189114-61-2Relevant articles and documents
TASK SPECIFIC CHELATING IONIC LIQUIDS FOR REMOVAL OF METAL IONS FROM AQUEOUS SOLUTION VIA LIQUID/LIQUID EXTRACTION AND ELECTROCHEMISTRY
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Paragraph 0227; 0232; 0238, (2020/02/15)
Disclosed are methods of extracting metal ions using ionic liquids (ILs), IL complexes, and mixtures comprising an IL and a metal-chelating group. Also disclosed are IL complexes, and mixtures comprising an IL and a metal-chelating group.
Gold(I) Complexes Stabilized by Nine- and Ten-Membered N-Heterocyclic Carbene Ligands
Cervantes-Reyes, Alejandro,Rominger, Frank,Rudolph, Matthias,Hashmi, A. Stephen K.
supporting information, p. 11745 - 11757 (2019/08/20)
Nine- and ten-membered N-heterocyclic carbene (NHC) ligands have been developed and for the first time their gold(I) complexes were synthesized. The protonated NHC pro-ligands 2 a–h were prepared by the reaction of readily available N,N′-diarylformamidines with bis-electrophilic building blocks, followed by anion exchange. In situ deprotonation of the tetrafluoroborates 2 a–h with tBuOK in the presence of AuCl(SMe2) provided fast access to NHC-gold(I) complexes 3–10. These new NHC-gold(I) complexes show very good catalytic activity in a cycloisomerization reaction (0.1 mol % catalyst loading, up to 100 % conversion) and their solid-state structures reveal high steric hindrance around the metal atom (%Vbur up to 53.0) which is caused by their expanded-ring architecture.
Regioselective Asymmetric Allylic Alkylation Reaction of α -Cyanoacetates Catalyzed by a Heterobimetallic Platina-/Palladacycle
Weiss, Marcel,Holz, Julia,Peters, Ren
, p. 210 - 227 (2016/01/20)
Allylic substitution reactions provide a valuable tool for the functionalization of CH acidic pronucleophiles. Often, control over the stereocenter generated at the nucleophilic reactant is still a challenge. The majority of studies that address this issue employ metal complexes with a low metal oxidation state (e.g. Pd0) to form allyl complexes through oxidative addition. In this article we describe the use of heterobimetallic PtII/PdII complexes, which probably activate the olefinic substrates through an SN2′ pathway. The reaction of α-cyanoacetates delivers linear allylation products with exclusive regioselectivity and high E/Z-selectivity for the new C=C double bond. Although the enantioselectivities attained are moderate, they are significantly higher than with related mono-PdII or -PtII catalysts or the corresponding bis-PdII complex, which indicates cooperation of the different metals. Control experiments suggest simultaneous activation of both reaction partners.
Synergistic gold(I)/trimethylsilyl catalysis: Efficient alkynylation of N,O-acetals and related pro-electrophiles
Michalska, Malina,Songis, Olivier,Taillier, Catherine,Bew, Sean P.,Dalla, Vincent
supporting information, p. 2040 - 2050 (2014/07/07)
We report a unique mechanism-guided reaction that enhances and expands the chemical space that readily generated gold(I) acetylides currently operate in. Our strategy exploits the propensity of gold(I) carbophilic catalysts with specific counteranions (LAuX - X=triflate or triflimidate) to efficiently activate and desilylate trimethylsilylalkynes, thereby mediating the in situ formation of equal and catalytic quantities of a silyl Lewis acid (TMSX) of tunable strength and a nucleophilic gold(I) acetylide. This unprecedented manifold opens avenues for developing synergistic silyl-gold(I)-catalyzed alkynylation strategies of diverse pro-electrophiles which were heretofore unattainable, the proof of concept being principally exemplified herein with the first catalytic alkynylation of N,O-acetals. The reaction proceeds at low catalyst loading, employs mild reaction conditions, is easily scalable, and affords propargylic lactam products in good to excellent yields. Furthermore, it is fully amenable to a diverse array of structure and function substrates, and also expands to other pro-electrophiles beyond N,O-acetals. Control experiments have been carried out that strongly support our dual reaction mechanism proposal which, furthermore, itself outlines an inextricable link between the strength of the ancillary silyl Lewis acid (TMSOTf versus TMSNTf2) and the coordinating ability of the gold counter anion employed. This underlying feature of our system underscores its significant potential and flexibility, which indeed manifests with the demonstration that by carefully selecting the gold counter ion, it is possible to manipulate the strength of the ancillary silyl Lewis acid so that it can be tailored to the ionizing ability of a particular pro-electrophile.
Copper(I) and silver(I) bis(trifluoromethanesulfonyl)imide and their interaction with an arene, diverse olefins, and an NTf2 --based ionic liquid
Stricker, Marion,Oelkers, Benjamin,Rosenau, Carl Philipp,Sundermeyer, J?rg
, p. 1042 - 1057 (2013/02/23)
The chemistry of coinage metal bis(triflyl)imides of technological interest, CuNTf2 and AgNTf2, their synthesis and complexes with excess of comparatively weakly coordinating NTf2- as well as with ether, olefins
Propylene and propane solubility in imidazolium, pyridinium, and tetralkylammonium based ionic liquids containing a silver salt
Fallanza, Marcos,Ortiz, Alfredo,Gorri, Daniel,Ortiz, Inmaculada
, p. 2147 - 2153 (2013/09/02)
The gas solubility of propane and propylene in seven ionic liquids, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4), 1-hexyl-3-methylimidazolium tetrafluoroborate (HMImBF4), 1-octyl-3-methylimidazolium tetrafluoroborate (OMImBF4), 3-methylimidazolium nitrate (BMImNO3), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonylimide) (BMImTf2N), methyltrioctylammonium bis(trifluoromethylsulfonylimide) (MOOONTf2N), and butyltrimethylammonium bis(trifluoromethylsulfonylimide) (BMMMN Tf 2N), is reported. The equilibrium isotherms of both pure gases were measured in the pure ionic liquids and in presence of a silver salt containing the same anion of the ionic liquid in a range of concentration of (0 to 0.77) mol·kgIL-1 at temperatures between (288 and 308) K and pressures ranging from (0 to 700) kPa. Henry's law constant values for physical solubility as well as the characteristic parameters for chemical solubility such as chemical equilibrium constants and enthalpies of the chemical reactions between silver cations and propylene are reported. Based upon the experimental results, ionic liquids based on imidazolium cations with less and shorter alkyl substituents improve the selective separation of propylene from these mixtures. Regarding to the structure of the anion it was gathered that ionic liquids with the BF4- anion, combined with the AgBF4 silver salt, provided the best results in terms of olefin capacity and selectivity. In this article we provide valuable data that evidence that the separation of propane/propylene gas mixtures by reactive absorption could represent an efficient alternative to the traditional separation process based on cryogenic distillation and serve for the new process design.
Development of a Ag/Ag+ micro-reference electrode for electrochemical measurements in ionic liquids
Huber, Benedikt,Roling, Bernhard
, p. 6569 - 6572 (2011/11/07)
We report on a novel miniaturized Ag/Ag+ reference electrode (RE) design suitable for electrochemical measurements in room temperature ionic liquids (RTILs). The electrode is based on capillaries with an outer diameter of 365 μm and contains a 10 mmol/l solution of a silver salt in a RTIL. The silver salt bears the same type of anion as the RTIL. While potential shifts of several hundred millivolts have been observed for common platinum or silver pseudo-reference electrodes, our Ag/Ag+ micro electrode provides a stable and reliable reference potential over a period of more than two weeks, if protected from light and stored in a nitrogen atmosphere. Due to the small dimensions of the RE, it can be placed close to the working electrode (WE) and it is well-suited for application in electrochemical micro cells as well as for potential-controlled in situ AFM, STM or electrochemical impedance measurements. The electrode characteristics were determined by voltammetric measurements on ferrocene and cobaltocenium hexafluorophosphate dissolved in a RTIL. The highest expected contamination of the sample with Ag+ ions was calculated and found to be below 4 ppm.
Ionic liquid silver salt complexes for propene/propane separation
Agel, Friederike,Pitsch, Fee,Krull, Florian Felix,Schulz, Peter,Wessling, Matthias,Melin, Thomas,Wasserscheid, Peter
, p. 725 - 731 (2014/03/21)
Properties of the room-temperature liquid complex salt [Ag(propene) x][Tf2N] have been studied to probe its suitability for acting as active separation layer in immobilised liquid membrane (ILM) concepts for propane/propene separation. The pressure/temperature range of complex formation has been determined and the thermal properties of Ag[Tf2N] and [Ag(propene)x][Tf2N] have been studied by DSC (differential scanning calorimetry) and TGA (thermogravimetric analysis) measurements. Pressure dependent measurements of solubility and diffusivity showed that the observed membrane selectivity is dominated by the solubility selectivity. The self-diffusion coefficient of propene is always smaller compared to propane as propene is temporarily bound to the silver ion in the [Ag(propene)x][Tf2N] ionic liquid.
EQCM measurement of Ag (I) /Ag reaction in an amide-type room-temperature ionic liquid
Serizawa, Nobuyuki,Katayama, Yasushi,Miura, Takashi
, p. D503-D507 (2009/12/06)
Electrodeposition of silver was investigated using an impedance technique (separately excited, passive technique) electrochemical quartz crystal microbalance (EQCM) in a room-temperature ionic liquid. The mass changes during silver deposition and dissolut
Coordination chemistry of the bis(trifluoromethylsulfonyl)imide anion: Molecular interactions in room temperature ionic liquids
Williams, D. Bridget,Stoll, Michael E.,Scott, Brian L.,Costa, David A.,Oldham Jr., Warren J.
, p. 1438 - 1440 (2007/10/03)
Room temperature ionic liquids composed of bis(trifluoromethylsulfonyl) imide anions and 1,3-ethylmethylimidazolium (EMI) cations are shown to stabilize monomeric ligand deficient transition metal complexes via four distinct binding modes: monodentate nit
