- Et4N[NO3(SnClPh3)2(SnPh 3NO3)]: A trinuclear organostannate complex and related derivatives
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Four new di- and triorganonitrato stannate complexes and related derivatives have been synthesized and characterized by infrared and Moessbauer spectroscopy. The structure of Et4N[NO 3(SnClPh3)2(SnPh3NO3)](1) has been determined by single-crystal X-ray diffraction analysis. In the trinuclear organostannate complex, each Sn IV atom is five-coordinated and adopts a trigonal-bipyramidal trans -OXSnC3(X = O or Cl) geometry. The overall coordination environment of the SnIV atoms is trans-octahedral for 2 and 3 or cis-trigonal-bipyramidal for 4. In the related derivatives, the NO3- anions behave as monodentate ligands.
- Diop, Tidiane,Diop, Libasse,Michaud, Francois,Ardisson, Jose Domingos
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- Nucleophilic Opening of the Oxirane Ring with Tetraalkylammonium Salt Anions in the Presence of Proton Donors
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Abstract: The behavior of tetraethylammonium salts in nucleophilic opening of the oxirane ring of epichlorohydrin (ECH) in the system ECH–proton donor–Et4N+ X–, where proton donor is benzoic acid or 4-nitrophenol and X = PhCOO or NO3, was studied by the kinetic and spectrophotometric methods. The order of the reaction in tetraethylammonium salt, benzoic acid, and 4-nitrophenol was estimated as first, zero, and less than zero, respectively. The mechanism of nucleophilic opening of the oxirane ring of ECH was elucidated on the basis of monitoring of the accumulation of 4-nitrophenoxide ion in the system ECH–4-nitrophenol–Et4NX upon variation of the initial concentrations of both tetraethylammonium salt and proton donor (4-nitrophenol) itself. The anion X of the initial tetraethylammonium salt was found to be irreversibly consumed as a result of its attack on the oxirane ring with participation of the proton donor, which led to generation of tetraethylammo-nium 4-nitrophenoxide, and the latter catalyzed the subsequent formation of the final product. An increase in the concentration of 4-nitrophenol was accompanied by reduction of both the rate of formation of 4-nitrophenoxide ion and the overall reaction rate, which corresponds to a mechanism involving nucleophilic attack of the anion X on the oxirane ring that is not activated by the proton donor.
- Bakhtin, S. G.,Bespalko, Yu. N.,Shved, E. N.,Sinelnikova, M. A.
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p. 524 - 531
(2021/06/02)
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- Tetraalkylammonium Salts of Platinum Nitrato Complexes: Isolation, Structure, and Relevance to the Preparation of PtOx/CeO2 Catalysts for Lowerature CO Oxidation
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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.
- Vasilchenko, Danila,Topchiyan, Polina,Berdyugin, Semen,Filatov, Evgeny,Tkachev, Sergey,Baidina, Iraida,Komarov, Vladislav,Slavinskaya, Elena,Stadnichenko, Andrey,Gerasimov, Evgeny
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p. 6075 - 6087
(2019/04/25)
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- Efficient method for varying the anions in quaternary onium halides
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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.
- Jeon, Jong Yeob,Varghese, Jobi Kodiyan,Park, Ji Hae,Lee, Suck-Hyun,Lee, Bun Yeoul
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experimental part
p. 3566 - 3569
(2012/08/14)
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- Silver (I) activated quaternization of tertiary amines by alkyl iodides: Overall analysis coupling homogeneous and heterogeneous processes
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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.
- Santos, M. Soledade C.S.,Barbosa, Ester F.G.
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experimental part
p. 106 - 113
(2012/04/17)
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- Thermochemistry of Polyhalides. Part 5. Standard Enthalpies of Formation of Tetramethylammonium and Tetraethylammonium Tetrachloroiodates
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The standard enthalpies of formation of methyl- and ethyl-ammonium tetrachloroiodates NRnH4-nICl4 (R = Me or Et, 0 /= n /= 4), have been determined by a solution reaction method using aqueous silver nitrate.Lattice energies have been estimated from these data and trends in these and in the standard enthalpies of formation as a function of alkyl substitution are discussed.
- Derakhshan, B. Mokhtar,Finch, Arthur,Gates, Peter N.,Stephens, Michael
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p. 997 - 1000
(2007/10/02)
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