Diethyl Ether Solution Research Articles

Effects of Coordinating a Hemilabile Ligand to 14e Cp*M(NO) Scaffolds (M = Mo, W)

This article describes the differing chemical properties imparted by the two ligands, hemilabile 2-[(diisopropylphosphino)methyl]-3-methylpyridine (iPr2PN) and the related 1,2-bis(dimethylphosphino)ethane (dmpe), when attached to the 14e Cp*M(NO) scaffolds (Cp* = η5-C5Me5; M = W, Mo). For instance, the treatment of [Cp*W(NO)Cl2]2 with 2 or 1 equiv of dmpe in C6H6 affords excellent yields of [Cp*W(NO)(κ2-dmpe)Cl]Cl (1) or [Cp*W(NO)Cl2]2[μ-dmpe] (2). In contrast, the treatment of [Cp*W(NO)Cl2]2 with 1 equiv of iPr2PN in C6H6 does not produce the complex analogous to 1 but rather affords orange [Cp*W(NO)(κ2-P-N-iPr2PN)Cl][Cp*W(NO)Cl3] (3) in 90% yield. Furthermore, subsequent reduction of 1 or 2 with 2 or 4 equiv of Cp2Co in tetrahydrofuran (THF), respectively, results in the production of orange Cp*W(NO)(κ2-dmpe) (4) in good yields. However, a similar treatment of 3 with 1 equiv of Cp2Co in THF does not result in the production of Cp*W(NO)(κ2-P,N-iPr2PN), the analogue of 4, but rather generates a 1:1 mixture of the novel complexes Cp*W(NO)(H)(κ1-P-iPr2PN)Cl (5) and Cp*W(NO)(κ2-P,N-iPr2PCH-2-(3-Me-C5H3N))Cl (6), which are separable by crystallization from pentane and diethyl ether solutions, respectively. The divergent reactivity imparted by the dmpe and iPr2PN proligands is a unique demonstration of the unusual properties of a mixed-donor ligand. In the case of molybdenum, the reaction of [Cp*Mo(NO)Cl2]2 with 2 equiv of iPr2PN in C6H6 first forms Cp*Mo(NO)(κ1-P-iPr2PN)Cl2, which then converts to [Cp*Mo(NO)(κ2-P,N-iPr2PN)Cl][Cp*Mo(NO)Cl3], the analogue of 3. Reduction of the Cp*Mo(NO)(κ1-P-iPr2PN)Cl2 intermediate complex with 2 equiv of Cp2Co affords dark-green Cp*Mo(NO)(κ2-P,N-iPr2PN) (7). All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them have been established by single-crystal X-ray crystallographic analyses.

Antimicrobial activities of semi polar-nonpolar and polar secondary metabolites of sponge Dysidea pallescens from Hengam Island, Persian Gulf

Sponges are the simplest multicellular animals that lack defense mechanisms and rely on chemical defense that have been used by mankind to develop antimicrobial drugs against diseases. The present study was designed to demonstrate the antibacterial and antifungal activities of marine sponge Dysidea pallescens semipolar and nonpolar extracts. In this study, D. pallescens were collected from Hengam Island in the Persian Gulf. The extracts were produced by Bligh and Dyer method. Broth Dilution Methods were used to check the antimicrobial activity of D. pallescens extracts against Escherichia coli (ATCC 15224), Pseudomonas aeruginosa (ATCC 25619), Staphylococcus aureus aureus (ATCC 1764), Bacillus subtilis pizizenii (ATCC 6633), Candida albicans (ATCC10231) and Aspergillus fumigates (PTCC5009). The results showed diethyl ether extract has bactericidal activity against S. aureus aureus (MBC=10mg/mL) and B. subtilis spizizenii (MBC=20mg/mL). D. pallescens diethyl ether extract showed a very weak antifungal activity but methanol extract showed fungicidal activity against A. fumigates (MFC=5mg/mL) and C. albicans (MFC=1.5 mg/mL). Therefore nonpolar-semipolar secondary metabolites of D. pallescens solutions in diethyl ether have shown significant antibacterial activity and polar- secondary metabolites solutions in methanol have shown significant antifungal activity.

Color change of an iodinated poly(vinyl alcohol) film by physical deformation

ABSTRACTThe color change of an iodinated poly(vinyl alcohol) (PVA) film caused by physical deformation was investigated in this study. The color of a PVA film soaked in an aqueous potassium iodide (KI)/I2 solution was light yellow, but it turned light blue when the film was physically deformed. The ultraviolet–visible absorption spectrum of the iodinated PVA film extended uniaxially in air was measured at various extension levels. Without deformation, the film showed UV absorption bands at 210, 290, and 360 nm. However, under deformation, the film showed new visible light absorption bands at 440 and 620 nm. From the UV–vis absorption spectra of several iodinated solutions, we found that the absorption wavelength of iodine was affected by the cohesive energy of the solvents. The KI/I2 diethyl ether solution showed an absorption band at 460 nm, and this provided a clue to understanding the color change of the PVA–iodine complexes caused by physical deformation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43036.

New Lanthanide Alkynylamidinates and Diiminophosphinates

This contribution reports the synthesis and structural characterization of several new lithium and lanthanide alkynylamidinate complexes. Treatment of PhC≡CLi with N,N′-diorganocarbodiimides, R–N=C=N–R (R = iPr, Cy (cyclohexyl)), in THF or diethyl ether solution afforded the lithium-propiolamidinates Li[Ph–C≡C–C(NCy)2] S (1: R = iPr, S = THF; 2: R = Cy, S = THF; 3: R = Cy, S = Et2O). Single-crystal X-ray diffraction studies of 1 and 2 showed the presence of typical ladder-type dimeric structures in the solid state. Reactions of anhydrous LnCl3 (Ln = Ce, Nd, Sm or Ho) with 2 in a 1:3 molar ratio in THF afforded a series of new homoleptic lanthanide tris(propiolamidinate) complexes, [Ph–C≡C–C(NCy)2]3Ln (4: Ln = Ce; 5: Ln = Nd; 6: Ln = Sm; 7: Ln = Ho). The products were isolated in moderate to high yields (61%–89%) as brightly colored, crystalline solids. The chloro-functional neodymium(III) bis(cyclopropylethynylamidinate) complex [{c-C3H5–C≡C–C(NiPr)2}2Ln(µ-Cl)(THF)]2 (8) was prepared from NdCl3 and two equiv. of Li[c-C3H5–C≡C–C(NiPr)2] in THF and structurally characterized. A new monomeric Ce(III)-diiminophosphinate complex, [Ph2P(NSiMe3)2]2Ce(µ-Cl)2Li(THF)2 (9), has also been synthesized in a similar manner from CeCl3 and two equiv. of Li[Ph2P(NSiMe3)2]. Structurally, this complex resembles the well-known “ate” complexes (C5Me5)2Ln(µ-Cl)2Li(THF)2. Attempts to oxidize compound 9 using trityl chloride or phenyliodine(III) dichloride did not lead to an isolable cerium(IV) species.

Reaction of Dilithio Reagents with PhSiH3: Formation of Siloles and 3-Silacyclopentenes.

The reaction chemistry between 1,4-dilithio-1,3-butadienes (dilithio reagents for short) and PhSiH3 has been investigated. Direct substitution of two hydride ions from PhSiH3 with the dilithio reagents led to multisubstituted siloles (silacyclopentadienes) in diethyl ether solution, with the concomitant generation of LiH. When THF was used as the solvent, the reaction between PhSiH3 and 1,4-bis(silyl) dilithio reagents afforded cis-3-silacyclopentenes stereoselectively. Experimental results demonstrated that reactive LiH was generated in situ in the reaction system. Formal syn addition of LiH to silacyclopentadiene intermediates would afford silacyclopentenes, most likely via pentavalent organosilicates.

A Simple and Efficient Preparation of High-Purity Hydrogen Trioxide (HOOOH).

A simple and efficient method allows the synthesis of solutions of high-purity hydrogen trioxide (HOOOH), released in the low-temperature methytrioxorhenium(VII) (MTO)-catalyzed transformation of the ozonized polystyrene-supported dimethylphenylsilane. High-purity hydrogen trioxide solutions in diethyl ether, separated from the polymer and free of any reactants and by-products, can be stored at -20 °C for weeks. By removing the solvent in vacuo, HOOOH could be isolated in highly pure form or transferred to other solvents, thus significantly extending the research perspectives of HOOOH for novel applications.

A Simple and Efficient Preparation of High‐Purity Hydrogen Trioxide (HOOOH)

AbstractA simple and efficient method allows the synthesis of solutions of high‐purity hydrogen trioxide (HOOOH), released in the low‐temperature methytrioxorhenium(VII) (MTO)‐catalyzed transformation of the ozonized polystyrene‐supported dimethylphenylsilane. High‐purity hydrogen trioxide solutions in diethyl ether, separated from the polymer and free of any reactants and by‐products, can be stored at −20 °C for weeks. By removing the solvent in vacuo, HOOOH could be isolated in highly pure form or transferred to other solvents, thus significantly extending the research perspectives of HOOOH for novel applications.

Adducts of ruthenium(IV) thiolates with substituted pyridines. Syntheses and structures of [Ru(SMes)4(R-py)] (R = 4-Et, 4-tBu, and 3,5-Me2) and [{Ru(SMes)4}2(μ-4,4’-bipy)] (Mes = 2,4,6-trimethylphenyl)

Treatment of the trigonal-bipyramidal ruthenium(IV)–thiolate complex, [Ru(SMes)4(MeCN)] (Mes = 2,4,6-trimethylphenyl, 1), with an anhydrous diethyl ether solution of hydrogen chloride in THF afforded [Ru(SMes)3Cl(MeCN)] (2), whereas interaction of 1 with [Et4N]Cl in THF gave an anionic ruthenium(IV)–thiolate complex, [Et4N][Ru(SMes)4Cl] (3). Reaction of 1 with one equivalent of substituted pyridines in dichloromethane gave the corresponding pyridine-coordinated ruthenium(IV)–thiolate complexes, [Ru(SMes)4(R-py)] (R = 4-Et, 4; 4-tBu, 5; 3,5-Me2, 6), while reaction of 1 with 0.5 equiv. of 4,4’-bipy (4,4’-bipy = 4,4’-bipyridine) in dichloromethane resulted in the formation of a dinuclear ruthenium(IV)–thiolate complex [{Ru(SMes)4}2(μ-4,4’-bipy)] (7). Complexes 2–7 have been spectroscopically characterized along with their electrochemical analyses, and their structures have been determined by single-crystal X-ray diffraction.

Sensitization of Xanthophylls-Chlorophyllin Mixtures on Titania Solar Cells

Co-sensitization of natural dyes on TiO 2 for dye-sensitized solar cell (DSSC) was proposed between chlorophyllin (C) and xanthophylls (X at various volume ratios of C/X. Chlorophyllin is chlorophyll derivative providing -COOH groups essential for binding to TiO 2 . The chlorophyll was extracted from dried spinach ( amaranthus viridis ) leaves in a mixture of methanol-acetone (70%:30%). Chlorophyll extract dye was obtained after partition of the crude extracts in diethyl ether solution. Then, it was hydrolyzed under alkaline condition to get chlorophyllin. Xanthophyll was extracted from fresh petal of chrysanthemum ( chrysanthemum indicum ) flowers. Blending of chlorophyllin and xanthophyll was carried out at various volume ratios of C to X (1:0, 5:1, 1:1, 1:5, 0:1). Titania solar cells were constructed in sandwich system of conducting glass-titania/dyes as the photoanode and conducting glass-platinum as the photocathode. Electrolyte solution containing I - /I 3 - was inserted between the electrodes by capillary action. All dye extracts and blending solutions were analyzed by UV-Vis spectrophotometer. It is shown that the absorption spectra of blending dyes are complimentary in the visible region resulted in a panchromatic response of the dyes. From the cyclic voltammogram of the dyes and blended-dyes, it is found that the energy level of xanthophyll is the lowest. The I-V test at 100 mw/cm 2 irradiation confirmed that the energy conversion efficiency ( h ) of the blended dyes of xanthophyll and chlorophyllin-sensitized solar cell resulted in significant improvement than those of the single dye. Beneficially, the mixed dyes can be adsorbed from solution blend using single dipping step.

Six-coordinate NbF5 and TaF5 complexes with tertiary mono-phosphine and -arsine ligands

The syntheses of the extremely moisture sensitive, neutral [MF5(PR3)] (M = Nb or Ta, R = Me or Ph) and [MF5(AsR′3)] (R′ = Me or Et), from reaction of the ligands with MF5 in anhydrous diethyl ether solution are reported. Attempts to isolate analogous complexes with SbMe3 were unsuccessful. The products are characterised by IR and mutinuclear NMR (1H, 19F{1H}, 31P{1H} and 93Nb) spectroscopic studies. These are the first examples of six-coordinate phosphine or arsine complexes of the Group 5 pentafluorides. The ionic species, trans-[MF4(PMe3)2][MF6], are obtained from diethyl ether solution of [MF5(PMe3)] containing excess PMe3 and similarly characterised. All complexes are extremely moisture and oxygen sensitive and decomposed by many common solvents. In solution in toluene the [MF5(PMe3)] (M = Nb or Ta) and [MF5(AsR′3)] are extensively dissociated at ambient temperatures. The [MF5(PPh3)] dissolve in CH2Cl2 with decomposition to form [PPh3H][MF6]. Attempts to isolate phosphine complexes of NbOF3 were unsuccessful.

Electropolymerization and Electrocatalytic Activity of Poly(4-thienylacetyl-amino-2,2,6,6-tetramethylpiperidinyl-1-yloxy)/(2,2′-bithiophene) Copolymer

Monomer 4-thienylacetyl-amino-2,2,6,6-tetramethylpiperidinyl-1-yloxy (TATEMPO) has been synthesized. The homopolymer poly(2,2′-bithiophene) (PBTh), and poly(4-thienylacetyl-amino-2,2,6,6-tetramethylpiperidinyl-1-yloxy)/(2,2′-bithiophene) (PTATEMPO/BTh) copolymer are successfully prepared on platinum in boron trifluoride diethyl etherate solution by electrochemical polymerization. They are characterized by scanning electron microscopy. The electrochemical copolymerization of TATEMPO and BTh may be accomplished through a radical reaction process. The electrocatalytic oxidation performance of benzyl alcohol in 0.1 M NaClO4-CH3CN solution in the presence of 2,6-lutidine on PTATEMPO/BTh electrode is investigated by cyclic voltammetry and in situ FTIR. Benzyl alcohol is selectively converted to benzaldehyde on the PTATEMPO/BTh electrode, and the overoxidation to benzoic acid is suppressed.

Enantioselective analysis of tolvaptan in rat and dog sera by high-performance liquid chromatography and application to pharmacokinetic study.

Tolvaptan is a competitive vasopressin V2-receptor antagonist that inhibits water reabsorption in the renal collecting ducts. A selective high-performance liquid chromatography method for determining tolvaptan enantiomers in rat and dog sera was developed and validated. Benzyl salicylate was used as an internal standard. Sample preparation involved liquid-liquid extraction with an n-hexane:diethyl ether (1:1, v/v) solution, followed by solid-phase extraction using a silica-gel cartridge. Chromatographic separation was performed on a cellulose-based chiral stationary phase in the reversed phase mode. The analytes were monitored with UV detection. The calibration curve showed linearity over the concentration range from 0.025 to 2.5 μg/mL for each analyte. Precision as the percentage coefficient of variation did not exceed 14.8%, and accuracy as relative error was within ±14.6% for the analytes. The validated method was successfully applied to evaluate the pharmacokinetics of oral tolvaptan enantiomers in rats and dogs, indicating gender and species differences in the systemic exposure to tolvaptan enantiomers.

Selective Acylation of Phenols in Boron Trifluoride Diethyl Etherate Solution and the Mechanistic Implication

Selective Acylation of Phenols in Boron Trifluoride Diethyl Etherate Solution and the Mechanistic Implication

Facile Fabrication of PEDOT:PSS/Polythiophenes Bilayered Nanofilms on Pure Organic Electrodes and Their Thermoelectric Performance

A pure organic PEDOT:PSS nanofilm was used as a working electrode for the first time to electrodeposit polymer films of polythiophene (PTh) and its derivatives in a boron trifluoride diethyl ether (BFEE) solution, fabricating a novel generation of bilayered nanofilms. Cyclic voltammetry (CV) demonstrated good electrochemical stability of the as-formed films. Structures and surface morphologies were systematically investigated by the characterizations of cross-section SEM, FT-IR, UV-vis, SEM, and AFM. The resulting films revealed stable and enhanced thermoelectric (TE) performances. The electrical conductivity values of PEDOT:PSS/PTh, PEDOT:PSS/P3MeT, and PEDOT:PSS/P3HT nanofilms were determined to be 123.9, 136.5, and 200.5 S cm(-1), respectively. The power factor reached up to be a maximum value of 5.79 μW m(-1) k(-2). Thus, this technique offers a facile approach to a class of bilayered nanofilms, and it may provide a general strategy for fabricating a new generation of conducting polymers for more practical applications.

Effects of a proton scavenger on the thermoelectric performance of free-standing polythiophene and its derivative films

In this study, thermoelectric (TE) performance of free-standing polythiophene (PTh), poly(3-methylthiophene) (P3MeT), and poly(3-octylthiophene) (P3OT) films electrosynthesized in a freshly distilled boron trifluoride diethyl etherate (BFEE) solution containing 2,6-di-tert-butylpyridine (DTBP) as a proton scavenger, was systematically investigated. Free-standing PTh, P3MeT, and P3OT films obtained from the BFEE system displayed electrical conductivities of 46.1, 98.5, and 9.4Scm−1, respectively. When DTBP was added, the electrical conductivities improved to 65.9, 147.3, and 15.9Scm−1. The Seebeck coefficients of the films with improved electrical conductivities were 36.7, 13.7, and 24.9μVK−1, respectively; these values were slightly lower than the original values of 42.5, 14.9, and 26.8μVK−1 for the polymer films electrochemically synthesized in BFEE without DTBP. As a result, the power factor of polymer films increased from 8.33, 2.19, and 0.68μWm−1K−2 to 8.88, 2.76, and 0.99μWm−1K−2 with DTBP introduced, and the maximum figure of merit (ZT) maintained around 10−2 by estimate.

Microanalytical method for studying paintings by use of fluorescence spectroscopy combined with principal component analysis

The study of several different naturally aged films of organic painting materials, is described. Materials studied include drying oils (walnut, poppy seed and linseed oil) resin-based paint varnishes (the triterpenoid dammar and the diterpenoids sandarac and turpentine) and protein-based binding media (egg yolk and casein). A not expensive methodology for a rapid identification of binding media and varnishes, that applies principal component analysis (PCA) to Excitation Emission (EE) fluorescence spectra, is proposed. PCA was performed on a data matrix where the rows represent studied materials and columns the variables; the variables include the fluorescence intensities associated to different points (coordinates are λex/λem) in EE spectra. Results suggest that the new method can be used to classify micro samples on the basis of their fluorescence spectra, because the placement of the different materials in the score plot reflects their origin and chemical composition. The method described has been used for the analysis of materials of an oil painting on canvas, representing a mother with her child and on three mural paints. A small area of painting has been sampled with a cotton swab soaked in acetone, and subsequently the same area was sampled with a cotton swab and diethyl ether. The results of the application of the proposed microanalytical method to oil painting show that the author has used the linseed oil as binding medium and subsequently the surface of painting has been treated with a varnish containing the sandarac as resin. Given the great diversity and complexity of the products used for the realization of a painting, Fourier Transform Infrared (FTIR) spectra of acetone and diethyl ether solutions have been performed, confirming the results of PCA applied to EE spectra.

Synthesis and Spectral Electrochemical Properties of a Symmetrical Tin-Bridged [3.3]Ferrocenophane

The symmetrical bisferrocene 1,1,14,14-tetra-n-butyl-2,2,13,13,15,15,26,26-octamethyl-1,2,13,14,15,26-hexastanna[3.3]ferrocenophane ([(η5-C5H4)Fe(η5-C5H4SnMe2Sn(n-Bu)2SnMe2)]2, 8) was synthesized in good yield (82%) from the reductive coupling reaction of 1,1′-bis(dimethylstannyl)ferrocene, 6, with one equivalent of di-n-butylbis(diethylamino) stannane, 7a, at 0 °C in diethyl ether solution. Compound 8 is stable to ambient light but decomposes in the presence of moisture or chlorinated solvents. The title compound 8 was characterized by NMR (1H, 13C, 117Sn, 119Sn) spectroscopy, HRMS, and elemental analysis. A statistical model to account for the 117Sn/119Sn coupling patterns, observed in both the 117Sn and 119Sn NMR spectra, was undertaken and is a good fit to experimental data. Investigations by UV–vis spectroscopy display a visible d–d transition at λmax at 455 nm (e = 74 L mol–1 cm–1), while cyclic voltammetry reveals two reversible oxidation events at 0.01 and 0.23 V (relative to the ferrocene/ferroce...

Synthesis and reactivity of ruthenium(II) complex with an ortho-metalated bis(diphenylthiophosphoryl)imide

Reaction of RuCl(CHCHPh)(CO)(PPh3)2 with K[N(Ph2PS)2] afforded a σ-aryl complex, Ru(CO)[η1(C),η2(S,S′)-N{(C6H4)PhPS}(Ph2PS)](PPh3)2 (1), with an ortho-metalated bis(diphenyl-thiophosphoryl)imide ligand in a quantitative yield. Treatment of 1 with an excess hydrogen chloride in diethyl ether solution led to isolation of a binuclear complex {RuCl(CO)(PPh3)}2(μ-Cl)(μ-η2(S),η2(S′)-N(Ph2PS)2) (2) which was also obtained from the direct reaction of RuCl(CHCHPh)(CO)(PPh3)2 with HN(Ph2PS)2 in dichloromethane. The structures of complexes 1 and 2 have been established by X-ray crystallography.

Surface Initiation from Adsorbed Polymer Clusters: A Rapid Route to Superhydrophobic Coatings

We introduce the use of a hydroborated polyisoprene (PIP) macroinitiator for the rapid surface-initiated growth of superhydrophobic polymethylene (PM) films. Rinsing of a dip-coated PIP film on a methyl-terminated surface atop silicon or gold substrates results in robustly bound, isolated PIP clusters. After hydroboration of the internal olefins, these clusters result in extremely rapid growth of polymethylene coatings upon exposure to a diazomethane solution in diethyl ether at -17 °C. The resulting PM films achieve 6 μm thicknesses within 20 min of polymerization and become superhydrophobic with advancing and receding water contact angles of 166° and 156°, respectively, within 1 min. The PM films grown from these PIP clusters exhibit 3× greater propagation velocities, 30% lower termination rates, and more highly textured morphologies than PM films grown from hydroborated monolayers.

Titanium Complexes of Tridentate Aminebiphenolate Ligands Containing Distinct N-Alkyls: Profound N-Substituent Effect on Ring-Opening Polymerization Catalysis

The synthesis, structural characterization, and reactivity studies of titanium complexes supported by tridentate amine biphenolate ligands of the type [RN(CH(2)-2-O-3,5-C(6)H(2)(tBu)(2))(2)](2-) {[R-ONO](2-); R = tBu (1a), iPr (1b), nPr (1c)} are described. Alcoholysis of Ti(OiPr)(4) with H(2)[1a-1c] in diethyl ether solutions at 25 °C generates quantitatively the corresponding [R-ONO]Ti(OiPr)(2) (2a-2c) as a yellow crystalline solid. X-ray diffraction studies of 2b and 2c showed them to be five-coordinate, trigonal-bipyramidal species. Ring-opening polymerization of ε-caprolactone (ε-CL) catalyzed by 2b and 2c proved to be living, as evidenced by the narrow molecular weight distributions of the derived polymers and the linear dependence of number-averaged molecular weights on the monomer-to-catalyst ratios or polymerization time. Kinetic studies revealed that the polymerization rates are first-order in the concentration of ε-CL and first-order in that of 2b and 2c. The propagation rate of 2c is ca. 15 times faster than that of 2b, highlighting a profound substituent effect of primary versus secondary N-alkyls. In sharp contrast, reactions employing catalytic 2a produce either low-molecular-weight oligomers or polymers characteristic of somewhat wider molecular weight distributions, depending on the polymerization temperatures.