Reaction Of Titanium Tetrachloride Research Articles

Thermal Atomic Layer Deposition of TiNx Using TiCl4 and N2H4

Atomic layer deposition (ALD) of titanium nitride (TiN) is carried out by the alternate surface reactions of titanium tetrachloride (TiCl4) and hydrazine (N2H4) at temperatures ranging from 150 to 350°C. The film deposition process is monitored in situ by quartz piezoelectric microweighing (QPM) and Fourier transform infrared spectroscopy (FTIRS). The QPM data detects the self-limiting character of the surface reactions between TiCl4 and N2H4, as well as the linearity of the film growth with the number of cycles at 200 and 225°C. The growth constant of the TiNx film is found to be 0.36 A/cycle at the optimum growth temperature of 275°C. The roughness and density of the 116.3-A-thick film deposited at this temperature are determined to be 7.2 A and 87.5% (of the TiN volume’s density), respectively. The X-ray photoelectron spectroscopy (XPS) analysis of these films shows the content of chlorine impurities to be below the instrument’s sensitivity limit (<0.2 аt %) and the oxygen content to be near 14 at %. The X-ray diffraction measurements indicate the cubic polycrystalline structure of these films. The FTIRS method is used for surface deposition chemistry at 200 and 275°C. The possibility of depositing titanium-aluminum nitride (TiAlxNy) films by ALD with trimethylaluminum (TMA) as a precursor is also shown. Films deposited at 275°С are found to contain oxygen and chlorine impurities near 3 and 4 at %, respectively.

Crystallographic Insights into the Behavior of Highly Acidic Metal Cations in Ionic Liquids from Reactions of Titanium Tetrachloride with [1-Butyl-3-Methylimidazolium][X] Ionic Liquids (X = Chloride, Bromide, Tetrafluoroborate).

Highly charged metal ions are difficult to investigate in weakly coordinating ionic liquids (ILs) because of the insolubility of their solid forms, but the molecular liquid TiCl4 offers a way to react tetravalent metal ions in an IL. Reactions of TiCl4 with 1-butyl-3-methylimidazolium ([C4mim]+)-based ILs containing chloride or bromide lead to mixtures of highly metastable amorphous solids and small amounts of crystalline chlorotitanate salts including [C4mim]2[TiCl6] and two polymorphs of [C4mim]2[Ti2Cl10] in a manner not well correlated with stoichiometry or anion identity. The reaction of TiCl4 with [C4mim][BF4] yields crystals of the mixed fluoro-chloro complex [C4mim]2[Ti4F6Cl12], indicating spontaneous reaction of the IL ions to generate HF in situ. These unusual behaviors are explained in terms of the exceptionally high acidity of Ti4+ and the unusual behavior of TiCl4 among metal halides as a nonpolar molecular compound.

Mechanism of formation of titanium dioxide crystallites in the reaction of titanium tetrachloride with magnesium hydrosilicate nanotubes

Explored herein is the first cycle of atomic layer deposition of titanium dioxide from titanium tetrachloride and water vapours on the nanotubular magnesium hydrosilicate Mg3Si2O5(OH)4, a synthetic analogue of chrysotile. The structure and morphology of the products are characterised by X-ray diffraction, infrared spectroscopy, electron microscopy and nitrogen adsorption measurements. A side reaction between chrysotile and hydrogen chloride is followed by in situ gravimetry. At 150 °C, titanium tetrachloride chemisorption is shown to produce a monomolecular layer of titanium–chlorine groups on the surface of the chrysotile nanotube preserving its original crystal structure. By contrast, at higher temperatures, 300–400 °C, the process is complicated by a secondary interaction including dehydroxylation of the substrate and a reaction of released water with titanium tetrachloride to form titanium dioxide crystallites in the free space between nanotubes. Structural transformations of chrysotile lowering its thermal stability and leading to its dehydroxylation are caused by the action of hydrogen chloride, a by-product of titanium tetrachloride chemisorption and titanium dioxide formation.

Reaction of TiCl4 with diethyl ether. Experimental and quantum-chemical study

The reaction of titanium tetrachloride with diethyl ether at various ratios of components and temperatures was studied by the NMR and mass spectrometry methods. The TiCl4·2Et2O complex does not pass in the gas phase. Formation of ethoxytrichlorotitanium among reaction products was established by the X-ray structure analysis. The model of conversion from initial components to titanium dioxide was suggested on the basis of the obtained experimental data and quantum-chemical calculations (B3LYP/def2-SVP level of theory).

Octahedral titanium(IV) complexes with five novel hydroximic acid ligands: Synthesis, spectroscopic characterization, and in vitro activities on IMR-32 and CHO cell lines and ten bacterial strains

Complexes with the composition TiCl4L2 where L = benzohydroxamic acid, 2-hydroxybenzo-hydroxamic acid, acetohydroxamic acid, hydroxyurea, and N-hydroxy-N-phenylbenzamide have been synthesized by reaction of titanium tetrachloride with 2 equiv of the corresponding hydroxamic acids. The structure of these complexes has been studied by analytical and spectroscopic (FT-IR, UV-Vis, MS, 1H and 13C NMR) techniques. The free ligands and the complexes have been tested in vitro to evaluate their activities against IMR-32 (neuroblastoma) cancer cell line, CHO p-40 (Chinese hamster ovary) normal cells, and ten pathogenic bacterial strains.

Combinatorial Atmospheric Pressure Chemical Vapor Deposition of F:TiO2; the Relationship between Photocatalysis and Transparent Conducting Oxide Properties

Combinatorial atmospheric pressure chemical vapor deposition (APCVD) is used to deposit anatase TiO2 with a graded level of F‐doping between 1.10 ≤ F:Ti (at%) ≤ 2.57 from the reaction of titanium tetrachloride, ethyl acetate and trifluoroacetic acid at 500 °C on glass. The photocatalytic activity and electrical resistivity of 200 allotted positions across a grid are screened using high‐throughput techniques. A blue region of film is singled out for containing the lowest electrical resistivities of any previously reported doped or undoped TiO2‐based system formed by APCVD (ρ ≈ 0.22–0.45 Ω cm, n = 0.8–1.2 × 1018 cm−3, μ = 18–33 cm2 V−1 s−1). The blue region contains a lower fluorine doping level (F:Ti ≈ 1.1–1.6%, Ebg ≈ 3.06 eV) than its neighboring colorless region (F:Ti ≈ 2.3–2.6%, Ebg ≈ 3.15–3.21 eV, ρ ≈ 0.61–1.3 Ω cm). State‐of‐the‐art hybrid density functional theory calculations were employed to elucidate the nature of the different doping behaviors. Two distinct fluorine doping environments were present. At low concentrations, F substituting for O (FO) dominates, forming blue F:TiO2. At high concentrations, negatively charged fluorine interstitials (Fi−1) begin to dominate, forming transparent F:TiO2.

Binary Titanium (IV) Metal-organic Frameworks with Multidentate Ligands

Some volatile binary metal-organic frameworks of titanium (IV), [Ti(OOCR) 4 ] (where R = C 13 H 27, C 15 H 31, C 17 H 35 or C 21 H 43 ) were synthesized by the reaction of titanium tetrachloride and sodium salts of the straight chain fatty acids (prepared in situ) in 1:4 molar ratio. The isolated solid products were showing poor crystallinity and were characterized by their elemental analyses, molecular weight determinations, conductance, spectral (infrared, 1 H NMR, 13 C NMR, FAB mass and powder XRD) and TEM studies. Their monomeric nature was confirmed by molecular weight determinations and FAB mass spectra. Eight coordination number of titanium (IV) have been assigned in the isolated compounds. TEM indicated the particles are spherical in shape having ~200 nm diameter.

Synthesis, Characterization, and Sol-Gel Behavior of Dichlorotitanium(IV) (O-Alkyl, O-Cycloalkyl, and O-Aryl Trithiophosphates)

Dichlorotitanium(IV) trithiophosphates of the type TiCl2[(RO)P(S)S2] (where R = Me, Et, Prn, Pri, Bun, Bus, Bui, Ami, Ph and cyclohexyl) have been synthesized for the first time by the reaction of titanium tetrachloride with potassium trithiophosphates in a 1:1 molar ratio in anhydrous benzene. Sol-gel chemistry of these titanium(IV) compounds has been studied in dry benzene by treatment with hydrogen sulfide gas. These newly synthesized derivatives have been characterized by elemental analysis (C, H, S, Cl, and Ti), molecular weight measurement, and spectral [IR and multinuclear NMR (1H, 13C, and 31P)] studies. The bonding mode of trithiophosphate ligands and tentative structure around titanium(IV) are discussed.

Size control synthesis of sulfur doped titanium dioxide (anatase) nanoparticles, its optical property and its photo catalytic reactivity for CO 2 + H 2O conversion and phenol degradation

Sulfur doped anatase TiO 2 nanoparticles (3 nm-12 nm) were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO 2 nanoparticles were studied along with Degussa commercial TiO 2 particles (24 nm). The results show that band gap of TiO 2 particles decreases from 3.31 to 3.25 eV and for that of commercial TiO 2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at 4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO 2+H 2O in which formation of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and sulfur doping of 4.80% and 5.26%. For TiO 2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area and the light source used.

Fundamental study on synthesis and enrichment of titanium subchloride

In order to establish a new high-speed/(semi-)continuous titanium production process based on the magnesiothermic reduction of titanium subchlorides (subhalide reduction process), a novel synthetic process for obtaining titanium subchlorides (TiCl x , x = 2, 3) by the reaction of titanium tetrachloride (TiCl 4) with titanium metal at 1273 K was investigated. It was demonstrated that the efficiency of the TiCl x formation improved drastically when molten salts were used as the reaction medium as compared with that of the synthesis by employing the direct reaction of TiCl 4 gas with solid titanium. The feasibility of the enrichment process of TiCl x in molten salt was also demonstrated. The method for producing the titanium subchlorides investigated in this study can be applied to the new high-speed production process of titanium.

Effect of Mixing on the Nucleation and Growth of Titania Particles

Aerosol processes that produce titania particles by reacting gaseous precursors (such as titanium tetrachloride) initially must mix the precursor into the oxidizer at elevated temperatures to initiate the formation of product. Oftentimes the rate of reaction is sufficiently large as to be mixing limited. Thus the rate of mixing of the reacting species will control the chemistry and morphological properties of the particles that are produced. The interplay between mixing, nucleation, and growth in these systems is difficult to observe experimentally due to the small time scales that are involved and the spatial limitations of most diagnostics. An alternative approach is direct numerical simulation (DNS). DNS refers to a class of numerical solutions of the three-dimensional time-dependent governing equations for a particular system in which no turbulence modeling assumptions are made. To within the precision of the numerical algorithm, DNS can be thought of as a numerical experiment. Here we apply DNS to the mixing, reaction, nucleation, and growth of titania particles formed from the reaction of titanium tetrachloride with oxygen. The simulation solves for the velocity, species concentration, and eight moments of the particle size distribution using a combination of a pseudospectral method (for the velocity) and a compact finite difference scheme (for all of the scalars). The results show that increasing the rate of mixing increases the rate of particle formation while decreasing the variance in the particle size distribution. However, for a given extent of reaction, poorer mixing leads to larger mean particle sizes and larger standard deviations. The results are most easily interpreted in terms of the reaction volume between the unmixed reactants, where most of the reaction occurs. Based on this analysis, we present rules of thumb for controlling the particle size distribution in aerosol reactors.

COMPLEXES OF TITANIUM TETRACHLORIDE WITH BENZILMONOXIME AND BENZILDIOXIME

Some new titanium(IV) derivatives of benzilmonoxime and benzildioxime have been synthesized by the reactions of titanium tetrachloride and the sodium salt of oximes in different molar ratios. All of the newly synthesized complexes have been characterized by elemental analyses, molecular weight determinations, and spectral (IR, 1H, and 13C NMR) studies.

Addition compounds of titanium tetrachloride with aromatic nitrogen bases

Three reaction products of an addition reaction of titanium tetrachloride with aromatic nitrogen bases are presented. trans-Tetrachlorobis(3,4-dimethylpyridine)titanium, [TiCl 4 (C 7 H 9 N) 2 ], (I), and trans-tetrachlorobis(4-methylpyridine)titanium, [TiCl 4 (C 6 H 7 N) 2 ], (II), are both neutral complexes in which the central Ti atom is bonded to four Cl and two N atoms of two 3,4-dimethylpyridine and 4-methylpyridine ligands, respectively, resulting in a slightly distorted octahedral environment around the Ti atom. The methylpyridine ligands occupy axial positions, with the four chloro ligands in the equatorial plane. The ionic structure of bis(1-methylimidazolium) hexachlorotitanate(IV) pentachloro(N-methylimidazole-N 3 )titanate(IV), (C 4 H 7 N 2 ) 2 [TiCl 5 (C 4 H 6 N 2 )][TiCl 6 ] 0.5 , (III), consists of a pentachloro(N-methylimidazole-N 3 )titanate anion and half a [TiCl 6 ] 2- complex anion, in both of which the Ti atom appears in a nearly perfect octahedral coordination sphere with two N-methylimidazolium cations as counter-ions.

Synthesis, Structure, and Properties of Group 4 and 5 Metal Pyrazolato Chloride Complexes.

Treatment of titanium tetrachloride with 3,5-di-tert-butylpyrazole (2 equiv) and triethylamine (2 equiv) in toluene afforded dichlorobis(3,5-di-tert-butylpyrazolato)titanium(IV) (93%). A similar reaction with 3 equiv of 3,5-di-tert-butylpyrazole and triethylamine gave chlorotris(3,5-di-tert-butylpyrazolato)titanium(IV) (91%). Trichloro(3,5-di-tert-butylpyrazolato)titanium(IV) was prepared in 93% yield through reaction of titanium tetrachloride with 1-trimethylsilyl-3,5-di-tert-butylpyrazole (1 equiv) in toluene. Treatment of zirconium and hafnium tetrachlorides with 3,5-di-tert-butylpyrazolatopotassium (4 equiv) in toluene afforded the homoleptic pyrazolato complexes tetrakis(3,5-di-tert-butylpyrazolato)zirconium(IV) (90%) and tetrakis(3,5-di-tert-butylpyrazolato)hafnium(IV) (68%). Analogous reaction of 3,5-di-tert-butylpyrazolatopotassium (>/=3 equiv) with niobium and tantalum pentachlorides gave dichlorotris(3,5-di-tert-butylpyrazolato)niobium(V) (98%) and dichlorotris(3,5-di-tert-butylpyrazolato)tantalum(V) (83%). Reaction of the complexes tetrakis(3,5-di-tert-butylpyrazolato)metal(IV) (metal = Zr, Hf) and dichlorotris(3,5-di-tert-butylpyrazolato)metal(V) (metal = Nb, Ta) with the metal tetrachlorides and metal pentachlorides, respectively, in dichloromethane afforded the complexes chlorotris(3,5-di-tert-butylpyrazolato)metal(IV) (metal = Zr, 89%; Hf, 97%) and trichlorobis(3,5-di-tert-butylpyrazolato)metal(V) (metal = Nb, 90%; Ta, 84%). Crystal structures of trichloro(3,5-di-tert-butylpyrazolato)titanium(IV), chlorotris(3,5-di-tert-butylpyrazolato)hafnium(IV), and dichlorotris(3,5-di-tert-butylpyrazolato)niobium(V) were determined. Trichloro(3,5-di-tert-butylpyrazolato)titanium(IV) crystallizes in the space group C2/c with a = 22.6542(8) Å, b = 9.5147(3) Å, c = 16.5329(6) Å, beta = 113.5780(10) degrees, and Z = 8. Chlorotris(3,5-di-tert-butylpyrazolato)hafnium(IV) crystallizes in the space group P2(1)/c with a = 10.4529(7) Å, b = 10.1437(6) Å, c = 36.986(3) Å, beta = 93.3080(10) degrees, and Z = 4. Dichlorotris(3,5-di-tert-butylpyrazolato)niobium(V) crystallizes in the space group P2(1)/c with a = 10.2051(3) Å, b = 38.3650(12) Å, c = 9.7585(3) Å, beta = 93.3280(10) degrees, and Z = 4. Kinetic analysis of a dynamic process observed for dichlorotris(3,5-di-tert-butylpyrazolato)niobium(V) is described. The results of this study suggest that eta(2)-pyrazolato donors may be useful ancillary ligands in the development of new reactive early transition metal complexes.

Adducts of titanium tetrachloride with organosulfur compounds. Crystal and molecular structures of TiCl 4(C 4H 8S) 2 and (TiCl 4) 2(CH 3SSCH 3)

Treatment of titanium tetrachloride with a range of organothiols affords adducts of the formula TiCl 4(HSR) 2 in 77–89% yields. Reaction of titanium tetrachloride with organic sulfides gives sulfide adducts of the formula TiCl 4(SR 2) 2 in 87–98% yields. These complexes are volatile and monomeric with cis-organosulfur ligands. Treatment of titanium tetrachloride with methyl disulfide affords the adduct (TiCl 4) 2(CH 3SSCH 3) in 98% yield, which adopts a dinuclear structure with a Ti 2Cl 8 core and a bridging disulfide ligand. The crystal structures of TiCl 4(C 4H 8S) 2 and (TiCl 4) 2(CH 3SSCH 3) were determined. The relevance of these observations to the chemical vapor deposition of titanium disulfide and trisulfide films is discussed.

SYNTHESIS AND CHARACTERISATION OF TITANIUM(IV) COMPLEXES OF BENZILMONOTHIOSEMICARBAZONE

Titanium(IV) derivatives of benzilmonothiosemicarbazone have been synthesised by the reaction of titanium tetrachloride with the sodium salt of benzilmonothiosemicarbazone (prepared in situ) in 1: 1, 1:2, 1:3 and 1:4 molar ratios and have been characterised on the basis of elemental (C, H, N, S, C1 and Ti) analyses, molecular weight determinations and spectral (IR and PMR) studies.

Synthese und Kristallstruktur von Pentakis(dimethylsulfoxid)- oxo-titan(IV)chlorid / Synthesis and Crystal Structure of Pentakis(dimethylsulfoxide)-oxo-titanium(IV) Chloride

Abstract Pentakis(dimethylsulfoxide)-oxo-titanium(IV) chloride is obtained by reaction of titanium tetrachloride with a stoichiometric amount of water in dimethylsulfoxide. A single crystal structure determination (P1̄, a = 9.564(6), b = 10.504(7), c = 12.510(8) Å, α = 70.21(5), β = 83.48(5), γ = 89.82(5)°, V = 1174 Å3, Z = 2) shows a dicationic titanium(IV) complex with five dimethylsulfoxide ligands and one oxygen atom. The two chlorine anions are not bonded to the complex cation. The TiO6-fragment is a distorted octahedron, where five of the six oxygen atoms belong to the coordinated dimethylsulfoxide molecules.

Titanium amide molecular precursors for titanium nitride

The reaction of titanium tetrachloride in toluene at −78°C with 2 equivalents of N,N′,N″-trimethylethylenediamine yields a monomeric titanium tetrachloride adduct, [TiCl 4(Me 2NCH 2CH 2MNeH)] ( 1). The complex [TiCl 2(Me 2NCH 2CH 2NMeH) 2] ( 2) is prepared by the reaction of titanium tetrachloride with 4 equivalents of N,N′,N″-trimethylethylenediamine at −78°C. The X-ray crystal structure of 1 reveals that it has a distorted octahedral structure, with the chelating amine ligand in a delta- gauche conformation.

Reactions of titanium tetrachloride with carboxylic acids. Crystal and molecular structure of the dinuclear titanium oxo compound [{TiCl2(O2CBut)(ButCO2H)}2O

Reaction of TiCl4(1 mol) with 2,2-dimethylpropanoic acid (2.5 mol) at room temperature yields the dinuclear oxo-bridged species [{TiCl2(O2CBut)(ButCO2H)}2O]1 which has been fully characterised by an X-ray crystal structure analysis. The two metal atoms are bridged by the oxo and two carboxylate groups, which with a co-ordinated acid molecule and two chlorine atoms on each titanium gives a slightly distorted octahedral environment around each metal centre. At 40 °C compound 1 decomposes to the trinuclear species [Ti3Cl3(O2CBut)5O2], and at higher temperatures (100–120 °C) to another dinuclear oxo derivative [{TiCl(O2CBut)2}2O] which can also be obtained from the action of 2,2-dimethylpropanoic anhydride on TiCl4 in refluxing toluene. Acetic acid produces a similar, but less soluble, species to 1. Aromatic acids react differently; para-substituted aryl acids generally yield trinuclear compounds [Ti3Cl3(O2CC6H4X-p)5O2](X = Cl or Br) although the p-But acid forms [{TiCl(O2CC6H4But-p)2}2O]. In contrast the ortho-and meta-substituted acids react to give either [Ti3Cl4(O2CR)4O2](R = C6H4Cl-o or -m) or [Ti4Cl5(O2CR)7O2](R = C6H4Me-o) derivatives.

A class of single-source precursors to titanium disulfide films. Synthesis, structure, and chemical vapor deposition studies of [TiCl4(HSR)2

Titanium disulfide is one of the desirable cathode materials for lithium batteries. Recent emphasis on the development of thin-film batteries has underscored the need for high-purity, crystallographically oriented, stoichiometric coatings. The majority of chemical vapor deposition (CVD) routes of TiS[sub 2] films are based on the reaction between titanium tetrachloride and hydrogen sulfide, organic sulfides, or disulfides. Recently we reported a new atmospheric pressure CVD process for TiS[sub 2] films, which relies upon the reaction of titanium tetrachloride with organothiols at temperature [ge]200 [degrees]C and affords highly pure, crystallographically oriented, stoichiometric, adhesive coatings[sup 5]. It was envisaged the use of a single-source precursor in the deposition of TiS[sub 2] films could provide precise control of titanium and sulfur stoichiometry, could reduce toxic/odiferous waste, and would eliminate the problem of mixing two or more gaseous reactants in a low-pressure CVD reactor. However, no such precursor had been described in the literature. Herein the authors report the synthesis of the first class of single-source precursors to high quality TiS[sub 2] films. These complexes are of the formula [TiCl[sub 4](HSR)[sub 2]] and are obtained upon treatment of titanium tetrachloride with alkanethiols. Significantly, the crystallographic orientation of the films produced from these precursors ismore » ideal for use as cathodes in lithium batteries.« less