Isospecific homo- and copolymerization of styrene with ethylene in the presence of VCl3, AlCl3 as catalyst

The homopolymerization of styrene and its copolymerization with ethylene in the presence of a vanadium-based supported catalyst, {VCI₃, 1 AICI₃}, associated to triethylaluminium is examined. As indicated by means of ¹³C nuclear magnetic resoance and differential scanning calorimetry analysis, the homopolystyrenes obtained present a highly isotactic microstructure and are semicrystalline (melting temperature 220°C). In the case of styrene/ethylene random copolymerization, the formation of both, polyethylene blocks and isotactic polystyrene sequences was identified by analysis of the crude polymer. Solubility characteristics and structural characteristics from nuclear magnetic resonance spectra of these products support the formation of copolymers with ethylene and isotactic styrene blocks rather than that of two distinct homopolymers.     

Catalytic transformations of oligocarbosilanes induced by AlCl3

Catalytic activation of Si−C bonds in poly(vinyltrimethylsilane) was studied using a model reaction of catalytic transformations of oligocarbosilanes Me₃Si(CH₂) _n SiMe₃ (n=2, 3) in dichlorodimethylsilane in the presence of AlCl₃ as an example. The formation of ClMe₂Si(CH₂) _n SiMe₃ was established by chromato-mass spectrometry and GLC. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2265–2266, December, 1997.     

AlCl3 · 3NH3 — eine Verbindung mit der Kristallstruktur eines Tetraammindichloroaluminium-diammintetrachloroaluminats: [AlCl2(NH3)4]+[AlCl4(NH3)2]−

AlCl₃ · 3NH₃ — a Compound with the Crystal Structure of a Tetraammine Dichloro Aluminium-Diammine Tetrachloro Aluminate: [AlCl₂(NH₃)₄]⁺[AlCl₄(NH₃)₂]^? . AlCl₃ · 3 NH₃ ? [AlCl₂(NH₃)₄]⁺ [AlCl₄(NH₃)₂]^? forms during the reaction of two mole NH₃ with AlCl₃(NH₃) at T ≥ 200°C. Repeated heating and cooling within 48 h between 200°C and 250°C gives a homogeneous product with total uptake of the necessary amount of NH₃. Slow sublimation in a vacuum line apparatus at 200°C gives crystals of the triammoniate sufficient for a X-ray structure determination: The compound contains elongated [AlCl₂(NH₃)₄]⁺ octahedra and compressed [AlCl₄(NH₃)₂]^? octahedra. Besides ionic bonding hydrogen bridge bonds with 3.369 Å ? d(N—H … Cl) ? 3.589 Å stabilize the atomic arrangement.     

AlCl3 · 2NH3 – eine Verbindung mit der Kristallstruktur eines Tetraammindichloroaluminium-tetrachloroaluminats – [AlCl2(NH3)4]+[AlCl4]−

ACl₃ · 2NH₃ – a Compound with the Crystal Structure of a Tetraammine Dichloroaluminiumtetrachloroaluminate – [AlCl₂(NH₃)₄]⁺[AlCl₄]^? Ammoniates of aluminiumchloride AlCl₃ · xNH₃ are in discussion as starting materials for the synthesis of aluminiumnitride. Therefore the reactions of melts of monoamminealuminiumchloride with ammonia were investigated. They react at 150°C within 10 min with one mole of ammonia to the diammoniate, [AlCl₂(NH₃)₄]⁺[AlCl₄]^?. The pure compound can be obtained by sublimation at 200°C in vacuumline apparatus. X-ray structure determination on [AlCl₂(NH₃)₄]⁺[AlCl₄]^? was carried out: see “Inhaltsübersicht”.     

AlCl3-Catalyzed transformations of organo(trichloromethyl) silanes

Reactions of organo(trichloromcthyl)silanes RMc₂SiCCl₃ (R = Me, Ph, Mc₃Si) with aluminum chloride have been studied. The interaction of trimetltyl(tricltlorometltyl)silane with AlCl₃ carried out in cyclohexane or in benzene leads to Me₃SiCHCI₂ (in 75 % yield) or ClMe₂SiCPh₂Me (in 70 % yield), respectively; whereas no conversions are observed inn-hexane and methylene chloride. Treatment of dimetltyl(phenyl)(ricltloromethyl)silane with aluminum chloride in a_n-C₅H₁₂/CH₂CI₂ mixture gives an aromatic cross-linked insoluble polymer. The reaction of pentamethyl(trichloromcthyl)disilane (R = Mc₃Si) with AICl₃ in pentane affords the rearrangement product, Me₃SiCCl₂SiMc₂Cl, in 65 % yield. In methylene chloride the further cleavage of the disilane occurs to yield Me₂SiCl₂ and CH₂=CHMe₂SiCl.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1511-1515, June, 1996.     

Über Addukte und Salze von Schwefelchloriden mit AlCl3

Adducts and Salts Formed by Sulphurchlorides with AlCl₃ The instability of the adduct 2 S₂Cl₂ · AlCl₃ is proven. S₂Cl₂ · AlCl₃ and S₂Cl₂ · 2 AlCl₃ reported in the literature could not be found under proper conditions, their formation seems improbable. The product 2 SCl₄ · 3 AlCl₃, obtained by the reaction of [SCl₃]⁺[AlCl₄]^? with elementary sulphur, is characterized as a double salt [SCl₃]₂+[AlCl₄]^? [Al₂Cl₇]^?. The [Al₂Cl₇]^? anion is also found as an intermediate during the thermal decomposition of [SCl₃]⁺[AlCl₄]^? and when metallic aluminium reacts directly with S₂Cl₂. For SCl₂ · AlCl₃, the ionic character with a chlorsulfenium cation [SCl]⁺ is proven spectroscopically.     

Aluminum-27 NMR study of some AlCl3−MCl molten systems

Aluminum-27 NMR was used to investigate AlCl₃–MCl (M=Li, Na, K, Butylpyridinium) molten mixtures. In AlCl₃ rich mixtures, the²⁷Al resonance line was resolved into two components corresponding to the AlCl ₄ ^– and Al₂Cl ₇ ^– species, which were shown to undergo chemical exchange line broadening. This broadening was found to be cation and temperature dependent.     

Determination of aluminium in AlCl3 and Al2O3 modified silica catalyst supports

X-ray fluorescence spectrometry (XRF) was applied to determine aluminium in AlCl₃- and Al₂O₃-modified silica catalyst supports that were prepared by gas-solid reactions in an atomic layer epitaxy (ALE) process using aluminium chloride or aluminium chloride and water as adsorbates and silica as support. INAA and AAS were used as reference methods to determine the aluminium content of the supports. The calibration of XRF results was done by plotting the Al/Si intensity ratios against the aluminium content as determined by atomic absorption spectrometry (AAS) and verified by instrumental neutron activation analysis (INAA). Correlation factors for the calibration graphs were 0.984 for AlCl₃/SiO₂ and 0.995 for Al₂O₃/ SiO₂ samples in the aluminium content range 0–2.6 g Al per 100 g of sample. Received: 19 October 1998 / Accepted: 14 December 1998     

Determination of aluminium in AlCl3 and Al2O3 modified silica catalyst supports

X-ray fluorescence spectrometry (XRF) was applied to determine aluminium in AlCl₃- and Al₂O₃-modified silica catalyst supports that were prepared by gas-solid reactions in an atomic layer epitaxy (ALE) process using aluminium chloride or aluminium chloride and water as adsorbates and silica as support. INAA and AAS were used as reference methods to determine the aluminium content of the supports. The calibration of XRF results was done by plotting the Al/Si intensity ratios against the aluminium content as determined by atomic absorption spectrometry (AAS) and verified by instrumental neutron activation analysis (INAA). Correlation factors for the calibration graphs were 0.984 for AlCl₃/SiO₂ and 0.995 for Al₂O₃/ SiO₂ samples in the aluminium content range 0–2.6 g Al per 100 g of sample. Received: 19 October 1998 / Accepted: 14 December 1998     

Water and aluminium self-diffusion in aqueous AlCl3 solutions

Self-diffusion coefficients of ²⁷Al and H₂O were determined by the NMR pulsed-field-gradient method in a series of AlCl₃ solutions. From these data, bulk water self-diffusion coefficients are derived. It is shown that the relative influence on the bulk water translational motion agrees reasonably with the relative influence on the reorientational motion as reported in previous work. The bulk water self-diffusion is interpreted using a hydrodynamical model.     

Theoretical characterization and many-body expansion analysis of BF3, BCl3, AlF3 and AlCl3 interactions

Summary Metalloid-nonmetal and Metal-nonmetal interactions of BF₃, BCl₃, AlF₃ and AlCl₃ were examined at the matrix Hartree Fock level ofab initio theory. Structural and energetic properties, many-body expansion convergence, short- and long-range components of interaction energies, and group-theoretical parameters were found to uniquely characterize these interactions.     

Zur Kenntnis des Aluminiumchlorids. Die Umsetzung von AlCl3 mit PCl5 und Methylamin

Aluminium trichloride forms the adducts AlCl₃ · NH₂CH₃, AlCl₃ · 2NH₂CH₃, AlCl₃ · 4NH₂CH₃; AlCl₃ · NH₃CH₃Cl, AlCl₃ · 2NH₃CH₃Cl. The interaction between AlCl₃, PCl₅ and NH₃CH₃Cl in the molar ratio 1:3:2 proceeds according to the reaction equation in “Inhaltsübersicht”. On applying other stoichiometric amounts, [Cl₂(NHCH₃)P? N(CH₃)? AlCl₃] · HCl and [Cl₃P? N(CH₃)? AlCl₃] · HCl are obtained; the latter reacts as [Cl₃P? NHCH₃][AlCl₄]. At the molar ratio AlCl₃:PCl₅:NH₃CH₃Cl = 1:2:4 a compound is formed being presumably the six-membered heterocycle formulated in “Inhaltsübersicht”. With [Cl₃P?N? PCl₃] and aluminium chloride [Cl₃P?N? PCl₃][AlCl₄] is formed.     

Reactions of pentafluoroaniline with aromatic trihalomethyl derivatives in the presence of AlCl3

The reactions of pentafluoroaniline with aromatic CX₃-derivatives (X = F, Cl) in the presence of AlCl₃ were studied. It was shown that compounds with a CF₃ group can be used in reactions with polyfluoroaromatic amines instead of CCl₃-derivatives for the synthesis of imidoyl chlorides. In the case of compounds with several CX₃ groups, the formation of the imidoyl chloride moiety predominantly involves one of the CX₃ groups under the conditions studied. The introduction of a second CX₃ group can be carried out only under more drastic conditions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1089–1094, June, 1994.     

AlCl3/PCC-SiO2-Promoted Oxidation of Azaindoles and Indoles

Abstract

A simple and efficient method is described for the oxidation of 7-azaindoles and indoles to 7-azaisatins and isatins using pyridinium chlorochromate–silica gel (PCC-SiO₂) with the aid of Lewis acid catalyst aluminium chloride (AlCl₃) in dichloroethane. Simplicity of the reaction conditions, easy workup procedure, and good yields are the key features of this protocol.     

Copolymerization of vinyl monomers with Gd(OCOCCl3)3-(i-Bu)3Al-Et2AlCl

The polymerization of polar monomers such as methyl methacrylate (MMA), methyl acrylate (MA), methacrylonitrile (MAN), and acrylonitrile (AN) was carried out with gadolinium-based Ziegler–Natta catalysts [Gd(OCOCCl₃)₃-(i-Bu)₃Al-Et₂AlCl] in hexane at 50°C under N₂ to elucidate the effect of the monomer's HOMO(highest occupied moleculor orbital) and LUMO (lowest unoccupied molecular orbital) levels on the polymerizability. In the case of homopolymerization, all monomers were found to polymerize and the order of relative polymerizability was as follows: MM > MA > MAN > AN. On the other hand, the result of copolymerization of St with MMA shows that the values of the monomer reactivity ratios are r₁ = 0.06 and r₂ = 1.98 for St(M₁)/MMA(M₂). The monomer reactivity ratios of styrene (St), p-methoxystyrene (PMOS), p-methylstyrene (PMS), and p-chlorostyrene (PCS) evaluated as r₁ = 0.55 and r₂ = 1.07 for St(M₁)/PMOS(M₂), r₁ = 0.38 and r₂ = 0.51 for St(M₁)/PMS(M₂), and r₁ = 0.72 and r₂ = 1.25 for St(M₁)/PCS(M₂) were compared with those for St(M₁)/MMA(M₂). The copolymerization behavior is apparently different from the titanium-based Ziegler—Natta catalyst, regarding a larger monomer reactivity ratio of PCS. The lower LUMO level of PCS and MMA may enhance a back-donation process from the metal catalyst, therefore resulting in high polymerizability. These results are discussed on the basis of the energy level of the gadolinium catalyst and the HOMO and LUMO levels of the monomers. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2591–2597, 1997     

Vibrational spectra and structure of AlCl3NH3 and molten mixtures with MCl-AlCl3 (M = Li,Na, K OR Cs)

Raman and IR spectra were obtained of molten AlCl₃NH₃, AlCl₃ND₃ and AlBr₃NH₃ in addition to chloroaluminate mixtures of the AlCl₃NH₃. The main spectral features of the gaseous AlCl₃NH₃ molecules having a C_3v-symmetry are retained in the molten and glassy states. Some additional bands were observed both in the pure liquid and in mixtures with chloroaluminate melts. The spectra indicated that the discussion reaction 2AlCl₃NH₃ = AlCl⁻₄ + [AlCl₂(NH₃)₂]⁺ occurs with K ⋍ 3 × 10⁻³ (mole fraction basis). Frequency shifts found on liquefaction demonstrate that extensive hydrogen bonding takes place between AlCl₃NH₃ molecules. This observation is supported by the glass-forming nature of AlCl₃NH₃. The molecule Al₂Cl₆NH₃ seems to exist in binary AlCl₃-AlCl₃NH₃ melts.     

Gaskomplexe mit den Komponenten AlCl3, AlJ3 oder FeCl3, ihre Häufigkeit und Stabilität

Gas Complexes with AlCl₃, All₃ (or FeCl₃), their Abundance and Stability Gas complexes MCl_m · xAlCl₃ (FeCl₃) cover a large area of the periodic table. The thermodynamic discussion shows the great stability of these complexes below 1200°K. The ΔH°-values for the stepwise complex formation MCl₂/MAlCl₅/MAl₂Cl₈ are discussed. The important factor is the supplement of the coordination sphere.     

Radioanalytical method for determination of the chemical forms of35S hot atoms in reactor-irradiated AlCl3−FeCl3

A radioanalytical procedure for the determination of the chemical forms of³⁵S in reactor irradiated crystals AlCl₃, FeCl₃ and AlCl₃?FeCl₃ is described. The method includes:³⁵S extraction with trichloroethylene, precipitation of³⁵S^2? as iron sulfide and of (³⁵SO ₄ ^2? +³⁵SO ₃ ^2? ) as Ba-salts. All fractions are converted to, and measured as, BaSO₄.     

Synthese und Kristallstruktur des Lewis‐Säure/Base‐Addukts AlCl3·C3N3Cl3

Synthesis and Crystal Structure of the Lewis Acid‐Base Adduct AlCl₃·C₃N₃Cl₃ The reaction between cyanuric chloride (C₃N₃Cl₃) and the strong Lewis acid AlCl₃ yielded colorless crystals of the adduct AlCl₃·C₃N₃Cl₃. The crystal structure was determined by single crystal X‐ray diffraction at room temperature and was solved in the space group with Z = 4, a = 7.3802(7) Å, b = 9.688(1) Å, c = 16.272(2) Å, α = 72.80(1)°, β = 89.97(1)°, γ = 87.23(1)°, and V = 1110.0(2) ų. In the crystal structure, AlCl₃ is closely associated to the triazine ring with Al–N distances of 2.042(3) Å and 2.067(4) Å, respectively. The AlCl₃·C₃N₃Cl₃ units are connected with each other via intermolecular N···Cl donor–acceptor interactions, forming tape‐like arrangements in the ac‐plane, with tapes running parallel to the a‐axis.     

Synthese de materiaux polymeres transparents. Partie I Synthese du trifluoroacrylate de trideuteromethyle

The acrylic ester F₂CCFCO₂CD₃ is prepared from a mixture of difluorotetrachloroethanes CFCI₂CFCI₂ and CF₂CICCI. The dehalogenation of these Freons, followed by the addition of CFCI₃ by means of AICI₃ leads to a mixture of chlorofluoropropanes. The hydrolysis with oleum gives the acid chlorides which are then esterified by CD₃OD. The dehalogenation of the mixture by the zinc stirred in oxalic acid enables isolation of the expected ester by distillation. This compound, the refractive index of which n²⁰_D=1.3667 does not show a major absorption in the near infra-red between 0.6 and 1.4 μm. Thus the corresponding polymer is likely to provide a good material for the core of optical fibers.