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The reaction of the 2,3,4,5-tetrafluorobenzoate (6H-tfb) compounds [Cd(H2O)4-(6H-tfb)]n • n(6H-tfb) (1) and [Tb(H2O)2(6H-tfb)3]n (2) with 1,10-phenanthroline (phen) affords the heterometallic complex [Cd2Tb2(phen)2(6H-tfb)10] (3). The 2,3,5,6-tetra-fluorobenzoate (4H-tfb) complexes [Cd2Tb2(phen)4(4H-tfb)10]·4MeCN (4) and [Cd2Tb2(phen)2(4H-tfb)10] • 4 C6H6 (5) were obtained by reacting cadmium and terbium nitrates with K(4H-tfb) and phen. Depending on the crystallization medium, compounds of different compositions and structures are formed. The use of two isomers of tetrafluorobenzoic acid allowed the analysis of the effect of the substituent position on the structure and the crystal packing of the resulting complexes. Unlike {CdLn} pentafluorobenzoate compounds, new complexes 3–5 do not have a polymer structure, which may be evidence of weaker intermolecular interactions of these isomeric tetrafluorobenzoate anions compared to compounds containing pentafluorobenzoate anions. The synthesized compounds were characterized by X-ray diffraction, IR spectroscopy, and elemental analysis. Noncovalent interactions were investigated using the Hirshfeld surface analysis. The main contribution to the stabilization of the crystal packing is made by π⋯π, C−H⋯F, and C−F⋯π interactions. For complex 2, the luminescence quantum yield and the excited state lifetime are 45% and 1.95 ms, respectively, which are comparable with the corresponding values for heterometallic phenanthroline-containing pentafluorobenzoate complexes. [ABSTRACT FROM AUTHOR]

This paper presents the content and structure of learning activities aimed at the study of Babinet’s principle by undergraduate students and its use in the experimental justification of Rayleigh criterion to resolve the power of an optical device. The learning activities include the elementary theory of Fraunhofer diffraction at a slit, wire, and circular aperture and training experiments confirming the results of the theory. This content is structured in the form of two sets of theoretical and experimental tasks that are to be performed by the students independently. Possible variants for solving the problems in the tasks are also considered. [ABSTRACT FROM AUTHOR]

A modern version of Hertz's classical experiments that demonstrate the electromagnetic nature of light waves is proposed herein. The demonstration kit includes a 433 MHz micropower generator, a sufficiently sensitive electromagnetic-radiation detector with an LED output, two semi-wave vibrators, a rod polariser, an LED flashlight, three Polaroid polarisers, and a matte screen. [ABSTRACT FROM AUTHOR]

For conducting laboratory experiments on Fresnel diffraction, the use of a simple point light source from an LED and the application of a modern smartphone for photographing the diffraction patterns are proposed. The developed devices allow the experiments to be carried out under normal laboratory lighting. [ABSTRACT FROM AUTHOR]

The efficiency of students' educational activity in a physical laboratory increases if students independently assemble experimental installations and use them to study physical phenomena. This paper describes a simple installation for the manufacture of a sinusoidal grating by the holographic method. Such a grating is used in many demonstration and laboratory experiments. It is used, for example, in a simple device for making photos of optical spectra on a smartphone, and this device is also described in this paper. First, students study the elementary theory of a holographic diffraction grating. They use this theory to calculate the parameters of the installation that allows them to obtain a grating with the required period and use an experiment to verify the validity of the theory. Then they calculate the parameters of the spectroscope on the basis of the studied theory and again make sure that the theory is valid. Thus, it is possible to organize a learning process in which the theory is fully confirmed by the experiment. [ABSTRACT FROM AUTHOR]

We have successfully synthesized Eu-based luminophores promising for inkjet printing with almost 100% efficiency of energy transfer from ligands to the lanthanide ion. The luminophores with β-diketonate ligands are characterized by means of optical spectroscopy. We reveal the impact of different types of β-diketonates on the quantum yield of luminescence and determine a β-diketonate complex exhibiting the highest luminescence quantum yield and promising for organic light-emitting diode (OLED) applications. We discuss the reasons for decreasing quantum efficiencies of other types of investigated ligands. [ABSTRACT FROM AUTHOR]

By 31P, 13C, 13C-{1H}, and 1H NMR spectroscopy the chlorination of 4-and 5-methyl-2,2,2-trichlorobenzo-1,3,2-dioxaphosphols was shown to provide in quantitative yield 4-methyl-2,2,2,5-tetrachloroand 6-methyl-2,2,2,5-tetrachlorobenzo-1,3,2-dioxaphosphols. Their hydrolysis led to the formation of difficultly available 4-methyl-5-chloro-and 3-methyl-4-chloro-1,2-dihydroxybenzenes. The structure of the latter compound was established by XRD analysis. The 5-methyl-2-chlorobenzo-1,3,2-dioxaphosphol treated with excess chlorine was converted in succession into 5-methyl-2,3,4,5,6,6-hexachlorocyclohex-1-en-3-yl dichlorophosphate and 5-methyl-1,2,4,4,5,6-hexachlorocyclohex-1-en-3-yl dichlorophosphate. The hydrolysis resulted in 5-methyl-2,3,4,5,6,6-hexachlorocyclohex-2-en-1-yl dihydrophosphate. The configuration of three chiral carbon atoms in the latter was established by XRD study. In the course of the chlorination the aromaticity of the ortho-phenylene fragment was distorted and 3,3-sigmatropic shift of the dichlorophosphoryl group occurred. The reaction with chlorine of 5- tert-butyl-2,2,2-trichlorobenzo-1,3,2-dioxaphosphol and 2,2,2-trichloro-benzo-1,3,2-dioxaphosphol was not selective: The reaction product obtained in excess chlorine transformed on hydrolysis into tetrachloropyrocatechol. Its solvates with water and dioxane were studies by XRD analysis. [ABSTRACT FROM AUTHOR]

The 4-aryl(alkyl)benzo[e]-1,2-oxaphosphorine derivatives (phosphacoumarins) were obtained by the reaction of 2,2,2-trihalogenobenzo[d]-1,3,2-dioxaphospholes with terminal acetylenes. The reactions of phosphacoumarins with halogens and Grignard reagents were investigated. [ABSTRACT FROM AUTHOR]

2,2,2,6-Tetrachloro-4-phenylbenzo[ e][1,2]oxaphosphinine and 2,2,6-trichloro-4-phenylbenzo[ e][1,2λ5]-oxaphosphinin-2-ylium hexachlorophosphate were prepared by treatment of 2,6-dichloro-4-phenylbenzo[ e][1,2λ5]-oxaphosphinine 2-oxide with phosphorus pentachloride. The structure of the latter compound was proved by means of X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

It was shown for the first time that 3-chloro-, 3-bromo-, and 3-iodopropynes can react with 2,2,2-trichloro-, 2,2,2-trichloro-5-methyl-, and 5,6-dibromo-2,2,2-trichloro-1,3,2λ5-benzodioxaphospholes to give derivatives of 4-(halomethyl)-2-chloro-2 H-1,2λ5-benzoxaphosphinin-2-ones. The reaction involves nonselective chlorination of the phenylene substituent in different positions, and the resulting isomer ratio is temperature-dependent. In the reactions of 3-bromo-and 3-iodopropynes with 2,2,2-trichloro-1,3,2λ5-benzo-dioxaphosphole, a side process takes place, viz. nucleophilic substitution of bromine and iodine with chlorine. The structure of some of the prepared 4-(chloromethyl)-1,2-benzoxaphosphinines was studied by means of X-ray diffraction. [ABSTRACT FROM AUTHOR]

According to NMR data, the reaction of 2,2,2-trichloro-1,3,2λ5-benzodioxaphosphole with 1-iodo-2-phenylethyne leads to formation of 2,6-and 2,8-dichloro-3-iodo-4-phenyl-1,2λ5-benzoxaphosphinine 2-oxides which undergo partial hydrodeiodination to 2,6-and 2,8-dichloro-4-phenyl-1,2λ5-benzoxaphosphinine 2-oxides, respectively. [ABSTRACT FROM AUTHOR]

The article reports on the finding that 4,6-di-tert-butyl-2,2,2-trichloro-1,3,2λ5-benzodioxaphosphole, which has bulky tert-butyl groups, can react with 1-hexyne under mild conditions. This reaction produces exclusively 1,2λ5-benzoxaphosphinine derivatives. The product was confirmed by 31P nuclear magnetic resonance spectroscopy.

The article presents a study about the product in the chemical reaction of 2,2,2-trichloro-1,3,2λ5-benzodioxaphosphole-5-carbonyl chloride with hex-1-yne. The reactions of aryl- and alkylacetylenes with 2,2,2-trichloro(bromo)-1,3,2λ5-benzodioxaphosphole and some of its derivatives underlie a synthetic approach to 4-butyl-2,5-dichloro-2-oxo-1,2λ5-benzoxaphosphinine-6-carbonyl chloride.

We report a synthesis of a series of molecular compounds and coordination polymers of Zn2+, Mn2+ Cd2+, Eu3+, and Tb3+ with 4-allyl-2,3,5,6-tetrafluorobenzoic acid (4-Afb) anions and 1,10-phenanthroline with compositions [Zn(H2O)(phen)(4-Afb)2] (1), [Mn(H2O)(phen)(4-Afb)2]n·nH2O (2), [Cd(H2O)(phen)(4-Afb)2]n (3), [Cd(phen)(4-Afb)2]n (4), [Ln2(phen)2(4-Afb)6] (Ln = Eu 5Eu; Tb 5Tb). It is shown that the obtained cadmium coordination polymers have various compositions and structures, depending on crystallization conditions. The prepared compounds are characterized by single-crystal XRD, powder XRD, IR spectroscopy, and CHN analysis. Noncovalent interactions are analyzed using the Hirshfeld surface analysis. It is determined that the crystal packings is mainly stabilized by π⋯π, C–H⋯F, and C–F⋯π interactions. The photoluminescent properties of the 5Eu and 5Tb complexes are studied. It is shown that the structure-forming effects of non-covalent "arene–perfluoroarene" interactions can be possibly used for preorganizing reactive functional groups in the crystal. [ABSTRACT FROM AUTHOR]

The use of dicyanamide and chelating phenanthroline ligands resulted in the synthesis of organometallic europium and neodymium coordination polymers [Ln(Phen)2{N(CN)2}3–xClx(CH3OH)](CH3OH)y]∞ (Ln = Eu (I), Nd (II)) in which the dicyanamide ligand forms 1D chains, while the phenanthroline ligand provides packing of the 1D polymer in the crystal lattice. Under similar conditions, the binuclear complex [Gd(Phen)2(μ-OH){N(CN)2}(H2O)]2Cl2 (III) was obtained for gadolinium, with the dicyanamide ligands being coordinated to only one gadolinium ion without forming a polymer chain (CCDC CIF files nos. 1936378 (I), 1936379 (II), 1936377 (III)). [ABSTRACT FROM AUTHOR]

The article investigates the reaction of dioxaphosphol with unsubstituted alkylacetylene. The reaction with propargyl chloride with phosphol resulted in two phosphorus-containing substances which gave rise to characteristic doublet signals of benzophosphorinines which were converted by hydrolysis into the corresponding acids.

Four new complexes [Ln(pfaa)3(H2O)2] n (Ln = Eu (1), Tb (2)) and [Ln2Cd2(pfaa)10 (phen)2(EtOH)2]·2MeCN (Ln = Eu (3), Tb (4), phen = 1,10-phenanthroline) based on pentaphorphenylacetic acid (Hpfaa) have been prepared and completely investigated. The structures of compounds 1 and 3 were studied by single crystal X-ray diffraction analysis: the isostructural complexes 1 and 2 represent 1D coordination polymer, while the isostructural complexes 3 and 4 are molecular compounds. Complexes 1–4 show strong lanthanide-centred luminescence, since the introduction of phenanthroline leads to a significant increase in the observed lifetime (τ obs) and photoluminescent quantum yield. New complexes of Eu3+ and Tb3+ with pentafluorophenylacetic acid have been studied. During synthesis under hydrothermal conditions, polymer structures are formed, while the introduction of phenanthroline and Cd2+ makes it possible to obtain molecular complexes. A change in the structure leads to significant changes in the luminescent properties. [ABSTRACT FROM AUTHOR]

We present a composite material based on polymer matrices doped with a new europium(III) complex exhibiting high quantum yield. The Eu(III) complex was introduced into two types of polymer matrices. We investigate the concentration influence of the complex embedded into polymers on luminescent properties of the composite material. This Eu(III) complex proved to be highly dispersible in polymers and compatible with ink-jet technology. [ABSTRACT FROM AUTHOR]

It has been established experimentally that the equilibrium of the plane surface of transformer oil under a corona electrode (needle) becomes unstable when the critical voltage, which increases with the oil layer thickness, is attained at the corona point. When the voltage at the needle exceeds the critical value, regular static cells are formed on the oil surface with characteristic sizes decreasing upon an increase in voltage. The theoretically estimated parameters of the experiment are found to be close to the experimental data. Comparison of the parameters corresponding to the occurrence of instability in the equilibrium of the oil surface in the field of the corona discharge with the parameters of instability in the equilibrium of the charged surface of liquid helium in a uniform electric field [7] demonstrates the similarity of the effects. [ABSTRACT FROM AUTHOR]

Reactions of 5- tert-butyl-2,2,2-trichloro-, 2,2,2-tribromo-5- tert-butyl-, and 2,2-dibromo-5- tert-butyl-2-fluoro-1,3,2λ-benzodioxaphospholes with aryl- and alkylacetylenes lead to quantitative formation of 2-halo-1,2λ-benzoxaphosphinine 2-oxides which may be regarded as phosphorus analogs of natural heterocyclic compounds, coumarin and chromene. The major products (>70%) are 4-aryl-7- tert-butyl-2,6-dichloro-, 4-aryl-2-bromo-7- tert-butyl-, and 4-aryl-7- tert-butyl-2-fluoro-1,2λ-benzoxaphosphinine 2-oxides. Hydrolysis of these compounds and their treatment with amines gives the corresponding 2-hydroxy and 2-amino derivatives, as well as ammonium salts. The structure of some compounds was proved by X-ray analysis. [ABSTRACT FROM AUTHOR]

A reaction of 2,2,2-trihalobenzo-1,3,2-dioxaphospholes with terminal alkylacetylenes proceeds under mild conditions (∼20 °C) and leads to the formation of 4-alkylbenzo[ e]-1,2-oxaphosphinine 2-oxide derivatives. The presence of aliphatic substituents in acetylene decreases (as compared to their aromatic counterparts described earlier) regioselectivity of halogenation of benzo fragment in 4-alkylbenzo[ e]-1,2-oxaphosphinines: besides predominant 4-alkyl-2,6-dihalobenzo[ e]-1,2-oxaphosphinines, minor 2,7- and 2,8-dihalo-substituted 4-alkylbenzo[ e]-1,2-oxaphosphinines are formed. An unusual thermal isomerization of 4-alkyl-2-fluorobenzo[ e]-1,2-oxaphosphinines to 4-alkylidene-2-fluoro-3,4-dihydrobenzo[ e]-1,2-oxaphosphinines was discovered. Molecular and supramolecular structures of some 4-alkylbenzo[ e]-1,2-oxaphosphinines were studied by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

2,2,2-Trichloro-4-fluoro-1,3,2?5-benzodioxaphosphole reacts with phenylacetylene to give 2,7-dichloro-5-fluoro-4-phenyl-2H-1,2?5-benzoxaphosphinine 2-oxide. Hydrolysis of the latter leads to opening of the oxaphosphinine ring with formation of (E)-2-(4-chloro-2-fluoro-6-hydroxyphenyl)-2-phenylethenylphosphonic acid. [ABSTRACT FROM AUTHOR]

NMR and IR spectroscopy and X-ray diffraction were used to show that the reaction of 2,2,2-trichloro- and 2,2,2-tribromo-5-methylbenzo[d][1,3,2]dioxaphospholes withpara-substituted arylacetylenes proceeds with regioselective formation of 4-aryl-2-halo-7-methyl-2-oxobenzo[e][1,2]oxaphosphorines. With the trichlorophosphole, selective chlorination of the phenylene fragment in theparaposition to the endocyclic oxygen atom occurs. With the tribromophosphole, 6-bromo- and unsubstituted benzo[e][1,2]oxaphosphorines are formed as major products. The molecular and supramolecular structure of some of the obtained oxaphosphorines was studied by X-ray diffraction. [ABSTRACT FROM AUTHOR]

The reaction of Cd(NO3)2 · 4H2O and Eu(NO3)3 · 6H2O or Tb(NO3)3 · 6H2O with potassium 3,5-di-tert-butylbenzoate (Kbzo) and N-donor ligands (1,10-phenanthroline (phen), 2,4-lutidine (2,4-lut), 3,4-lutidine (3,4-lut), phenanthridine (phtd), 2,3-cyclododecenopyridine (cdpy), acridine (acr)) afforded heterometallic LnCd2 complexes: [EuCd2(bzo)7(EtOH)2(phen)] (2), [LnCd2(bzo)7(2,4-lut)4] (Ln = Eu (3), Tb (4)), [EuCd2(bzo)7(H2O)2(2,4-lut)2] · MeCN (5), [EuCd2(NO3)(bzo)6(EtOH)2(2,4-lut)2] (6), [EuCd2(bzo)7(H2O)(EtOH)(3,4-lut)2] · 5EtOH (7), 3[EuCd2(bzo)7(H2O)2(phtd)2] · 4phtd (8), [EuCd2(bzo)7(EtOH)3(cdpy)] (9), 2[EuCd2-(bzo)2(EtOH)4] · acr (10). The structures of complexes 2, 3, and 5–10 were determined by single-crystal X-ray diffraction. The isostructurality of complexes 3 and 4 was confirmed by powder X-ray diffraction. The structure of the trinuclear {Ln2Cd} metal core is stable and independent of the type of peripheral ligands coordinated to cadmium atoms. Photoluminescent properties of compounds 3 and 4 were studied. [ABSTRACT FROM AUTHOR]

The reactions of Cd(NO3)2 ∙ 4H2O and Eu(NO3)3 ∙ 6H2O with potassium salts of the benzoic acid derivatives and 2,2'-bipyridine (Bipy) in ethanol, under the same synthesis conditions, afford the homo- and heterometallic complexes: [Eu2Cd2(BA)8(NO3)2(Bipy)2] (I, BA is benzoic acid anion), [Ln2Cd2(4-TBA)10(Bipy)2] (Ln = Eu (II), Tb (III); 4-TBA is 4-(trifluoromethyl)benzoic acid anion), [Cd(4-CBA)2(H2O)(Bipy)] (IV, 4-CBA is 4-cyanobenzoic acid anion), [Cd(PFBA)2(H2O)(Bipy)]n (V, PFBA is pentafluorobenzoic acid anion), and [Cd2(4-APFBA)4(Bipy)2] ∙ 4H2O (VI, 4-ATFBA is 4-amino-2,3,5,6-tetrafluorobenzoic acid anion). The structures of new complexes I, II, IV, and VI are determined by X-ray structure analysis (CIF files CCDC nos. 1970348, 1970350, 1970347, and 1970351, respectively). The isostructural character of complexes II and III is confirmed by X-ray diffraction analysis. The structures and compositions of the series of isolated compounds I–VI are determined by the nature of substituents in the benzoate anion. The photoluminescence properties of compounds II and III are studied. [ABSTRACT FROM AUTHOR]

New trinuclear Cd–Ln molecular complexes [EuCd2(O2CC6F5)6(NO3)(Bipy)2] (I, Bipy is 2,2'-bipyridine) and [LnCd2(Bzo)6(NO3)(Phen)2] · 4MeCN (Ln = Tb (II), Eu (III), Bzo is anion of 3,5-di-tert-butylbenzoic acid, Phen is 1,10-phenanthroline) are studied. Their structures are determined by X-ray structure analysis (СIF files CCDC nos. 1938125 (I), 1938124 (II)) or by X-ray diffraction analysis (III), and the photoluminescence properties are studied. The reactions of complexes I and II with terephthalic acid (H2Bdc) are accompanied by the destruction of the heterometallic molecules to form 2D coordination polymers [Cd3(Bbdc)3(Bipy)2]3n · 4nMeCN · nH2O (IV) and [Cd2(Bdc)2(Phen)2]n · 2nDMF (V) (СIF files CCDC nos. 1938126 and 1937492, respectively). [ABSTRACT FROM AUTHOR]

Herein, syntheses, crystal structures, and photoluminescence properties of 24 new ammonia and alkali metal ATCN salts characterized via single-crystal X-ray diffraction are reported. Moreover, ten structure types of these salts have been described, three of which are predominant. Some ATCNs were obtained as two crystalline polymorphs. It was estimated that most ATCN powders exhibited yellow-green fluorescence (at 450–600 nm). For samples that possess fluorescence of low intensity in the solid state, several optical centers of emission exist. It was speculated that the obtained spectral features were due to anion-anion intermolecular interactions. ATCN being a new representative of stable tetracyanoallyl salts is a promising candidate for creation of various 1D, 2D, and 3D supramolecular structures and potential functional materials. [ABSTRACT FROM AUTHOR]