Trifluoromethanesulfonate Complexes Research Articles

Communication—Voltammetry of Lanthanide (III) Triflates Accessible in Acetonitrile at Nafion Modified Electrodes

Lanthanides are common in catalysis and advanced technologies, but difficult to assess voltammetrically. Voltammetry for seven lanthanide(III) trifluoromethanesulfonate complexes Ln(OTf)3 is enabled at Nafion® modified platinum electrodes in acetonitrile. Voltammetric morphologies for La3+, Pr3+, Nd3+, Sm3+, Gd3+, Dy3+, and Yb3+ trifluoromethanesulfonate (triflate) complexes exhibit reduction waves between 0.2 to 0.1 V and −0.7 to −0.8 V vs NHE with coupled chemical processes.

Synthesis of 4-[(2-imidazylethynyl)]-5-(2-pyridylethynyl)veratrole and characterization of the coordination complexes with silver(I) and palladium(II)

We describe the design, synthesis and characterization of the ligand, 4-[(2-imidazylethynyl)]-5-(2-pyridylethynyl)veratrole as well its coordination complexes with silver(I) and palladium(II). 1H NMR titration clearly indicates that 1:1 coordination complexes are formed with both cations. The X-ray structure of the palladium dichloride complex confirms the trans coordination of palladium(II) and the silver trifluoromethanesulfonate complex confirms the linear coordination geometry about silver(I). [Display omitted]

Solid State Structures, Solution Behavior, and Luminescence of Simple Tetrakis(2‐pyridylmethyl)ethylenediamine Lanthanide Complexes

We report the synthesis, characterization, solid‐state structure and solution behavior of simple lanthanide trifluoromethanesulfonate complexes supported by a hexadentate tetrakis(2‐pyridylmethyl)ethylenediamine ligand. The complexes' solid‐state structures exhibit different trifluoromethanesulfonate coordination, correlating with the size difference of the lanthanide ions. The ligand is capable of sensitizing Nd, Sm, Eu, Tb, Dy, and Yb yielding metal‐centered emission with moderate quantum yields.

Mono- and dinuclear CuII complexes of the benzyldipicolylamine (BDPA) ligand: crystal structure, synthesis and characterization.

The crystal structures of mono- and dinuclear CuII trifluoromethanesulfonate (triflate) complexes with benzyldipicolylamine (BDPA) are described. From equimolar amounts of Cu(triflate)2 and BDPA, a water-bound CuII mononuclear complex, aqua(benzyldipicolylamine-κ3N,N',N'')bis(trifluoromethanesulfonato-κO)copper(II) tetrahydrofuran monosolvate, [Cu(CF3SO3)2(C19H19N3)(H2O)]·C4H8O, (I), and a triflate-bridged CuII dinuclear complex, bis(μ-trifluoromethanesulfonato-κ2O:O')bis[(benzyldipicolylamine-κ3N,N',N'')(trifluoromethanesulfonato-κO)copper(II)], [Cu2(CF3SO3)4(C19H19N3)2], were synthesized. The presence of residual moisture in the reaction medium afforded water-bound complex (I), whereas dinuclear complex (II) was synthesized from an anhydrous reaction medium. Single-crystal X-ray structure analysis reveals that the CuII centres adopt slightly distorted octahedral geometries in both complexes. The metal-bound water molecule in (I) is involved in intermolecular O-H...O hydrogen bonds with triflate ligands and tetrahydrofuran solvent molecules. In (II), weak intermolecular C-H...F(triflate) and C-H...O(triflate) hydrogen bonds stabilize the crystal lattice. Complexes (I) and (II) were also characterized fully using FT-IR and UV-Vis spectroscopy, cyclic voltammetry and elemental analysis.

Crystal structures of two ansa-titanocene tri-fluoro-methane-sulfonate complexes bearing the Me2Si(C5Me4)2 ligand.

The crystal structures of two ansa-titanocene tri-fluoro-methane-sulfonate complexes bearing the Me2Si(C5Me4)2 ligand are reported, namely [di-methylbis-(η5-tetra-methyl-cyclo-penta-dien-yl)silane](tri-fluoro-methane-sulfonato-κ2O,O')titanium(III) toluene monosolvate, [Ti(CF3O3S)(C20H30Si)]·C7H8, 1, and chlorido-[di-methyl-bis-(η5-tetra-methyl-cyclo-penta-dien-yl)silane](tri-fluoro-methane-sulfonato-κO)titanium(IV), [Ti(CF3O3S)(C20H30Si)Cl], 2. Both complexes display a bent metallocene unit, the metal atom being coordinated in a distorted tetra-hedral geometry, with the tri-fluoro-methane-sulfonate anion acting as a bidentate or monodentate ligand in 1 and 2, respectively. In 1, weak π-π stacking inter-actions involving the toluene solvent mol-ecules [centroid-to-centroid distance = 3.9491 (11) Å] are observed.

ChemInform Abstract: Asymmetric Aldol Reaction Catalyzed by a Chiral Phosphine—Silver Complex.

A catalytic asymmetric aldol reaction of alkenyl trihaloacetates or a γ,δ-unsaturated δ-lactone with aldehydes or an α-keto ester was achieved by using a 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl·silver trifluoromethanesulfonate complex as the chiral precatalyst and N,N-diisopropylethylamine as the base precatalyst in the presence of methanol. Optically active α-alkyl β-hydroxy ketones with enantioselectivities of up to 95 % ee were diastereoselectively obtained in moderate to high yields through the in situ generated chiral silver enolates.

Asymmetric Aldol Reaction Catalyzed by a Chiral Phosphine–Silver Complex

AbstractA catalytic asymmetric aldol reaction of alkenyl trihaloacetates or a γ,δ‐unsaturated δ‐lactone with aldehydes or an α‐keto ester was achieved by using a 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl·silver trifluoromethanesulfonate complex as the chiral precatalyst and N,N‐diisopropylethylamine as the base precatalyst in the presence of methanol. Optically active α‐alkyl β‐hydroxy ketones with enantioselectivities of up to 95 % ee were diastereoselectively obtained in moderate to high yields through the in situ generated chiral silver enolates.

Cyclic versus Polymeric Supramolecular Architectures in Metal Complexes of Dinucleating Ligands: Silver(I) Trifluoromethanesulfonate Complexes of the Isomers of Bis(di(1H-pyrazolyl)methyl)-1,1′-biphenyl.

In the search for new examples of systems that self-assemble into cyclic metal–organic architectures, the six isomers of X,Y′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, LXY, and their silver(I) trifluoromethanesulfonate complexes were prepared. Five of the six silver complexes gave crystals suitable for single crystal X-ray diffraction, with only the microcrystalline derivative of 2,3′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, L23, proving to be unsuitable for this analysis. Of the structurally characterized silver(I) complexes, that with L22 showed an unusual trans-spanning chelating coordination mode to silver. At the same time the ligand was also bound to a second silver center giving rise to a cyclic supramolecular isomer with a 22-membered metallacycle. The complex of L34 also gave a cyclic dication but with a remarkable 28-membered metallacycle ring. The remaining three derivatives were polymeric. The results of this study underscore that a 120° angle between dipyrazolylmethyl moieties across aro...

Structures of crystalline and amorphous phases of the poly(ethylene oxide)/lithium trifluoromethanesulfonate complexes as studied by solid-state high-resolution 13C nuclear magnetic resonance

Solid-state high-resolution 13C NMR studies are carried out on a series of PEO/LiCF3SO3 complexes with different EO/Li molar ratios at room temperature. The obtained spectra clearly show that there are four phases, namely the crystalline PEO, the amorphous PEO, the PEO3:LiCF3SO3 crystalline complex and the PEO3:LiCF3SO3 amorphous complex, coexisting in the samples with EO/Li molar ratios larger than 3. The solid-state 13C NMR spectrum of the PEO3:LiCF3SO3 crystalline complex exhibits six peaks with high resolution at room temperature, while the previously reported 13C NMR spectra showed only one peak. These six peaks are assigned with the combination of the 13C dipolar-INADEQUATE and the two-dimensional exchange spectra. Moreover, remarkable helical jumps of PEO segments are demonstrated to exist in the crystalline complex. Our study paves the way towards a better understanding of the phase structures and subsequently the conduction mechanism of PEO-based solid polymer electrolytes.

Synthesis, Characterisation and Biological Evaluation of Copper and Silver Complexes based on Acetylsalicylic Acid

Metalcarbonyl complexes with ligands derived from acetylsalicylic acid demonstrated high cytotoxic potential against various tumor cell lines and strong inhibition of the cyclooxygenase enzymes COX-1 and 2. In this study we tried to achieve comparable effects with [alkyne]silver or copper trifluoromethanesulfonate complexes which are more hydrophilic then the uncharged metalcarbonyl derivatives. All compounds were evaluated for growth inhibition against breast (MCF-7, MDA-MB 231) and colon cancer (HT-29) cell lines and for COX-1 and COX-2 inhibitory effects at isolated isoenzymes. Pure ligands showed neither cytotoxic nor COX-inhibitory effects. While the silver complexes of (but-2-ynyl)-2-acetoxybenzoate (But-ASS-Ag) and (but-2-yne-1,4-diyl)-bis(2-acetoxybenzoate) (Di-ASS-But-Ag) were strong cytostatics, only the copper complex Di-ASS-But-Cu was active. At the COX enzymes the complexes were more effective than their ligands and aspirin.

Tri(3-pyridyl)phosphine as Amphiphilic Ligand in the Rhodium-catalysed Hydroformylation of 1-Hexene

The molecular structure of carbonylchlorobis(tri(3-pyridyl)phosphine)rhodium, 1, has been determined by X-ray diffraction methods. The N-protonated trifluoromethanesulfonate (triflate) complex 3 was synthesised as a model compound for the extraction of a rhodium complex bearing amphiphilic ligands which can allow catalyst recycling in the hydroformylation of alkenes by using their distribution behavior in organic and aqueous solvents of different pH. The high water-solubility of the employed ligand renders the recycling method as only partly successful due to insufficient extraction from the water phase into the organic phase. In the hydroformylation of 1-hexene the production of n-heptanal is slightly disfavoured when using the ligand tri(3-pyridyl)phosphine as compared to triphenylphosphine which can be ascribed to a higher amount of ligand-deficient active rhodium complexes of the less basic pyridyl phosphine ligand under CO pressure.

Enantioselective Michael Additions of β‐Keto Esters to α,β‐Unsaturated Carbonyl Compounds Catalyzed by a Chiral Biquinoline N,N′‐Dioxide‐Scandium Trifluoromethanesulfonate Complex.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Enantioselective Michael additions of β-keto esters to α,β-unsaturated carbonyl compounds catalyzed by a chiral biquinoline N, N′-dioxide–scandium trifluoromethanesulfonate complex

A catalytic, enantioselective Michael addition of β-keto esters to α,β-unsaturated carbonyl compounds was achieved by using a chiral biquinoline N, N′-dioxide–scandium trifluoromethanesulfonate complex as a catalyst. The corresponding Michael adducts were obtained in high yields and with enantioselectivities up to 84% ee.

A structural study of the hydrated and the dimethylsulfoxide, N, N′-dimethylpropyleneurea, acetonitrile, pyridine and N, N-dimethylthioformamide solvated nickel(II) ion in solution and solid state

The structure of the solvated nickel(II) ion has been studied in solution by EXAFS in a series of solvents with different coordinating properties. The solvents studied are water, dimethylsulfoxide, N, N′-dimethylpropyleneurea (oxygen donors), acetonitrile, pyridine (nitrogen donors) and N, N-dimethylthioformamide (sulfur donor). A number of solid solvate structures has been determined crystallographically, hexakis(dimethylsulfoxide)nickel(II) perchlorate, [Ni(OS(CH 3) 2) 6](ClO 4) 2, tetrakis(dimethylsulfoxide)bis( N, N′-dimethylpropyleneurea)nickel(II) perchlorate, [Ni(OS(CH 3) 2) 4(OCN 2(CH 3) 2(CH 2) 3) 2](ClO 4) 2, tetrakis(pyridine)bis(trifluoromethanesulfonato)nickel(II), [Ni(NC 5H 5) 4(O 3SCF 3) 2], bisaquatetrakis(pyridine)nickel(II) perchlorate pyridine solvate, Ni(NC 5H 5) 4(OH 2) 2(ClO 4) 2·C 5H 5N, and hexakis( N, N-dimethylthioformamide)nickel(II) perchlorate, [Ni(SCHN(CH 3) 2) 6](ClO 4) 2, in order to be used as model compounds in the EXAFS studies of the solutions. The hydrated and the dimethylsulfoxide, acetonitrile and N, N-dimethylthioformamide solvated nickel(II) ions are all octahedral in solution with Nisolvent bond distances of 2.055(2), 2.064(2), 2.062(2) and 2.454(2) Å, respectively. Pyridine has too low permittivity to allow dissociation of nickel(II) salts. The nickel(II) trifluoromethanesulfonate complex is solvated by four pyridines in the equatorial plane with two oxygen atoms from the trifluoromethanesulfonate anions in the axial positions completing the octahedron, and the perchlorate salt takes up water very easily, forming a bisaqua(tetrakispyridine)nickel(II) solvate in both solid state and pyridine solution. The NiN and NiO bond distances are approximately 2.10 Å in these complexes. The nickel(II) ion is five-coordinated, probably in square-pyramidal fashion, in N, N′-dimethylpropyleneurea with a mean NiO bond distance of 2.000(2) Å. The reason for this lower coordination number is certainly sterical due to the bulkiness of the N, N′-dimethylpropyleneurea molecule. The octahedral complexes with oxygen and sulfur donor solvents are green, while with nitrogen donor solvents they are blue due to different ligand field splitting ability versus the nickel(II) ion. The five-coordinated N, N′-dimethylpropyleneurea solvated nickel(II) ion has a deep red color.

TG-DTA study on the lanthanoid trifluoromethanesulfonate complexes

The thermal decomposition of the lanthanoid trifluoromethanesulfonate (triflate) complexes {Ln(CF3SO3)3·9H2O; Ln=La-Lu{ was studied by TG and DTA methods. From the endothermic and exothermic data of Ln(CF3 SO3)3·9H2O complexes, pyrolysis behavior of the complexes is classified into three groups: 1) La-Nd salts, 2) Sm-Ho salts, 3) Er-Lu salts. It has also shown that all the final decomposition products were found to result in the formation of LnF3.

(C5Me5)2U(Me)(OTf)]2: A New Reagent for Uranium Metallocene Chemistry. Preparation of the First Actinide Hydrazonato Complexes

The synthesis and characterization of the first actinide hydrazonato complex, (C5Me5)2U(η2(N,N‘)-CH3NNCPh2)(OTf) (3), has been made possible by use of the organouranium(IV) trifluoromethanesulfonate (triflate) complex [(C5Me5)2U(CH3)(OTf)]2 (2; OTf = OSO2CF3), which is derived from the reaction between (C5Me5)2U(CH3)2 and Ph3COTf. The related chemistry for (C5Me5)2U(CH3)(Cl) is also reported. All new complexes have been structurally characterized.

ChemInform Abstract: Enantioselective Michael Addition of β‐Keto Esters to Methyl Vinyl Ketone Employing a Chiral N,N′‐Dioxide—Scandium Trifluoromethanesulfonate Complex as a Catalyst.

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Enantioselective Michael addition of beta-keto esters to methyl vinyl ketone employing a chiral N,N'-dioxide-scandium trifluoromethanesulfonate complex as a catalyst.

An enantioselective Michael addition of beta-keto esters to methyl vinyl ketone exploiting a chiral N,N'-dioxide-scandium trifluoromethanesulfonate complex as a catalyst affords the corresponding Michael adducts in high yields and with enantioselectivities of up to 80% ee.

Synthesis of (phosphine)silver(I) trifluoromethanesulfonate complexes and the molecular structure of di-μ-trifluoromethylsulfonate-(tetrakis-triphenylphosphine)disilver(I)

Reactions of silver trifluoromethanesulfonate (triflate) and equimolar amounts of triphenylphosphine, 1,2-bis(diphenylphosphino)ethane, bis(diphenylphosphino)methane, or 1,1-bis(diphenylphosphino)ethane in either DME or CH2Cl2 solution produced the corresponding 1:1 complexes [(L)Ag(I)(SO3CF3)] (2–5) in >80% yields. A related 2:1 complex [(Ph3P)2Ag(I)(SO3CF3)] (1) was also obtained using 2 equiv. of Ph3Ph. Both 31P NMR variable temperature solution spectra as well as solid state spectra were recorded for the new complexes, and were generally helpful in structural assignments. An X-ray crystallographic study of 1 shows this to be a dimeric complex with bridging triflate ions; the silver atoms having distorted tetrahedral coordination.

Lanthanide trifluoromethanesulfonate complexes with ε‐caprolactam: Synthesis, characterization and structure of the praseodymium compound

Complexes of formulas [Ln(e-cl)8] (F3C-SO3)3 (Ln = La-Eu) and [Ln(ε‐cl)7] (F3C-SO3)3 (Ln = Gd, Tb, Dy, Yb, Lu, ε‐cl = ε‐caprolactam) were synthesized and characterized by elemental analysis, infrared spectroscopy, visible absorption spectroscopy of the Nd compound and emission spectroscopy of the Eu compound and the Gd compound, doped with Eu. IR experimental data suggest that the e-caprolactams are bonded to the central ions through the carbonyl oxygen and that the anions are not coordinated. The parameters calculated from the visible absorption spectrum of the Nd compound suggest electrostatic metal-ligand bonds. The emission spectrum of the europium compound suggests a D2d distorted towards C2v symmetry. X-ray single crystal analysis of the Pr compound shows that the anions are not coordinated and that the coordination polyhedron around the Pr3+ion has a slightly distorted D2d (dodecahedral) symmetry.