в шариковых радиальных подшипниках

The study is devoted to the determination of the coefficientsof the degree of contact of rolling surfaces, considering the tolerance field of rolling bodies, as well as the influence of the coefficients of the degreeof contact on the maximum contact stresses in ball radial bearings. A method has been developed for determining the maximum value of the coefficient of the degree of contact of rolling surfaces of ball radial bearings, taking into account the tolerance field of rolling bodies. It is established thatthe coefficient of the degree of contact of the rolling surfaces for each bearing size with a certain radius of the raceways is located in a range that depends on the limiting dimensions of the rolling elements. It is shown that the coef-ficient of the degree of contact of the rolling elements with the tracks ofthe outer ring, with the same auxiliary value, considering the sum and difference of the curvatures of the rolling surfaces, is greater than the inner one. Therefore, in order to reduce contact stresses on the outer ring ofthe bearing, the radius of its raceway can be made smaller than the inner one. A method has been developed for calculating the maximum contact stresses on the raceways of radial ball bearings, taking into accountthe coefficient of the degree of contact of rolling surfaces and the tolerance field of rolling bodies, which allows calculating contact stresses for radial ball bearings of any size at any coefficients of the degree of contact of rolling surfaces.Исследование посвящено определению коэффициентов степени соприкосновения поверхностей качения с учетом поля допуска тел качения, а также влияния коэффициентов степени соприкосновения на максимальные контактные напряжения в шариковых радиальных подшипниках. Разработана методика определения максимальной величины коэффициента степени соприкосновения поверхностей качения шариковых радиальных подшипников с учетом поля допуска тел качения. Установлено, что коэффициент степени соприкосновения поверхностей качения для каждого типоразмера подшипника с определенным радиусом дорожек качения располагается в диапазоне, который зависит от предельных размеров тел качения. Показано, что коэффициент степени соприкосновения тел качения с дорожками наружного кольца при одинаковой вспомогательной величине, учитывающей сумму и разность кривизн поверхностей качения, больше, чем внутреннего. Поэтому для снижения контактных напряжений на наружном кольце подшипника радиус его дорожки качения может быть выполнен меньше, чем на внутреннем. Разработана методика расчета максимальных контактных напряжений на дорожках качения шариковых радиальных подшипников с учетом коэффициента степени соприкосновения поверхностей качения и поля допуска тел качения, которая позволяет выполнять расчет контактных напряжений для радиальных шариковых подшипников любого типоразмера при любых коэффициентах степени соприкосновения поверхностей качения

Dynamics of the Ligand Excited States Relaxation in Novel β-Diketonates of Non-Luminescent Trivalent Metal Ions

Complexes emitting in the blue spectral region are attractive materials for developing white-colored light sources. Here, we report the luminescence properties of novel coordination compounds based on the trivalent group 3, 13 metals, and the 1-phenyl-3-methyl-4-cyclohexylcarbonyl-pyrazol-5-onate (QCH) ligand. [M(QCH)3] (M = Al, Ga, and In), [M(QCH)3(H2O)] (M = Sc, Gd, and Lu), [Lu(QCH)3(DMSO)], and [La(QCH)3(H2O)(EtOH)] complexes were synthesized and structurally characterized by a single-crystal X-ray diffraction study. It has been found that the luminescence quantum yields of the ligand increase by one order of magnitude upon metal coordination. A significant correspondence between the energies of the ligand’s excited states and the luminescence quantum yields to the metal ion’s atomic numbers was found using molecular spectroscopy techniques. The replacement of the central ion with the heavier one leads to a monotonic increase in singlet state energy, while the energy of the triplet state is similar for all the complexes. Time-resolved measurements allowed us to estimate the intersystem crossing (ISC) rate constants. It was shown that replacing the Al3+ ion with the heavier diamagnetic Ga3+ and In3+ ions decreased the ISC rate, while the replacement with the paramagnetic Gd3+ ion increased the ISC rate, which resulted in a remarkably bright and room-temperature phosphorescence of [Gd(QCH)3(H2O)]

New Carboxylate Anionic Sm-MOF: Synthesis, Structure and Effect of the Isomorphic Substitution of Sm³⁺ with Gd³⁺ and Tb³⁺ Ions on the Luminescent Properties

Two new compounds, namely {(NMe2H2)}[Ln(TDA)(HCOO)] 0.5H2O, Ln = Sm3+ (Sm-TDA) and Gd3+ (Gd-TDA), where TDA3− is the anion of 1H-1,2,3-triazole-4,5-dicarboxylic acid (H3TDA), were synthesized by the solvothermal method in a DMF:H2O mixture. According to single-crystal X-ray diffraction data, the compounds are 3d-MOFs with an anionic lattice and dimethylammonium cations occupying part of the cavities. Based on these compounds, two series of mixed-metal complexes, [NMe2H2][SmxLn1-x(TDA)(HCOO)], (x = 0.9 (Sm0.9Ln0.1-TDA), x = 0.8 (Sm0.8-Ln0.2-TDA)…Sm0.02Ln0.98-TDA, Ln = Tb, Gd), were also obtained and characterized by powder XRD. The luminescent properties of the compounds were studied and it was shown that the resulting compounds are two- or three-component emitters with the possibility of fine color tuning by changing the intensities of fluorescence and phosphorescence of the ligand, as well as the luminescence of Sm3+ and Tb3+ f-ions

Economic evaluation of type 2 diabetes mellitus burden and its main cardiovascular complications in the Russian Federation

Background. Diabetes Mellitus Type 2 (DMT2) is a complex medical and social problem in the world and in the Russian Federation also due to prevalence and probability of cardio-vascular complications (CVC). Aim. Economic burden evaluation of DMT2 in the Russian Federation. Methods. Complex analysis of expenditures (direct and non-direct costs) based on epidemiological, pharmacoeconomics and clinical investigations, population and medical statistics data. Results. Calculated expenditures for DMT2 are 569 bln RUR per year, that is correspond to 1% of the Russian GDP, and 34,7% of that are expenditures for main CVC (ischemic heart disease, cardiac infarction, stroke). Main part of expenses are non-medical (losses GDP) due to temporary and permanent disability, untimely mortality – 426,7 bln RUR per year. Expenditures in estimated group of patients with non-diagnosed DMT2 but with already having CVC were at least 107 bln per year (18,8% from total cost). Relationship between cost of DMT2 and degree of it’s control was found in the Russian conditions. Estimated cost for compensated patient (HbA1c6,5%) per year was 88 982 RUR, in the same time cost of non-control patient (HbA1c9,5%) was in 2,8 times higher due to more often main CVC in this group. Conclusion. DMT2 diagnosis improvement as well as effective treatment of early stages of illness can decrease probability of CVC and social economic expenditures

l‑Alanine/Nickel-Induced Size Sorting of Lanthanide(III) Ions in 4f–4f′ Heterometallic Complexes

A versatile approach to create a novel class of mixed-lanthanide compounds with predetermined locations of different lanthanides in cationic and anionic positions has been developed. Pure 4f–4f′ heterometallic complexes were constructed from two independent building blocks: the complex cation [Ln­{Ni­(ala)₂}₆]³⁺ (ala = l-alaninate), which can be formed by La³⁺, Ce³⁺, Pr³⁺, and Nd³⁺ exclusively, and the anion [Gd­(NO₃)₃(OH)₃(H₂O)]^3–. The compositions and structures of the complexes were studied by X-ray crystallography, energy-dispersive X-ray spectroscopy, and inductively coupled plasma mass spectrometry. The X-ray structural analysis showed the high rigidity of the l-alanine/Ni­(II) supramolecular unit in the complex cations, which affected immediately its selectivity toward certain lanthanides