Dehalogenative aromatization of perchlorofluoroalicyclic compounds C6Cl6F6, C10Cl8F8 and C5Cl4F5N in the vapour phase or in solution

Dehalogenation of perhalogenated cyclohexanes C₆Cl₆F₆, 1-azacyclohexenes C₅Cl₄F₅N and bicyclo[4.4.0]dec-1(6)-enes C₁₀Cl₈F₈ in the vapour phase over iron filings at 350-500 °C and in solution with Zn and additivities (Cu, NiCl₂·6H₂O + bpy) at 80 °C (heterogeneous reaction) or with P(NEt₂)₃ at 20 °C (homogeneous reaction) was studied. In all cases, perfluoroarenes, chloroperfluoroarenes and dichloroperfluoroarenes (benzenes, naphthalenes and pyridines) were obtained in good overall yield.     

Perfluororganozink-verbindungen: darstellung und eigenschaften von (Rf)2Zn-komplexen (Rf = CF3, C2F5, C3F7, C6F5) [1]

A new method for the preparation of bis(perfluoroorgano) zinc compounds is described: CF₃I and C₆F₅I react with dialkylzinc in the presence of a Lewis base quantitatively to give (CF₃)₂Zn and (C₆F₅)₂Zn complexes, while the analogous reactions with C₂F₅I and iC₃F₇I do not yield the pure compounds. ¹H, ¹⁹F n.m.r, i.r. and Raman spectra are presented.     

Structural investigations on new iron-acyl derivatives of B(C6F5)3

Reactions between [Fe(η-C₅H₅)(MeCO)(CO)(L)], L = PPh₃ (1), PMe₃ (2), PPhMe₂ (3), PCy₃ (4), CO (5), and B(C₆F₅)₃ give new complexes [Fe(η-C₅H₅){MeCOB(C₆F₅)₃}(CO)(L)] L = PPh₃ (7), PMe₃ (8), PPhMe₂ (9), PCy₃ (10), CO (11), where B(C₆F₅)₃ coordinates selectively to the O-acyl groups. Hydrolysis of 7 gives [Fe(η-C₅H₅){HOB(C₆F₅)₃}(CO)(PPh₃)] (6). The X-ray structures of 6, 8 and 11 have been determined. Calculations, using density functional theory, demonstrate that the charge transfer to the acyl group on Lewis acid coordination is more significant in the σ than the π system. Both effects lead to a lengthening of the acyl C-O bond thus π populations cannot be inferred from the distance changes.     

Synthesis and molecular structures of heptafluoropropylated fullerenes: C70(n-C3F7)8, C70(n-C3F7)6O, and C70(C3F7)4

Ampoule reactions of C₇₀ with n- and i-C₃F₇I were carried out at 250-310 °C. Two step HPLC separations allowed the isolation of several C₇₀(n-C₃F₇)_4-8 and C₇₀(i-C₃F₇)₄ compounds. Crystal and molecular structures of C₇₀(n-C₃F₇)₈-V, C₇₀(n-C₃F₇)₆O, C₇₀(n-C₃F₇)₄, and three isomers of C₇₀(i-C₃F₇)₄ have been determined by X-ray crystallography using synchrotron radiation. Molecular structures of the new compounds were compared with the known examples and discussed in terms of addition patterns and relative energies of their formation.     

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.     

Intramolecular nucleophilic substitution in C6F5 moiety. The fluoride-dialkylamino exchange in decafluorodiphenlamino moiety

The reactions of [In(NEt₂)₃]₂ and Sb(NEt₂)₃ with an equimolar amount of decafluorodiphenylamine (DFDPA, LH) lead to the indium or antimony amides [(C₆F₅)₂NIn(NEt₂)₂]₂ (1) and (C₆F₅)₂NSb(NEt₂)₂ (2). Compound 2 rearranged further to give monofluoride Et₂NSb(F)[N(o-Et₂N-C₆F₄)(C₆F₅)] (3) and then difluoride F₂Sb[N(o-Et₂N-C₆F₄)₂] (4). The hydrolysis of 4 gave free ligand HN(o-Et₂N-C₆F₄)₂ (5). Closely related HN(o-Me₂N-C₆F₄)₂ (6) was prepared from the reaction of Bi(NMe₂)₃ with DFDPA. The reactions of LiN(C₆F₅)₂·THF with metal halides gave Sb[N(C₆F₅)₂]₃ (7), Me₃Sb(Br)[N(C₆F₅)₂] (8), Me₃Sb(Cl)[N(C₆F₅)₂] (9), Me₃Sb[N(C₆F₅)₂]₂ (10), [Li(THF)₂][In{N(C₆F₅)₂}₃Cl] (11). The X-ray structural investigations of 2 and 8 are presented.     

A widely varying range of products in reactions of C6F5BrF2, C6F5IF2, and C6F5IF4 with Lewis acids of different strength

The relative fluoride donor ability: C₆F₅BrF₂ > C₆F₅IF₂ > C₆F₅IF₄ was outlined from reactions with Lewis acids of graduated strength in different solvents. Fluoride abstraction from C₆F₅HalF₂ with BF₃·NCCH₃ in acetonitrile (donor solvent) led to [C₆F₅HalF·(NCCH₃)_n][BF₄]. The attempted generation of [C₆F₅BrF]⁺ from C₆F₅BrF₂ and anhydrous HF or BF₃ in weakly coordinating SO₂ClF gave C₆F₅Br besides bromoperfluorocycloalkenes C₆BrF₇ and 1-BrC₆F₉. In reactions of C₆F₅IF₂ with SbF₅ in SO₂ClF the primary observed intermediate (¹⁹F NMR, below 0 °C) was the 4-iodo-1,1,2,3,5,6-hexafluorobenzenium cation, which converted into C₆F₅I and 1-IC₆F₉ at 20 °C. The reaction of C₆F₅IF₄ with SbF₅ in SO₂ClF below −20 °C gave the cation [C₆F₅IF₃]⁺ which decomposed at 20 °C to C₆F₅I, 1-iodoperfluorocyclohexene, and iodoperfluorocyclohexane. Principally, the related perfluoroalkyl compound C₆F₁₃IF₄ showed a different type of products in the fast reaction with AsF₅ in CCl₃F (−60 °C) which resulted in C₆F₁₄. Intermediate and final products of C₆F₅HalF_n−1 (n = 3, 5) with Lewis acids were characterized by NMR in solution. Stable solid products were isolated and analytically characterized.     

Synthesis and molecular structures of heptafluoroisopropylated fullerenes: C60(i-C3F7)8, C60(i-C3F7)6, and C60(CF3)2(i-C3F7)2

One isomer of C₆₀(i-C₃F₇)₈, three isomers of C₆₀(i-C₃F₇)₆, and the first mixed perfluoroalkylated fullerene, C₆₀(CF₃)₂(i-C₃F₇)₂, have been isolated by HPLC from a mixture prepared by reaction of C₆₀ with heptafluoroisopropyl iodide in a glass ampoule at 260-290 °C. The molecular structures of the four new compounds have been determined by means of X-ray single crystal diffraction partially also by use of synchrotron radiation. Theoretical calculations at the DFT level of theory have been employed to rationalize the energetics of isomers and of C₆₀-R_f binding.     

新型取代基炔类分子的合成及其与B(C6F5)3的反应

合成了5种不同取代基的炔类化合物Mes2HSiC≡CPh(1,Mes=2,4,6-Me3C6H2)、[tBuC(NAr)2]GeC≡CPh(2,Ar=2,6-iPr2C6H3)、[PhC(NtBu)2]SnC≡CPPh2(3)、[HC(CMe)2(NAr)2]Sn C≡CPPh2(4)和[HC(CMe)2(NAr)2]ZnC≡CPPh2(5),研究了这些化合物与B(C6F5)3的反应.在与B(C6F5)3的反应中,1和2均发生1,1-碳硼化反应生成烯烃化合物(Ph)(Mes2HSi)C=C(C6F5)B(C6F5)2 (6)和{[tBuC(NAr)2]Ge}(Ph)C=C(C6F5)B(C6F5)2 (7), 7是一种GeⅡ/B松散Lewis酸碱对化合物;3~5则都发生B(C6F5)3与配体金属基的位置交换、进而配体金属基转换键合PPh2的反应,分别生成新颖的分子内双性离子炔烃化合物[PhC(NtBu)2]SnP(Ph2)C≡CB(C6F5)3 (8)、[HC(CMe)2(NAr)2]SnP(Ph2)C≡CB(C6F5)3(9)、[HC(CMe)2(NAr)2]ZnP(Ph2)C≡CB(C6F5)3 (10).文中还讨论了反应机理.     

Synthesis and characterisation of bis(pentafluorophenyl)antimony(V) cations, [(C6F5)2SbL3]

Pentacoordinate complex cations of the general formula [(C₆F₅)₂SbL₃]³⁺ stabilized as solid salts in combination with tetraphenylborate (BPh₄), tetrafluorobroate (BF₄) anions, where L=DMSO, Ph₃AsO, PyO, DMF, α-, β- and γ-picoline have been isolated. The newly formed complexes were characterized by elemental analysis, molar conductance measurements, solid-state IR and and NMR. From these results, a five-fold coordination around antimony was required.     

Synthesis and characterization of new sulfide aggregates of the type [{Pt2(μ3-S)2(P-P)2}M(C6F5)2] (M=Ni, Pd, Pt; P-P=2PPh3, 2PMe2Ph, dppf)

The reaction of [Pt₂(μ-S)₂(P-P)₂] (P-P=2PPh₃, 2PMe₂Ph, dppf) [dppf=1,1^′-bis(diphenylphosphino)ferrocene] with cis-[M(C₆F₅)₂(PhCN)₂] (M=Ni, Pd) or cis-[Pt(C₆F₅)₂(THF)₂] (THF=tetrahydrofuran) afforded sulfide aggregates of the type [{Pt₂(μ₃-S)₂(P-P)₂}M(C₆F₅)₂] (M=Ni, Pd, Pt). X-ray crystal analysis revealed that [{Pt₂(μ₃-S)₂(dppf)₂}Pd(C₆F₅)₂], [{Pt₂(μ₃-S)₂(PPh₃)₂}Ni(C₆F₅)₂], [{Pt₂(μ₃-S)₂(PPh₃)₂}Pd(C₆F₅)₂] and [{Pt₂(μ₃-S)₂(PMe₂Ph)₂}Pt(C₆F₅)₂] have triangular M₃S₂ core structures capped on both sides by μ₃-sulfido ligands. The structural features of these polymetallic complexes are described. Some of them display short metal-metal contacts.     

B(C6F5)3-catalyzed metal-free hydrogenations of 2-quinolinecarboxylates

A metal-free hydrogenation of 2-quinolinecarboxylates has been realized by using 5?mol% of B(C₆F₅)₃ as catalyst. A variety of tetrahydroquinolines were obtained in 57–99% yields. An attempt for the asymmetric hydrogenation with chiral boron Lewis acids generated from chiral dienes afforded very low ee’s.     

Platinum derivatives of decafluorophosphorobenzene and decafluoroarsenobenzene. The crystal structure of Pt(PPh3)2 (PC6F5)2

The platinum complexes Pt(PPh₃)₂ (PC₆F₅)₂ and Pt(PPh₃)₂(AsC₆F₅)₂ have been isolated from reactions of Pt(PPh₃)₃ with (PC₆F₅)₄ and (AsC₆F₅)₄ respectively. A single-crystal X-ray analysis of Pt(PPh₃)₂(PC₆F₅)₂ has shown that the compound crystallizes in space group P2₁ with a = 9.286(5), b = 20.95(1), c = 11.226(5) Å, β = 90.7(1)°, Z = 2. The structure has been solved by Patterson and Fourier methods and refined to R = 0.043 from three-dimensional diffractometer data. The complex contains the decafluorophosphorobenzene unit C₆F₅PPC₆F₅ bound through each P atom to the platinum. Coordination around the platinum is distorted square planar; the dihedral angle between the two PtP₂ planes is 20.4°.     

Synthesis, structural characterization and reactivity of the amino borane 1-(NPh2)-2-[B(C6F5)2]C6H4

The bright red title compound 1 was synthesized from (2-lithiophenyl)diphenylamine and bis(pentafluorophenyl)boron chloride. Its reactions with small acids like H₂O and HCl proceeded easily giving zwitterionic compounds. For 1 and its water adduct 2 the crystal structures were determined, the latter featuring an ammonium borate structure containing a short intramolecular hydrogen bond bridge. Treatment of 1 with Jutzi's acid, [H(OEt₂)₂][B(C₆F₅)₄], did not result in protonation of the nitrogen, but reaction of 1 with LiH in the presence of 12-crown-4, led to the isolation of the aminoborate [1-(Ph₂N)-2-{B(H)(C₆F₅)₂}C₆H₄][Li(12-crown-4)] (3). Borohydride 3 reacted with Jutzi's acid to regenerate 1 and liberate hydrogen.     

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.     

Role of B(C6F5)3 in activating the nickel-methyl complex (η-C5H5)Ni(CH3)(PPh3) to initiate the vinyl polymerization of norbornene

The Ni-methyl complex (η⁵-C₅H₅)Ni(CH₃)(PPh₃) (1) reacted with B(C₆F₅)₃ to give an unstable contact ion-pair complex with a μ-methyl bridge between the Ni and B atoms. Formation of the B-CH₃ bond was confirmed by the reaction of this complex with PPh₃ to give [(η⁵-C₅H₅)Ni(PPh₃)₂][B(CH₃)(C₆F₅)₃] which was structurally characterized. Spontaneous decomposition of the contact ion-pair complex yielded (η⁵-C₅H₅)Ni(C₆F₅)(PPh₃) which is very stable and does not show any reactions with norbornene with or without added B(C₆F₅)₃. ¹⁹F NMR study showed that the polynorbornene obtained by the catalysis of 1/B(C₆F₅)₃ system has the C₆F₅ end-group. A series of reactions, which includes CH₃/C₆F₅ exchange between the Ni and B centers with concomitant dissociation of PPh₃ to accept coordination of a norbornene monomer, is proposed as the route to active species that can initiate vinyl polymerization of norbornene.     

Formation of perfluorinated polyphenylenes by multiple pentafluorophenylation using C6F5Si(CH3)3

Pentafluorophenylation of perfluoroarenes with C₆F₅Si(CH₃)₃ was investigated by using NMR and MALDI-TOF-MS techniques. Successive multiple pentafluorophenylation easily occurred not only on the para-position but also on the ortho-positions to provide perfluorinated p-phenylene and m-phenylene compounds. The perfluoroarenes having electron-withdrawing substituents provided oligo- to poly-(phenylene)s depending on the added amounts of C₆F₅Si(CH₃)₃, while the perfluoroarenes having electron-donor substituents gave H(C₆F₄)_nF polymers produced from C₆F₅H, which was the decomposed product of C₆F₅Si(CH₃)₃.     

Synthesis and characterization of monomeric siloxo palladium(II) complexes: crystal structure of [Pd(tmeda)(C6F5)(OSiPh3)]

Mononuclear palladium-hydroxo complexes of the type [Pd(N-N)(C₆F₅)(OH)] [(N-N)=2,2^′-bipyridine (bipy), 4,4^′-dimethyl-2,2^′-bipyridine (Me₂bipy), or N,N,N^′,N^′-tetramethylethylenediamine (tmeda)] react with silanols HOSiR₃ in toluene giving the corresponding siloxo complexes [Pd(N-N)(C₆F₅)(OSiR₃)]. The X-ray crystal structure of [Pd(tmeda)(C₆F₅)(OSiPh₃)] has been determined. In one of the two molecules in the asymmetric unit there is an intramolecular interaction by phenyl-pentafluorophenyl π-stacking.     

Formation and structural characterization of novel polynuclear palladium selenolato complexes [Pd3Se(SePh)3(PPh3)3]Cl and [Pd6Cl2Se4(SePh)2(PPh3)6]

In addition to well-known dinuclear phenylselenolato palladium complexes, the reaction of [PdCl₂(PPh₃)₂] and NaSePh affords small amounts of novel trinuclear and hexanuclear complexes [Pd₃Se(SePh)₃(PPh₃)₃]Cl (1) and [Pd₆Cl₂Se₄(SePh)₂(PPh₃)₆] (2). Complex 1 is triclinic, P1?, a=13.6310(2), b=16.2596(2), c=16.9899(3) Å, α=83.1738(5), β=78.9882(5), γ=78.7635(5)°. Complex 2 is monoclinic, C2/c, a=25.7165(9), b=17.6426(8), c=27.9151(14) Å, β=110.513(2)°. There are no structural forerunners for 1, but the hexanuclear complex 2 is isostructural with [Pd₆Cl₂Te₄(TeR)₂(PPh₃)₆] (R=Ph, C₄H₃S) that have been observed as one of the products in the oxidative addition of R₂Te₂ to [Pd(PPh₃)₄]. Mononuclear palladium complexes may play a significant role as building blocks in the formation of the polynuclear complexes.