- Reactions of tetrathiotungstate and tetrathiomolybdate with substituted haloalkanes
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Reactions of [PPh4]2[WS4] in CH3CN with excess n-hexylbromide, 1,4-dichlorobutane, 2-(bromomethyl)tetrahydro- 2H-pyran) (bmthp), and 2-(bromoethyl)-1,3-dioxane (bedo) followed by extraction with THF afforded a series of alkylthiolatotrithiotungstate complexes, [PPh4][(RS)WS3] (1: R = n-hexyl; 2: R = ClCH2CH2CH2CH2; 3: R = mthp; 4: R = edo), and the analogous reactions of [PPh4]2[MoS4] in CH3CN-THF with excess bmthp and bedo also generated [PPh4][(RS)MoS3] (5: R = mthp; 6: R = edo), albeit in low yields. Treatment of [PPh4]2[WS4] in CH3CN with excess (S)-(+)-3-bromo-2-methyl-1-propanol turned out to give a trinuclear, [PPh4]2[W3S8((S)-(+)-OCH 2CH(Me)CH2Br)2] (7). Compounds 1-7 were characterized spectroscopically and the crystal structures of 2-7 were determined by X-ray analysis. All the mononuclear complexes 2-6 assume tetrahedral structures, being coordinated by one thiolate sulfur and three terminal sulfido ligands, and no additional coordination was observed by the O-donor portions of mthp or edo. The structure of 7 consists of a linear W3 spine and two (S)-(+)-OCH2CH(Me)CH2Br ligands are coordinated at the central W atom.
- Lang, Jian-Ping,Kawaguchi, Hiroyuki,Tatsumi, Kazuyuki
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- Nitryl cyanide, NCNO2
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The elusive nitryl cyanide, NCNO2, has been synthesized and characterized. It was prepared in good yield, isolated by fractional condensation, characterized by NMR and vibrational spectroscopy, and studied by theoretical calculations. Nitryl cyanide holds promise as a high energy density material (HEDM) and might also prove useful as a HEDM building block. The simplicity and inherent stability of nitryl cyanide, together with the known multitude of nitriles in interstellar space, suggest that the compound might also be a potential candidate for observations in atmospheric and interstellar chemistry. Small yet feisty: The elusive small molecule nitryl cyanide, NCNO2, has been synthesized and characterized. It has a high kinetic stability, is extremely energetic, has a perfect oxygen balance with respect to combustion to CO2 and N2, and has potential as a building block for other energetic materials. Nitryl cyanide might also be of interest for atmospheric and interstellar chemistry. Isp=specific impulse.
- Rahm, Martin,Belanger-Chabot, Guillaume,Haiges, Ralf,Christe, Karl O.
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- Solute-Solvent Interactions with Metal Chelate Electrolytes. Part III. Salting in of Tris(acetylacetonato)cobalt(III) and Benzene by Aromatic and Aliphatic Ions
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Salting effects of the metal chelate electrolytes, Br2, Br2, Br3, Br3, and Br3 (where phen = 1,10-phenanthroline, bpy = 2,2'-bipyridyl, en = ethylenediamine, and ph 1,2-propanediamine), as well as the tetraalkylammoniumbromides (Bu4NBr and Pr4NBr), tetraphenylphosphonium bromide (Ph4PBr), sodium tetraphenylborate (NaBPh4), and sodium halides on the solubility in benzene and tris (acetylacetonato) cobalt(III) in water at 15, 20, 25, and 35 deg C were studied, and the transfer free energies of the nonelectrolytes from pure water to the electrolyte solutions were obtained.Co(acac)3 is strongly salted in by Br2, NaBPh4, and Ph4PBr with large positive transfer enthalpies and entropies, weakly salted in by Bu4NBr and Pr4NBr with much less positive enthalpies and entropies and is salted out by the other electrolytes.The differences between salting effects of aromatic and aliphatic ions are discussed using the transfer enthalpy-entropy relation.
- Iwamoto, Etsuro,Tanaka, Yoshie,Kimura, Hirofumi,Yamamoto, Yuroku
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- Effect of the Linking Group on the Thermoelectric Properties of Poly(Schiff Base)s and Their Metallopolymers
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As polymer-based thermoelectric (TE) materials possess attractive features such as light weight, flexibility, low toxicity and ease of processibility, an increasing number of conducting polymers and their composites with high TE performances have been developed in recent years. Up to date, however, the research focusing on the structure-performance relationship remains rare. In this paper, two series of poly(Schiff base)s with either C=C or C≡C linker and their metallopolymers were synthesized and doped with single-walled carbon nanotubes to evaluate how the linking groups affected the TE properties of the resulting composites. Apart from the effect exerted by the morphology, experimental results suggested that the linkers played a key role in determining the band gaps, preferred molecular conformation and extent of conjugation of the polymers, which became key factors that influenced the TE properties of the resulting materials. Additionally, upon coordination with transition metal ions, the TE properties could be tuned readily.
- Li, Jiahua,Wang, Zitong,Sun, Zelin,Xu, Linli,Wong, Wai-Yeung
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supporting information
p. 1911 - 1917
(2021/06/21)
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- Continuous synthesis method of tetraphenylphosphinophenylphenol salt
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The method uses triphenylphosphine, halogenated benzene and phenol as raw materials, and the sodium hydroxide solution is an acid binding agent. The preparation method comprises the following steps: triphenylphosphine. The halogenated benzene and the reaction solvent are mixed in a continuous flow reactor to prepare a tetraphenylhalogenated phosphine solution, a prepared tetraphenylhalogenated phosphine solution, phenol and sodium hydroxide solution with a concentration 32% are mixed in a continuous flow reactor to prepare a tetraphenylphosphine phenol salt. Compared with a conventional stirred tank reactor, the reactor used in the preparation method is smaller in size, simple to operate, continuous in reaction, high in yield, environmentally friendly, stable in pH value during reaction, relatively mild in reaction conditions and stable in prepared tetraphenylphenol salt.
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Paragraph 0022; 0029-0034; 0037-0038; 0041-0044
(2021/09/01)
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- NOVEL PHASE CHANGE MATERIAL AND METHODS OF USE
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The invention relates to a phase change material including one or more salts of low vapour pressure and low flammability and an energy storage system, method and device comprising the phase change material.
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- Palladium-catalyzed synthesis of functionalized tetraarylphosphonium salts
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(Chemical Equation Presented) An efficient method to synthesize functionalized tetraarylphosphonium salts is described. This palladium-catalyzed coupling reaction between aryl iodides, bromides, or triflates and triphenylphosphine generates phosphonium salts in high yields. The coupling is compatible with a variety of functional groups such as alcohols, ketones, aldehydes, phenols, and amides.
- Marcoux, David,Charette, Andre B.
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p. 590 - 593
(2008/09/17)
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- Phenylation of Organic Derivatives of Mercury, Silicon, Tin, and Bismuth with Pentaphenylantimony and Pentaphenylphosphorus
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Pentaphenylantimony and -phosphorus react with arylmercury chlorides in toluene at room temperature to give diaryl derivatives of mercury in yields of up to 95%. The reactions of pentaphenylantimony and -phosphorus with silicon and tin halides involve ary
- Sharutin,Sharutina,Senchurin,Egorova,Ivanenko,Petrov
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p. 202 - 203
(2007/10/03)
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- Thermal stability, decomposition paths, and Ph/Ph exchange reactions of [(Ph3P)2Pd(Ph)X] (X = I, Br, Cl, F, and HF2)
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Complexes of the type [(Ph3P)2Pd(Ph)X], where X = I (1), Br (2), Cl (3), F (4), and HF2 (5), possess different thermal stability and reactivity toward the Pd-Ph/P-Ph exchange reactions. While 1 decomposed (16 h) in toluene at 110 °C to [Ph4P]I, Pd metal, and Ph3P, complexes 2 and 3 exhibited no sign of decomposition under these conditions. Kinetic studies of the aryl-aryl exchange reactions of [(Ph3P)2Pd(C6D5)X] in benzene-de demonstrated that the rate of exchange decreases in the order 1 > 2 > 3, the observed rate constant ratio, kI:kBr:kCl, in benzene at 75 °C being ca. 100:4:1 for 1-d5, 2-d5, and 3-d5. The exchange was facilitated by a decrease in the concentration of the complex, polar media, and a Lewis acid, e.g., Et2O·BF3. Unlike [Bu4N]PF6, which speeded up the exchange reaction of 2-d5, [Bu4N]-Br inhibited it due to the formation of anionic four-coordinate [(Ph3P)Pd(C6D5)Br2]-. The latter and its iodo analogue were generated in dichloromethane and benzene upon addition of [Bu4N]X or PPN Cl to [(Ph3P)2Pd2(Ph)2(μ-X) 2] (X = I, Br, or Cl) and characterized in solution by 1H and 31P NMR spectral data. The mechanism of the aryl-aryl exchange reactions of [(Ph3P)2Pd(C6D5)X] in noncoordinating solvents of low polarity may not require Pd-X ionization but rather involves phosphine dissociation, the ease of which decreases in the order X = I > Br > Cl, as suggested by crystallographic data. Two mechanisms govern the thermal reactions of [(Ph3P)2Pd(Ph)F], 4. One of them is similar to the aryl-aryl exchange and decomposition path for 1-3, involving a tight ion pair intermediate, [Ph4P][(Ph3P)PdF], within which two processes were shown to occur. At 75 °C, the C-P oxidative addition restores the original neutral complex (4). At 90 °C, reversible fluoride transfer from Pd to the phosphonium cation resulted in the formation of covalent [Ph4PF] and [(Ph3P)Pd], which was trapped by PhI to produce [(Ph3P)2Pd2(Ph)2(μ-I) 2]. The other decomposition path of 4 leads to the formation of [(Ph3P)3Pd], Pd, Ph2 , Ph3PF2, and Ph2P-PPh2 as main products. Unlike the aryl-aryl exchange, this decomposition reaction is not inhibited by free phosphine. The formation of biphenyl was shown to occur due to PdPh/PPh coupling on the metal center. Mechanisms accounting for the formation of these products are proposed and discussed. The facile (4 h at 75 °C) thermal decomposition of [(Ph3P)2Pd(Ph)(FHF)] (5) in benzene resulted in the clean formation of PhH, Ph3PF2, Pd metal, and [(Ph3P)3Pd].
- Grushin, Vladimir V.
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p. 1888 - 1900
(2008/10/08)
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- Preparation and reactions of 2,3,4,6-tetrafluoropyridine and its derivatives
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A reliable route to 2,3,4,6-tetrafluoropyridine has been established starting from the readily available 3,5-dichlorotrifluoropyridine by halogen exchange under controlled conditions to give 3-chlorotetrafluoropyridine and its subsequent hydrodechlorination using hydrogen over palladium on alumina at 250-270°C. The formation and reactions of the 3-lithio derivative have been studied with the aim of obtaining 3,4-disubstituted trifluoropyridines. Routes to such materials have been developed and their conversion to deazapurine derivatives as potential substrates for the generation of anti-sense nucleosides are reported.
- Coe, Paul L.,Rees, Anthony J.
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- Coordination Catalysis in Organic Electrosynthesis. Electrochemical Phosphorylation of Organic Halides in the Presence of Samarium Dichloride
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The feasibility was demonstrated for arylation (or alkylation) of white phosphorus under the action of electrochemically generated Sm(II).
- Budnikova,Yakhvarov,Kargin
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p. 566 - 569
(2007/10/03)
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- HORNER-WITTIG REACTIONS USING DIBENZOPHOSPHOLE OXIDES: STEREOCHEMICALLY CONTROLLED REDUCTION OF KETONES
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Reduction of ketones having an α-dibenzophosphole-5-oxide group with NaBH4, L-Selectride, or Superhydride gives threo Horner-Wittig intermediates and hence E-alkenes, while NaBH4/CeCl3 gives erythro intermediates and hence Z-alkenes.
- Elliott, Jason,Warren, Stuart
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p. 645 - 648
(2007/10/02)
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- Evaluation of Phosphinic Acid Derivatives as Reagents For Amine Protection in Peptide Synthesis
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The results of a kinetic study of the acid-catalysed methanolysis of a series of N-(2-phenyl-ethyl)phosphinamides incorporating selected substituents on phosphorus have been evaluated in order to define the optimum reagent and conditions for amine protection of α-amino acids during peptide synthesis.
- Ramage, Robert,Atrash, Butrus,Hopton, David,Parrot, Maxwell J.
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p. 1217 - 1226
(2007/10/02)
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- Synthesis of Substituted Dibenzophospholes. Part 1.
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Approaches to the synthesis of 4,6-diaryl-5-hydroxydibenzophosphole 5-oxides are described. 3,5,7-Trihydroxydibenzophosphole 5-oxide and several of its O-substituted derivarives were made either from 5-hydroxydibenzophosphole 5-oxide (convenient preparation described) by dinitration, reduction and tetrazotization or from 2,2'-dibromo-4,4'-dimethoxybiphenyl via lithiation and reaction with dichloromorpholinophosphine with subsequent oxidation. 3,5,7-Trihydroxydibenzophosphole 5-oxide could be selectively blocked in the 2,8-positions by methyl groups generated via a Mannich reaction.The bis-2-iodobenzyl ethers of 3,7-dihydroxy-5-methoxydibenzophosphole 5-oxide and of its 2,8-dimethyl derivative were cyclized by photolysis to form 4,6-diaryl derivatives in poor yield.
- Cornforth, John,Cornforth, R. H.,Gray, Robin T.
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p. 2289 - 2298
(2007/10/02)
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- ARYLATION CATALYTIQUE D'ORGANOPHOSPHORES. PRODUITS DE L'ARYLATION, CATALYSEE PAR LES SELS DE NICKEL (II), DE COMPOSES DU PHOSPHORE TRICOORDINE
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Analysis of the products from the nickel (II) bromide catalysed arylation of tricoordinated phosphorus compounds R2P-Z (Z = H, Cl, SR,NR2) pointed out that this arylation always takes place on phosphorus resulting at first in formation of pseudophosphonium salts.Only the aminophosphonium salts are stable under reaction conditions; the other salts undergo several transformations which can be brought together in a general reactivity scheme to account for all the side products.On regard to other heteroatoms these results point out a particular ability of phosphorus to be arylated under nickel (II) catalysis.The reaction with secondary phosphines can be applied to synthetise diarylphosphonium salts.
- Cristau, Henri-Jean,Chene, Alain,Christol, Henri
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p. 283 - 296
(2007/10/02)
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- Synthesis of Some Dicyclohexyltin(IV) and Cyclohexylphenyltin(IV) Anionic Complexes
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Tetraalkylammonium, R4N (R = CH3, C2H5 or C4H9) and tetraphenyl-phosphonium, -arsonium and -stibonium salts of dicyclohexyl, dicyclohexylphenyl and cyclohexyldiphenyltin(IV)-halo or halo-pseudohalo anions nPh3-nSnX2 and CynPh3-nSnXY, where Cy = cyclo-C6H11, X = Cl, Br, I, N3 or NCS; Y = Br, I or NCS and n = 1 or 2> have been synthesised and characterized on the basis of melting points, elemental analyses and infrared spectra.Conductance measurements and values of Van't Hoff factor (i) suggest the presence of complex anions in the solution.Attempts to obtain complexes of the type and have been unsuccessful.
- Bhattacharya, S. N.,Raj, Prem,Awasthi, V. K.
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p. 592 - 594
(2007/10/02)
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