NSF3 und NSF2NMe2 als Liganden in der metallorganischen Chemie

Thiazyltrifluoride NSF₃ and Thiazyldifluoridedimethylamide NSF₂NMe₂: Ligands in Organometallic Chemistry From the reaction of [Re(CO)₅SO₂]⁺AsF₆^? ( 1 ) and [CpFe(CO)₂SO₂]⁺AsF₆^? ( 6 ) with NSF₃ ( 2 ) and NSF₂NMe₂ ( 4 ) the complexes [Re(CO)₅NSF₃]⁺AsF₆^? ( 3 ), [Re(CO)₅NSF₂NMe₂]⁺AsF₆^? ( 5 ), [CpFe(CO)₂NSF₃]⁺AsF₆^? ( 7 ), and [CpFe(CO)₂NSF₂NMe₂]⁺AsF₆^? ( 8 ) were obtained. The compounds have been characterised by X-ray crystallography, the ligand properties of 2 and 4 are discussed.     

Isolation and Characterization of a Non‐Rigid Hexamethylbenzene–SO2+ Complex

During our studies towards the preparation of the pentagonal‐pyramidal hexamethylbenzene dication C₆(CH₃)₆²⁺, we isolated the unprecedented dicationic species C₆(CH₃)₆SO²⁺ (AsF₆⁻)₂ from the reaction of hexamethylbenzene with a mixture of anhydrous HF, AsF₅, and liquid SO₂. This compound can be understood as a complex of unknown SO²⁺ with hexamethylbenzene. Herein, we report on its synthesis, molecular structure, and spectroscopic characterization.     

The relationship of graphite/AsF5 intercalation compounds to Cx+AsF6− salts

Graphite intercalated by AsF₅ has been reported to give compounds of formula C_8nAsF₅ where n is the stage. It is doubtful however if materials of exact composition C_8nAsF₅ have ever been obtained. The intercalation of graphite by AsF₅ is associated with electron oxidation of the graphite according to the equation: 3AsF₅ + 2e^? → 2AsF₆^? + AsF₃. Because of the easy removal or displacement of AsF₃ the As:F ratio is readily increased beyond 5. By treating graphite with excess AsF₅, removing volatiles under vacuum and repeating the cycle seven times a first stage salt C₁₀⁺AsF₆^? (C_o = 7.96 ā) is made. Interaction of graphite with AsFs in the molar ratio 8:1, within a small volume reactor, yields a material of approximate composition C₈AsF₅. The major component of the volatiles at the onset of their removal is AsF₅,, but, at a composition close to C₁₀AsF₅, is AsF₃. ‘Graphite AsF₅’ can be prepared by adding AsF₃ to C_xAsF₆ salts. The electrical conductivities of ‘AsF₅’ and AsF₆ relatives will be compared and discussed.     

X-ray crystal structure and raman spectrum of tribromine(1+) hexafluoroarsenate(V), Br3+AsF6−, and raman spectrum of pentabromine(1+) hexafluoroarsenate(V), Br5+AsF6−

A single crystal of Br₃⁺AsF₆^? was isolated from a sample of BrF₂⁺AsF₆^? which had been stored for 20 years. It was characterized by x-ray diffraction and Raman spectroscopy. It is shown that Br₃⁺AsF₆^? (triclinic, a = 7.644(7) Å, b = 5.641(6) Å, c = 9.810(9) Å, α = 99.16(8)°, β = 86.61(6)°, γ = 100.11(7)°, space group P1 R(F) = 0.0608) is isomorphous with I₃⁺AsF₆^?. The structure consists of discrete Br₃⁺ and AsF₆^? ions with some cation-anion interaction causing distortion of the AsF₆^? octahedron. The Br₃⁺ cation is symmetric with a bond distance of 2.270(5) Å and a bond angle of 102.5(2)°. The three fundamental vibrations of Br₃⁺ were observed at 297 (ν₃), 293 (ν₁), and 124 cm^?1 (ν₂). The Raman spectra of Cl₃⁺AsF₆^? and I₃⁺AsF₆^? were reinvestigated and ν₃(B₁) of I₃⁺ was reassigned. General valence force fields are given for the series Cl₃⁺, Br₃⁺, and I₃⁺. Reactions of excess Br₂ with either BrF₂⁺AsF₆^? or O₂⁺AsF₆^? produce mixtures of Br₃⁺AsF₆^? and Br₅⁺AsF₆^?. Based on its Raman spectra, the Br₅⁺ cation possesses a planar, centrosymmetric structure of C_2h symmetry with three semi-ionically bound, collinear, central Br atoms and two more covalently, perpendicularly bound, terminal Br atoms.     

Reactions of Bromine Fluoride Dioxide,BrO2F,for the Generation of the Mixed‐Valent Bromine Oxygen Cations Br3O4+ and Br3O6+

A reliable synthesis of unstable and highly reactive BrO₂F is reported. This compound can be converted into BrO₂⁺SbF₆^?, BrO₂⁺AsF₆^?_, and BrO₂⁺AsF₆^??2 BrO₂F. The latter decomposes into mixed‐valent Br₃O₄?Br₂⁺AsF₆^? with five‐, three‐, one‐, and zero‐valent bromine. BrO₂⁺ H(SO₃CF₃)₂^? is formed with HSO₃CF₃. Excess BrO₂F yields mixed‐valent Br₃O₆⁺OSO₃CF₃^? with five‐ and three‐valent bromine. Reactions of BrO₂F and MoF₅ in SO₂ClF or CH₂ClF result in Cl₂BrO₆⁺Mo₃O₃F₁₃^?. The reaction of BrO₂F with (CF₃CO)₂O and NO₂ produces O₂Br‐O‐CO‐CF₃ and the known NO₂⁺Br(ONO₂)₂^?. All of these compounds are thermodynamically unstable.     

Fluorierung von Cyanurchlorid und Tieftemperatur-Kristallstruktur von [(ClCN)3F]+ [AsF6]−

Fluorination of Cyanuric Chloride and Low-Temperature Crystal Structure of [(ClCN)₃F]⁺[AsF₆]^? The low-temperature fluorination of cyanuric chloride, (ClCN)₃, with F₂/AsF₅ in SO₂F₂ solution yielded the salt [(ClCN)₃F]⁺ [AsF₆]^? ( 1 ) essentially in quantitative yield. Compound 1 was identified by a low-temperature single crystal X-ray structure determination: R 3 c, trigonal, a = b = 10.4246(23) Å, c = 15.1850(24) Å, V = 1429.1(4) Å 3, Z = 6, R_F = 0.056, R_w = 0.076 (for significant reflections), R_F = 0.088, R_w = 0.079 (for all reflections). Fluorination of neat (ClCN)₃ with [NF₄]⁺ [Sb₂F₁₁]^? yielded NF₃, CClF₃, SbF₃, N₂ and traces of CF₄. A qualitative scale for the oxidizing strength of the oxidative fluorinators NF₄⁺ and (XCN)₃F⁺ (X = H, F, Cl) has been computed ab initio.     

Li+ cation coordination in [Li2(CF3SO3)2(diglyme)] and [Li3(C2F3O2)3(diglyme)]

The title compounds, poly­[[[bis(2‐methoxy­ethyl) ether]­lithium(I)]‐di‐μ₃‐tri­fluoro­methanesulfonato‐lithium(I)], [Li₂(CF₃SO₃)₂(C₆H₁₄O₃)]_n, and poly­[[[bis(2‐methoxy­ethyl) ether]­lithium(I)]‐di‐μ₃‐tri­fluoro­acetato‐dilithium(I)‐μ₃‐tri­fluoro­acetato], [Li₃(C₂F₃O₂)₃(C₆H₁₄O₃)]_n, consist of one‐dimensional polymer chains. Both structures contain five‐coordinate Li⁺ cations coordinated by a tridentate diglyme [bis(2‐methoxy­ethyl) ether] mol­ecule and two O atoms, each from separate anions. In both structures, the [Li(diglyme)X₂]^? (X is CF₃SO₃ or CF₃CO₂) fragments are further connected by other Li⁺ cations and anions, creating one‐dimensional chains. These connecting Li⁺ cations are coordinated by four separate anions in both compounds. The CF₃SO₃^? and CF₃CO₂^? anions, however, adopt different forms of cation coordination, resulting in differences in the connectivity of the structures and solvate stoichiometries.     

Über das Donor‐Verhalten von Bis(pyrazolyl)‐Schwefel‐Derivaten

The Donor Properties of Bis(pyrazolyl)‐Sulfur Derivatives From the reactions of bis(pyrazolyl)sulfane S(pz)₂ ( 1 ) with the fluoro Lewis acids BF₃ and AsF₅ in liquid SO₂ the 1:2‐adducts S(pz·BF₃)₂ ( 2 ) and S(pz·AsF₅)₂ ( 3 ) are obtained. 1 reacts with [Co(SO₂)₄(FAsF₅)₂] to give the doubly bridged FAsF₄F dimeric complex [Co{S(pz)₂}(FAsF₅)(SO₂)(μ‐FAsF₄F)]₂ ( 5 ). From F₂S(pz)₂ and [Ni(SO₂)₆](AsF₆)₂, the fluorocubane [Ni₄F₄{S(pz)₂}₄(μ‐FAsF₄F)₂](AsF₆)₂·4SO₂ ( 8 ) is isolated. The X‐ray structures of the compounds 2 , 3 , 5 and 8 are reported.     

Chiral η6‐Arene/N‐Tosylethylenediamine–Ruthenium(II) Complexes: Solution Behavior and Catalytic Activity for Asymmetric Hydrogenation

Aromatic ketones are enantioseletively hydrogenated in alcohols containing [RuX{(S,S)‐Tsdpen}(η⁶‐p‐cymene)] (Tsdpen=TsNCH(C₆H₅)CH(C₆H₅)NH₂; X=TfO, Cl) as precatalysts. The corresponding Ru hydride (X=H) acts as a reducing species. The solution structures and complete spectral assignment of these complexes have been determined using 2D NMR (¹H‐¹H DQF‐COSY, ¹H‐¹³C HMQC, ¹H‐¹⁵N HSQC, and ¹H‐¹⁹F HOESY). Depending on the nature of the solvents and conditions, the precatalysts exist as a covalently bound complex, tight ion pair of [Ru⁺(Tsdpen)(cymene)] and X^?, solvent‐separated ion pair, or discrete free ions. Solvent effects on the NH₂ chemical shifts of the Ru complexes and the hydrodynamic radius and volume of the Ru⁺ and TfO^? ions elucidate the process of precatalyst activation for hydrogenation. Most notably, the Ru triflate possessing a high ionizability, substantiated by cyclic voltammetry, exists in alcoholic solvents largely as a solvent‐separated ion pair and/or free ions. Accordingly, its diffusion‐derived data in CD₃OD reflect the independent motion of [Ru⁺(Tsdpen)(cymene)] and TfO^?. In CDCl₃, the complex largely retains the covalent structure showing similar diffusion data for the cation and anion. The Ru triflate and chloride show similar but distinct solution behavior in various solvents. Conductivity measurements and catalytic behavior demonstrate that both complexes ionize in CH₃OH to generate a common [Ru⁺(Tsdpen)(cymene)] and X^?, although the extent is significantly greater for X=TfO^?. The activation of [RuX(Tsdpen)(cymene)] during catalytic hydrogenation in alcoholic solvent occurs by simple ionization to generate [Ru⁺(Tsdpen)(cymene)]. The catalytic activity is thus significantly influenced by the reaction conditions.     

Cationic Allyl Complexes of the Rare‐Earth Metals: Synthesis,Structural Characterization,and 1,3‐Butadiene Polymerization Catalysis

Monocationic bis‐allyl complexes [Ln(η³‐C₃H₅)₂(thf)₃]⁺[B(C₆X₅)₄]^? (Ln=Y, La, Nd; X=H, F) and dicationic mono‐allyl complexes of yttrium and the early lanthanides [Ln(η³‐C₃H₅)(thf)₆]²⁺[BPh₄]₂^? (Ln=La, Nd) were prepared by protonolysis of the tris‐allyl complexes [Ln(η³‐C₃H₅)₃(diox)] (Ln=Y, La, Ce, Pr, Nd, Sm; diox=1,4‐dioxane) isolated as a 1,4‐dioxane‐bridged dimer (Ln=Ce) or THF adducts [Ln(η³‐C₃H₅)₃(thf)₂] (Ln=Ce, Pr). Allyl abstraction from the neutral tris‐allyl complex by a Lewis acid, ER₃ (Al(CH₂SiMe₃)₃, BPh₃) gave the ion pair [Ln(η³‐C₃H₅)₂(thf)₃]⁺[ER₃(η¹‐CH₂CH?CH₂)]^? (Ln=Y, La; ER₃=Al(CH₂SiMe₃)₃, BPh₃). Benzophenone inserts into the La? C_allyl bond of [La(η³‐C₃H₅)₂(thf)₃]⁺[BPh₄]^? to form the alkoxy complex [La{OCPh₂(CH₂CH?CH₂)}₂(thf)₃]⁺[BPh₄]^?. The monocationic half‐sandwich complexes [Ln(η⁵‐C₅Me₄SiMe₃)(η³‐C₃H₅)(thf)₂]⁺[B(C₆X₅)₄]^? (Ln=Y, La; X=H, F) were synthesized from the neutral precursors [Ln(η⁵‐C₅Me₄SiMe₃)(η³‐C₃H₅)₂(thf)] by protonolysis. For 1,3‐butadiene polymerization catalysis, the yttrium‐based systems were more active than the corresponding lanthanum or neodymium homologues, giving polybutadiene with approximately 90 % 1,4‐cis stereoselectivity.     

Reaktionen von Trihalogendithiatriazinen und Trifluortriazin mit Halogen-Lewis-Säuren

Reactions of Trihalodithiatriazines and Trifluorotriazine with Halogen-Lewis-Acids . From the reaction of (XCN)(XSN)₂ and MX₅ (X = Cl, M = Sb; X = F, M = As) the corresponding salts [(XCN)(XSN)(SN)]⁺MX₆^? ( 2, 4 ) are obtained. (FCN)₃ adds AsF₅ to the nitrogen-bonded adduct (FCN)₃ · AsF₅ ( 6 ). The X-ray-structure of 6 is reported.     

Pertechnetyl Fluorosulfate, [TcO3]+[SO3F]−

A one step synthesis of [TcO₃]⁺[SO₃F]^? is reported. The compound is volatile at room temperature and has according to calculations a tetrahedral coordination around Tc and a monodentate SO₃F group. In the solid state the [SO₃F]^? anion bridges three [TcO₃]⁺ cations, and vice versa. Space group P2₁/c, Z = 4, lattice dimensions at 173 K: a = 695.4(11), b = 808.6(12), c = 893.3(14) pm, β = 97.36(8)°.     

Fluoride-fluorosulfates of arsenic (V) and arsenic (III)

The synthesis of AsF₃(SO₃F)₂ by the reaction AsF₃ + S₂O₆F₂→AsF₃(SO₃F)₂ is described. Various alternate routes leading to similar arsenic (V) fluoride-fluorosulfates are discussed. All materials are clear, viscous, strongly associated liquids of the general formula AsF_n(SO₃F)_5?n, with n ranging from about 2 to 4. The presence of fluorosulfate bridges is ascertained by IR and Raman spectra.The spectroscopic investigation is also extended to arsenic (III) fluoride- fluorosulfates.     

Cationic versus neutral Ru(II)--N-heterocyclic carbene complexes as latent precatalysts for the UV-induced ring-opening metathesis polymerization

A series of cationic and neutral Ru^II complexes of the general formula [Ru(L)(X) (tBuCN)₄]⁺X^? and [Ru(L)(X)₂(tBuCN)₃)], that is, [Ru(CF₃SO₃){NCC(CH₃)₃}₄(IMesH₂)]⁺[CF₃SO₃]^? ( 1 ), [Ru(CF₃SO₃){NCC(CH₃)₃}₄(IMes)]⁺[CF₃SO₃]^? ( 2 ), [RuCl{NCC(CH₃)₃}₄(IMes)]⁺Cl^? ( 3 ), [RuCl{NCC(CH₃)₃}₄(IMesH₂)⁺Cl^?]/[RuCl₂{NCC(CH₃)₃}₃(IMesH₂)] ( 4 ), and [Ru(NCO)₂{NCC(CH₃)₃}₃(IMesH₂)] ( 5 ) (IMes=1,3‐dimesitylimidazol‐2‐ylidene, IMesH₂=1,3‐dimesityl‐imidazolin‐2‐ylidene) have been synthesized and used as UV‐triggered precatalysts for the ring‐opening metathesis polymerization (ROMP) of different norborn‐2‐ene‐ and cis‐cyclooctene‐based monomers. The absorption maxima of complexes 1 – 5 were in the range of 245–255 nm and thus perfectly fit the emission band of the 254 nm UV source that was used for activation. Only the cationic Ru^II‐complexes based on ligands capable of forming μ²‐complexes such as 1 and 2 were found to be truly photolatent in ROMP. In contrast, complexes 3 – 5 could be activated by UV light; however, they also showed a low but significant ROMP activity in the absence of UV light. As evidenced by ¹H and ¹³C NMR spectroscopy, the structure of the polymers obtained with either 1 or 2 are similar to those found in the corresponding polymers prepared by the action of [Ru(CF₃SO₃)₂(IMesH₂)(CH‐2‐(2‐PrO)‐C₆H₄)], which strongly suggest the formation of Ru‐based Grubbs‐type initiators in the course of the UV‐based activation process. Precatalysts that have the IMesH₂ ligand showed significantly enhanced reactivity as compared with those based on the IMes ligand, which is in accordance with reports on the superior reactivity of IMesH₂‐based Grubbs‐type catalysts compared with IMes‐based systems.     

Dihalogen(pentafluorphenyl)sulfonium(IV)-hexafluoroarsenat C6F5SX2+AsF6− (X = Cl,Br) und Kristallstruktur von Di(pentafluorphenyl)sulfan (C6F5)2S

Dihalogen(Pentafluorophenyl)sulfonium(IV) Hexafluoroarsenate C₆F₅SX₂⁺AsF₆^? (X = Cl, Br) and Crystal Structure of Di(pentafluorophenyl)sulfane (C₆F₅)₂S The preparation and spectroscopic characterisation of the halogensulfonium salts C₆F₅SCl₂⁺AsF₆^? and C₆F₅SBr₂⁺AsF₆^? is reported. The new salts are much more stable than their trifluoromethyl derivatives. In addition the crystal structure of (C₆F₅)₂S is reported. Space group P4₃2₁2, Z = 4, 478 unique observed diffractometer data, R_int. = 0.07, lattice constants: a = 569.0(5) pm, c = 3785.8(22) pm, V = 1225 times; 10^?30 m³.     

Pentafluorethylschwefeltrifluorid: Synthese und Reaktionen

Pentafluorethyl Sulfurtrifluoride: Synthesis and Reactions By oxidation of (C₂F₅S?)₂ ( 1 ) with AgF₂ at 0°C a mixture of C₂F₅SF₃ ( 2 ) and C₂F₅SF₅ ( 3 ) besides C₂F₅S(O)F ( 4 ) is formed. With elemental fluorine only 3 is isolated, an intermediate in this reaction is (C₂F₅SF₄?)₂ ( 5 ). At ?40 to ?30°C the mixture of 2, 3 and 4 was reacted with TASF and AsF₅, to give TAS⁺ C₂F₅SF₄^? ( 6 ), TAS⁺ C₂F₅S(O)F₂^? ( 7 ) and C₂F₅SF₂⁺AsF₆^? ( 8 ), respectively. While 6 and 7 decompose rapidly in solution even at low temperatures, of thermally stable 8 the solid state structure was determined by x-ray diffraction.     

Univalent Gallium Complexes of Simple and ansa‐Arene Ligands: Effects on the Polymerization of Isobutylene

Using [Ga(C₆H₅F)₂]⁺[Al(OR^F)₄]^?( 1 ) (R^F=C(CF₃)₃) as starting material, we isolated bis‐ and tris‐η⁶‐coordinated gallium(I) arene complex salts of p‐xylene (1,4‐Me₂C₆H₄), hexamethylbenzene (C₆Me₆), diphenylethane (PhC₂H₄Ph), and m‐terphenyl (1,3‐Ph₂C₆H₄): [Ga(1,4‐Me₂C₆H₄)_2.5]⁺ ( 2⁺ ), [Ga(C₆Me₆)₂]⁺ ( 3⁺ ), [Ga(PhC₂H₄Ph)]⁺ ( 4⁺ ) and [(C₆H₅F)Ga(μ‐1,3‐Ph₂C₆H₄)₂Ga(C₆H₅F)]²⁺ ( 5²⁺ ). 4⁺ is the first structurally characterized ansa‐like bent sandwich chelate of univalent gallium and 5²⁺ the first binuclear gallium(I) complex without a Ga?Ga bond. Beyond confirming the structural findings by multinuclear NMR spectroscopic investigations and density functional calculations (RI‐BP86/SV(P) level), [Ga(PhC₂H₄Ph)]⁺[Al(OR^F)₄]^?( 4 ) and [(C₆H₅F)Ga(μ‐1,3‐Ph₂C₆H₄)₂Ga(C₆H₅F)]²⁺{[Al(OR^F)₄] ^?}₂ ( 5 ), featuring ansa‐arene ligands, were tested as catalysts for the synthesis of highly reactive polyisobutylene (HR‐PIB). In comparison to the recently published 1 and the [Ga(1,3,5‐Me₃C₆H₃)₂]⁺[Al(OR^F)₄]^? salt ( 6 ) (1,3,5‐Me₃C₆H₃=mesitylene), 4 and 5 gave slightly reduced reactivities. This allowed for favorably increased polymerization temperatures of up to +15 °C, while yielding HR‐PIB with high contents of terminal olefinic double bonds (α‐contents=84–93 %), low molecular weights (M_n=1000–3000 g mol^?1) and good monomer conversions (up to 83 % in two hours). While the chelate complexes delivered more favorable results than 1 and 6 , the reaction kinetics resembled and thus concurred with the recently proposed coordinative polymerization mechanism.     

Di­methyl(2‐methyl­phenyl)­ammonium hydroxo­tris­(penta­fluoro­phenyl)­borate

In the title compound, [(CH₃)₂(C₇H₇)NH][(C₆F₅)₃B(OH)] or C₉H₁₄N⁺·C₁₈HBF₁₅O^?, the distorted tetrahedral borate anions are strongly hydrogen bonded to the substituted ammonium cations. The N?O separation in the N—H?O hydrogen bond is 2.728 (3) Å.     

Protonation of CH3N3 and CF3N3 in Superacids: Isolation and Structural Characterization of Long‐Lived Methyl‐ and Trifluoromethylamino Diazonium Ions

The methylamino diazonium cations [CH₃N(H)N₂]⁺ and [CF₃N(H)N₂]⁺ were prepared as their low‐temperature stable [AsF₆]^? salts by protonation of azidomethane and azidotrifluoromethane in superacidic systems. They were characterized by NMR and Raman spectroscopy. Unequivocal proof of the protonation site was obtained by the crystal structures of both salts, confirming the formation of alkylamino diazonium ions. The Lewis adducts CH₃N₃?AsF₅ and CF₃N₃?AsF₅ were also prepared and characterized by low‐temperature NMR and Raman spectroscopy, and also by X‐ray structure determination for CH₃N₃?AsF₅. Electronic structure calculations were performed to provide additional insights. Attempted electrophilic amination of aromatics such as benzene and toluene with methyl‐ and trifluoromethylamino diazonium ions were unsuccessful.     

Zur Kenntnis der Chemie und der Struktur von Olefin-monocyano-dicarbonyl-ferrat-Anionen

About Chemistry and Structure of Olefin-monocyano-dicarbonyl-ferrate Anions By the reactions of olenFe(CO)₃ [olen = C₅H₈(isoprene), C₇H₁₀(cycloheptadiene-1,3), C₈H₁₄(2,5-dimethylhexadiene-1,3)] with sodium bis [trimethylsilyl]amide the new anions [olenFe(CO)₂CN]^? are formed. All so far known [olenFe(CO)₂CN]^? complexes [olen = C₅H₈(isoprene), C₇H₁₀[cycloheptadiene-1,3], C₄H₆(butadiene), C₅H₈(pentadiene-1,3), C₆H₈(cyclohexadine-1,3), C₆H₁₀(2,3-dimethylbutadiene), C₈H₈(cyclooctatetraene)] have fluctional structures in solution as shown by ¹³C NMR spectroscopic investigations. At low temperatures only the isomer exists, in which the CN^? ligand and one of the two CO molecules occuppy the basal positions of a square pyramide together with 2 C atoms of the diene part.