Boron Fluoride Complexes Research Articles

Planar chiral [2.2]paracyclophanyl-based boron fluoride complexes: synthesis, crystal structure and photophysical properties.

Planar chiral [2.2]paracyclophanyl-based boron fluoride complexes (3a-3d) were designed and facilely synthesized. The X-ray structure study, theoretical calculations and CD spectra reveal the intense emission and planar chiral structures of these complexes. In particular, 3a-3d show moderate quantum yields and large Stokes shifts both in solution and solid state. Furthermore, the blue-shifted mechanochromic properties of 3a and 3b were both investigated in the solid state. This work is the first study on planar chiral boron monofluoride complexes within the boron fluoride complex field.

Экспериментальное и теоретическое исследование спектроскопии биядерных борфторидных комплексов дипиррометенов

The spectroscopic characteristics of mono and binuclear boron fluoride complexes of dipyrromethenes in various solvents and solid-state polymer media (films) are investigated depending on the wavelength and intensity of the exciting radiation. Along with experimental studies, quantum-chemical calculations of the electronic structure and geometry of electronically excited molecules were carried out, an interpretation of the experimental data (absorption and emission bands) was given, and a connection between the absorption spectra and the structure of bis (dipyrromethenes) and their conformations was established. The analysis of the obtained results is carried out in comparison with the modern literature data. The possibilities of practical application of the studied compounds in the development of liquid and solid-state lasers and optical solvent polarity sensor are discussed.

The apoptotic, cytotoxic and genotoxic effect of novel binuclear boron-fluoride complex on endometrial cancer.

Endometrial cancer (EC) is one of the most common types of gynecologic cancer of the female genital tract; it considered being the fourth leading death factor among other types of cancer. Therefore, developing new anti-cancer agents are crucial for cancer treatment. Based on the potential of Schiff based complexes for the induction of apoptosis, Schiff base compounds, and their metal complexes displayed excellent anticancer properties. In this current study, antiproliferative activity of [L(BF2)2] as a novel binuclear boron-fluoride complex was examined to preliminary research in eight different cell lines, HELA, DU-145, PC3, DLD-1, ECC-1, PNT1-A, HT-29, and MCF-7, it was found to have a potent, suppressive effect on human endometrial adenocarcinoma cell line ECC-1. Based on this data, later investigated its apoptotic, cytotoxic, and genotoxic properties on human endometrial adenocarcinoma cell line ECC-1 in different concentrations. Apoptotic and cytotoxic tests such as single cell gel electrophoresis assay (comet assay), DNA fragmentation laddering, acridine orange test for DNA damage, and ELISA for apoptotic measurement was performed. We also gauged the oxidative status by evaluating total antioxidant status (TAS) and total oxidant status (TOS). Oxidative stress index (OSI) was calculated too. As a result [L(BF2)2] has been found to have a marvelous effect on ECC-1 cells, especially in damaging their DNA and cause a series of reactions lead to apoptosis. Taken together, it suggests that the [L(BF2)2] complex can induce the apoptotic pathway of endometrial cancer cells and is a possible candidate for future cancer treatment studies.

Photonics of coordination complexes of dipyrrins with p- and d-block elements for application in optical devices

In the present paper spectral–luminescent, lasing, photochemical, sensory, and photosensitized characteristics of a number of Zn(II) and B(III) coordination complexes of dipyrrins with different structures are investigated. The results show that alkyl-, phenyl-, and propargylamino-derivatives of dipyrrin core in these complexes have excellent luminescent characteristics and can be used as active media for tunable liquid and solid-state lasers. Zinc (Zn-dpm2) and boron fluoride complexes of dipyrrins (BODIPYs) with halogen atoms and aza-substitution in meso-position in their ligands do not exhibit effective fluorescence, but some of them have long-lived emission due to increased nonradiative intersystem processes in an excited state proceeding by the mechanism of heavy atom and the presence of low-lying nπ- and σπ-states of different natures and multiplicities. The reason for the short-wavelength shift of the Zn-dpm2 spectra compared to the corresponding BODIPY is studied using quantum-chemical calculation. For solid samples based on halogenated complexes, a dependence of the long-lived emission intensity on the oxygen concentration in the surrounding gas mixture is established that indicates the possibility of application of these complexes for the creation of optical oxygen sensors. Moreover, results of investigations of halogen-substituted tetraphenyl-aza-BODIPY complexes as photosensitizers of singlet oxygen production are presented. Such complexes are promising for creating media for generation of singlet oxygen, which is important for photodynamic therapy and oxidation catalysis. In addition, data on the stability of these compounds in different electronic states are presented.

Different Hemi-Salen/Salan Ligand Containing Binuclear Boron-Fluoride Complexes: Synthesis, Spectroscopy, Fluorescence Properties, and Catalysis

ABSTRACTA family of hemi-salen (L1H–L6H) and hemi-salan (L1aH–L2aH) ligands-based N,O-chelated binuclear boron-fluoride [Ln(BF2)2] (n = L1–L6 or L1a–L2a) complexes have been prepared and characterized by a variety of spectroscopic techniques (1H, 13C and 19F NMR, FT-IR, UV-Vis, LC-MS, and fluorescence spectra) and elemental analysis. All of the binuclear boron-fluoride complexes exhibit strong absorption bands due to S0→S1 transitions and strong fluorescence properties were observed at room temperature in the solution. The binuclear boron complexes containing two naphthyl groups are significantly red-shifted in comparison with the other binuclear boron-fluoride complexes. After the structures are characterized, these hemi-salen and salan ligand-based N, O-chelated binuclear boron-fluoride complexes were utilized to the transfer hydrogenation of the different acetophenone derivatives conversion to 1-phenylethanol derivatives as catalysts.

Experimental study of fluorite solubility in acidic solutions as a method for boron fluoride complexes studying

Fluorite solubility in HCl and HF solutions with varied concentrations of boric acid was studied at 81, 155, and 208°C and saturated vapor pressure. Our experimental results demonstrate that fluorite solubility increases with increasing B(OH)3 concentration, and this was interpreted as the formation of the BF3OH–complex (Ryss, 1956). The experimental data were used to determine, using the OptimA software, the free energies of formation of HF°(aq) and, which were then used to calculate the constants of the reactions HF = H+ + F– (1) and B(OH)3(aq) + 2H+ + 3 F– (2). The pK 1 values are 3.71 ± 0.013, 4.28 ± 0.015, and 4.89 ± 0.017 and pK 2 13.60 ± 0.02, 13.99 ± 0.02, and 14.95 ± 0.03 at saturated vapor pressure and 81, 155, and 208°C, respectively.

Photonics and application of dipyrrinates in the optical devices

In this paper spectral-luminescent, lasing, photochemical, and sensory characteristics of a number of Zn(II) and B(III) coordination complexes with dipyrrinates with different structures are presented. We have discussed relations of the structure of investigated compounds and formed solvates with their optical characteristics. The results showed that alkyl substituted dipyrrinates derivatives have excellent luminescent characteristics and demonstrated effective lasing upon excitation of Nd:YAG-laser. They can be used as active media for liquid tunable lasers. Zinc and boron fluoride complexes of dipyrrinates with heavy atoms in structure don't have fluorescence but have long-lived emission due to increased nonradiative intersystem processes in the excited state by the mechanism of a heavy atom. For solid samples based on halogenated complexes was found dependency of the long-lived emission intensity of the oxygen concentration in gas flow. The presence of line segment indicates the possibility of the use of these complexes as a basis for creation of optical sensors for oxygen. Moreover, results of a study of halogen-substituted aza-complexes under irradiation are presented. Such complexes are promising for the creating media for generation of singlet oxygen (1O2), which is important for photodynamic therapy in medicine and photocatalytic reactions in the industry.

New AIE-active pyrimidine-based boronfluoride complexes with high solid-state emission and reversible mechanochromism luminescence behavior.

A new family of pyrimidine-based BF2 complexes () with aggregation-induced emission (AIE) and mechanochromic luminescence properties were developed. These compounds exhibit intense fluorescence in their aggregation/solid-state resulting from their large Stokes shift and AIE. X-ray crystallographic analysis shows that the weak intermolecular interactions by fixing the molecular conformations of are responsible for the intense fluorescence in solid-state. In addition to their pronounced AIE behaviour, also exhibits a reversible chromic response to grinding, and a distinct red-shift of emission is observed. The high solid-state luminescence and grinding-stimuli response properties of these compounds make them potential candidates for smart materials.

Lasing characteristics of difluoroborates of 2,2′-dipyrromethene derivatives in solid matrices

The luminescence-spectral, lasing and photochemical characteristics of laser media based on boron fluoride complexes of dipyrromethenes, embedded into solid bulk matrices of polymethylmethacrylate and its modifications (obtained by adding polyhedral oligomeric silsesquioxane during polymerisation) and into polymer films, in which polyhedral silsesquioxane enters the composition of monomeric unit, have been investigated.

Optical characteristics of new luminophores based on boron-fluoride complexes of substituted dipyrromethenes

The physical-chemical (spectral-luminescence and lasing) characteristics of newly synthesized compounds (difluoroborides of dipyrromethenes) have been obtained as functions of their chemical structure, solvents (liquid and frozen solutions, solid-state matrices), excitation wavelength and intensity, and temperature (77–295K) of the solution. On the basis of an analysis of the results, the possibilities of applying the new compounds to construct various optical devices are discussed.

Spectral, luminescent, photochemical, and laser properties of a series of boron fluoride complexes of dipyrrolylmethenes in solutions

We have studied the spectroscopic and lasing characteristics of active media based on two synthesized boron fluoride complexes of alkyl-substituted dipyrrolylmethenes and the photostability of the complexes in comparison with complexes of this kind that were previously studied in the literature under identical excitation conditions. We have determined and analyzed conditions under which new compounds have either merits or drawbacks as compared to the known dye with respect to both lasing efficiency and resource characteristics.

Quantum-chemical study of interaction of dipyrrolylmethenes with boron trifluoride and other lewis acids

The geometric parameters and energies of the products of donor-acceptor interaction of dipyrrolylmethenes with BF3 and other inorganic Lewis acids were calculated by quantum-chemical methods. The bond nature and the energies of formation of the donor-acceptor complexes under consideration were analyzed. It was shown that the complexes with p-element fluorides are noticeably stabilized by hydrogen bonds involving the hydrogen atom of the NH group of dipyrrolylmethene and the nearest fluorine atom of a Lewis acid. Hydrogen bonding promotes further elimination of HF in the synthesis of boron fluoride complexes of dipyrrolylmethenes. The energy profile was calculated for the reaction of formation of the boron fluoride complex with dipyrrolylmethene through the intermediate donor-acceptor complex.

Ultrasensitive microchip sensor based on boron-containing polyfluorene nanofilms

A fluorene-based π-conjugated copolymer with on-chain dibenzoborole units was used in the development of a nanocoated gold interdigitated microelectrode array device which successfully detects fluoride in a broad range of concentrations (10 −11–10 −4 M) in aqueous solution, upon impedance spectroscopy measurements. A calibration curve obtained over this range of concentrations and a new analytical method based on impedance spectroscopy measurements in aqueous solution is proposed. The sensor nanofilm was produced by spin-coating and diagnosed via spectroscopic ellipsometry, AFM, and electrically conductivity techniques. Changes in the conductivity due to the boron–fluoride complex formation seem to be the major mechanism behind the dependence of impedimetric results on the fluoride concentration.

NMR Spectra of Guest–Host Complexes of Boron and Silicon Fluorides with Crown Ethers in Nonaqueous Solutions

19F, 11B, and 29Si NMR spectroscopy was used to examine the behavior of the guest–host complexes (BF3· H2O)2· 18-crown-6 · 2H2O, (BF3· H2O)2· DCH-6B, and (DCH-6A · H3O)SiF5in acetone (DCH-6B and DCH-6A are the cis-anti-cis- and cis-syn-cis-isomers of dicyclohexano-18-crown-6, respectively). It was shown that molecular boron fluoride complexes undergo partial solvolysis in acetone to yield BF3· acetone as the main product; the ionic pentafluorosilicate complex does not experience significant solvolysis transformations.

Synthesis of boron-containing complexes of 1-(2-hydroxyphenyl)-3-phenyl-2-propen-1-one

Condensation of o-hydroxyacetophenone with benzaldehyde in alcohol in the presence of a triple excess of a sodium hydroxide solution leads to 2'-hydroxychalcone sodium salt. The latter was heated with boron trifluoride etherate in toluene to a 2'-hydroxychalcone boron fluoride complex in which the boron atom is coordinated to the carbonyl oxygen atom. The same complex was obtained by boiling of the o-hydroxyacetophenone boron fluoride complex with benzaldehyde in acetic anhydride.

ChemInform Abstract: Reaction of 1‐Alkyl‐2‐aryl‐3‐(2‐methyl‐2,3‐epoxypropionyl)aziridines with Boron Trifluoride Etherate in Methanolic Solution.

AbstractDie Aziridinylketone (I) bilden mit Bortrifluoridetherat in Abhängigkeit von der Raumerfüllung der Substituenten des Aziridinstickstoffs und der cis‐ oder trans‐Ständigkeit der Substituenten am Azirid instickstoff die Bortrifluoridkomplexe (II) oder unter Öffnung des Aziridin‐ bzw. des Oxiranringes die Verbindungen (III)‐(V).

Reaction of 1-alkyl-2-aryl-3-(2-methyl-2,3-epoxypropionyl)aziridines with boron trifluoride etherate in methanol

The reaction of boron trifluoride etherate in methanol with trans-1-methyl(ethyl)-or cis-1-cyclohexyl-2-aryl-3-(2-methyl-2,3-epoxypropionyl)aziridines leads to the formation of the corresponding boron fluoride complexes on the nitrogen atom of the aziridine ring. Reaction with trans-1-cyclohexyl-2-phenyl-3-(2-methyl-2,3-epoxypropionyl)aziridines occurs with stereospecific opening of the aziridine ring to give diastereomeric 2-methyl-5-methoxy-5-phenyl-4-cyclohexylamino-1,2-epoxypen-tan-3-ones, as well as products from the opening of the epoxide and aziridine rings — tetrahydrofuranones and tetrahydropyranones.

Alkylation of phenol with polybutenes in the presence of benzenesulfonic acid

The purpose of this work is to test benzenesulfonic acid (BSA) as a catalyst in the alkylation of phenol with polyisobutylene (PIB). This material is used as a catalyst in the production of technical C/sub 5/-C/sub 12/ tert-alkylphenol. Finds that the optimal compromise between acceleration of the reaction and the alkylate viscosity increase that limits the reaction rate is achieved at a temperature of about 105 C and a BSA/PIB mole ratio of 0.15. Recommends BSA as an effective replacement for boron fluoride, boron fluoride complexes, and other highly corrosive catalysts used in the alkylation of phenol with polybutenes.

Boron Isotope Exchange between Boron Fluoride and Its Alkyl Halide Complexes. I. Relation between Equilibrium Constant of Isotopic Exchange Reaction, Stability, and Catalytic Activity of Boron Fluoride Complex

Boron Isotope Exchange between Boron Fluoride and Its Alkyl Halide Complexes. I. Relation between Equilibrium Constant of Isotopic Exchange Reaction, Stability, and Catalytic Activity of Boron Fluoride Complex

Effect of Hardener Composition On the Chemical Resistance of Epoxy Resins

Abstract One of the factors influencing the chemical resistance of epoxy resin is the hardener used in their curing. To demonstrate this, three chemically different types of hardeners (anhydride, amine, boron fluoride complex) were used to cure a conventional liquid epoxy resin. All systems were checked for changes in flexural strength after a six-month immersion period in various chemicals at room temperature. Media in which tests were made include sodium chloride, sodium bisulfite, sulfuric acid, hydrochloric acid, nitric acid, glacial acetic acid, caustic soda, sodium carbonate, ammonia solution, and four weak organic solvents. In addition, samples were also placed in water at room temperature as well as boiling water for a six-month immersion period. Diaminodiphenyl sulfone gave resins the best over-all chemical resistance. Weak solvents, such as hydrocarbons, alcohols or glycols, affected all systems only slightly. Anhydride - cured systems exhibited better resistance to diluted acids while amine-cur...