The reaction of perfluoroalkanesulfinates: IV. Perfluoroalkyl radical addition to olefins initiated by single electron oxidation of perfluoroalkanesulfinate

Sodium perfluoroalkanesulfinates [Cl (CF₂)_n SO₂ Na (1), a , n = 4; b , n = 6; c , n = 8] with the reduction potentials about 0.95—1.00V could be oxidized readily with various oxidizing agents such as Mn (OAc)₃ 2H₂O, Ce (SO₄)₂, HgSO₄ and Co₂O₃ to generate perfluoroalkyl radicals which added to the olefins RCH ? CHR' to give two kinds of adducts, namely RCH (R_f) CHXR' (3, X ? H; 4, X ? OAc), with good yields depending upon the solvent system used. Different oxidizing agents showed slight variation on the yields of the adducts. The reaction time could be greatly shortened at higher temperature. Thus, this reaction provides a new way for introducing a perfluoroalkyl group into olefinic compounds.     

Atmospheric pressure chemical vapour deposition of fluorine‐doped tin(IV) oxide from fluoroalkyltin precursors

Perfluoroalkytin compounds R_(4−n)Sn(R_f)_n (R = Me, Et, Bu, R_f = C₄F₉, n = 1; R = Bu, R_f = C₄F₉, n = 2, 3; R = Bu, R_f = C₆F₁₃, n = 1) have been synthesized, characterized by ¹H, ¹³C, ¹⁹F and ¹¹⁹Sn NMR, and evaluated as precursors for the atmospheric pressure chemical vapour deposition of fluorine‐doped SnO₂ thin films. All precursors were sufficiently volatile in the range 84–136 °C and glass substrate temperatures of ca 550 °C to yield high‐quality films with ca 0.79–2.02% fluorine incorporation, save for Bu₃SnC₆F₁₃, which incorporated <0.05% fluorine. Films were characterized by X‐ray diffraction, scanning electron microscopy, thickness, haze, emissivity, and sheet resistance. The fastest growth rates and highest quality films were obtained from Et₃SnC₄F₉. An electron diffraction study of Me₃SnC₄F₉ revealed four conformations, of which only the two of lowest abundance showed close F Sn contacts that could plausibly be associated with halogen transfer to tin, and in each case it was fluorine attached to either the γ‐ or δ‐carbon atoms of the R_f chain. Copyright © 2005 John Wiley & Sons, Ltd.     

Localization of Hydrogen and Content of Oxonium Cations in Alunite via Neutron Diffraction

Polycrystalline alunite‐d₆ KAl₃(OD)₆(SO₄)₂, prepared by hydrothermal reaction of Al₂(SO₄)₃, K₂SO₄ and D₂SO₄, was studied by neutron powder diffraction performed on the diffractometer E2 (HMI‐BENSC, Berlin). Rietveld refinement of the data set for T = 2 K yielded the crystallographic data: space group R3m, Z = 3, trigonal setting, a = 694.3(1) pm, c = 1722.7(2) pm, N(I/σ(I) > 1) = 172, N(Var.) = 19, R_p = 0.036, wR_p = 0.046, R_B(I/σ(I) > 1) = 0.020. The deuterium nuclei could be located precisely. Three equivalent O–D bonds with nuclear distances r(O(4)–D) = 96.6(3) pm directed to each of the terminal oxygen atoms of the SO₄ groups are found. Partial substitution of K⁺ by D₃O⁺ was also considered in the refinement procedure. In good agreement with results of other methods a site occupation fraction n(D₃O⁺) = 0.0104 was obtained.     

Apparent Molar Volumes and Heat Capacities of Aqueous Trifluoromethanesulfonic Acid and Its Sodium Salt from 283 to 328 K

Apparent molar heat capacities C_\textp,fC_{{\text{p}},\phi } and volumes V_fV_\phi of aqueous trifluoromethanesulfonic (triflic) acid, HCF₃SO₃ (aq.) were determined with a Picker flow microcalorimeter and vibrating-tube densimeter at temperatures from 283 to 328 K and molalities from 0.05 to 9.5 mol-kg^-1. Values of V_fV_\phi and C_\textp,fC_{{\text{p}},\phi } display a maximum near 0.8 mol-kg^-1. V_fV_\phi also displays a shallow minimum at ~5 mol-kg^-1, while C_\textp,fC_{{\text{p}},\phi } continues to decrease smoothly up to the limit of our measurements at 9.5 mol-kg^-1. We attribute this behavior to ion–ion interaction between triflate and the hydrated proton to form the aqueous complex H_2n+1O_n⁺ CF₃SO₃^- (aq.), n = 5. Standard partial molar properties C_p^o and V^o are consistent with results obtained from NaCF₃SO₃ (aq.) and yield values for the triflate anion CF₃SO₃^- (aq.), over this range.     

Studies on fluoroalkylation and fluoroalkoxylation: 2. Perfluoroalkylation of aromatics with perfluoroalkyl iodides in the presence of copper

Perfluoroalkyl iodide R_fI [R_f = (CF₂)_nO(CF₂)₂SO₂F, n = 2, (a); n = 4, (b); (CF₂)₄Cl, (c)] reacted with substituted benzene C₆H₅Y (Y = alkyl, OCH₃, CF₃, F, Cl, Br, I) in the presence of copper in acetic anhydride to give the corresponding mixture of isomeric disubstituted benzene (R_fC₆H₄Y). The conversion and yield depend on both the amount of copper used and nature of substituent. The likely explanation is that the reaction may involve a free radical process. The perfluoroalkyl radical can be trapped by cyclohexene, isopropylbenzene and styrene. Using DMSO in place of acetic anhydride as a solvent the reaction takes a different course, it is believed that the reaction in DMSO proceeds through a perfluoroalkylcopper intermediate.     

Aromatic compounds with new fluorine-containing substituents

The introduction of strong electron-accepting fluorine-containing substituents into the aromatic moiety gives compounds with unique properties. Determination of the electronic nature of the grouping (R_f)₂PO in arylbis(perfluoroalkyl)-phosphine oxides has shown that this substituent is comparable with R_fSO₂, one of the most electron-accepting groups.A general principle is proposed for the construction of the new superstrong electron-accepting substituents by the replacement of oxygen atoms for trifluoromethylsulfonylimino groups. For example, when the oxygen atoms in CF₃SO and CF₃SO₂ groups are replaced by CF₃SO₂N=, new stable and even more electron-accepting substituents are formed. The grouping CF₃S(O)=NSO₂CF₃ corresponds to two nitro groups. A similar increase in electron-accepting ability is observed in groupings derived from other elements by replacement of oxygen atoms by the CF₃SO₂N= group.     

Reversible SO2 Uptake by Tetraalkylammonium Halides: Energetics and Structural Aspects of Adduct Formation Between SO2 and Halide Ions

Contact with SO₂ causes almost immediate dissolution of tetraalkylammonium halides, R₄NX, (R = CH₃ (Me), X = I; R = C₂H₅ (Et), X = Cl, Br, I; R = C₄H₉ (nBu), X = Cl, Br), with the formation of an adduct, [R₄N]⁺[(SO₂)_nX]^– (n = 1–4). Vapor pressure measurements indicate the proclivity for SO₂ uptake follows the order N(CH₃)₄⁺ < N(C₂H₅)₄⁺ < N(C₄H₉)₄⁺. This trend is in accord with the Jenkins–Passmore volume‐based thermodynamic model. Born–Haber cycles, incorporating the lattice energy and gas phase energy terms, are used to evaluate the energetic feasibility of reactions. Density functional theory calculations (B3PW91; 6‐311+G(3df)) have been used to calculate the energetics of (SO₂)_nX^– (X = Cl and Br) anions in the gas phase. The experimental studies show that tetraalkylammonium halides are feasible sorbents for SO₂. In order to correlate the theoretical model, experimental enthalpy, Δ_rH° and entropy, Δ_rS° changes have been determined by the van't Hoff method for the binding of one SO₂ molecule to (C₂H₅)₄NCl, resulting in the liquid adduct (C₂H₅)₄NCl · SO₂. The structure of the analogous 1:1 bromide adduct, (C₂H₅)₄NBr · SO₂, has been determined by single‐crystal X‐ray diffraction (monoclinic, P2₁/c, a = 9.1409(14) Å, b = 12.3790(19) Å, c = 11.3851(17) Å, β = 107.952(2)°, V = 1225.6(3) ų). The structure consists of discrete alkylammonium cations, bromide anions and SO₂ molecules with short contacts between the anion and SO₂ molecules. The (C₂H₅)₄N⁺ cationadopts a transoid conformation with D_2d symmetry, and represents a rare example of a well‐ordered (C₂H₅)₄N⁺ cation in a crystal structure. The Br^– anions and SO₂ molecules forms a chain, (SO₂Br^–)_n, with bifurcated contacts. Non‐bonding electron pairs on the halide anions engage in electrostatic interactions with the sulfur atoms and charge‐transfer interactions with the antibonding S–O orbitals of the bound SO₂ moiety. Raman and ¹⁷O NMR spectra provide compelling evidence for a charge‐transfer interaction between SO₂ molecules and the halide ions.     

Studies on the reactions of fluoroalkanesulfonyl azide with aromatic compounds

The thermal decomposition reactions of fluoroalkanesulfonyl azides R_fSO₂N₃ (1) in the presence of various substituted benzene X_nC₆H_6−n [X: CH₃ (n=1, 2, 4, 6), OCH₃ (n=1, 2), C₆H₅CH₂ (n=1), F, Cl, Br] were studied in detail. The N-aryl fluoroalkanesulfonyl amides [R_fSO₂NHC₆H_5−nX_n] were produced as the major products. The ortho/para ratio resembled that of an electrophilic aromatic substituted reaction. An ionic π- or σ-complex was postulated as the intermediate for these reactions.     

UV resistance of encapsulated low molecular weight aromatic compounds in fluoroalkyl end‐capped trimethoxyvinylsilane oligomer/silica nanocomposites

Sol–gel reactions of fluoroalkyl end‐capped trimethoxyvinylsilane oligomer in the presence of low molecular weight aromatic compounds (ArH) such as 1,1′‐bi(2‐naphthol) (BINOL) and 2‐hydroxy‐4‐methoxy benzophenone (HMB) were found to proceed smoothly under alkaline conditions at room temperature to give the corresponding fluorinated oligomeric silica nanocomposites‐encapsulated aromatic compounds (BINOL and HMB) [R_F‐(VM‐SiO₂)_n‐R_F/ArH nanocomposites]. UV light irradiation (λ_max: 254 nm) toward R_F‐(VM‐SiO₂)_n‐R_F/ArH nanocomposites showed that photodegradation of encapsulated ArH was not observed at all in the fluorinated nanocomposites cores, although the parent ArH can exhibit an effective photodegradation behavior under similar conditions. Especially, encapsulated ArH can exhibit no weight loss corresponding to the contents of the aromatic compounds in the fluorinated nanocomposites even after calcination at 800°C. Therefore, fluoroalkyl end‐capped trimethoxyvinylsilane oligomer has high potential for not only the thermal resistance but also the UV resistance fluorinated polymeric materials. Copyright © 2014 John Wiley & Sons, Ltd.     

Unexpected formation of N-fluoroalkaneacyl anilides from the reactions of fluoroalkanesulfonyl azides with nitrobenzene and its derivatives

The thermal reactions of fluoroalkanesulfonyl azides R_fCF₂SO₂N₃1 with nitrobenzene and its derivatives XC₆H₄NO₂ (X=H, F, Cl, CF₃) gave the unexpected N-fluoroalkaneacyl anilides R_fCONHC₆H₄X (X=H, Cl, F, CF₃) in addition to fluoroalkanesulfonyl amides R_fCF₂SO₂NH₂. Under the same reaction conditions, however, nitrobenzene containing an electron-donating group RC₆H₄NO₂ (R=CH₃, OCH₃) reacted with 1 affording the corresponding N-fluoroalkanesulfonyl anilides R_fCF₂SO₂NHC₆H₃(NO₂)R. Other electron-poor benzene derivatives, such as benzaldehyde, benzoate, and acetophenone C₆H₅Y(Y=CHO, COCH₃, CO₂CH₃) all gave the meta-substituted N-fluoroalkanesulfonyl anilides R_fCF₂SO₂NHC₆H₄Y.     

Reduction of aromatic nitro compounds with NaBH4 catalysed by nickel complexes ofo-aminothiophenol Schiff base derivatives

Summary The nickel complexes of Schiff bases formed fromo-aminothiophenol and -dicarbonyl compounds, Ni(o-SC₆H₄N=CRCR=NC₆H₄S-o) (R=H, Me, Ph) (1a-c), catalyse the reduction of aromatic nitro compounds by NaBH₄. The reduced species [Ni(o-SC₆H₄N=CHCH=NC₆H₄S-o)]^– (2) and [Ni(o-SC₆H₄NHCH₂CH=NC₆H₄S-o)]^– (3) were identified as intermediates in the catalytic cycle.     

Low-temperature heat capacity and standard entropy of PdO(cr.)

The temperature dependence of the heat capacity C _p ^o = f(T) of palladium oxide PdO(cr.) was studied for the first time in an adiabatic vacuum calorimeter in the range of 6.48–328.86 K. Standard thermodynamic functions C _p ^o(T), H ^o(T) — H ^o(0), S ^o(T), and G ^o(T) — H ^o(0) in the range of T → 0 to 330 K (key quantities in different thermodynamic calculations with the participation of palladium compounds) were calculated on the basis of the experimental data. Based on an analysis of studies on determining the thermodynamic properties of PdO(cr.), the following values of absolute entropy, standard enthalpy, and Gibbs function of the formation of palladium oxide are recommended: S ^o(298.15) = 39.58 ± 0.15 J/(K mol), Δ_f H ^o(298.15) = −112.69 ± 0.32 kJ/mol, Δ_f G ^o(298.15) = −82.68 ± 0.35 kJ/mol. The stability of Pd(OH)₂ (amorph.) with respect to PdO(cr.) was estimated.     

Synthesis of sulphonated aminomethylphosphines and some nickel(II), palladium(II), platinum(II) and rhodium(I) complexes. Crystal structure of [Et3NH][(Ph2PCH2)2 N(CH2)2SO3]

Summary Aminoalkanesulphonic acids H₂N(CH₂) _n SO₃H, (n = 1, 2 or 3) react with phosphonium salts [R₂P(CH₂OH)₂]Cl (R = Ph or Cy, Cy = cyclohexyl) in the presence of Et₃N to give the sulphonated aminomethylphosphines [Et₃NH] [(R₂PCH₂)₂N(CH₂) _n SO₃] (R = Ph, n = 1, 2 or 3; R = Cy, n = 1). The single crystal X-ray structure of [Et₃NH] [(Ph₂PCH₂)₂N(CH₂)₂SO₃] has been determined. Some Ni^II, Pd^II, Pt^II and Rh^I complexes of the phosphines have been prepared.     

Synthesis and characterization of the new 22-π aromatic furan-containing macrocycle, “ozaphyrin”

The new 22-π, aromatic “pentaplanar” macrocycle, ozaphyrin ( 6 ), has been synthesized by a McMurry coupling of 5,5′-diformyl-4,4′-dipropyl-2,2′-bipyrrole ( 1 ) with 2,5-bis(5-formyl-4-propyl-2-pyrrolyl)furan ( 5 ). This synthetic pathway to ozaphyrin and its characterization by ¹H nmr spectroscopy, uv-visible spectroscopy, cyclic voltammetry, and X-ray crystallography are described. The structure consists of layers of planar, staggered macrocycles stacked perpendicular to the α-axis. Ozaphyrin crystallizes with four formula units in the monoclinic space group C⁵_2h-P2₁/n in a cell of dimensions a = 10.481(7) Å, b = 17.353(17) Å, c = 18.726(12) Å, and β = 102.84(5)° (108 K). The structure has been refined on F² (5171 unique reflections, 411 variables) to R_w(F_o²) = 0.165. The conventional agreement index R(F) is 0.074 for the 3289 reflections have F_o²>2o(F_o²).     

Two novel organic amine templated lanthanide sulfates: Layer H3DETA · [Nd(H2O)(SO4)3] and chain-like H3DETA · [Ho(H2O)2(SO4)3]

Two novel organic amine templated lanthanide sulfates, layer (H₃DETA)[Nd(H₂O)(SO₄)₃] (I) and chain-like (H₃DETA)[Ho(H₂O)₂(SO₄)₃] (II), are hydrothermally synthesized by using diethylenetriamine (DETA) as template, and are structurally characterized by ICP, elemental analysis, X-ray single-crystal diffraction, X-ray powder diffraction, IR, and TG. Compound I is monoclinic with space group P2₁ and data of unit cell: a = 6.6518(13), b = 10.373(2), c = 11.091(2) ?, β = 93.61(3)°, V = 763.7(3) ?³, ρ _c = 2.421 g/cm³, μ(MoK _α) = 3.885 mm⁻¹, Z = 2, R ₁ = 0.0194 for 3312 reflections with F _o > 2σ(F _o). The Nd ions are nine-coordinated by one oxygen atom of coordinated water and eight oxygen atoms of sulfates. Compound I displays the layer structure constructed by linking Nd ions with three-linkage SO₄ tetrahedra as the bridge (affording one coordinated vertex and coordinated edge). Compound II crystallizes in the monoclinic space group P2₁/c with unit cell data: a = 6.594(13) ?, b = 14.783(3) ?, c = 16.599(3) ?, β = 93.47(3)°, V = 1614.2(6) ?³, ρ _c = 2.454 g/cm³, μ(MoK _α) = 5.37 mm⁻¹, Z = 4, R ₁ = 0.0259 for 1815 reflections with F _o > 2σ(F _o). The Ho ions are eight-coordinated by two oxygen atoms of coordinated water and six oxygen atoms of sulfates. The straight chain-like structure of II is attained by alternatively arranging HoO₈ polyhedra and two-linkage SO₄ tetrahedra (affording two coordinated vertices). The TG results indicate that the two compounds experience three weight losses and lead to distinct residues: Nd₂O₃ for I and HoO(SO₄)_0.5 for II.     

Biological Studies of Some Perfluorophenyl Antimony Compounds

Perfluoroorganoantimony(III) (R_f)_nSbCl_{3? n} and -antimony(V) (R_f)_nSbCl_{5? n} (n = 1,2,3, R_f = C₆F₅) compounds are screened for the first time for biological activity. The compounds exhibited significant in vitro antitumor activity against MCF-7 (human breast cancer) cell line and antibacterial activity against three pathogenic bacteria: Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae. They also showed antifungal activity against Aspergillus flavus and Aspergillus niger as well as insecticidal activity against cockroach (Periplanata americana), housefly (Musca domestica), Tobacco caterpillar (Spodoptera litura), and spider mite (Tetranychus urticae). These studies suggest a better biocidal activity for the pentafluorophenyl antimony halides compared to the corresponding phenyl analogues.     

Determination of enthalpies of formation of organic free radicals from bond dissociation energies 1. Hydrocarbon radicals

The enthalpies of formation (ΔH _f ^o) for 24 hydrocarbon radicals (R^?), mainly polycyclic aromatic radicals with the complex structure, were determined from the published data on bond dissociation energies. The ΔH _f ^o values of the corresponding molecules were calculated, in the majority of cases, by the macroincrement method. Calculations by the group contribution method were performed. Some ΔH _f ^o(R^?) values were compared to those calculated by the additive-group method. Calculations were performed, and the conjugation energies of the radicals were discussed. The errors of determination of the ΔH _f ^o(R^?) values found were estimated. Due to this work, the database for ΔH _f ^o values of hydrocarbon radicals was increased more than by 25%.     

Morphology-dependent luminescence properties of poly(benzyl ether) dendrimers

Poly(benzyl ether) dendrimers with o-, m-, and p-isomers of dialkoxybenzene at their focal points [o-, m-, and p-(Gn)₂Ar], having generation numbers (n) of 0–3, were synthesized. ¹H NMR pulse relaxation times (T₁) of the exterior MeO groups of o- and m-(Gn)₂Ar (n = 0–3) all remained in the range of 0.92–1.43 s. In sharp contrast, an exceptionally short T₁ value (0.23 s) was observed for p-(G3)₂Ar. Although their absorption spectral profiles were slightly different from one another, an essential difference was observed for their fluorescence properties. When the generation number was increased, the fluorescence efficiency of o-(Gn)₂Ar increased, but that of p-(Gn)₂Ar decreased, whereas m-(Gn)₂Ar exhibited a relatively small change in the fluorescence efficiency. Fluorescence depolarization studies showed a highly efficient intramolecular energy migration in p-(G3)₂Ar as compared with o-(G3)₂Ar and m-(G3)₂Ar. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3524–3530, 2003     

Synthesis and Characterization of Diorganotin(IV) Complexes Bearing Binary Schiff‐Bases and Crystal Structure of nBu2SnL1

Four novel diorganotin(IV) complexes with general formula R₂SnL (R = nBu, PhCH₂) were synthesized from diorganotin dichlorides and binary Schiff‐bases (H₂L) containing N₂O₂ donor atoms in the presence of sodium ethoxide. The Schiff bases were prepared by reactions of o‐phenylenediamine with 3‐tert‐butyl‐2‐hydroxy‐5‐methylbenzaldehyde (H₂L¹) and salicylaldehyde (H₂L²) respectively. The compounds were characterized by elemental analyses, IR, and NMR spectroscopy. The solid‐state crystal structure of the compound nBu₂SnL¹ was determined by single‐crystal structural analysis.     

全氟烷基磺酰亚胺盐催化芳香化合物硝化反应的研究

利用系列全氟烷基磺酰亚胺盐[M(NPf₂)_n]作为一种新型的Lewis酸催化剂，用于催化芳香化合物与等摩尔65% (m∶m)硝酸的硝化反应. 通过考察不同的催化剂、反应时间、反应温度和反应介质效应等因素对甲苯硝化的影响，以及比较1 mol% Yb[N(C₄F₉SO₂)₂]₃催化不同结构的取代芳烃硝化反应的效果，表明全氟烷基磺酰亚胺盐不仅具有环境友好和原子经济的特点，而且是一类比常规Lewis酸更有效的、芳香化合物硝化反应的催化剂.