Formation of gaseous intermediates in titanium(IV) chloride plasma oxidation

A number of experiments were made to study tire gas phase reactions that precede TiO₂ aerosol formation from TiCl₄ in an O₂/Ar plasma. The gaseous .species from the plasma-aerosol reactor were detected by a high-resolution QP mass spectrometer. The feed ratio of Ar: O₂: TiCl₄ was typically 4. l: 0.1. Under such conditions both titanium oxychlorides and oxides of chlorine could be recognized. In the reactor the decay of oxychlorides from the reactions it-as fast, compared to the decay of chlorine. A rough estimate of the quantities of both ClO(g) and Ti0Cl_x(g) metastable species present is given. TiCl₄ oxidation reaction mechanisms with mentioned oxychlorides as intermediates are discussed The theoretical calculations were conducted in tire temperature range from 800 to 3500°C.     

Ti2Nb6Cl14O4: A Unique 2D–1D Network Combination in Niobium Cluster Chemistry

Layers of niobium clusters that are linked to each other through zigzag chains of edge-sharing [TiCl₄O₂] ocatahedra are the central structural features of the title compound. Bridging of the chains by [(Nb₆Cl₈ⁱO₄ⁱ)Cl₆^a]⁶⁻ clusters results in the formation of empty tunnels (a section of the structure is shown on the right).     

Das Dimerisierungsgleichgewicht 2 TiCl3,g = Ti2Cl6,g

The Dimerization Equilibrium 2 TiCl_3,g = Ti₂Cl_6,g The dimerization of gaseous titanium(III)chloride has been investigated. The measurement have been made in the presence of an excess of TiCl₄ by means of a static method using gold as a manometer liquid. The results for the equilibrium 2 TiCl_3,g = Ti₂Cl_6,g are ΔH°(298) = ?40.6 kcal; ΔS°(298) = ?36.4 cl; ΔCp = 4 cal/°, mole.     

Titanium-based lewis acids for living cationic polymerizations of vinyl ethers and styrene: Control of lewis acidity in design of initiating systems

This brief account discusses the development of HCl/TiCl_4-n(OR)_n (n = 1–4), the titanium-based new initiating systems for living cationic polymerizations of vinyl ethers and styrene. The focus of this development is controlling the Lewis acidity of the metal halide components [TiCl_4-n(OR)_n] or “activators” in relation to the structure of the monomers. Thus, for vinyl ethers, relatively mild Lewis acids such as TiCl(OiPr)₃ and TiCl₂(OiPr)₂ are effective, whereas for styrene, a stronger Lewis acid such as TiCl₃(OiPr) is employed along with an added salt (nBu₄N⁺Cl⁻). In both cases, living polymers of controlled molecular weights can be obtained in methylene chloride solvent at −15°C.     

Bildung und NMR-spektroskopische Charakterisierung von Alk-(ar-)oxyderivaten von Trichlorphosphazen-N-phosphoryldichlorid,Cl3PN?P(O)Cl2, Imido- und N-Methylimidodiphosphoryltetrachlord,Cl2P(O)NHP(O)Cl2 bzw. Cl2P(O)N(CH3)P(O)Cl2

Formation and N.M.R.-Spectroscopic Characterization of Alk-(ar-)oxy Derivatives of Trichlorophosphazene-N-phosphoryldichloride, Cl₃P?N? P(O)Cl₂, Imido- and N-Methylimidodiphosphoryltetrachloride, Cl₂P(O)NHP(O)Cl₂ and Cl₂P(O)N(CH₃)P(O)Cl₂ The ester chlorides and esters P₂NOCl_5?x(OR)_x (x = 1?5), P₂(NH)O₂Cl_4?x(OR)_x (x = 1–4) and P₂(NCH₃)O₂Cl_4–x(OR)_x (x = 1–4) derived from the title compounds by substitution of chlorine atoms by alk- or aroxy groups are characterized by their ³¹P-n.m.r. data. The possibilities for forming these compounds by alcoholysis, chloridolysis, dealkylation and P? N-bond formation are discussed.     

Die Chloride Na3xM2–xCl6 (M = La?Sm) und NaM2Cl6 (M = Nd,Sm): Derivate des UCl3-Typs. Synthese,Kristallstruktur und Röntgenabsorptionsspektroskopie (XANES)

The Chlorides Na_3xM_2–xCl₆ (M = La? Sm) and NaM₂Cl₆ (M = Nd, Sm): Derivatives of the UCl₃-Type of Structure. Synthesis, Crystal Structure and X-Ray Absorption Spectroscopy (XANES) Single crystals of the derivatives of the UCl₃-type structure Na_3xM_2–xCl₆ (M = La/x = 0.364(4); Ce/0.349(5); Pr/0.318(8); Nd/0.305(5); Sm/0.246(4)) and NaSm₂Cl₆ were grown by different methods generally under reducing conditions. They are addition [Na(Sm₂)Cl₆] and addition/substitution variants [Na_2x(Na_xM_2–x)Cl₆] of the UCl₃ structure type [□(U₂)Cl₆]. X-Ray Absorption Spectroscopy (XANES) at the L_III edge characterizes NaSm₂Cl₆ and NaNd₂Cl₆ as mixed-valence compounds with valences of +2 and +3 in statistical distribution (approximately 1:1) for Sm and Nd, respectively.     

Dismutation of Titanium Sub-oxide into TiO and TiO2 with Structural Hierarchy Assisted by Ammonium Halides

Black TiO_2−x attracts enormous attention due to its large solar absorption and improved conductivity. In this work, a novel structure of TiO_2−x with conductive TiO layer, performing full-spectrum absorption, was synthesized in one step by the unforeseen dismutation reaction of titanium sub-oxides (Ti_nO_2n−1) in ammonium halide atmosphere. For this new reaction, a possible mechanism of decomposition-etching-disproportionation-rehydrolysis process was proposed. The vital intermediate reactant TiCl₄, which verifies the assumption, has been captured in the form of (NH₄)₂TiCl₆, especially where Ti₂O₃ is the reactant. Furthermore, this work not only can nominate TiO as an alternative for noble metals or carbon materials in the aim to improve the electron conductivity and solar absorption of black TiO_2−x, which are important in electrochemistry and optoelectronics fields, but also can be a new route to synthesize special structures for other multivalent transition metals.     

Direct Mass Spectrometric Study of the Ionic Species Content of a C<Subscript>2</Subscript>HCl<Subscript>3</Subscript>/He/O<Subscript>2</Subscript> Microwave Discharge Plasma

Direct on-line studies of a C₂HCl₃/He/O₂ microwave discharge plasma made possible the evolution and detection of many unfamiliar ionic species. Numerous ionic chlorocarbons, chlorohydrocarbons, oxygenated chlorohydrocarbons, oxygenated hydrocarbon radicals, and simple hydrocarbon species were identified mass spectrometrically as by-products: C _m Cl _n (m = 1–4, 6, 8; n = 1–8), C _m H _n Cl _x (m = 1–4, 6, 7, 10; n, x = 1–6), C _m H _n Cl _x O _y (m = 1–5, 12; n = 1–7; x = 1, 2, 4, 6; y = 1–3), C _n H_2n−1O (n = 2, 3), C _m H _n (m = 2, 4, 6, 8; n = 2, 4), and so on. The studies clearly showed the presence of various unfamiliar positive ionic O-containing species such as C₂ClO₂, CCl₃CO, C₂H₂Cl₄O₂, and C₄H₂Cl₆O₃. It is apparent that positive-ion reactions play a significant role in producing many ionic species in the chemistry of C₂HCl₃ plasmas.     

Synthesis and structure of The Novel Layered Phase CsTi2Cl7

Reactions in the CsCl? TiCl₃? Ti system afford CsTiCl₃ (CsNiCl₃ type, a = 7.3086(7) Å, c = 6.0670(8) Å) and the new phase CsTi₂Cl₇, the structure of which was determined by single crystal X-ray diffraction means (P2/c, Z = 2, a = 7.0076(4) Å, b = 6.2256(4) Å, c = 12.000(2) Å, β = 92.175(6)°, R/R_w = 0.026/0.035 for 1403 reflections, 2Θ ≤ 60°, MoKα). The structure can be generated by condensation of TiCl₆ groups first through cis edges to form TiCl₂Cl_4/2 ribbons and then by interconnection of these with one chlorine per titanium to give layers, viz., [Ti(Cl)Cl_4/2Cl_1/2]^?. The remaining, singly bonded chlorine projects into the interlayer region and has a Ti? Cl distance 0.208 Å less than the average for the five, 2.466 Å, reflecting significant pi bonding of the chlorine to titanium. Possible interaction of the d orbitals on adjacent titanium(III) atoms is also considered.     

Olefin polymerization and copolymerization by complexes bearing [ONNO]‐Type salan ligands: Effect of ligand structure and metal type (titanium,zirconium, and vanadium)

A series of novel titanium(IV) complexes bearing tetradentate [ONNO] salan type ligands: [Ti{2,2′‐(OC₆H₃‐5‐t‐Bu)₂‐NHRNH}Cl₂] (Lig¹TiCl₂: R = C₂H₄; Lig²TiCl₂: R = C₄H₈; Lig³TiCl₂: R = C₆H₁₂) and [Ti{2,2′‐(OC₆H₂‐3,5‐di‐t‐Bu)₂‐NHC₆H₁₂NH}Cl₂] (Lig⁴TiCl₂) were synthesized and used in the (co)polymerization of olefins. Vanadium and zirconium complexes: [ M{2,2′‐(OC₆H₃‐3,5‐di‐t‐Bu)₂‐NHC₆H₁₂NH}Cl₂] (Lig⁴VCl₂: M = V; Lig⁴ZrCl₂: M = Zr) were also synthesized for comparative investigations. All the complexes turned out active in 1‐octene polymerization after activation by MAO and/or Al(i‐Bu)₃/[Ph₃C][B(C₆F₅)₄]. The catalytic performance of titanium complexes was strictly dependent on their structures and it improves for the increasing length of the aliphatic linkage between nitrogen atoms (Lig¹TiCl₂ << Lig²TiCl₂ < Lig³TiCl₂) and declines after adding additional tert‐Bu group on the aromatic rings (Lig³TiCl₂ < Lig⁴TiCl₂). The activity of all titanium complexes in ethylene polymerization was moderate and the properties of polyethylene was dependent on the ligand structure, cocatalyst type, and reaction conditions. The Et₂AlCl‐activated complexes gave polymers with lover molecular weights and bimodal distribution, whereas ultra‐high molecular weight PE (up to 3588 kg mol^?1) and narrow MWD was formed for MAO as a cocatalyst. Vanadium complex yielded PE with the highest productivity (1925.3 kg mol_v^?1), with high molecular weight (1986 kg mol^?1) and with very narrow molecular weight distribution (1.5). Copolymerization tests showed that titanium complexes yielded ethylene/1‐octene copolymers, whereas vanadium catalysts produced product mixtures. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2111–2123     

Heteroatomige Silicium-Sauerstoff-Achtringe – Sn2O4Si2, ElO4Si3 (El  Si,Ge, P,As, Ti) – Synthese eines cyclischen Silylesters der Phosphorigen Säure

Heteroatomic Silicon-Oxygen Eightmembered Rings – Sn₂O₄Si₂, ElO₄Si₃ (El ? Si, Ge, P, As, Ti) – Synthesis of a Cyclic Silylester of the Phosphorous Acid The reaction of dilithiated di-tert.-butylsilandiol with Cl₂SnMe₂ leads in a molar ratio 1:1 to the formation of 1,5-disila-3,7-distanna-2,4,6,8-tetraoxane ( 1 ). The dilithium salt of 1,1,5,5-tetra-tert.-butyl-3,3-dimethyltrisiloxane reacts with polyfunctional element halides – Cl₂SiMe₂, GeCl₄, PF₃, AsF₃, TiCl₄ – plainly to eightmembered 1-element-3,5,7-trisila-2,4,6,8-tetrasiloxanes – ElO₄Si₃ ( 2–6 ). The hydrolysis of the PF-containing ring 4 leads to the formation of the stable, cyclic silylester of the phosphorous acid 7 .     

Zur Bildung gasförmiger MCl2-Komplexe. Vergleichende Untersuchung zur Eignung von Al2Cl6, Ga2Cl6, In2Cl6, Fe2Cl6, SiCl4, TiCl4, PCl5, TaCl5 und U2Cl10 als Komplexbildner

Formation of Gaseous MCl₂ Complexes. Comparative Study on the Suitability of Al₂Cl₆, Ga₂Cl₆, In₂Cl₆, Fe₂Cl₆, SiCl₄, TiCl₄, PCl₅, TaCl₅, and U₂Cl₁₀ as Complex Former The thermodynamic data for reactions of the type MCl_2,s + L₂Cl_6,g = ML₂Cl_8,g are – as expected – nearly independent on L(Al, Ga, In, Fe). Transport rates e. g. of CoCl₂ something smaller with L ? Ga may be traced back on uncertainties concerning the Ga₂Cl₆ dissociation, and with L ? Fe they may be traced back on the incorporation of FeCl₂ into MCl_2,s. SiCl₄ and TiCl₄ cause no noticable transport of CoCl₂ or CuCl₂ in a temperature gradient, which leads to a short bond consideration. PCl₅ and TaCl₅ cause the transport of small amounts of CoCl₂. U₂Cl₁₀/UCl₅ are able to transport a remarkable amount of CaCl₂ and CoCl₂, respectively.     

Synthese,Kristallstruktur und Magnetismus von Natriumtetrachlorotitanat(II), Na2TiCl4

Synthesis, Crystal Structure and Magnetism of Sodium Tetrachlorotitanate(II), Na₂TiCl₄ Na₂TiCl₄ is obtained as single crystals by metallothermic reduction of TiCl₃ with sodium (525°C, 90 d, Ta container). Pure powder samples may be prepared by synproportionation of TiCl₃ with Ti in the presence of NaCl (950–520°C, 21 d). The structure refinement from four-circle diffractometer data confirms that Na₂TiCl₄ is isotypic with Sr₂PbO₄ (orthorhombic, space group Pbam (No. 55), Z = 2 a = 694.2(1), b = 1 198.9(2), c = 385.6(1) pm, R = 0.055, R_w = 0,038). Ti²⁺ is surrounded by a distorted octahedron of Cl^?. The octahedra are connected via common edges to chains, [TiCl_2/1Cl_4/2]^2?, that run in the [001] direction. Magnetic susceptibility data were recorded in the 2 to 300 K temperature range at various field strengths. The interpretation of the data was carried out with the aid of crystal-field calculations taking magnetic interactions into account. The non-Curie behaviour of the reciprocal magnetic susceptibility of Ti²⁺ in Na₂TiCl₄ is due to the influence of spin-obit coupling.     

The investigation of the interaction of molten TlCl with TiCl4, SnCl4 and TlCl3 by Raman spectroscopy

The Raman spectra of the reaction products of TlCl with TiCl₄, SnCl₄ and TlCl₃ at different temperatures, and pressures up to 8 MPa, have been recorded from 1600 to 60 cm⁻¹. It was shown that complex anions TlCl⁻₄, Tl₂Cl³⁻₉ and TlCl³⁻₆ are present in salt fusions of TlCl-TlCl₃ and interaction of gaseous TiCl₄ and SnCl₄ with molten TlCl leads to formation of the ions TiCl²⁻₆ or SnCl²⁻₆. Other complex products of possible additional reactions were not discovered in these experiments.     

A simple and scalable procedure for TiCl4-promoted aldol reaction

TiCl₄-promoted aldol reaction was carried out by adding TiCl₄ to a solution of the aldol reaction substrates and (i-Pr)₂NEt (DIPEA) in CH₂Cl₂. Compared to the conventional order of addition (sequentially adding TiCl₄, DIPEA, and piperonal to the lactone 2 in CH₂Cl₂), this simplified procedure, gave a much cleaner reaction that could be executed on large scale and without cryogenic cooling. However this procedure provided no stereoselectivity.     

Polymerization with heterogeneous metalorganic catalysts. VI. Differences in polymerization activity of α-olefins and some kinetic results on butene-1 polymerization

Relative changes in polymerization activity of ethylene, propylene, and butene-1 in Ziegler-Natta polymerization were compared by use of TiCl₃ samples contaminated with O₂ and H₂O to various extents. Catalyst depletion varied for the three monomers which supported the existence of different active centers. In butene-1 polymerizations with the system Al(C₂H₅)₂Cl–TiCl₃, the formation of active centers involves an irreversible and a reversible (adsorption) reaction, the former pertaining to the formation of Al(C₂H₅)Cl₂ and dependent upon the purity of the TiCl₃. The kinetic treatment of the rate curves suggests a mixed order of catalyst deactivation and again points to the importance of Al(C₂H₅)Cl₂.     

A Non-Hydrolytic Sol-Gel Approach for the Preparation of Mg x Al2(1−x)Ti(1+x)O5 Powders

The study of non-hydrolytic reactions for the synthesis of Mg _x Al_2(1?x)Ti_(1+x)O₅ solid solution with x = 0.6 is reported. The reagents chosen were Al(OsBu)₃, Ti(OiPr)₄, TiCl₄ and Mg(NO₃)₂·6H₂O in toluene. The reactions were followed using ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy. Sol-gel synthesized powders were calcined in air at 300, 500, 1000, and 1200°C for 1 h. The powders were analysed by X-Ray Diffraction (XRD) demonstrating the formation of a Mg_0.6Al_0.8Ti_1.6O₅ phase in samples treated at the higher calcination temperature.     

Ti7Cl16 und Ti7Br16 sowie weitere Untersuchungen mit Titanhalogeniden. Al2X6 als Komplexbildner

Ti₇Cl₁₆ and Ti₇Br₁₆ and Further Investigations with Titanium Halides. Al₂X₆ as a Complex Forming Agent TiCl_3,s can be transported with Al₂Cl₆ via TiAlCl_6,g in a temperature gradient. The equilibrium of this reaction was studied by mass spectroscopy. There is no indication of the existence of a TiAl₂Cl₉ molecule as assumed in the literature. β-TiBr₃ was prepared from the elements in the presence of the transporting agent Al₂Br_6,g. The transport of TiCl₂ with Al₂Cl_6,g involves, as an important step, the disproportionation which is favoured by the reaction of Ti with the glass wall. If the disproportionation is made impossible by addition of Ti the novel compound Ti₇Cl₁₆ is obtained. Independent of Ti₇Cl₁₆, a phase TiCl_{(2 + x)} with a broad range of homogeneity exists. The compound Ti₇Br₁₆, being isostructural with Ti₇Cl₁₆, was also prepared. Results of magnetic measurements and observations on the thermal decomposition of the compounds are reported.     

CsTi2Cl7‐II: Synthese,Kristallstruktur und magnetische Eigenschaften

CsTi₂Cl₇‐II: Synthesis, Crystal Structure, and Magnetic Properties Single crystals of a second modification of CsTi₂Cl₇ (II) were obtained from the reaction of CsCl with TiCl₂ and C₆Cl₆ (monoclinic, P2₁/m (No. 11), Z = 2, a = 635.4(3), b = 1163.0(2), c = 728.0(2) pm, β = 91.49(4)°). X‐ray pure powder samples are obtained from the binary components in 1 : 2 molar mixtures of CsCl and TiCl₃ (melting at 900 °C and annealing at 550 °C below the melting point). The crystal structure of CsTi₂Cl₇‐II contains layers of densest packings of spheres of the compositions CsCl₃ and Cl₄, respectively, that are stacked alternatively in the [010] direction according to the sequence … ABAC … Ti³⁺ resides in one quarter of the octahedral holes between these layers in a way that confacial bioctahedra are connected via two common edges forming a zigzag chain running parallel to [010]. This structure with Ti³⁺–Ti³⁺ distances of 323 and 347 pm, respectively, is reflected in the antiferromagnetic behavior with interactions about sixteen times stronger within the dimers than between them (J = –490 cm^–1 bzw. J = –30 cm^–1).     

Enantiomerenreine Pyrrolidin-Derivate aus trans-4-Hydroxy-L-prolin durch elektrochemische oxidative Decarboxylierung und Titantetrachlorid-vermittelte Umsetzung mit Nukleophilen

Enantiomerically Pure Pyrrolidine Derivatives from trans-4-Hydroxy-L -proline by Electrochemical Oxidative Decarboxylation and Titanium-Tetrachloride-Mediated Reaction with Nucleophiles Preparative electrolysis of N-methoxycarbonyl-O-[(t-butyl)dimethylsilyl]hydroxyproline 4 in MeOH leads to substitution of the COOH by a MeO group (oxidative decarboxylation). The mixture 5 of the two diastereoisomers (ca 1:1) thus obtained was reacted in CH₂Cl₂ with nucleophilic silylated compounds (such as allylsilane, silyl cyanide and 1-phenyl-1-silyloxyethane) or with trimethyl phosphite in the presence of TiCl₄ to give 2-allyl-, 2-cyano-, 2-(2-oxo-2-phenylethyl)- and 2-phosphono-substituted hydroxypyrrolidines, respectively, with high diastereoselectivities (≥ 90%, products 6-12 ). The configuration of two of the products ( 6/7 and 8/9 ) was shown to be cis.