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Abstract The reaction of lithium β-diketiminate [{2,6-Me2C6H3N=CMe}2CH]Li with benzophenone in toluene at 25°C affords the coordination complex [{2,6-Me2C6H3N=CMe}2CH]Li(Ph2C=O) (I). New keto-β-diketimine {2,6-Me2C6H3N=C(Me)}2CHC(tert-Bu)=O (II) is synthesized by the reaction of tert-Bu(C=O)Cl with [{2,6-Me2C6H3N=CMe}2CH]Li. The metallation of keto-β-diketimine II with n-butyllithium in THF at 0°C gives lithium keto-β-diketiminate {[{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]Li(THF)}n (III). The exchange reaction of YCl3 with compound III (molar ratio 1 : 2, THF) affords the yttrium bis(keto-diketiminate) complex [{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]2Y(μ2-Cl)2L-(THF)2 (IV). The molecular structures of complexes I, III, and IV are determined by X-ray diffraction analysis (CIF files CCDC nos. 2001131 (I), 2001132 (III), and 2001133 (IV)). Complex IV in the crystalline state exists as an ate complex with one LiCl molecule. Complexes I, III, and IV are catalysts of ring-opening polymerization of ε-caprolactone in toluene at 25°С.

Pretreatment of the organic fraction of municipal solid waste (OFMSW) is a necessary step to accelerate the process of anaerobic digestion in order to avoid rapid acidification and inhibition of methanogenesis. This work shows for the first time the effect of pretreatment in a vortex-layer apparatus (VLA) on the physicochemical properties and characteristics of the anaerobic thermophilic, two-phase fermentation of OFMSW. Pretreatment in a VLA led to a decrease in the amount of fat, an increase in pH, a slight increase in the amount of protein in dry matter, and a change in the density and dry matter content. OFMSW processing in a VLA for 2 min increased the specific yield of biogas and methane by 11.6 and 15.8%, respectively.

Materials based on copolymers of isobornylacrylate (IBA) with methylmethacrylate (MMA) or acrylonitrile (AN) have been synthesized by radical copolymerization using monomeric mixtures with different composition. The copolymer compositions were determined and relative activities of monomers were calculated by different methods. All copolymers have transparency up to 80% in the ultraviolet region. The mechanical and thermophysical properties of the copolymers depend on composition. The best combination of optical transparency and tensile strength is achieved in the copolymers containing 13% and 49% units of IBA (in the case of MMA and AN, respectively. The prospects of application of the copolymers as a matrix for creating photoinduced nanocomposites containing CdS are shown. Using the specially selected compounds of cadmium, materials with new optical properties were obtained by UV irradiation.

The thermal decomposition of cluster Nd3I5(S2)(S2N2)(THF)10 (I) at 50–400°C affords a mixture of products among which tetrahydrofuran (THF), sulfur, diiodine, HI, H2S, CS2, S3N6, S3N5, MeI, thiophene, tetrahydrothiophene, diiodobutane, iodobutene, and NdI3 are identified. The treatment of Ln3I5(S2)(S2N2)(THF)10 (Ln = Nd (I), Dy (II)) with phenanthroline (Phen) in THF at room temperature results in the partial substitution of ТНF to form new complexes Ln3I5(S2)(S2N2)(THF)4(Phen)3. The dissolution of compound I in pyridine gives a pyridine (Py) complex Ln3I5(S2)(S2N2)(THF)3(Py)7. The dissolution of compounds I and II in acetonitrile at 20°C is accompanied by the fast rearrangement and fragmentation of the complexes to form LnI3(MeCN)6, [LnI(S2)(MeCN)], and [LnI(S2N2)(MeCN)]. Complex I in THF does not react with white phosphorus, carbon monoxide, fullerene C60, and chromium hexacarbonyl.

The reaction of NdN and SmN with iodine gave the iodide-nitrides (NdI2)3N(DME)4 and (SmI)3N2(THF)2, which are inert towards sulfur, in contrast to the neodymium and dysprosium iodide-nitrides prepared by the reaction of LnI2 with N2. Reaction of NdN and SmN with C6F5OH and CpH gave the organolanthanide derivatives Ln(C5F5O)3(THF)n (Ln = Nd or Sm) and Cp3Sm with moderate and low yields, respectively. Phenylacetylene and styrene do not react with SmN.

Alkoxides [Ln(OR)3(DME)]2 (R = CH(CF3)2, Ln = Sm (1), Yb (2)), [Ce(OR)3(Phen)]2 (3) (Phen = 1,10-phenanthroline), [Ce(OR′)3(DME)2]2 (R′ = C(CF3)3) (4), {Gd(OR′)3(DME)2} (5), {Ln2[O(CF3)2C–C(CF3)2O]3} (Ln = Ce (6), Gd (7)), {Ce2[O(CF3)2C–C(CF3)2O]3(Phen)2} (8), and {Ce[O(CF3)2C–C(CF3)2O][O(CF3)2–C(CF3)2OH](Phen)2} (9) were synthesized by the reactions of silylamides Ln[N(SiMe3)2]3 with respective fluorinated alcohols. The heterovalent trinuclear complex {Sm2(μ2-OR)3(μ3-OR)2Sm(OR)2(THF)2.5(Et2O)0.5} (10) was obtained by treatment of SmI2(THF)2 with ROK. The reaction of europium(II) and yttrium(III) silylamides with ROH afforded the heterobimetallic alkoxide {Eu2(μ2-OR)3(μ3-OR)2Y(OR)2(DME)2} (11) containing divalent europium. The molecular structures of 1, 2, 3, 9, 10 and 11 were determined by X-ray analysis. All the prepared cerium derivatives as well as the europium–yttrium isopropoxide upon UV excitation exhibited photoluminescence in the regions of 370–425 (for Ce3+) and 485 nm (for Eu2+) which was assigned to 4d→5f transitions.

Rapid method was developed for determining the mass fraction of total carbon in boron carbide with a Vario El cube elemental analyzer (Elementar, Germany) intended for a CHNS analysis of organic and inorganic samples. The metrological characteristics of the suggested procedure were evaluated. The modification of the fluxing agent composition enabled a 1.5 times decrease in the time of oxygen dosing in oxidation of a sample, which substantially prolonged the service life of the reducing tube of the device. The key advantages of the suggested analytical procedure are the high rate of analysis and simplicity. The time required for a single analysis does not exceed 6 min.

(2-Benzox(thi)azol-2-yl)phenolate and -naphtholate ate complexes of Sc, Y, La, Sm, Tb, and Yb are synthesized. The structure of (benzoxazolyl)phenolate complexes of La, Sm, and Yb are determined by X-ray diffraction analysis. All synthesized compounds manifest ligand-centered photo- and electroluminescence in a range of 510–540 nm. In addition, the spectra of the samarium and terbium complexes exhibit narrow bands of f-f transitions characteristic of Sm3+ and Tb3+ ions.

A series of Pr, Nd, Ho, Er, Tm, and Yb complexes with 3-(2-benzoxazol-2-yl)-2-naphtholate and 3-(2-benzothiazol-2-yl)-2-naphtholate ligands was synthesized. The structure, as well as the photo- and electroluminescent properties of these complexes were studied. An extraordinary bright emission of Yb3+ was detected. To explain the phenomenon, a novel excitation mechanism involving intramolecular electron transfer was proposed.

Complexes M(NpOON) n and M(NpSON) n (NpOON = 3-(2-benzoxazol-2-yl)-2-naphtholate, NpSON = 3-(2-benzothiazol-2-yl)-2-naphtholate, M = Li, Sc, Sm, Eu, Gd, Tb, Dy) were prepared by the reactions of silylamides M[N(SiMe 3 ) 2 ] n ( n = 1, 3) with corresponding O,N-chelating ligand. For the synthesis of zinc complexes Zn(NpOON) 2 and Zn(NpSON) 2 diethylzinc was used. Li, Zn and Sc naphtholates exhibited strong green electroluminescence. The OLED device based on Sc(NpOON) 3 showed luminance 8780 cd/m 2 (12 V) – the highest value among the devices prepared with organoscandium luminophores.

1-(2-Pyridyl)naphth-2-ol (pynH) was synthesized from 2-bromopyridine and 1-bromo-2-hydroxynaphthalene and structurally characterized. This ligand and the known 2-(2-pyridyl)phenol (ppH) ligand were reacted with LiN(SiMe 3 ) 2 , ZnEt 2 and Sc[N(SiMe 3 ) 2 ] 3 to prepare the new luminescent complexes Li(pp), Li(pyn), Zn(pyn) 2 , Sc(pp) 3 , Sc(pyn) 3 and known Zn(pp) 2 . Photoluminescent (PL) spectra of the compounds contained a single broad band with a maximum at 447–473 nm. The OLED devices with a configuration of ITO/TPD/complex/Bath/Yb gave blue–green emission. The emission spectra of these devices resembled the PL spectra; however, the bands of electroluminescence (EL) were shifted 20–40 nm to the long-wavelength side. A maximum current efficiency 15.3 cd/A and a power efficiency 8.12 lm/W at 100 cd/m 2 were measured for the device with the zinc luminophore Zn(pp) 2 , whereas the highest luminance of 8300 cd/m 2 at 22.5 V was observed with the device with the scandium complex Sc(pp) 3 . DFT calculations showed that the latter complex exhibited the lowest HOMO and the highest LUMO energy levels compared with the other investigated compounds. The calculated trends with respect to the influence of the metal and the ligand on the LUMO–HOMO gap agree well with the shifts of the electronic transitions observed in the PL spectra of the complexes.

By reactions of 1-(2-pyridyl)naphth-2-ol (pynH) with silylamides Ln[N(SiMe3)2]3 (Ln = Sc, Eu, Gd, or Tb), the Ln(pyn)3 complexes of the metals have been synthesized. Only the scandium complex in a THF solution has displayed photoluminescence (band with a maximum at 455 nm and a halfwidth of 65 nm). Electroluminescent properties have been revealed for the scandium and terbium complexes. In an ITO/TPD/Sc(pyn)3/Bath/Yb three-layer light emitting diode, the scandium complex exhibits yellow-green luminescence with a brightness of 4750 cd/m2 at a voltage of 21 V. The terbium complex Tb(pyn)3 in the same device has displayed a single, broad luminescence band with λmax = 570 nm due to excimer emission. By density functional theory quantum chemical calculations, different structures of the complexes have been revealed, mononuclear for Sc(pyn)3 and binuclear for Ln2(pyn)6. This difference in structure seems to be responsible for differences in electroluminescent activity between the synthesized complexes.

Lanthanide semiquinolates Ln(SQ)3 (SQ-3,5-di-tert-butyl-o-benzosemiquinone) were prepared by the reactions of Dy, Tm, Yb with 3 equiv of 3,5-di-tert-butyl-o-benzoquinone (Q). Crystallization of thulium product from DME yields structurally characterized cluster Tm3(SQ)4(Cat)2(QH)(DME)2 (1) (Cat-3,5-di-tert-butyl-catecholate, QH-o-hydroxyphenolate). The reactions of Q with excess of metal (Sm, Eu, Tm, Yb) afford catecholates Ln2(Cat)3. For samarium product Sm4(Cat)6(THF)6 (2) X-ray diffraction study was performed. In the reaction of EuI2 with Li2(Cat) ate-complex EuLi4(LiI)2(SQ)2(Cat)2(THF)6 (3) was isolated. X-ray analysis revealed that a molecule of the complex contains two semiquinone groups, two catecholate ligands, Eu2+ cation, four Li+ cations and two LiI species bonded by bridging O and I atoms. Catecholates of Eu(II), Sm(II) as well as trivalent Ce, Nd, Gd, and Tb were obtained by treatment of corresponding lanthanide silylamides Ln[N(SiMe3)2]n (n = 2, 3) with the 3,5-di-tert-butyl-catechol. It was established that gadolinium product Gd4(Cat)6(THF)6 (4) is isostructural to samarium complex 2. Terbium catecholate Tb2(Cat)3 in THF solution revealed photoluminescence typical for Tb3+ cation.