1941-27-1Relevant academic research and scientific papers
Ion exchange synthesis and thermal characteristics of some [N +4444] based ionic liquids
Bhatt, Vasishta D.,Gohil, Kuldip
, p. 23 - 29 (2013)
Eight salts, derived from tetrabutylammonium cation [N+ 4444] and inorganic anions like BF4-, NO 3-, NO2-, SCN-, BrO 3-, IO3-, PF6- and HCO3- were synthesized using the ion exchange method. These ionic liquids (ILs) were characterized using thermogravimetry, differential scanning calorimetry and infrared spectroscopy. Thermophysical properties such as density, volume expansion, heat of fusion, heat of solid-solid transitions, specific heat capacity and thermal energy storage capacity were determined. The total of heat of solid-solid transitions observed below the melting points exceeded the heat of fusion in some cases. The thermal conductivity of the samples was determined both in solid and liquid phases. High values of thermal energy storage capacity and handsome liquid phase thermal conductivities made many of the ionic liquids under investigation were recommended as Thermal Energy Storage Devices (TESDs) as well as heat transfer fluids.
Tetraalkylammonium Salts of Platinum Nitrato Complexes: Isolation, Structure, and Relevance to the Preparation of PtOx/CeO2 Catalysts for Lowerature CO Oxidation
Vasilchenko, Danila,Topchiyan, Polina,Berdyugin, Semen,Filatov, Evgeny,Tkachev, Sergey,Baidina, Iraida,Komarov, Vladislav,Slavinskaya, Elena,Stadnichenko, Andrey,Gerasimov, Evgeny
, p. 6075 - 6087 (2019/04/25)
A series of tetraalkylammonium salts with anionic platinum nitrato complexes (Me4N)2[Pt2(μ-OH)2(NO3)8] (1), (Et4N)2[Pt2(μ-OH)2(NO3)8] (2), (n-Pr4N)2[Pt2(μ-OH)2(NO3)8] (3b), (n-Pr4N)2[Pt(NO3)6] (3a), and (n-Bu4N)2[Pt(NO3)6] (4) were isolated from nitric acid solutions of [Pt(H2O)2(OH)4] in high yield. The structures of salts 2, 3a, 3b, and 4, prepared for the first time, were characterized by X-ray diffraction. The sorption of [Pt(NO3)6]2- and [Pt2(μ-OH)2(NO3)8]2- complexes onto the ceria surface from acetone solutions of salts 4 and 1 was examined. The dimeric anion was shown to quickly and irreversibly chemisorb onto the CeO2 carrier, selectively transforming into Pt(II) centers after thermal treatment, becoming active in the lowerature CO oxidation reaction (T50% = 110 °C at a space velocity of 240 000 h-1). By contrast, the homoleptic complex [Pt(NO3)6]2- did not interact with the ceria, which may be attributed to the substitutional inertness of the [Pt(NO3)6]2- anion. We believe that the strategy based on the sorption of polynuclear platinum nitrato complexes is an effective route to prepare ionic platinum species uniformly distributed on an oxide carrier for various catalytic applications.
Silver (I) activated quaternization of tertiary amines by alkyl iodides: Overall analysis coupling homogeneous and heterogeneous processes
Santos, M. Soledade C.S.,Barbosa, Ester F.G.
experimental part, p. 106 - 113 (2012/04/17)
Kinetic data for the silver (I) activated homogeneous and heterogeneous quaternization of tributylamine by alkyl iodides in toluene is presented. Silver iodide was used as a solid catalyst. Solution and surface parameters were obtained applying the multistep kinetic model, previously proposed by Santos and Barbosa. A scrutiny of the derived quantities evidences competing structural and electronic effects. The solution reaction is dominated by structural factors while electronic effects govern the surface process. An overall analysis considering data from triethylamine systems, earlier investigated, allowed the establishment of a parallelism between the homogeneous and heterogeneous processes. A molecular level study involving size, shape and orientation of the chemical species on the surface, lead to estimates of interfacial layer thicknesses. A combination of surface parameters superficial reacting monolayer thicknesses and, the parallelism between homogeneous and heterogeneous catalysis consented the evaluation of "volumetric surface rate constants" which are directly comparable with their solution counterparts.
Efficient method for varying the anions in quaternary onium halides
Jeon, Jong Yeob,Varghese, Jobi Kodiyan,Park, Ji Hae,Lee, Suck-Hyun,Lee, Bun Yeoul
experimental part, p. 3566 - 3569 (2012/08/14)
Quaternary onium salts of halides can be efficiently converted into the corresponding quaternary onium salts of various anions [NO3 -, BF4-, PF6-, CF 3SO3-, CH3SO3 -, ClO4-, p-CH3C6H 4SO3-, CF3CO2 -, 2,4-(NO2)2C6H3O -] by treating the onium halide with trimethyl phosphate under neat condition in the presence of an equivalent amount of conjugate acid of the desired anion.
A safe two-step process for manufacturing glycidyl nitrate from glycidol involving solid-liquid phase-transfer catalysis
Ochoa-Gomez, Jose R.,Blanco-Gomez, Juan J.
experimental part, p. 1454 - 1457 (2012/01/12)
A new and safer two-step process for manufacturing glycidyl nitrate from glycidol is reported. In the first step glycidyl tosylate is obtained by reacting glycidol with p-tosyl chloride in the presence of triethylamine according to any one of the well-known procedures for obtaining tosyl esters described in the literature. In the second step, glycidyl tosylate is reacted with NaNO3 in refluxing acetonitrile under solid-liquid phase-transfer catalysis conditions using tetrabutylammonium nitrate as catalyst. Acetonitrile and the phase-transfer catalyst were recycled 12 times without deactivation, yielding 99% pure glycidyl nitrate in a cumulative isolated yield of 81.5% with a catalyst turnover number of 85.7 mol substrate per mol phase-transfer catalyst. This procedure avoids the use of the dangerous reactants used in the current manufacturing processes of glycidyl nitrate and could be useful as a safe and general method for obtaining nitrate esters.
Interaction between methanol and the Cl-, Br-, I-, NO3-, ClO4-, BF4-, SO3CF3- and PF6- anions studied by FTIR spectroscopy
Kristiansson, Olof,Schuisky, Mikael
, p. 270 - 273 (2007/10/03)
The interaction between methanol and the Cl-, Br-, I-, NO3-, ClO4-, BF4-, SO3CF3- and PF6- anions in dilute dichloromethane solutions has been investigated. The OH stretching vibration was used to monitor the hydrogen bonds formed between the anions and the methanol molecules, providing a direct measure of the hydrogen-bond strength. Concentrations of free and anionbonded methanol molecules were measured and the equilibrium constants calculated. The wavenumber shift and the free energy of hydrogen-bond formation was found to be significantly correlated. For the anions studied it was found that the hydrogen-bond strength increases in the order: PF6- 4- 4- 3CF3- 3- - -. Acta Chemica Scandinavica 1997.
The reaction of ionic nitrites with liquid dinitrogen tetraoxide
Addison, C. Clifford,Arrowsmith, Stephen,Dove, Michael F. A.,Johnson, Brian F. G.,Logan, Norman,Wood, Simon A.
, p. 781 - 784 (2008/10/09)
The reaction of nitrites of Na+, Bun4N+ and Ni2+ with liquid dinitrogen tetraoxide and the factors affecting the rate and extent of the reaction have been studied. Oxidation occurs to the corresponding nitrate in a manner consistent only with the heterolytic dissociation of N2O4 into NO+ and NO3. The synthesis of anhydrous Ni(NO2)2 is described in detail.
