- Electrochemical studies of the nickel catecholate complexes for detection of sulphur dioxide gas
-
Nickel catecholate complexes, bis(diphenylphosphino)ethanenickelcatecholate [(dppe)NiO2C6H34-R1] R1 = CH3 (1), C(CH3)3 (2), H (3) and F (4)] were studied using CV and
- Tembwe, Inonge,Ngila, J. Catherine,Kgarebe, Boitumelo,Darkwa, James,Iwuoha, Emmanuel
-
-
Read Online
- External oxidant-free cross-coupling: Electrochemically induced aromatic C-H phosphonation of azoles with dialkyl-: H -phosphonates under silver catalysis
-
A convenient external oxidant-free method of phosphorylation of azole derivatives (benzo-1,3-azoles, 3-methylindole, 4-methyl-2-acetylthiazole) by using dialkyl-H-phosphonates through the catalytic oxidation of their mixture under electrochemical mild conditions (room temperature, normal pressure) in the presence of silver salts or oxide (1%) is proposed. This method allows us to obtain the desired azole dialkylphosphonates with good yield (up to 75%). The transformations of silver and phosphorus precursors and intermediates using cyclic voltammetry, ESR, and NMR spectroscopy were investigated, and a radical process mechanism was proposed. It has been found that AgP(O)(OEt)2 is oxidized earlier than other components of the reaction mixture with the elimination of a radical. The ESR spectrum of this radical's adduct was obtained in the presence of the radical trap PBN. Ag2+ is out of the catalytic cycle.
- Yurko,Gryaznova,Kholin,Khrizanforova,Budnikova
-
-
Read Online
- Controlling Metal-to-Oxygen Ratios via M=O Bond Cleavage in Polyoxovanadate Alkoxide Clusters
-
In this manuscript, we further investigate the use of Lindqvist polyoxovanadate alkoxide (POV-alkoxide) clusters as homogeneous molecular models of reducible metal oxides (RMO), focusing on the structural and electronic consequences of forming one or two oxygen-deficient sites. We demonstrate the reactivity of a neutral POV-alkoxide cluster, [V6O7(OCH3)12]0, with a reductant, revealing routes for controlling metal-to-oxygen ratios in self-assembled polynuclear ensembles through post-synthetic modification. The outlook of this science is bolstered by the fact that, in both cases, O-atom removal reveals reduced V ions at the surface of the cluster. Extending our entry into small-molecule activation mediated by surface defect sites, we report the reactivity of mono- and divacant clusters with a model substrate, tert-butyl isocyanide, demonstrating the electronic consequences of small-molecule coordination to reduced ions in RMO materials.
- Petel, Brittney E.,Fertig, Alex A.,Maiola, Michela L.,Brennessel, William W.,Matson, Ellen M.
-
-
Read Online
- Halogen-free ionic liquids: Effect of chelated orthoborate anion structure on their lubrication properties
-
In transportation vehicles, a large portion of energy is consumed to overcome friction in the engine and associated components. An efficient lubricant system has a direct impact on saving energy and material loss by reducing the friction, wear, and corrosion. Herein, halogen-free chelated orthoborate ionic liquids were designed, synthesized and then evaluated as potential lubricant additives. The effect of the orthoborate anion structure on the thermal stability, corrosion, friction, and wear properties of ionic liquids were studied. The copper strip tests revealed the non-corrosiveness of bis(mandalato)borate (BMdB), bis(salicylato)borate (BScB), and bis(malonato)borate (BMlB) anion constituted ionic liquids. Whereas, the bis(oxalato)borate (BOxB) anion, eventually developed micro-pits of corrosion owing to its lower stability and acidic nature of the decomposed product. These ionic liquids as additives to the synthetic lube base oil significantly reduced both friction and wear. The degree of friction and wear reduction was influenced by the structure of associated anions. BMdB and BScB anion constituted ionic liquids exhibited excellent thermal stability, friction-reduction, and antiwear properties, which are attributed to their compact and chemically stable structure driven by higher intermolecular interactions and rigidity of aromatic rings. The chemical analysis of tribo-interfaces suggested the formation of an ionic liquid composed tribochemical product and that enhanced the lubrication properties. Being halogen-free, these ionic liquids could be energy efficient and environmentally-friendly substitutes to the conventional friction-reducing and antiwear additives. This journal is
- Gusain, Rashi,Khatri, Om P.
-
-
Read Online
- Assessing the Electrocatalytic Properties of the (Cp*RhIII)2+-Polyoxometalate Derivative [H2PW11O39(RhIIICp*(OH2))]3- towards CO2 Reduction
-
Storage of electricity produced intermittently by renewable energy sources is a societal issue. Besides the use of batteries and supercapacitors, conversion of excess electricity into chemical energy is also actively investigated. The conversion of CO2 to fuel or fuel precursors is an option that requires the use of a catalyst to overcome the high activation energy barrier. Of molecular catalysts, metal complexes with polypyridyl ligands are well represented, among which the [Cp*Rh(bpy)Cl]+ and [M(bpy)(CO)3X] (M = Re, Mn) complexes. As redox non-innocent ligand, the bipyridine ligand is generally involved in the reduction mechanisms. It is thus tempting to replace it by other redox non-innocent ligands such as vacant polyoxometalates (POMs). We have thus prepared [α-H2PW11O39(RhIIICp*(OH2))]3- which is closely related to [Cp*RhIII(bpy)Cl]+ by substitution of the monovacant [PW11O39]7- Keggin-type POM for the bipyridine ligand. Its activity towards CO2 reduction has been assessed in acetonitrile in the presence of water. Compared to [Cp*Rh(bpy)Cl]+ that produces formate selectively over CO and H2, the POM derived catalyst favors proton reduction over CO2 reduction.
- Girardi, Marcelo,Platzer, Dominique,Griveau, Sophie,Bedioui, Fethi,Alves, Sandra,Proust, Anna,Blanchard, Sébastien
-
-
Read Online
- Transition-metal Complexes of Crown Ether Benzodithiolenes. Part 2. The Effects of Alkali-metal Cation Binding
-
The binding of Li(+), Na(+) and K(+) cations to the crown ether rings of a series of transition-metal complexes with crown ether benzodithiolene ligands has been monitored.Fast atom bombardment mass spectrometry and UV/VIS spectroscopy have been used to demonstrate the binding of the cations to the complexes, and cyclic voltammetric studies provide a quantitative measure of the perturbations which result upon cation binding.The results support the view that the electronic transitions arise primarily from sulfur-to-metal charge-transfer transitions, provide information concerning the dithiolate(2-) or dithioketonic form of the dithiolene ligand, and indicate whether a particular redox process is primarily metal- or ligand-based.Some selectivity within the series Li(+), Na(+) and K(+) is observed, with the benzo-15-crown-5 ring showing a preference for the first two and the benzo-18-crown-6 ring preferring K(+).Tris(crown ether benzodithiolene) complexes of molybdenum and tungsten show the most promise as sensors for alkali-metal cations.
- Lowe, Nigel D.,Garner, C. David
-
-
Read Online
- Stereoelectronic and Resonance Effects on the Rate of Ring Opening of N-Cyclopropyl-Based Single Electron Transfer Probes
-
N-Cyclopropyl-N-methylaniline (5) is a poor probe for single electron transfer (SET) because the corresponding radical cation undergoes cyclopropane ring opening with a rate constant of only 4.1 × 104 s-1, too slow to compete with other processes such as radical cation deprotonation. The sluggish rate of ring opening can be attributed to either (i) a resonance effect in which the spin and charge of the radical cation in the ring-closed form is delocalized into the phenyl ring, and/or (ii) the lowest energy conformation of the SET product (5a¢+) does not meet the stereoelectronic requirements for cyclopropane ring opening. To resolve this issue, a new series of N-cyclopropylanilines were designed to lock the cyclopropyl group into the required bisected conformation for ring opening. The results reveal that the rate constant for ring opening of radical cations derived from 1′-methyl-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-quinoline] (6) and 6′-chloro-1′-methyl-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-quinoline] (7) are 3.5 × 102 s-1 and 4.1 × 102 s-1, effectively ruling out the stereoelectronic argument. In contrast, the radical cation derived from 4-chloro-N-methyl-N-(2-phenylcyclopropyl)aniline (8) undergoes cyclopropane ring opening with a rate constant of 1.7 × 108 s-1, demonstrating that loss of the resonance energy associated with the ring-closed form of these N-cyclopropylanilines can be amply compensated by incorporation of a radical-stabilizing phenyl substituent on the cyclopropyl group. Product studies were performed, including a unique application of EC-ESI/MS (Electrochemistry/ElectroSpray Ionization Mass Spectrometry) in the presence of 18O2 and H218O to elucidate the mechanism of ring opening of 7a¢+ and trapping of the resulting distonic radical cation.
- Grimm, Michelle L.,Suleman, N. Kamrudin,Hancock, Amber N.,Spencer, Jared N.,Dudding, Travis,Rowshanpour, Rozhin,Castagnoli, Neal,Tanko, James M.
-
supporting information
p. 2640 - 2652
(2020/02/18)
-
- Lewis Acidity Scale of Diaryliodonium Ions toward Oxygen, Nitrogen, and Halogen Lewis Bases
-
Equilibrium constants for the associations of 17 diaryliodonium salts Ar2I+X- with 11 different Lewis bases (halide ions, carboxylates, p-nitrophenolate, amines, and tris(p-anisyl)phosphine) have been investigated by titrations followed by photometric or conductometric methods as well as by isothermal titration calorimetry (ITC) in acetonitrile at 20 °C. The resulting set of equilibrium constants KI covers 6 orders of magnitude and can be expressed by the linear free-energy relationship lg KI = sI LAI + LBI, which characterizes iodonium ions by the Lewis acidity parameter LAI, as well as the iodonium-specific affinities of Lewis bases by the Lewis basicity parameter LBI and the susceptibility sI. Least squares minimization with the definition LAI = 0 for Ph2I+ and sI = 1.00 for the benzoate ion provides Lewis acidities LAI for 17 iodonium ions and Lewis basicities LBI and sI for 10 Lewis bases. The lack of a general correlation between the Lewis basicities LBI (with respect to Ar2I+) and LB (with respect to Ar2CH+) indicates that different factors control the thermodynamics of Lewis adduct formation for iodonium ions and carbenium ions. Analysis of temperature-dependent equilibrium measurements as well as ITC experiments reveal a large entropic contribution to the observed Gibbs reaction energies for the Lewis adduct formations from iodonium ions and Lewis bases originating from solvation effects. The kinetics of the benzoate transfer from the bis(4-dimethylamino)-substituted benzhydryl benzoate Ar2CH-OBz to the phenyl(perfluorophenyl)iodonium ion was found to follow a first-order rate law. The first-order rate constant kobs was not affected by the concentration of Ph(C6F5)I+ indicating that the benzoate release from Ar2CH-OBz proceeds via an unassisted SN1-type mechanism followed by interception of the released benzoate ions by Ph(C6F5)I+ ions.
- Legault, Claude Y.,Mayer, Robert J.,Mayr, Herbert,Ofial, Armin R.
-
supporting information
(2020/03/13)
-
- Charge-Assisted phosph(v)azane anion receptors
-
Coordination of Cu(i) or Pd(ii) to seleno-cyclodiphosph(v)azanes of the type [RNH(Se)P(μ-NtBu)]2 results in positively charged anion receptor units which have increased anion affinity over the neutral seleno-phosph(v)azanes, due to the increase in electrostatic interactions between the receptor and the guest anions. The same effect is produced by replacement of one of the PSe units by a P-Me+ unit.
- Bond, Andrew D.,Goodman, Jonathan M.,Lee, Sanha,Plajer, Alex J.,Wright, Dominic S.
-
p. 3403 - 3407
(2020/04/02)
-
- METHOD FOR PRODUCING IONIC LIQUID AND METHOD FOR PRODUCING INTERMEDIATE BODY FOR PRODUCTION OF IONIC LIQUID
-
PROBLEM TO BE SOLVED: To provide a method for producing an ionic liquid for synthesizing a desired ionic liquid with high purity, and to provide a method for producing an intermediate body for synthesizing the ionic liquid. SOLUTION: A method for producing an ionic liquid which produces a desired ionic liquid Q+Z- formed from cation Q+ and anion Z- includes: a step of purifying a high-melting point intermediate body Q+Y- that is formed from the cation Q+ and the anion Z- and has such a melting point as to be recrystallized, by recrystallization; and a step of obtaining the ionic liquid Q+Z- directly or indirectly from the purified high-melting point intermediate body Q+Y-. A method for producing a strongly acidic intermediate body and a super-hydrophilic intermediate body includes: a step of obtaining a strongly acidic intermediate body or a super-hydrophilic intermediate body from the purified high-melting point intermediate body Q+Y- by a double decomposition precipitation method or obtaining the strongly acidic intermediate body from the purified high-melting point intermediate body Q+Y- by a double decomposition precipitation method, or a step of obtaining the super-hydrophilic intermediate body from the strongly acidic intermediate body by a neutralization method. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2018,JPOandINPIT
- -
-
Paragraph 0117
(2018/02/22)
-
- Preparation and optoelectronic behaviours of novel electrochromic devices based on triphenylamine-containing ambipolar materials
-
Two new triphenylamine-containing ambipolar electrochromic materials with ether linkages, 1-(2-(4-(bis(4-methoxyphenyl)amino)phenoxy)ethyl)-1′-ethyl-[4,4′-bipyridine]-1,1′-diium tetrafluoroborate (TPA-Vio) and 2-(4-(bis(4-methoxyphenyl)amino)phenoxy)anthracene-9,10-dione (TPA-OAQ), were successfully synthesized and fabricated into novel electrochromic devices. These devices demonstrated interesting and much higher performance than devices derived from TPA-3OMe with respect to driving voltage, switching time, and electrochromic stability.
- Huang, De-Cheng,Wu, Jung-Tsu,Fan, Yang-Ze,Liou, Guey-Sheng
-
p. 9370 - 9375
(2017/09/29)
-
- METHOD FOR PREPARATION OF CYANO COMPOUNDS OF BORON WITH A BRONSTEDT ACID
-
The invention discloses a method for preparation of cyano compounds of boron with 1, 2, 3 or 4 cyano residues, represented by formula (I): [Catn+] [(BF4-m(CN)m)- ]n by a reaction of compound of formula (A1) with trimethylsilylcyanide in the presence of a Bronstedt acid; [Catn+] [(BF4)- ]n (A1); n+ Cat is a cation, m is 1, 2, 3 or 4 and n is 1, 2, 3 or 4. In a specific embodiment, the method is for prepration of the following three compounds: [(n-Bu)4N][BF(CN)3] (1), [(n-Pr)3NH][BF(CN)3] (2), [(n-Pr)3NH][B(CN)4] (3).
- -
-
Page/Page column 30-31
(2016/10/31)
-
- Lewis Acid Catalyzed Synthesis of Cyanidophosphates
-
Salts containing new cyanido(fluorido)phosphate anions of the general formula [PF6-n(CN)n]- (n=1-4) were synthesized by a very mild Lewis-acid-catalyzed synthetic protocol and fully characterized. All [PF6-n(CN)n]- (n=1-4) salts could be isolated on a preparative scale. It was also possible to detect the [PF(CN)5]- but not the [P(CN)6]- anion. The best results with respect to purity, yield, and low cost were obtained when the F-/CN- substitution reactions were carried out in ionic liquids. Cyanido(fluorido)phosphates: Salts containing [PF6-n(CN)n]- (n=1-4) ions were isolated on a preparative scale by utilizing Lewis acids (LA) catalysts under mild conditions (see equation). The best results with respect to purity, yield, and low cost were obtained when the F-/CN- substitution reactions were carried out in ionic liquids.
- Bl?sing, Kevin,Ellinger, Stefan,Harloff, J?rg,Schulz, Axel,Sievert, Katharina,T?schler, Christoph,Villinger, Alexander,Zurt?schler, Cornelia
-
supporting information
p. 4175 - 4188
(2016/03/16)
-
- Lewis Acid Catalyzed Synthesis of Cyanidoborates
-
The reactions of [BF4]- salts with Me3SiCN were studied at different temperatures and in the presence of several different Lewis acids, which led to the generation of the well-known [BF4-n(CN)n]- (n = 1-4) salts. Depending on the catalyst and the reaction conditions, the whole series of [BF4-n(CN)n]- salts is now accessible under ambient conditions, and long preparation times and the excessive production of waste materials can be avoided. The best results were obtained when the F-/CN- substitution reactions were performed in ionic liquids.
- Bl?sing, Kevin,Ellinger, Stefan,Harloff, J?rg,Schulz, Axel,Sievert, Katharina,T?schler, Christoph,Villinger, Alexander,Zur T?schler, Cornelia
-
supporting information
p. 1175 - 1183
(2016/03/19)
-
- Method for Preparation of Cyano Compounds of the 13th Group with a Lewis Acid
-
The invention discloses a method for preparation of cyano compounds of the 13th group of the periodic table with 1, 2, 3 or 4 cyano residues, represented by formula (I): [Catn+][(Z1F4-m(CN)m)?]n by a reaction of [(Z1F4)?] with trimethylsilylcyanide in the presence of a Lewis acid and in the presence of the cation Catn+; Catn+ is a cation, Z1 is B, Al, Ga, In or Tl, m is 1, 2, 3 or 4 and n is 1, 2, 3 or 4.
- -
-
Paragraph 0342; 0343; 0344; 0345; 0346; 0347; 0348-0351
(2016/09/12)
-
- Controlled Synthesis of Polyglutamates with Low Polydispersity and Versatile Architectures
-
Polyglutamates are well known to be highly biocompatible, biodegradable and multifunctional polymers, which have been already used as building blocks in polymer drug conjugates and polymeric micelles. Those systems have been applied to various medical applications ranging from therapy to molecular imaging. Furthermore a polyglutamic acid (PGA) paclitaxel conjugate has already entered clinical studies (Opaxio? PGA-PTX conjugate currently in phase III of Clinical trials). In this context, a synthetic pathway to a plethora functional polyglutamates (homopolymers, block-co-polymers, triblocks) with well-defined structure, adjustable molecular weight (Mw) and low dispersity (D=Mw/Mn1.2) applying the ring opening polymerization (ROP) of N-carboxyanhydrides (NCA) has been developed. Additionally, the acid moieties of the polyglutamates can be activated with 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium (DMTMM) and various functionalities can be easily introduced by “post-polymerization modification” yielding a set orthogonal reactive attachment sides. The reactive moieties, such as azides, maleimides, thiols, alkynes (linear or cyclic) offer the opportunity of specific conjugation of the drugs, targeting moieties or markers. Besides introducing reactive groups the functionalization strategy was also used for PEGylation of PGA reducing charge induced interactions and therefore pharmacological properties, such as blood circulation time may be adjusted. In summary, a tool kit of various polyglutamates has been developed enabling the synthesis of a variety of polymer drug conjugates or polymer based imaging agents. The functional polymeric precursors developed will allow us to functionalize and therefore adjust the polymer properties to a desired application.
- -
-
Paragraph 0069
(2015/03/31)
-
- METHOD FOR THE PREPARATION OF TETRAALKYLAMMONIUM OR TETRAALKYLPHOSPHONIUM|TRICYANIDOFLUOROBORATES
-
The invention discloses a method for the preparation of tetra alkylammonium and tetra alkylphosphonium tricyanidofluoroborate starting from tetraalkylammonium or tetra alkylphosphonium tetrafluoroborate and trimethylsilylcyanide.
- -
-
Page/Page column 11; 12
(2014/03/25)
-
- METHOD FOR THE PREPARATION OF TETRAALKYLAMMONIUM TETRACYANIDOBORATES
-
The invention discloses a method for the preparation of tetra alkylammonium tetracyanidoborate starting from tetraalkylammonium tetrafluoroborate and trimethylsilylcyanide.
- -
-
Page/Page column 9; 10
(2014/03/25)
-
- Method for preparation of tricyanidofluoroborates in 2 steps
-
The invention discloses a method for the preparation of tricyanidofluoroborate in two steps via tetra alkylammonium and tetra alkylphosphonium tricyanidofluoroborate, starting from tetraalkylammonium or tetra alkylphosphonium tetrafluoroborate and trimethylsilylcyanide in the first step and exchanging the cation in the second step.
- -
-
Paragraph 0084-0085
(2014/09/17)
-
- Addition of amines to a carbonyl ligand: Syntheses, characterization, and reactivities of iridium(iii) porphyrin carbamoyl complexes
-
Treatment of (carbonyl)chloro(meso-tetra-p-tolylporphyrinato)iridium(III), (TTP)Ir(CO)Cl (1), with excess primary amines at 23°C in the presence of Na2CO3 produces the trans-amine-coordinated iridium carbamoyl complexes (TTP)Ir(NH2R)[C(O)NHR] (R = Bn (2a), n-Bu (2b), i-Pr (2c), t-Bu (2d)) with isolated yields up to 94%. The trans-amine ligand is labile and can be replaced with quinuclidine (1-azabicyclo[2.2.2]octane, ABCO), 1-methylimidazole (1-MeIm), triethyl phosphite (P(OEt)3), and dimethylphenylphosphine (PMe2Ph) at 23°C to afford the hexacoordinated carbamoyl complexes (TTP)Ir(L)[C(O)NHR] (for R = Bn: L = ABCO (3a), 1-MeIm (4a), P(OEt)3 (5a), PMe2Ph (6a)). On the basis of ligand displacement reactions and equilibrium studies, ligand binding strengths to the iridium metal center were found to decrease in the order PMe2Ph > P(OEt)3 > 1-MeIm > ABCO > BnNH 2 ? Et3N, PCy3. The carbamoyl complexes (TTP)Ir(L)[C(O)NHR] (L = RNH2 (2a,b), 1-MeIm (4a)) undergo protonolysis with HBF4 to give the cationic carbonyl complexes [(TTP)Ir(NH2R)(CO)]BF4 (7a,b) and [(TTP)Ir(1-MeIm)(CO)] BF4 (8), respectively. In contrast, the carbamoyl complexes (TTP)Ir(L)[C(O)NHR] (L = P(OEt)3 (5a), PMe2Ph (6a,c)) reacted with HBF4 to afford the complexes [(TTP)Ir(PMe 2Ph)]BF4 (9) and [(TTP)IrP(OEt)3]BF4 (10), respectively. The carbamoyl complexes (TTP)Ir(L)[C(O)NHR] (L = RNH 2 (2a-d), 1-MeIm (4a), P(OEt)3 (5b), PMe2Ph (6c)) reacted with methyl iodide to give the iodo complexes (TTP)Ir(L)I (L = RNH2 (11a-d), 1-MeIm (12), P(OEt)3 (13), PMe2Ph (14)). Reactions of the complexes [(TTP)Ir(PMe2Ph)]BF4 (9) and [(TTP)IrP(OEt)3]BF4 (10) with [Bu4N]I, benzylamine (BnNH2), and PMe2Ph afforded (TTP)Ir(PMe 2Ph)I (14), (TTP)Ir[P(OEt)3]I (13), [(TTP)Ir(PMe 2Ph)(NH2Bn)]BF4 (16), and trans-[(TTP) Ir(PMe2Ph)2]BF4 (17), respectively. Metrical details for the molecular structures of 4a and 17 are reported.
- Dairo, Taiwo O.,Ellern, Arkady,Angelici, Robert J.,Woo, L. Keith
-
p. 2266 - 2276
(2014/06/09)
-
- Synthesis, structure and reactivity of Ni site models of [NiFeSe] hydrogenases
-
A series of structural models of the Ni centre in [NiFeSe] hydrogenases has been developed which exhibits key structural features of the Ni site in the H2 cycling enzyme. Specifically, two complexes with a hydrogenase-analogous four-coordinate 'NiS3Se' primary coordination sphere and complexes with a 'NiS2Se2' and a 'NiS 4' core are reported. The reactivity of the complexes towards oxygen and protons shows some relevance to the chemistry of [NiFeSe] hydrogenases. Exposure of a 'NiS3Se' complex to atmospheric oxygen results in the oxidation of the selenolate group in the complex to a diselenide, which is released from the nickel site. Oxidation of the selenolate ligand on Ni occurs approximately four times faster than oxidation with the analogous sulfur complex. Reaction of the complexes with one equivalent of HBF4 results in protonation of the monodentate chalcogenolate and the release of this ligand from the metal centre as a thiol or selenol. Unrelated to their biomimetic nature, the complexes serve also as molecular precursors to modify electrodes with Ni-S-Se containing particles by electrochemical deposition. The activated electrodes evolve H2 in pH neutral water with an electrocatalytic onset potential of -0.6 V and a current density of 15 μA cm-2 at -0.75 V vs. NHE.
- Wombwell, Claire,Reisner, Erwin
-
p. 4483 - 4493
(2014/03/21)
-
- Ion exchange synthesis and thermal characteristics of some [N +4444] based ionic liquids
-
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.
- Bhatt, Vasishta D.,Gohil, Kuldip
-
-
- Reactions of perfluorinated alkenyl-, alkynyl-, alkyltrifluoroborates, and selected hydrocarbon analogues with the halogenating agents Hal2 (Hal = F, Cl, Br), "brF" (BrF3-Br2 1:1), and ICl
-
Reactions of [Bu4N][RBF3] [R = CnF 2n+1CF=CF (cis, trans), CF2=CF, CF2=C(CF 3), trans-C4H9CF=CF, trans-C6H 5CF=CF, C4H9CH=CH (cis, trans), CF 3C≡C, and C4H9C≡C] with chlorine, bromine, BrF3 + Br2 (as equivalent of "BrF"), and ICl in solution (CH2Cl2, CHCl3, CF 3CH2CF2CH3) led to 1, 2-addition of halogen and/or replacement of boron by halogen (halodeboration). The reaction of [Bu4N][CF3C≡CBF3] with less than equimolar amounts of diluted fluorine (5 %) in 1, 1, 1, 3, 3-pentafluorobutane (PFB) showed only [Bu4N][CF3CF2CF 2BF3] as fluorine addition product besides extensive fluorodeboration. Suspensions of the insoluble K[CF2=CFBF 3] salt reacted with Cl2 and Br2 in CH 2Cl2 giving preferentially products of halogen addition across the C=C bond. In reactions with ICl iododeboration with formation of CF2=CFI occurred besides 1, 2-addition with formation of [CF 2I-CFClBF3]-. The halodeboration reaction of[Bu4N][trans-C4H9CF=CFBF3] with Br2, "BrF", and ICl, of K[trans-C6H 5CF=CFBF3] with Br2, and of [Bu 4N][trans-C4F9CF=CFBF3] with ICl proceeded stereospecifically. Copyright
- Bardin, Vadim V.,Adonin, Nicolay Yu.,Frohn, Hermann-Josef
-
experimental part
p. 565 - 579
(2012/05/20)
-
- Reactions of fluoroalk-1-en-1-yltrifluoroborate and perfluoroalk-1-yn-1- yltrifluoroborate salts and selected hydrocarbon analogues with hydrogen fluoride and with halogenating agents in aHF and in basic solvents
-
The relative rate of the electrophilic hydrodeboration of K[R′BF 3] with HF (27-100%) diminishes in the series R′ = C 4H9CC > C4F9CFCFCC > CF 2C(CF3) > C3F7CC ~ (CF 3)2CFCC > CF3CC. When R′ = CF 3CC the new salt K[CF3CH2-CF2BF 3] was obtained by addition of HF besides CF3CCH and K[BF4]. Small amounts of water caused the formation of K[CF 3CH2-C(O)BF3] as a by-product. The electrophilic halofluorination of perfluoroalkenyltrifluoroborate salts with NCS or NBS in aHF (anhydrous HF) led to K[RFCFHal-CF2BF 3] (from K[RFCFCFBF3]) and K[R FCHal2-CF2BF3] (from K[R FCHalCFBF3] and K[RFCCBF3]) (Hal = Cl, Br). Treatment of K[RFCFCFBF3] and K[R FCCBF3] with 5% F2/N2 in MeCN gave the corresponding salts K[RFCF2-CF2BF 3] in 16-25% isolated yield. Reactions of K[trans-C4F 9CFCFBF3] with Cl2 in MeOH resulted in K[C 4F9CFCl-C(O)BF3] (major product). The latter was also obtained in reactions of K[trans-C4F9CFCFBF 3] with Cl2 in MeCN or sulfolane after sequential methanolysis of the primarily formed products. In contrast, the salts K[RCFCFBF3] (R = CnF2n+1, trans-C 4H9) and K[CF3CCBF3] underwent bromodeboration to RCFCFBr and CF3CCBr, respectively, when they were reacted with bromine in the polar solvents MeOH, MeCN, or sulfolane.
- Bardin, Vadim V.,Adonin, Nicolay Yu.,Frohn, Hermann-Josef
-
experimental part
p. 114 - 128
(2012/04/10)
-
- Efficient method for varying the anions in quaternary onium halides
-
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
-
experimental part
p. 3566 - 3569
(2012/08/14)
-
- Equilibrium acidities of superacids
-
In this paper, we report the most comprehensive equilibrium superacidity scale that is available to date. Contrary to most of the past works, this scale is set up in a medium of constant composition and the obtained acidity values characterize the acidities of molecules rather than acidities of media. The current scale is thus complementary to the well-known H0 scale in the information that it provides. The solvent used is 1,2-dichloroethane (DCE). DCE has very weak basic properties (but sufficiently high polarity) and is an appropriate solvent for measuring acidities of very strong acids of diverse chemical nature. DCE acidities of well-known superacids (CF3SO 2OH, (CF3SO2)2NH, cyanocarbon acids, etc.) as well as common mineral acids (H2SO4, HI, HBr, etc.) are reported. Acidities of altogether 62 acids have been determined from 176 interlinked relative acidity measurements. The scale spans 15 orders of magnitude (from picric acid to 1,1,2,3,3-pentacyanopropene) and is expected to be a useful tool in design, use, and further acidity measurements of superacidic molecules.
- Kuett, Agnes,Rodima, Toomas,Saame, Jaan,Raamat, Elin,Maeemets, Vahur,Kaljurand, Ivari,Koppel, Ilmar A.,Garlyauskayte, Romute Yu.,Yagupolskii, Yurii L.,Yagupolskii, Lev M.,Bernhardt, Eduard,Willner, Helge,Leito, Ivo
-
supporting information; experimental part
p. 391 - 395
(2011/04/17)
-
- Synthesis and electrochemical study of an original copper(II)-capped salen-cyclodextrin complex
-
A new metallocapped cyclodextrin (CD) was synthesized by the regioselective debenzylation, induced by diisobutylaluminium hydride (DIBAL-H), of perbenzylated cyclodextrins. This reaction allowed for the efficient preparation of an unprecedented CD-salen type copper(II) complex. The electrochemical behavior of both the bound and unbound CD-salen compounds was investigated by cyclic voltammetry. Notably, it was shown that the presence of tert-butyl groups at the ortho- and para-positions of the salen aromatic rings stabilized the copper(II) phenoxyl radical species that was generated upon the one-electron oxidation of the starting compound. Importantly, this stabilization remained effective when the salen-type ligand was covalently attached to the CD. This allowed for investigations of the reactivity of the copper(II) phenoxyl radical complex towards a primary alcohol to be performed by cyclic voltammetry. This reaction can be considered as mimicking the behavior of galactose oxidase. However, under these conditions, no reactivity was observed in the presence of benzyl alcohol. This may be due to distortion, either of the initially square planar salen ligand after its grafting to the CD primary face, and/or of the CD itself. On the other hand, the electrochemical reduction of the un-grafted copper(II) salen-type ligand led to a transient anionic species that exhibited significant stability on the time-scale of the slow cyclic voltammetry measurement in the absence of the CD, but was unstable in the presence of the CD. In the latter case, it was demonstrated that the anionic species was protonated by the CD. Importantly, this protonation was not fast enough to prevent catalytic activation of iodomethane by the electro-generated copper(I)-capped salen CD complex. A new metallocapped cyclodextrin was synthesized by a regioselective debenzylation reaction that was induced by diisobutylaluminium hydride (DIBAL-H). The electrochemical investigation of this original complex demonstrated that grafting of a copper salen-type complex to a cyclodextrin leads to changes in the reactivity of the intermediary species.
- Deunf, Elise,Zaborova, Elena,Guieu, Samuel,Bleriot, Yves,Verpeaux, Jean-Noel,Buriez, Olivier,Sollogoub, Matthieu,Amatore, Christian
-
experimental part
p. 4720 - 4727
(2011/02/28)
-
- Bis(perfluoroorganyl)bromonium salts [(RF)2Br]Y (RF = aryl, alkenyl, and alkynyl)
-
Bromonium salts [(RF)2Br]Y with perfluorinated groups RFC6F5, CF3CFCF, C 2F5CFCF, and CF3C≡C were isolated from reactions of BrF3 with RFBF2 in weakly coordinating solvents (wcs) like CF3CH2CHF2 (PFP) or CF3CH2CF2CH3 (PFB) in 30-90% yields. C6F5BF2 formed independent of the stoichiometry only [(C6F5)2Br][BF 4]. 1:2 reactions of BrF3 and silanes C6F 5SiY3 (Y = F, Me) ended with different products - C 6F5BrF2 or [(C6F5) 2Br][SiF5] - as pure individuals, depending on Y and on the reaction temperature (Y = F). With C6F5SiF3 at ≥-30 °C [(C6F5)2Br][SiF5] resulted in 92% yield whereas the reaction with less Lewis acidic C 6F5SiMe3 only led to C6F 5BrF2 (58%). The interaction of K[C6F 5BF3] with BrF3 or [BrF2][SbF 6] in anhydrous HF gave [(C6F5) 2Br][SbF6]. Attempts to obtain a bis(perfluoroalkyl) bromonium salt by reactions of C6F13BF2 with BrF3 or of K[C6F13BF3] with [BrF2][SbF6] failed. The 3:2 reactions of BrF3 with (C6F5)3B in CH2Cl2 gave [(C6F5)2Br][(C6F 5)nBF4-n] salts (n = 0-3). The mixture of anions could be converted to pure [BF4]- salts by treatment with BF3·base.
- Frohn, Hermann-Josef,Giesen, Matthias,Welting, Dirk,Bardin, Vadim V.
-
experimental part
p. 922 - 932
(2010/10/03)
-
- Direct observation of the ionization step in solvolysis reactions: Electrophilicity versus electrofugality of carbocations
-
Rates and equilibria of the reactions of highly stabilized amino-substituted benzhydrylium ions (Ar2CH+) with carboxylate ions have been determined photometrically in acetone and acetonitrile solutions. Treatment of covalent benzhydryl carboxylates (Ar 2CH-O2CR) with aqueous acetone or acetonitrile leads to the regeneration of the colored amino-substituted benzhydrylium ions Ar 2CH+, which do not undergo subsequent reactions with the solvent. One can, therefore, directly measure the first step of SN1 reactions. The electrofugality order, i.e., the relative ionization rates of benzhydryl esters Ar2CH-O2CR with the same anionic leaving group, does not correlate with the corresponding electrophilicity order, i.e., the relative reactivities of the corresponding benzhydrylium ions Ar 2CH+ toward a common nucleophile. Thus, benzhydrylium ions which are produced with equal rates by ionization of the corresponding covalent esters may differ by more than 2 orders of magnitude in their reactivities toward nucleophiles, e.g., carboxylate ions. Variable intrinsic barriers account for the breakdown of the rate-equilibrium relationships. Complete free-energy profiles for the ionization of benzhydryl carboxylates Ar2CH-O 2CR are constructed, which demonstrate that the transition states of these ionizations are not carbocation-like. As a consequence, variation of the solvent-ionizing power Y has only a small effect on the ionization rate constant (m = 0.35 to 0.55) indicating that small values of m in the Winstein-Grunwald equation do not necessarily imply an SN2 type mechanism.
- Schaller, Heike F.,Tishkov, Alexander A.,Feng, Xinliang,Mayr, Herbert
-
p. 3012 - 3022
(2008/09/20)
-
- Manganese complexes of the pentaphenylcyclopentadienyl ligand
-
The preparation and characterisation of [Mn(η5-C5Ph5)(CO)3] (1), [Mn(η5-C5Ph5)(CO)2(PMe2Ph)] (2), and [Mn(η5-C5(p-tol)5)(CO
- Field, Leslie D.,He, Taian,Humphrey, Paul,Masters, Anthony F.,Turner, Peter
-
p. 1498 - 1506
(2008/10/09)
-
- METHOD FOR PRODUCING ONIUM SALTS WITH A LOW CHLORIDE CONTENT
-
The invention relates to a method for producing onium salts with a low chloride content by reacting an onium chloride with an acid. According to the invention, the hydrochloric acid that is produced can be removed by co-ordination with an organic solvent, which forms an azeotropic mixture with water, and by subsequent azeotropic distillation.
- -
-
Page/Page column 23
(2008/06/13)
-
- Fluorinated amino polyhedral borate compounds
-
This invention provides a compound comprising fluorinated aminoborate monoanion of the formula: [R1R2R3N—BaHbFc]?1??I methods for preparing the same, and uses thereof, where R1, R2, R3, a, b, and c are those defined herein.
- -
-
-
- The tetracyanoborate M[B(CN)4], M = [Bu4N]+, Ag+, K+
-
The tetracyanoborate anion is prepared for the first time as the tetrabutylammonium salt by the reaction of [NBu4]BX and BX3 (X = Br, Cl) in toluene with KCN. After purification and recrystallization of the product from CHCl3 colorless and needle size single crystals of [Bu4N][B(CN)4] are formed. After metathesis with AgNO3 the silver salt and subsequently with KBr the potassium salt is prepared. The three salts are characterized by single crystal X-ray diffraction (Ag[B(CN)4] P 43m, a = 5.732(1) A, V = 188.3 A3, Z = 1, R1 = 0.75%; K[B(CN)4] I41/a, a = 6.976(1), c = 14.210(3) A, V = 691.5 A3, Z = 4, R1 = 1.90%; [Bu4N][B(CN)4] Pnna, a = 17.765(3), b = 11.650(2), c = 11.454(2) A, V = 2370.5 A3, Z = 4, R1 = 6.09%) and by NMR-, IR-, Raman- as well by UV-spectroscopy.
- Bernhardt,Henkel,Willner
-
p. 560 - 568
(2008/10/08)
-
- Transition Metal-Substituted Diphosphenes, XIII. - On the Synthesis of (ν5-C5Me5)(CO)(NO)Re-P=P-C6H2(tBu)3-(2,4,6) and (ν5-C5Me5)(CO)(NO)ReP=P-C6H2(tBu)3-(2,4,6)
-
Compound (ν5-C5Me5)(CO)(NO)ReBr (3), generated from 5-C5Me5)(CO)2(NO)Re>BF4 and (Bu4N)Br, reacts with LiP(SiMe3)2 to give the disilylphosphido complex (ν5-C5Me5)(CO)(NO)ReP(SiMe3)2 (4).Complex 4 is converted into the diphosphenyl complex (ν5-C5Me5)(CO)(NO)Re-P=P-C6H2(tBu)3-(2,4,6) (5) by treatment with 2,4,6-(tBu)3C6H2PCl2.The reaction of 5, which is stable in solution, with Cr(CO)3 affords stable (ν5-C5Me5)(CO)(NO)ReP=P-C6H2(tBu)3-(2,4,6) (7).For comparison, the complexes (ν5-C5Me5(CO)(NO)MnP=P-C6H2(tBu)3-(2,4,6) (9) and (ν5-C5Me5)(CO)2 FeP=P-C6H2(tBu)3-(2,4,6) (10) were synthesized as well.Compound 10 was characterized by an X-ray structure analysis.
- Weber, Lothar,Meine, Georg,Boese, Roland,Blaeser, Dieter
-
p. 853 - 858
(2007/10/02)
-
- Electrochemical Syntheses, XIX. An Electrochemical Synthesis of Polythiazyl
-
A facile synthesis of (chlorinated) polythiazyl by cathodic reduction of (S5N5) in (Bu4N)/CH2Cl2 at low temperatures is reported.The product was characterized by IR and mass spectra, Debeye-Scherrer diagrams and elemental analyses.Potential applications were tested. - Keywords: Electrochemical Syntheses, Polythiazyl
- Fritz, Heinz P.,Bruchhaus, Rainer
-
p. 1375 - 1382
(2007/10/02)
-
- Compounds of Transition Metal Ketenes, XVII. Synthesis of an Anionic η2-Ketenyl Complex
-
The η2-ketenyl compound reacts with tetrabutylammonium cyanide forming an anionic η2-ketenyl complex. - Key words: Anionic η2-Ketenyl Complex of Tungsten, Synthesis
- Sieber, Werner J.,Eberl, Karl,Wolfgruber, Mathias,Kreissl, Fritz R.
-
p. 1159 - 1160
(2007/10/02)
-