Tieftemperatur-flüssigphase-fluorierung von (C6F5)2Te: Bildung von (C6F5)2TeF2, (C6F5)2TeF4 und (C6F11)2TeF4 [1]

(C₆F₅)₂Te reacts with elemental fluorine step by step to form the tellurium fluorides (C₆F₅)₂TeF₂, (C₆F₅)₂TeF₄ and (C₆F₁₁)₂TeF₄, which can be isolated in pure states. The intermediates (C₆F_11?2n)₂TeF₄ (n = 1,2) are detected spectroscopically. (C₆F₅)₂TeF₂ is also formed from the reaction of (C₆F₅)₂Te with XeF₂. The preparations, properties and ¹⁹F n.m.r. spectra of these new compounds are discussed, the mass and vibrational spectra are described.     

Synthesis and reactivity of [N(C6H4Br)3][B(C6F5)4]: the X-ray crystal structure of [Fe(C5H5)2][B(C6F5)4]

A new chemical oxidant [N(4-C₆H₄Br)₃][B(C₆F₅)₄], was prepared and used to synthesize [Fe(C₅H₅)₂][B(C₆F₅)₄]. The crystal structure of [Fe(C₅H₅)₂][B(C₆F₅)₄] was determined.     

Reactions of [Pd(C6F5)2(CNR)2] with [PdCl2(NCPh)2]. Insertion of p-MeC6H4NC into Pd-C6F5 bonds

[Pd(C₆F₅)₂(CNR)₂] (R = Cy, Bu^t, p-MeC₆H₄ (p-Tol)) react with [PdCl₂(NCPh)₂] to give [Pd₂(μ-Cl)₂(C₆F₅)₂(CNR)₂]. In refluxing benzene insertion of isocyanide into the C₆F₅Pd bonds occurs only for R = p-Tol, to give a imidoyl bridged polynuclear complex cis-[Pd₂ (μ-Cl)₂[μ-C(C₆F₅) = N(Tol-p)]_2n]. This complex reacts with (a) Tl(acac) to give [Pd₂{μ-C(C₆F₅) = N(Tol-p)}₂(acac)₂]; (b) neutral monodentate ligands to afford dimeric complexes [Pd₂{μ-C(C₆F₅) = N(Tol-p)}₂Cl₂L₂] (L = NMe₃, py, 4-Me-py, SC₄H₈), and (c) isocyanides to give insoluble complexes of the same composition which are thought to be polymeric, [$\text{Pd}$(CNR)Cl{μ-C(C₆F₅) = $\text{N}$(p-Tol)}]_n (R = p-Tol, Me, Bu^t). Thermal decomposition of cis-[Pd₂ (μ-Cl)₂ [μ-C(C₆F₅) = N( p-Tol)]_2n] gives the diazabutadiene species (p-Tol)NC(C₆F₅)C(C₆F₅)N(p-Tol) in high yield.     

[1,1-Bis(diphenylphosphino)ferrocene]palladium(II) complexes with fluorinated benzenethiolate ligands: examination of the electronic effects in the solid state, solution and in the Pd-catalyzed Heck reaction with the catalytic system [Pd(dppf)(SRF)2]

A series of palladium thiolate complexes of the type [Pd(dppf)(SR_F)₂] have been synthesized in good yields by metathetical reactions of [Pd(dppf)Cl₂] with [Pb(SR_F)₂], (SR_F=⁻SC₆F₅, ⁻SC₆F₄-4-H, ⁻SC₆H₄-2-CF₃, ⁻SC₆H₄-4-F, ⁻SC₆H₄-3-F) and their crystal structures determined. The effect of the different thiolates in the structural properties of the complexes both in the solid state and in solution have been analyzed. Heck coupling reactions were carried out using the complexes [Pd(dppf)(SR_F)₂], SR_F=⁻SC₆F₅ (1), ⁻SC₆F₄-4-H (2), ⁻SC₆H₄-2-CF₃ (3), ⁻SC₆H₄-4-F (4), ⁻SC₆H₄-3-F (5) as catalysts in order to examine both the effect of the thiolates and the P-Pd-P bite angles in the reaction of bromobenzene and styrene. The results obtained indicate that electron-withdrawing substituents may favor higher yields in the Pd catalyzed Heck reaction using [Pd(dppf)(SR_F)₂] as catalysts.     

Synthese und Kristallstrukturen der Bismutchalkogenolate Bi(SC6H5)3, Bi(SeC6H5)3 und Bi(S‐4‐CH3C6H4)3

Synthesis and Crystal Structures of Bismuth Chalcogenolato Compounds Bi(SC₆H₅)₃, Bi(SeC₆H₅)₃, and Bi(S‐4‐CH₃C₆H₄)₃ Bismuth(III) acetate reacts with thiophenol in ethyl alcohol at 80 °C to yield Bi(SC₆H₅)₃ ( 1 ). Slow cool down of the deep yellow mixture lead to the formation of orange crystals of 1 . The homotype phenylselenolato compound of bismuth Bi(SeC₆H₅)₃ ( 2 ) has been prepared by the reaction of BiX₃ (X = Cl, Br) with Se(C₆H₅)SiMe₃ in diethyl ether. In the same way as Bi(SC₆H₅)₃ ( 1 ) the reaction between bismuth(III) acetate and 4‐tolulenethiole results in red crystals of Bi(S‐4‐CH₃C₆H₄)₃ ( 3 ). In consideration of three longer Bi–E distances (intermolecular interactions, E = S; Se) the Bi(EPh)₃ molecules form via face‐linked octahedra 1‐dimensional chains in the crystal lattice, while for 3 the 1‐dimensional chain is formed by face‐linked trigonal prisma. We reported herein the synthesis and structures of Bi(SC₆H₅)₃ ( 1 ), Bi(SeC₆H₅)₃ ( 2 ), and Bi(S‐4‐CH₃C₆H₄)₃ ( 3 ).     

Some reactions of copper(I) pentafluorothiophenolate as a nucleophile

Several aromatic compounds containing one or two C₆F₅S groups have been prepared by nucleophilic displacement reactions using CuSC₆F₅ in DMF solution. Aromatic iodine or bromine, rather than chlorine of fluorine is replaced by the SC₆F₅ group using CuSC₆F₅. A mechanism is postulated. New compounds prepared include $\text{p}$-(C₆F₆F₅S)₂C₆H₄, $\text{o}$- and $\text{m}$-(C₆F₅S)₂C₆F₄ and $\text{p}$XC₆H₄SC₆F₅(X=C1, NO₂, I, CH₃, CO₂C₂H₅).     

Darstellung und Eigenschaften neuer Tris(fluoraryl)borane

Preparation and Properties of New Tris(fluoroaryl)boranes B(2-FC₆H₄)₃, B(4-FC₆H₄)₃, B(2,6-F₂C₆H₃)₃ and B(C₅F₄N)₃ are prepared from the reactions of RMgX with boron trifluoride, B(OC₆F₅)₃ and B(SC₆F₅)₃ from C₆F₅XH (X = O, S) and boron trichloride. The synthetic routes and the properties of these mainly new compounds are described.     

Protonation of the metal—metal bond in Fe2(μ-A)(μ-A′)(CO)4L2 complexes (A  A′ SC6H5, P(C6H5)2, P(CH3)2; A  SC6H5, A′ z.dbnd; P(C6H5)2; L z.dbnd; P(C6H5)3-n(CH3)n). : III. Experimental study of the influence of the A and A′ bridges on the basicity of the metal—metal bond

In order to check the influence of the bridges on the basicity of the metal—metal bond in Fe₂(μ-A)(μ-A′)(CO)₄L₂ complexes, the compounds with A  A′ SC₆H₅, P(C₆H₅)₂; P(CH₃)₂; A  SC₅H₅, A′ P(C₆H₅)₂ and L  P(CH₃)_3-n (C₆H₅)_n (n  0—3) have been prepared. IR and PMR spectroscopic results are interpreted in structural terms, and show that the Fe₂(SC₆H₅)(P(C₆H₅)₂.)-(CO)₄L₂ complexes are non rigid on the NMR time scale for n = 0, 1. Replacement of the first SC₆H₅ bridge by a P(C₆H₅)₂ bridge markedly increase the basicity of the metal—metal bond, but replacement of the second SC₆H₅ bridge has no significant effect.     

Synthesis of fluorinated trithioether compounds: X-ray structures of 1,3,5-(CH2SRf)3-2,4,6-(CH3)3C6, Rf = C6F5, 4-HC6F4, or 2-FC6H4

A series of three new trithioether compounds containing fluorinated phenyl moieties, 1,3,5-(CH₂SR_f)₃-2,4,6-(CH₃)₃C₆, R_f = C₆F₅ (1), 4-HC₆F₄ (2), or 2-FC₆H₄ (3), were prepared by treatment of 1,3,5-(CH₂Br)₃-2,4,6-(CH₃)₃C₆ with the corresponding Pb(SC₆F₅)₂ or NaSR_f. The new structures were verified by elemental analyses, IR, ¹H NMR, ¹⁹F NMR spectroscopies, and mass spectra. The single crystal X-ray diffraction studies of 1-3 show a similar cis,trans,trans-conformation for the three fluorophenylthiomethyl groups attached to the central benzene ring with all dihedral angles between planes of central ring and external rings close to 0°, giving flat molecules. Comparing, 1-3 with closely related tripodal molecules built-up on 2,4,6-trimethylbenzene, arrangement of one SR group respect to others seems to be defined by the nature of the R substituent. Then in the case of 1-3, a parallel arrangement of rings is favored over an orthogonal one, which would bring the ortho-F atoms close to H atoms of the methylene groups.     

A first methodical approach to salts with unsymmetrical fluorophenyl(pentafluorophenyl)difluoroiodonium(V) cations [Rf(RF)IF2] (Rf=x-FC6H4, x=2, 3, 4; RF=C6F5)

A promising approach to the unknown type of [Ar′(Ar)IF₂]X salts is offered. x-FC₆H₄IF₄ (x=2, 3, 4) reacts with C₆F₅BF₂ in CH₂Cl₂ and forms [x-FC₆H₄(C₆F₅)IF₂][BF₄] salts in good yields. For [4-FC₆H₄(C₆F₅)IF₂][BF₄] the fluoro-oxidizer property is shown in reactions with weakly reducing agents like E(C₆F₅)₃ (E=P, As, Sb, Bi) and ArI (Ar=4-FC₆H₄, C₆F₅). The fluorine/aryl substitution method is also applied to the synthesis of [(4-FC₆H₄)₂IF₂][BF₄], an example with two identical aryl groups in the difluoroiodonium(V) moiety.     

Polynuclear palladium and gold perhalophenyl derivatives with dppm bridges. Crystal and molecular structure of trans-C6F5Au(μ-dppm)Pd(C6F5)2(μ-dppm)AuC6F5 (dppm = Ph2PCH2PPh2)

Reactions of PdRR′(η¹-dppm)₂ (R = R′= C₆F₅ or C₆Cl₅; R = C₆F₅, R′= Cl; dppm = Ph₂PCH₂PPh₂) with the gold derivatives ClAu(tht), C₆F₅Au(tht), (C₆F₅)₃Au(tht) or O₃ClOAuPPh₃ (tht = tetrahydrothiophen) in appropriate ratios yield the bi- or tri-nuclear complexes PdRR′(dppm)₂AuCl, PdRR′(dppm)₂Au(C₆F₅); PdRR′(dppm)₂Au(C₆F₅)₃; PdRR′(dppmAuCl)₂; PdRR′(dppmAuC₆F₅)₂; PdRR′[dppmAu(C₆F₅)₃]₂, [PdRR′(dppm)₂Au]X (X = ClO₄ or BPh₄); [PPh₃Au(dppm)Pd(C₆F₅)₂(dppm)AuCl]ClO₄ or [PPh₃ Au(dppm)Pd(C₆F₅)₂(dppm)Au(C₆F₅)₃]ClO₄. The structure of trans-Pd(C₆F₅)₂[dppmAu(C₆F₅)]₂ has been determined by X-ray diffraction.     

35Cl NQR spectra of pentafluorophenylchloromethanes. The electronic influence of the pentafluorophenyl group

³⁵Cl NQR spectra of pentafluorophenylchloromethanes C₆F₅CH(R)Cl (R = H, CH₃, Cl, COOC₂H₅, C₆F₅) have been studied to obtain information on the electronic influence of the C₆F₅ group. On the basis of the data thus obtained and literature data, the electronic influence of the C₆F₅ group is discussed.     

Five-coordinate pentafluorobenzothiolate osmium(IV) complexes [Os(SC6F5)4(P(C6H4X-4)3)] (X = OCH3, CH3, F, Cl or CF3): Solid and solution structural characterization

The reactions of OsO₄ with excess of HSC₆F₅ and P(C₆H₄X-4)₃ in ethanol afford the five-coordinate compounds [Os(SC₆F₅)₄(P(C₆H₄X-4)₃)] where X = OCH₃ 1a and 1b, CH₃ 2a and 2b, F 3a and 3b, Cl 4a and 4b or CF₃ 5a and 5b. Single crystal X-ray diffraction studies of 1 to 5 exhibit a common pattern with an osmium center in a trigonal-bipyramidal coordination arrangement. The axial positions are occupied by mutually trans thiolate and phosphane ligands, while the remaining three equatorial positions are occupied by three thiolate ligands. The three pentafluorophenyl rings of the equatorial ligands are directed upwards, away from the axial phosphane ligand in the arrangement “3-up” (isomers a). On the other hand, ³¹P{¹H} and ¹⁹F NMR studies at room temperature reveal the presence of two isomers in solution: The “3-up” isomer (a) with the three C₆F₅-rings of the equatorial ligands directed towards the axial thiolate ligand, and the “2-up, 1-down” isomer (b) with two C₆F₅-rings of the equatorial ligands directed towards the axial thiolate and the C₆F₅-ring of the third equatorial ligand directed towards the axial phosphane. Bidimensional ¹⁹F–¹⁹F NMR studies encompass the two sub-spectra for the isomers a (“3-up”) and b (“2-up, 1-down”). Variable temperature ¹⁹F NMR experiments showed that these isomers are fluxional. Thus, the ¹⁹F NMR sub-spectra for the “2-up, 1-down” isomers (b) at room temperature indicate that the two S-C₆F₅ ligands in the 2-up equatorial positions have restricted rotation about their C–S bonds, but this rotation becomes free as the temperature increases. Room temperature ¹⁹F NMR spectra of 3 and 5 also indicate restricted rotation around the Os–P bonds in the “2-up, 1-down” isomers (b). In addition, as the temperature increases, the ¹⁹F NMR spectra tend to be consistent with an increased rate of the isomeric exchange. Variable temperature ³¹P{¹H} NMR studies also confirm that, as the temperature is increased, the a and b isomeric exchange becomes fast on the NMR time scale.     

C6F5XeF, a versatile starting material in xenon-carbon chemistry

The molecules Ar_FXeF (Ar_F=C₆F₅, 2,4,6-C₆H₂F₃) with a more polar Xe-F bond than XeF₂ are versatile starting materials for substitution reactions. Fluorine-aryl substitutions with Cd(Ar_F)₂, C₆F₅SiMe₃/[F]⁻, and C₆F₅SiF₃ formed symmetric and/or asymmetric diarylxenon compounds. Applying C₆F₅BF₂, with a higher F⁻-affinity than the corresponding aryltrifluorosilane, in contrast gave the salt [RXe] [Ar_FBF₃]. Using the alkenyl and alkyl compounds CF₂=CFSiMe₃/[F]⁻, CF₃SiMe₃/[F]⁻, and Cd(CF₃)₂ in reactions with C₆F₅XeF, the perfluoroalkenyl or -alkyl transfer reagents were consumed without observing C₆F₅XeCF=CF₂ or C₆F₅XeCF₃ but the formation of Xe(C₆F₅)₂ (dismutation product) and in the latter case C₆F₅CF₃ (coupling product), gave hints of the desired intermediates.     

The thiolate anion as a nucleophile Part IV. Reactions of some pentafluorophenyl compounds

Direct nucleophilic substitution with sodium methanethiolate of the pentafluorophenyl compounds C₆F₅X (X = Cl, Br, I. NO₂, NH₂, CO₂H, SC₆F₅, OMe, OH) has given varying amounts of XC₆F₄(SMe), XC₆F₃(SMe)₂, C₆F₄(SMe)₂, XC₆F₂(SMe)₃ and C₆F₂(SMe)₄. In some cases cleavage of the aromatic carbon-X bond (X = Br, I, CO₂H, SC₆F₅) forming C₆F₄(SMe)H and C₆F₂(SMe)₃H, and the O-Me bond forming HOC₆F₂(SMe)₃ was observed. The new compounds isolated have been characterized by elemental analyses, infrared and mass spectra and their stereochemistries have been from their ¹H and ¹⁹F NMR spectra.     

Synthesis, NMR spectroscopic characterisation and reactions of 2,6-difluorophenylxenon fluoride, 2,6-F2C6H3XeF

[2,6-F₂C₆H₃Xe][BF₄] is quantitatively transferred into 2,6-F₂C₆H₃XeF in reactions with [NMe₄]F. The latter has been isolated as a colourless solid which is stable in dichloromethane solution at room temperature for approximately 1 h. 2,6-F₂C₆H₃XeF readily reacts with Me₃SiX (X = Cl, Br, CN, NCO, OCOCF₃, OSO₂CF₃, C₆F₅, 2,6-F₂C₆H₃) to give compounds of general compositions 2,6-F₂C₆H₃XeX which were identified by multinuclear NMR experiments. Evidence was found for C₆H₅Xe(2,6-F₂C₆H₃) as a product of the reaction with C₆H₅SiF₃.     

The direct electrochemical synthesis and crystal structure of salts of [M4(SC6H5)10]2− anions (M = Zn,Cd)

The salts [(C₂H₅)₃NH]₂[M₄(SC₆H₅)₁₀] (M = Zn, Cd) can be prepared by the electrochemical oxidation of the metal in an acetonitrile solution of triethylamine and benzenethiol. An X-ray crystal structure determination shows that the anion consists of a tetrahedron of metal atoms, each carrying a terminal -SC₆H₅ ligand, and connected to the three other metal atoms by bridging > SC₆H₅ groups. The results are compared with those for similar compounds reported in the literature.     

Reactions of (η5-C5H5)2Tir compounds with organic cyanides

The syntheses and properties of the titanium(III) complexes Cp₂Tir · R′CN (R = C₆H₅, o-, m-, p-CH₃C₆H₄, CH₂C₆H₅, C₆F₅, Cl; R′ = CH₃, t-C₄H₉, C₆H₅, o-CH₃C₆H₄, 2,6-(CH₃)₂C₆H₃) are described. In the complexes the nitrogen atom of the cyanide ligands is coordinated to the metal. The thermal stabilities of the complexes depend markedly on R and R′; on heating they undergo a novel reaction in which two cyanide ligands are coupled by formation of a CC bond, while the metal is oxidized to titanium(IV).     

Perhalophenyl complexes of palladium(II) containing keto-stabilized phosphorus ylides of the type Ph2P(CH2)nPPh2CHC(O)R

From suitable perhalophenyl derivatives of palladium(II), viz.: Pd(C₆F₅)₂-(SC₄H₈)₂, [Pd(μ-X′) (C₆X₅)₂]₂(NBu₄)₂, [Pd(μ-Cl)(C₆X₅)(SC₄H₈)]₂ (X = F, Cl, X′ = Cl, Br), new complexes of various types have been prepared, viz.: trans-Pd(C₆F₅)₂(Y)₂, Pd(C₆X₅)₂(Y), PdCl(C₆X₅)(Y) (X = F, Cl). The neutral ligand Y is a keto-stabilized phosphorus ylide of the type Ph₂P(CH₂)_nPPh₂CHC(O)R (n = 1, R = CH₃, C₆H₅; n = 2, R = C₆H₅) acting in a terminal monodentate P-donor or a bidentate chelate P,C-donor mode. The reaction of PdCl(C₆F₅)(Y) complexes with HCl leads to the corresponding PdCl₂(C₆F₅)(YH) complexes in which the phosphonium cation [YH]⁺ behaves as monodentate P-donor at its phosphinic end.IR and ³¹P NMR spectroscopy were used to decide the coordination mode of the ligands and, in some cases, to reveal the presence of two isomers.     

Reactions of metal carbonyl derivatives : XI. Tertiary phosphine,phosphite and stibine and ditertiaryphosphine and arsine derivatives of bis(μ-phenyl- sulphidotricarbonyliron)

The ditertiary phosphines (C₆H₅)₂P(CH₂)_nP(C₆H₅)₂ (n = 1 and 2), cis(C₆H₅)₂PC₂H₂P(C₆H₅)₂ and (C₆H₅)₂PN(C₂H₅)P(C₆H₅₂ and the ditertiary arsines (C₆H₅)₂As(CH₂)_nAs(C₆H₅)2 (_n = 1 and 2) react with [Fe(CO)₃SC₆H₅]₂ to give a wide range of products, the nature of which depends on the reaction conditions and the ligand involved. Examples of the different types of comp isolated include, (i) Fe₂(CO)₅[(C₆H₅)₂PCH₂P(C₆H₅)₂](SC₆H₅)₂, in which the ligand acts as a monodentate, (ii) {[Fe(CO)₂SC₆H₅]₂[(C₆H₅)₂PC₂H₄P(C₆H₅)₂]}₂, in which two [Fe(CO)₂SC₆H₅]₂ moieties are bridged by two diphosphine ligands, (iii) [Fe(CO)₂SC₆H₅]₂[(C₆H₅)₂PN(C₂H₅)P(C₆H₅)₂], in which the ligand bridges the two iron atoms, and (iv) Fe(CO)₃(SC₆H₅)₂Fe(CO)[(C₆H₅)₂PC₂H₂P(C₆H₅)₂], which contains the ligand chelated to a single iron atom. The tertiary phosphines PR₃ (R=C₂H₅ and C₆H₅), phosphites P(OR′)₃(R′ = CH₃, C₂H₅, i-C₃H₇ and C₆H₅) and the stibine Sb(C₆H₅)₃ bring about mono-, bis- or tris-substitution in [Fe(CO)₃SC₆H₅]₂ depending on the reaction conditions and the ligand involved. Whereas in solution [Fe(CO)₂L(SC₆H₅)]₂ [L = PR₃ (R = C₂H₅ and C₆H₅), P(OC₆H₅)₃ and Sb(C₆H₅)₃] exist as a single isomer, [Fe(CO)₂L′(SC₆H₅)]₂ [L′=P(OR′)₃ (R'=CH₃, C₂H₅ and i-C₃H₇)] occur as a mixture of isomers.