- In further pursuit of the carbene analogy: Preparation and crystal structure of (N,N,N′,N′-tetramethylethylenediamine)potassium [cis-ethene-1,2-di(tert-butylamido)]gallate(I)
-
The preparation and crystal structures of (N,N,N′,N′-tetramethylenediamine)potassium[cis-ethene-1,2-di (tert-butylamido)]gallate(I) were discussed. The structure of the compound consisted of dimeric structure with the potassium cations η5-coord
- Schmidt, Eva Susanne,Schier, Annette,Schmidbaur, Hubert
-
-
Read Online
- A family of Tri- and dimetallic pyridine dicarboxamide cryptates: Unusual O, N, O -coordination and facile access to secondary coordination sphere hydrogen bonding interactions
-
A series of tri- and dimetallic metal complexes of pyridine dicarboxamide cryptates are reported in which changes to the base and metal source result in diverse structure types. Addition of strong bases, such as KH or KN(SiMe3)2, followed by divalent metal halides allows direct access to trinuclear complexes in which each metal center is coordinated by a dianionic N,N,N-chelate of each arm. These complexes bind a guest K+ cation within the central cavity in a trigonal planar coordination environment. Minor changes to the solvent and equivalents of base used in the syntheses of the triiron(II) and tricobalt(II) complexes affords two trinuclear clusters with atypical O,N,O-coordination by each pyridine dicarboxamide arm; the amide carbonyl O atoms are oriented toward the interior of the cavity to coordinate to each metal center. Finally, varying the base enables the selective synthesis of dinuclear nickel(II) and copper(II) complexes in which one pyridine dicarboxamide arm remains protonated. These amide protons are at one end of a hydrogen bonding network that extends throughout the internal cavity and terminates at a metal bound hydroxide, carbonate, or bicarbonate donor. In the dinickel complex, the bicarbonate cannot be liberated as CO2 either thermally or upon sparging with N2, which differs from previously reported monometallic complexes. The carbonate or bicarbonate ligands likely arise from sequestration of atmospheric CO2 based on the observed reaction of the di(hydroxonickel) analog.
- Guillet, Gary L.,Gordon, Jesse B.,Di Francesco, Gianna N.,Calkins, Matthew W.,?i?már, Erik,Abboud, Khalil A.,Meisel, Mark W.,García-Serres, Ricardo,Murray, Leslie J.
-
-
Read Online
- 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)
-
- METHOD FOR PREPARING OXYSULPHIDE AND FLUORINATED DERIVATIVES IN THE PRESENCE OF AN ORGANIC SOLVENT
-
The present invention concerns a method for preparing an oxysulphide and fluorinated derivative of formula (III) Ea-SO3R (III) that comprises bringing a compound of formula (II) Ea-SOOR (II)—Ea representing the fluorine atom or a group having 1 to 10 carbon atoms chosen from the fluoroalkyls, the perfluoroalkyls and the fluoroalkenyls; and—R representing hydrogen, a monovalent cation or an alkyl group; into contact, in the presence of a polar aprotic organic solvent, with an oxidising agent.
- -
-
Paragraph 0187-0190
(2019/04/05)
-
- Preparation method of trifluoromethane sulfonic acid
-
The invention relates to a preparation method of trifluoromethane sulfonic acid. According to the preparation method, trifluoromethanesulphonyl fluoride and alkali metal hydroxide are subjected to a neutralizing hydrolysis reaction under existence of a fluorine fixing agent, after the reaction is completed, reaction liquid is filtered and dried, and fluorinated methyl sulfonic acid alkali metal salt is obtained; the fluorinated methyl sulfonic acid alkali metal salt and fuming sulphuric acid are subjected to acidizing treatment, then rectification is conducted multiple times, and high-purity trifluoromethane sulfonic acid is obtained. Through improvement of the preparation method, operating flexibility, production efficiency and product stability are improved, the comprehensive yield is raised, product purity can reach 99.90% or above, and the preparation method is suitable for industrial production.
- -
-
Paragraph 0023; 0024; 0026; 0034
(2017/01/09)
-
- FLUOROALKANESULFONIC ACID PRODUCTION METHOD
-
Disclosed is a method for producing a fluoroalkanesulfonic acid including (1) the step of reacting concentrated sulfuric acid and/or fuming sulfuric acid with a fluoroalkanesulfonate to cause an acid decomposition, thereby obtaining a reaction mixture containing the fluoroalkanesulfonic acid and a sulfur component; and (2) the step of adding an oxidizing agent to the reaction mixture obtained by the above step and then conducting a distillation, thereby obtaining the fluoroalkanesulfonic acid from the reaction mixture. It is possible by this method to efficiently reduce the sulfur component, thereby industrially advantageously obtaining fluoroalkanesulfonic acid of high purity.
- -
-
Paragraph 0057
(2014/06/24)
-
- Experimental and computational studies on the formation of cyanate from early metal terminal nitrido ligands and carbon monoxide
-
An important challenge in the artificial fixation of N2 is to find atom efficient transformations that yield value-added products. Here we explore the coordination complex mediated conversion of ubiquitous species, CO and N2, into isocyanate. We have conceptually split the process into three steps: (1) the six-electron splitting of dinitrogen into terminal metal nitrido ligands, (2) the reduction of the complex by two electrons with CO to form an isocyanate linkage, and (3) the one electron reduction of the metal isocyanate complex to regenerate the starting metal complex and release the product. These steps are explored separately in an attempt to understand the limitations of each step and what is required of a coordination complex in order to facilitate a catalytic cycle. The possibility of this cyanate cycle was explored with both Mo and V complexes which have previously been shown to perform select steps in the sequence. Experimental results demonstrate the feasibility of some of the steps and DFT calculations suggest that, although the reduction of the terminal metal nitride complex by carbon monoxide should be thermodynamically favorable, there is a large kinetic barrier associated with the change in spin state which can be avoided in the case of the V complexes by an initial binding of the CO to the metal center followed by rearrangement. This mandates certain minimal design principles for the metal complex: the metal center should be sterically accessible for CO binding and the ligands should not readily succumb to CO insertion reactions.
- Cozzolino, Anthony F.,Silvia, Jared S.,Lopez, Nazario,Cummins, Christopher C.
-
p. 4639 - 4652
(2014/03/21)
-
- Frustrated Lewis pair-like splitting of aromatic C-H bonds and abstraction of halogen atoms by a cationic [(FPNP)Pt]+ species
-
This manuscript explores new chemistry that can be related to the unobserved 14-electron [(FPNP)Pt]+ transient ( FPNP = (4-F-2-(iPr2P)C6H 3)2N). Its reactivity can be accessed via abstraction of triflate from (FPNP)PtOTf (1) with K[B(C6F 5)4] in various solvents serving as substrates. With benzene, toluene and fluorobenzene, net heterolytic splitting of an aromatic C-H bond across the N-Pt bond is observed, without any detectable intermediates, leading to the [(FPN(H)P)Pt-Ar]+ products (Ar = Ph, 3a; Ar = C6H4Me, 3b (ortho), 3c (meta), 3d (para); Ar = o-C 6H4F, 3e). The latter can be alternatively prepared by protonation of the neutral (FPNP)Pt-Ar compounds. Compounds 3a-3e do not release free arene under thermolysis at 80 °C, and compounds 3b/c/d do not interconvert under ambient temperature. With chlorobenzene and bromobenzene, the kinetic product is the κ1-Cl or κ1-Br adduct [(FPNP)Pt-Cl-Ph]+ (4) or [(FPNP)Pt-Br- Ph]+ (10). Compound 4 rearranges into a C-H splitting product [( FPN(H)P)Pt-C6H4Cl]+ (3f), while 10 slowly reacts by formal transfer of Br atom to Pt. An analogous Cl atom transfer to Pt is observed upon the reaction of 1 with K[B(C6F 5)4] in dichloromethane, producing [(FPNP)PtCl] [B(C6F5)4] (9a) which features an oxidized FPNP ligand framework. X-Ray diffractometry established structures of [(FPN(H)P)Pt-C6H4F-o][B(C6F 5)4] (3e, disordered rotamers), [(FPN(H)P)Pt- C6H4Me][B(C6F5)4] (disordered meta- and para-isomers 3c/d), and [(FPNP)PtCl][HCB 11Cl11] (9b). DFT calculations at the PBE0 and M06-L levels on the free [(FPNP)Pt]+ cation predict a relatively small (10-12 kcal mol-1) separation between the singlet and the triplet states. The relatively low triplet energy is probably related to the viability of the unexpected halogen atom abstraction reactions. The Royal Society of Chemistry 2013.
- Demott, Jessica C.,Bhuvanesh, Nattamai,Ozerov, Oleg V.
-
p. 642 - 649
(2013/03/14)
-
- COMPOUNDS CONTAINING PERFLUOROALKYL-CYANO-ALKOXY-BORATE ANIONS OR PERFLUOROALKYL-CYANO-ALKOXY-FLUORO-BORATE ANIONS
-
The present invention relates to compounds containing perfluoroalkyl-cyano-alkoxy-borate anions or perfluoroalkyl-cyano-alkoxy-fluoro-borate anions, ((per)fluoro)phenyl-cyano-alkoxy-borate anions or ((per)fluoro)phenyl-cyano-alkoxy-fluoro-borate anions or phenyl-cyano-alkoxy-borate anions which are monosubstituted or disubstituted with perfluoroalkyl groups having 1 to 4 C atoms or phenyl-cyano-alkoxy-fluoro-borate anions which are monosubstituted or disubstituted with perfluoroalkyl groups having 1 to 4 C atoms, the preparation thereof and the use thereof, in particular as part of electrolyte formulations for dye sensitized solar cells.
- -
-
Page/Page column 18-19
(2012/12/13)
-
- Nitrosobenzene as a hydrogen acceptor in rhodium catalysed dehydrogenation reactions of alcohols: Synthesis of aldehydes and azoxybenzenes
-
Acids, esters and amides have to date been the only isolated products from the dehydrogenation of primary alcohols with [Rh(trop2N)(L)] (trop = 5-H-dibenzo[a,d]cyclohepten-5yl) type complexes. With the reported method the available product family is finally to aldehydes. Using nitrosobenzene as a hydrogen acceptor the aldehydes could be isolated in up to 96% yield with substrate to catalyst ratios of up to 1000. Nitrosobenzene was found to be reductively coupled to azoxybenzene under the reaction conditions. Several symmetrically substituted azoxybenzene derivatives could be isolated in generally high yields after 2 to 4 h reaction time using a low catalyst loading. The Royal Society of Chemistry 2012.
- Annen, Samuel P.,Gruetzmacher, Hansjoerg
-
p. 14137 - 14145
(2013/01/15)
-
- CATALYSTS CONTAINING N-HETEROCYCLIC CARBENES FOR ENANTIOSELECTIVE SYNTHESIS
-
Novel N-heterocyclic carbene ligand precursors, N-heterocyclic carbene ligands and N-heterocyclic metal-carbene complexes are provided. Metal-carbene complexes comprising N-heterocyclic carbene ligands can be chiral, which are useful for catalyzing enantioselective synthesis. Methods for the preparation of the N-heterocyclic carbene ligands and N-heterocyclic metal-carbene complexes are given.
- -
-
Page/Page column 17-18
(2008/12/08)
-
- POTASSIUM PERFLUOROALKANESULFONATES AND PROCESS FOR PRODUCTION THEREOF
-
A process for the production of potassium perfluoroalkane- sulfonates which comprises the electrolytic fluorination step of electrofluorinating an alkanesulfonyl halide in anhydrous hydrofluoric acid to obtain a gas containing a perfluoro- alkanesulfonyl fluoride as the main component. The process may further comprise the gas absorption step of reacting the gas with an aqueous solution of potassium hydroxide to form a solution containing a potassium perfluoroalkanesulfonate, the purification step of removing contaminant potassium fluoride, potassium hydroxide and potassium sulfate from the solution, and the concentration/recovery step of subjecting the purified aqueous solution to concentration and drying. In the electrolytic fluorination, the formation of by-products can be inhibited by keeping the proton concentration of the electrolytic solution within the range of 150 to 1500ppm.
- -
-
Page/Page column 15-16
(2008/06/13)
-
- Dication Disulfides by Reaction of Thioureas and Related Compounds with Trifluoromethanesulfonic Anhydride. The Role of Triflic Anhydride as an Oxidizing Agent
-
Interaction of thiourea and substituted thioureas with trifluoromethanesulfonic acid anhydride in methylene chloride results in stable dication disulfide salts (R2N)2+CSSC+(NR2)2*2CF3SO3-.These results indicate that trifli
- Maas, Gerhard,Stang, Peter J.
-
p. 1606 - 1610
(2007/10/02)
-
- Studies on trifluoromethanesulfonic acid. Part 2. Conductivities of solutions of metal trifluoromethanesulfonates and other bases in trifluoromethanesulfonic acid
-
Electrical conductivity measurements are reported for solutions in trifluoromethanesulfonic acid of a number of simple and complex bases, including univalent and divalent metal trifluoromethanesulfonates.The univalent metal salts, water, aniline, and acetic acid behave as fully dissociated bases, while the alkaline earth metal salts show considerable ion association.The trifluoromethanesulfonate anion appears to have an abnormally high mobility, as compared to the metal cations, and is believed to conduct by a proton-transfer mechanism.Dissociation constants for some weak organic bases and association constants for strontium and barium trifluoromethanesulfonates are estimated.Sulfuric acid behaves as a weak electrolyte, while sulfur trioxide is effectively a non-electrolyte.The conductivities of potassium nitrate and potassium dihydrogenphosphate are consistent with the formation of the nitryl cation and the phocphate acidium ion, respectively.
- Russell, David G.,Senior, John B.
-
-