Staudinger – Reaktionen am Bornanylen(dimethylphosphino)methylimin. Phosphorylierung des dabei gebildeten Trimethylsilylphosphinimids mit Diorganochlorphosphinen: unerwartete Bildung von Verbindungen mit P=N–P–P-Einheiten

Staudinger Reactions with Bornanylene(dimethylphosphino)methylimine. Phosphorylation of the Trimethylsilylphosphine Imide formed with Diorganochlorophosphines: unexpected Formation of Compounds with P=N–P–P Units Phosphinimido derivatives of the chiral bornanylene(dimethylphosphino)methyl imine have been obtained from its reactions with trimethylsilyl-, phenyl- and 4-nitrobenzoyl azide. A single crystal X-ray structure determination has been conducted on the 4-nitro-benzoylphosphinimido derivative of bornanylene(dimethylphosphino)methyl imine. The compound was found to crystallize with two independent molecules in the chiral monoclinic space group P2₁. The trimethylsilylphosphinimido derivative of bornanylene(dimethylphosphino)methyl imine was allowed to react with diorgano-chlorophosphines, with unexpected formation of compounds with PP-bonded RR′₂P=N–P⁽⁺⁾R″₂–PR″₂ groups. The ³¹P-NMR spectra of two representative compounds are simulated and discussed.     

Extraction and separation of zirconium from hafnium by using nano-structured supramolecular solvent microextraction method

In the present study, a simple versatile extraction method based on supramolecular solvent microextraction followed by inductively coupled plasma atomic emission spectrometry was developed for the extraction, separation and determination of zirconium (Zr) from hafnium (Hf). Zr and Hf were complexed with bis(2,4,4-trimethylpentyl) phosphinic acid, to obtain hydrophobic complex, and extracted into supramolecular solvent phase. The effective parameters on the supramolecular solvent microextraction efficiency were studied and optimized by using two different optimization methods: one variable at a time and central composite design. Under the optimum conditions, the linear range of 0.3–200.0 and 2.0–200.0 µg L^?1, detection limits (S/N = 3) of 0.1 and 0.6 µg L^?1, and precisions (n = 5) of 3.2–4.9% and 3.0–5.1% were obtained for Zr and Hf, respectively. Finally, the proposed method has been successfully applied for the extraction and separation of these cations in zirconium ore sample.     

Synthesis of new dyes containing double tetrazole groups for sensitization of TiO<Subscript>2</Subscript> nanoparticles in dye-sensitized solar cells

Di(1H-tetrazol-5-yl)methane is employed as a new electron acceptor group in the synthesis of two metal-free organic dyes containing triphenylamine donor group. Dye-sensitized nanocrystalline TiO₂ solar cell (DSSC) applying these novel dyes is constructed for consideration of their photovoltaic properties. The electronic properties of the dyes are also considered with the aid of theoretical calculations. The DSSC constructed from 4-(2,2-di(1H-tetrazol-5-yl)vinyl)-N,N-diphenylaniline (T1) shows a short-circuit photocurrent density of 13.38 mA cm^?2, an open circuit voltage of 578 mV, and a fill factor of 0.54, with a resulted solar energy-to-electricity conversion efficiency of 4.18% under simulated 1 sun irradiation (100 mW cm^?2). This result reveals that the dye with the di(1H-tetrazol-5-yl)methane anchoring group injects more electrons to the conduction band of TiO₂ in comparison with its analogs with single tetrazole ring in their anchoring group. It is found that in spite of a red-shift of the absorption spectrum resulted from the lengthening of the molecule, the dye with two di(1H-tetrazol-5-yl)methane groups gives lower performance than the dye with a single electron acceptor.     

Cu1.5PMo12O40 as an efficient, mild and heterogeneous catalyst for the condensation of indole with carbonyl compounds

Bis(indoyl)methanes have been synthesized in excellent yields in the presence of catalytic amount of Cu_1.5PMo₁₂O₄₀ in molten tetraethylammonium chloride as an ionic liquid. The catalyst is recovered and recycled.     

Encapsulation of 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione into the silica gel matrix for capturing uranium(VI) ion species

Journal of Radioanalytical and Nuclear Chemistry - The thenoyl-trifluoro-acetone (tta: 4,4,4-Trifluoro-1-(2-Thienyl)-1,3-butanedione) has been successfully encapsulated into the silica gel matrix...     

Glycerin and [Iron(III)(salen)]Cl as an efficient catalytic medium for multicomponent reactions

In this investigation, glycerol and [Fe(III)(salen)]Cl as a green catalyst system were used in multicomponent reactions for the synthesis of bis(indolyl)methanes, 3,4-dihydropyrimidinones, and 1,4-dihydropyridines, respectively. Excellent product yields and short reaction times were achieved.     

Solid State S-Methylation of Thiols and O-Methylation of Phenols and Naphthols with Dimethyl Sulfate Under Microwave Irradiation

Abstract

Mild and efficient S-methylation of thiols and o-methylation of phenols and naphthols occurs with dimethyl sulfate (DMS) supported on basic alumina under microwave irradiation in solventless system.     

Pd-poly(N-vinyl-2-pyrrolidone)/KIT-6 nanocomposite: Preparation,structural study,and catalytic activity

The Pd-poly(N-vinyl-2-pyrrolidone)/KIT-6 nanocomposite was prepared by an in situ polymerization method and used as an efficient heterogeneous catalyst for C–C bond formation through the Heck coupling reaction of aryl iodides, bromides and chlorides with styrene. The physical and chemical properties of the catalyst were characterized by XRD, BET, FT-IR, TGA, UV-Vis and TEM techniques. The reactions were performed in methanol-water as solvent and the products were obtained in high yield and purity after a simple work-up. The stability of the nanocomposite catalyst was excellent and could be reused 8 times without much loss of activity in the Heck coupling reaction.     

Functionalization of the periphery of calix[4]resorcinarenes with P(III)-containing substituents via hydroxy,trimethylsiloxy, and ethoxy-tethered trimethylsiloxy intermediates

Unlike C-undecylcalix[4]resorcinarene, C-methylcalix[4]resorcinarene 1 reacted with chlorodifluorophosphine in the absence of an auxiliary base to give the unstable octakis(difluorophosphite)-substituted derivative 2. The existence of two conformational isomers of 2 in solution was observed by ¹⁹F and ³¹P NMR spectroscopy. Attempts to react the octakis(trimethylsilyl)calix[4]resorcinarene 3 and its tetrabromo derivative 4 with phosphorus trichloride and chlorodifluorophosphine were unsuccessful. The ethoxy-tethered C-methyl-octakis(trimeth-ylsilyl)calix[4]resorcinarene 5 was allowed to react with 2-chloro-1,3,5-trimethyl-1,3,5-triaza-2σ³λ³-phosphorin-4,6-dione and chlorodifluorophosphine. By substitution of all trimethylsilyl groups, the octakis(phosphorus(III))-substituted compounds 6 and 7 were formed. As for 2, dynamic behavior in solution was observed for 6 and 7, arising from the equilibrium between different conformational isomers. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:553–558, 1998     

Microwave‐Assisted Catalyst Free Three Component Synthesis of Mono and Bis Spiro Pyrazolopyridines in Solvent Free Reaction

Multicomponent synthesis of mono and bis‐spiro pyrazolopyridines from isatin derivatives, indanedione, and 3‐methyl‐5‐aminopyrazole under microwave irradiation in the absence of any catalyst or solvent with high yield and short reaction time is reported.