Hydrolysis and Condensation Processes of Titanium iso-Propoxide Modified with Catechol: An NMR Study

The hydrolysis and condensation processes of titanium iso-propoxide modified with catechol (C₆H₄(OH)₂; H₂cat) have been investigated by ¹H, ¹³C and ¹⁷O nuclear magnetic resonance spectroscopy. The hydrolysis reactions of the modified titanium iso-propoxide in the system with Ti:tetrahydrofuran (THF):H₂O = 1:20:x (x = 1, 2 and 5 in a molar ratio) are essentially completed in the initial stage (<1 h), and the condensation reactions also proceed significantly during this stage. Upon hydrolysis with H₂O/Ti = 1, the iso-propoxy groups are selectively hydrolyzed and the catecholate groups remain bound to titanium. With H₂O/Ti = 2 and 5, both the iso-propoxy and catecholate groups are hydrolyzed, and the hydrolysis of the iso-propoxy groups is relatively preferential. Approximately half the catecholate groups are stably bound to titanium, even after hydrolysis with H₂O/Ti = 5.     

Synthesis and Characterization of New Silicon and Titanium Derivatives of Bis(anilino)phosphine Oxide

The reactions of bis(anilino)phosphine oxide (C ₆ H ₅ NH) ₂ P(O) H with (C ₅ H ₅ )₂TiCl₂ or Me₂SiCl₂ in a 1:1 molar ratio in THF results in the isolation of new phosph(V)azane complexes (C₅H₅)₂Ti[(N C₆H₅)₂P(O)H] (1) or Cl ₂ Si[(N C ₆ H ₅ )₂P(O)H] (2), respectively. In these reactions, HCl or CH₄ elimination occurs and N-Ti or N-Si bonds form directly between a bis(anilino)phosphine oxide ligand and organotitanium or organosilicon compounds. The products(1) and (2) have been fully characterized by elemental analysis as well as ¹ H, ³¹ P, ²⁹ Si NMR, and IR spectroscopy.     

Factors affecting product distributions in ethylene/styrene copolymerization by (aryloxo)(cyclopentadienyl)titanium complexes‐MAO catalyst systems

Ethylene/styrene copolymerizations using Cp′TiCl₂(O‐2,6‐ⁱPr₂C₆H₃) [Cp′ = Cp* (C₅Me₅, 1 ), 1,2,4‐Me₃C₅H₂ ( 2 ), tert‐BuC₅H₄ ( 3 )]‐MAO catalyst systems were explored under various conditions. Complexes 2 and 3 exhibited both high catalytic activities (activity: 504–6810 kg‐polymer/mol‐Ti h) and efficient styrene incorporations at 25, 40°C (ethylene 6 atm), affording relatively high molecular weight poly (ethylene‐co‐styrene)s with unimodal molecular weight distributions as well as with uniform styrene distributions (M_w = 6.12–13.6 × 10⁴, M_w/M_n = 1.50–1.71, styrene 31.7–51.9 mol %). By‐productions of syndiotactic polystyrene (SPS) were observed, when the copolymerizations by 1 – 3 ‐MAO catalyst systems were performed at 55, 70 °C (ethylene 6 atm, SPS 9.0–68.9 wt %); the ratios of the copolymer/SPS were affected by the polymerization temperature, the [styrene]/[ethylene] feed molar ratios in the reaction mixture, and by both the cyclopentadienyl fragment (Cp′) and anionic ancillary donor ligand (L) in Cp′TiCl₂(L) (L = Cl, O‐2,6‐ⁱPr₂C₆H₃ or N=C^tBu₂) employed. Co‐presence of the catalytically‐active species for both the copolymerization and the homopolymerization was thus suggested even in the presence of ethylene; the ratios were influenced by various factors (catalyst precursors, temperature, styrene/ethylene feed molar ratio, etc.). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4162–4174, 2008     

Proton-transfer salts of diphenylphosphinic acid with substituted 2-aminopyridine: crystal structure,spectroscopic and DFT studies

Three proton-transfer salts of diphenylphosphinic acid (DPPA) with 2-amino-5-(X)-pyridine (AMPY, X = Cl, CN or CH₃), namely, 2-amino-5-chloropyridinium diphenylphosphinate, C₅H₆ClN₂⁺·C₁₂H₁₀O₂P⁻ ( 1 , X = Cl), 2-amino-5-cyanopyridinium diphenylphosphinate, C₆H₆N₃⁺·C₁₂H₁₀O₂P⁻ ( 2 , X = CN), and 2-amino-5-methylpyridinium diphenylphosphinate, C₆H₉N₂⁺·C₁₂H₁₀O₂P⁻ ( 3 , X = CH₃), have been synthesized and characterized by FT–IR and ¹H NMR spectroscopy, and X-ray crystallography. The crystal structures of compounds 1 – 3 were determined in the space group P for 1 and 2 , and C2/c for 3 . All three compounds contain N—H…O hydrogen-bonding interactions due to proton transfer from the O=P—OH group of DPPA as donor to the pyridine N atom of AMPY as acceptor. The proton transfer of compounds 1 – 3 was also verified by ¹H NMR and FT–IR spectroscopy. The stoichiometry of all three proton-transfer salts was determined to be 1:1 and the Benesi–Hildebrand equation was applied to determine the formation constant (K_CT) and the molar extinction coefficient (ϵ_CT) in each case. Theoretical density functional theory (DFT) calculations were performed to investigate the optimized geometries, the molecular electrostatic potentials (MEP) and the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) of all three proton-transfer salts. The results showed good agreement between the experimental data and the DFT computational analysis.     

A porous open-framework titanium oxophenylphosphate

Highly porous titanium oxophenylphosphate (TPP-1) has been synthesized hydrothermally at 448 K using phenylphosphonic acid (PPA) as the organophosphorus source without the aid of any template or structure-directing agent (SDA). Powder XRD, TEM, SEM-EDS, N₂ sorption, ICP-AES chemical analysis, ¹³C and ³¹P MAS NMR, UV-Vis, XPS spectroscopic tools, TG-DTA and NH₃-TPD were used to characterize this material. XRD, N₂ sorption and TEM image analysis suggested the disordered layered framework structure and the presence of large-size micropores along with mesopores in this material. Spectroscopic data suggested the presence of phenyl group, O, Ti and P in this open-framework material, where Ti centers can adopt both tetrahedral and octahedral geometry. TPP-1 showed fairly good H₂ adsorption capacity under normal pressure to high pressure at 77 K. Physisorption data on hydrogen has suggested the potential application of this porous material in H₂ storage.     

Synthesis of Branched Polyethylene by Tandem Catalysis

Linear low‐density polyethylene (LLDPE) can be prepared by addition of ethylene to a mixture of two catalysts. In this “tandem catalysis” scheme one catalyst dimerizes or oligomerizes ethylene to α‐olefins while the second site incorporates these α‐olefins into a growing polyethylene chain. A variety of classical catalyst combinations are available for this purpose. Better control over the polymerization process, and therefore product properties, is attained by the use of homogenous “single site” catalysts. The best‐behaved tandem processes take advantage of well‐defined catalysts that require stoichiometric quantities of activators. One such system employs [(C₆H₅)₂PC₆H₄C(OB(C₆F₅)₃)O‐κ²P,O]Ni(η³‐CH₂CMeCH₂) and {[(η⁵‐C₅Me₄)SiMe₂(η¹‐NCMe₃)]TiMe}{MeB(C₆F₅)₃}. The nickel sites are responsible for converting ethylene to 1‐butene or mixtures of 1‐butene with 1‐hexene. These olefins are copolymerized with ethylene at the titanium sites. It is possible to obtain a linear correlation between the branching content in the polymer product and the Ni/Ti ratio. The effect of ligand substitution at nickel has also been investigated. When the benzyl derivative [(C₆H₅)₂PC₆H₄C(O‐B(C₆F₅)₃)O‐κ²P,O]Ni(η³‐CH₂C₆H₅) is used instead of the methallyl counterpart [(C₆H₅)₂PC₆H₄C(OB(C₆F₅)₃)O‐κ²P,O]Ni(η³‐CH₂CMeCH₂), one obtains, at a constant Ni/Ti ratio, considerably more branching in the final polymer structure. These results are rationalized in terms of a more efficient initiation when the more labile benzyl ligand is used.     

Effect of Processing Parameters on the Optical Properties of TiO<Subscript>2</Subscript>/Ormosil Planar Waveguide

Hybrid TiO₂/ormosil waveguiding films have been prepared by the sol-gel method at low thermal treatment temperature of 150C. The influence of processing parameters including the molar ratios of titanium butoxide (Ti(OBu)₄)/3-glycidoxypropyltrimethoxysilane (GLYMO) and H₂O/Ti(OBu)₄ (expressed as R), especially aging of sol on the optical properties was investigated. The optical properties of films were measured with scanning electron microscope (SEM), UV/VIS/NIR spectrophotometer (UV-Vis), m-line and the scattering-detection method. The results indicate that the film thickness increases with the increase of sol aging time, but the variation of refractive index as a function of sol aging time depends on the relative ratios of GLYMO to Ti(OBu)₄. Higher transmittance and lower attenuation of the planar waveguide can be obtained in the sol with lower Ti(OBu)₄ contents and shorter aging time.     

Monomer-isomerization polymerization. XXIII.. Monomer-isomerization polymerization of 5-phenyl-2-pentene with ziegler–natta catalysts

5-Phenyl-2-pentene (5Ph2P) was found to undergo monomer-isomerization polymerization with TiCl₃–R₃Al (R = C₂H₅ or i-C₄H₉, Al/Ti > 2) catalysts to give a polymer consisting of exclusively 5-phenyl-1-pentene (5Ph1P) unit. The geometric and positional isomerizations of 5Ph2P to its terminal and other internal isomers were observed to occur during polymerization. The catalyst activity of alkylaluminum examined to TiCl₃ was in the following order: (C₂H₅)₃Al > (i-C₄H₉)₃Al > (C₂H₅)₂AlCl. The rate of monomer-isomerization polymerization of 5Ph2P with TiCl₃–(C₂H₅)₃Al catalyst was influenced by both the Al/Ti molar ratio and the addition of nickel acetylacetonate [Ni(acac)₂], and the maximum rate was observed at Al/Ti = 2.0 and Ni/Ti = 0.4 in molar ratios.     

Mixed ligand titanium(IV) complexes. Chlorobis(dithiocarbamato)bis(methylsalicylato)titanium(IV) andbis(dithiocarbamato)bis(methylsalicylato)titanium(IV)

Summary Dichlorobis(methylsalicylato)titanium(IV) reacts with potassium or amine salts of dialkyl or diaryl dithiocarbamates in 11 and 12 molar ratios in anhydrous benzene (room temperature) or in boiling CH₂Cl₂ to yield mixed ligand complexes: (AcOC₆H₄O)₂ Ti(S₂CNR₂)Cl (1) and (AcOC₆H₄O)₂ Ti(S₂CNR₂)₂ (2), R=Et, n-Pr, n-Bu, cyclo-C₄H₈ and cyclo-C₅H₁₀. These compounds are moisture sensitive and highly soluble in polar solvents. Molecular weight measurement in conjunction with i.r.,¹H and¹³C n.m.r. spectral studies suggest coordination number 7 and 8 around titanium(IV) in (1) and (2) respectively.     

Thermal Decomposition of Cu(II) Complexes with 2-Chloro- and 2,6-Dichlorobenzoic Acid and Imidazole

The reaction products of Cu(II) 2-chlorobenzoate and the imidazole (1), and of Cu(II) 2,6-dichlorobenzoate and the imidazole (2) formulated as CuL’₂⋅2imd⋅2H₂O and CuL”₂⋅2imd⋅2H₂O (L’=C₇H₄ClO₂ ⁻, L”=C₇H₃Cl₂O₂ ⁻, imd=imidazole), were prepared and characterized by means of spectroscopic measurements and thermochemical properties. The blue (1) and green (2) complexes were obtained as solids with a 1:2:2 molar ratio of metal to carboxylate ligand to imidazole. When heated at a heating rate of 10 K min⁻¹ the hydrated complexes, (1) and (2), lose some of the crystallization water molecules and then decompose to gaseous products. This revised version was published online in August 2006 with corrections to the Cover Date.     

Crystal Structure and Characterization of Two Layered Copper(II) Coordination Polymers with Anions of 3‐Phosphonopropionic Acid and (RS)‐2‐Phosphonobutyric Acid

Blue single crystals of Cu[μ₃‐O₃P(CH₂)₂COOH] · 2H₂O ( 1 ) and Cu[(RS)‐μ₃‐O₃PCH(C₂H₅)COOH] · 3H₂O ( 2 ) were prepared in aqueous solutions (pH = 2.5–3.5). 1 crystallizes in space group Pbca (no. 61) with a = 812.5(2), b = 919.00(9), and c = 2102.3(2) pm. Cu²⁺ is fivefold coordinated by three oxygen atoms stemming from [O₃P(CH₂)₂COOH]^2– anions and two water molecules. The Cu–O bond lengths range from 194.0(3) to 231.8(4) pm. The connection between the [O₃P(CH₂)₂COOH]^2– anions and the Cu²⁺ cations yields a polymeric structure with layers parallel to (001). The layers are linked by hydrogen bonds. 2 crystallizes in space group Pbca (no. 61) with a = 1007.17(14), b = 961.2(3), c = 2180.9(4) pm. The copper cations are surrounded by five oxygen atoms in a square pyramidal fashion with Cu–O bonds between 193.6(4) and 236.9(4) pm. The coordination between [O₃PCH(C₂H₅)COOH]^2– and Cu²⁺ results in infinite puckered layers parallel to (001). The layers are not connected by any hydrogen bonds. Each layer contains both R and S isomers of the [O₃PCH(C₂H₅)COOH]^2– dianion. Water molecules not bound to Cu²⁺ are intercalated between the layers. UV/Vis spectra suggest three d–d transition bands at 743, 892, 1016 nm for 1 and four bands at 741, 838, 957, and 1151 nm for 2 , respectively. Magnetic measurements suggest a weak antiferromagnetic coupling between Cu²⁺ due to a super‐superexchange interaction. Thermoanalytical investigations in air show that the compounds are stable up to 95 °C ( 1 ) and 65 °C ( 2 ), respectively.     

Reaction of titanocene dihalides with Na2H2 EDTA. Crystal structure of [Ti(EDTA)(H2O)]

Summary Titanocene complexes ([Ti(⁵-C₅H₄ R)₂ X ₂];R = H, SiMe₃;X=Cl, Br) react with Na₂H₂ EDTA in aqueous methanol to give an identical product ([Ti(EDTA)(H₂O)] by cleavage of the halogen and cyclopentadienyl ligands. The structure of [Ti(EDTA)(H₂O)] has been determined by X-ray diffraction; crystal data: monoclinica=13.923(6),b=7.048(3),c=13.252(5) Å, =90.81(1)°, space groupP2₁/c,Z=4. In this complex, Ti has a sevenfold coordination with a hexadentateEDTA ^4– ligand and a water molecule occupying an additional coordination site.

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Reaktion von Titanocen-Dihalogeniden mit Na₂H₂ EDTA. Kristallstruktur von [Ti(EDTA)(H₂O)]

Zusammenfassung Titanocenkomplexe ([Ti(⁵-C₅H₄ R)₂ X ₂];R=H, SiMe₃;X=Cl, Br) reagieren in wäßrigem Methanol mit Na₂H₂ EDTA unter Verdrängung der Halogen- und Cyclopentadienylliganden zum selben Produkt ([Ti(EDTA)(H₂O)]). Die Struktur von ([Ti(EDTA)(H₂O)]) wurde röntgenographisch bestimmt. Kristalldaten: monoklin,a=13.923(6),b=7.048(3),c=13.252(5) Å, =90.81(1)°, RaumgruppeP2₁/c,Z=4. In diesem Komplex ist das Titanatom mit einem sechszähnigenEDTA-Liganden und einem Wassermolekül, das eine zusätzliche Koordinationsstelle besetzt, siebenfach koordiniert.

     

[μ‐1κ2O,O′:2(η5)‐Cyclopentadienylcarboxylato][2(η5)‐diphenylphosphinocyclopentadienyl]bis[1,1(η5)‐tetramethylcyclopentadienyl]iron(II)titanium(III)

Reacting stoichiometric amounts of 1‐(diphenylphosphino)ferrocene­carboxylic acid and [Ti(η⁵‐C₅HMe₄)₂(η²‐Me₃SiC[triple‐bond]CSiMe₃)] produced the title carboxyl­atotitanocene complex, [{μ‐1κ²O,O′:2(η⁵)‐C₅H₄CO₂}{2(η⁵)‐C₅H₄P(C₆H₅)₂}{1(η⁵)‐C₅H(CH₃)₄}₂Fe^IITi^III] or [FeTi(C₉H₁₃)₂(C₆H₄O₂)(C₁₇H₁₄P)]. The angle subtended by the Ti/O/O′ plane, where O and O′ are the donor atoms of the κ²‐carboxy­late group, and the plane of the carboxyl‐substituted ferrocene cyclo­penta­dienyl is 24.93 (6)°.     

Determination of P/Al ratio in phosphorus-doped aluminium oxide thin films by XRF,RBS and FTIR

Phosphorus-doped aluminium oxide thin films were deposited in a flow-type ALE reactor from AlCl₃, H₂O and from either P₂O₅ or trimethyl-phosphate. Structural information of the films was obtained from Fourier transform infrared (FTIR) spectra. Rutherford backscattering spectroscopy (RBS) was used to quantitatively determine the composition of the films. The P/Al intensity ratios calculated from X-ray fluorescence (XRF) results were in a linear relation with the P/Al concentration ratios calculated from RBS results. For comparison, the intensity ratios of the phosphorus peak (P=O) at about 1250 cm^–1 and the aluminium peak (Al-O) at about 950 cm^–1 were determined from the IR absorption spectra. The calibration of FTIR peak intensities was done by plotting the intensity ratios of phosphorus and aluminium peaks against the P/Al concentration ratios measured by RBS. FTIR gave also a linear calibration curve with RBS but the method is less suitable for routine analysis of P/Al ratio than XRF.     

COORDINATION COMPOUNDS OF NICKEL WITH TRITHIOCYANURIC ACID

Abstract

Nickel(II) complexes with a combination of trithiocyanuric acid and diamines or triamines of composition [Ni(aepa)(ttcH)(H₂O)], [Ni(dien)(ttcH)(H₂O)], [Ni(dpta)(ttcH)(H₂O)] H₂O, [Ni(phen)₂(ttcH)]H₂O, [Ni(phen)₃](ttcH)-5H₂O and [Ni(1,2-pn)₃](ttcH)-H₂O (aepa = N-(2-aminoethyl)-1,3-propanediamine,dien = diethylenetriamine,dpta = dipropylenetnamine, phen = 1,10-phenanthroline, 1,2-pn = 1,2-diaminopropane. ttcH₃ = trithiocyanuric acid) have been prepared. The compounds have been characterized by means of elemental analysis, IR and electronic spectroscopies and magnetochemical measurements. Selected complexes were studied by thermal analysis. The compounds can be characterized as distorted octahedral Ni(II) complexes. It was found that the trithiocyanuric dianion can act either as a bidentate ligand or be situated out of the coordination sphere of nickel. The crystal and molecular structure of [Ni(dpta)(ttcH)(H₂O)] H₂O was determined. Crystals are monoclinic, space group P2₁/n, with a = 20.316(4), b = 7.967(2), c = 21.401(4) Å, β = 99.23(3)°, K=3419.1(13)ų, Z = 4, T = 293 K. The nickel(II) atom is six-coordinated by three nitrogen atoms from dipropylene-triamine, nitrogen and sulphur from trithiocyanuric acid, and an oxygen atom from a water molecule in a distorted octahedral geometry.     

Synthesis and characterization of nitrogen-containing Lewis base adducts of bis(O,O′-dialkylmonoselenophosphato)cobalt(II) complexes

The adducts of bis(O,O′-dialkylmonoselenophosphato)cobalt(II) complexes, Co{O(Se)P(OR)₂}₂(L)₄ (where R?=?n-Pr, i-Pr; L?=?C₅H₅N, NC₅H₄Me-2, NC₅H₄Me-3), were synthesized by in situ reactions of CoCl₂?·?6H₂O, Lewis base, and NaO(Se)P(OR)₂. The single crystal structure of Co{O(Se)P(OⁱPr)₂}₂(C₅H₅N)₄ shows distorted octahedral geometry around cobalt(II) and monoselenophosphates are trans. The CoN₄ forms a square plane. These bis(O,O′-dialkylmonoselenophosphato)cobalt(II) adducts were characterized by elemental analyses, spectroscopic techniques (UV-Vis, infrared, ¹H and ³¹P), and magnetic moment measurements.     

Lanthanide Coordination Polymers Constructed from Infinite Rod‐Shaped Secondary Building Units and Flexible Ligands

Three lanthanide coordination polymers constructed from infinite rod‐shaped secondary building units (SBUs), [Nd₂(H₂O)₂(cis‐chdc)₂(trans‐chdc)]?2H₂O ( 1 ), Nd₂(H₂O)₄(trans‐chdc)₃ ( 2 ), and [Sm₂(H₂O)₂(cis‐chdc)(trans‐chdc)₂]?4H₂O ( 3 ) (chdcH₂=1,4‐cyclohexanedicarboxylic acid), were hydrothermally synthesized and structurally characterized. The structures of 1 – 3 are modulated by different ratios of the cis and trans configurations of chdc^2? ligands, which was achieved by temperature control in the hydrothermal reactions. Crystal‐structure analysis revealed that 1 is a four‐connected pcu‐type rod packing network built from cross‐linking of rod‐shaped neodymium–oxygen SBUs by cis‐ and trans‐chdc^2? ligands in a 2:1 ratio, 2 displays a complicated six‐connected hex‐type rod packing structure built by connection of rod‐shaped neodymium–oxygen SBUs and trans‐chdc^2? ligands, and 3 features an unprecedented five‐connected rod packing pattern constructed from rod‐shaped samarium–oxygen SBUs and cis‐ and trans‐chdc^2? ligands in a 1:2 ratio.     

Mechanism of synthesis of anatase TiO2 pigment from low concentration of titanyl sulfuric–chloric acid solution under hydrothermal hydrolysis

In order to investigate the influence of Cl⁻/SO₄²⁻ molar ratios and hydrolysis temperature on the hydrolysis process and TiO₂ pigment, H₂TiO₃ was prepared with a low concentration of titanyl sulfuric–chloric acid solution by hydrothermal hydrolysis. Under the optimal hydrolysis conditions, 1.5–2.2 μm of H₂TiO₃ samples were achieved. After doping and calcination, anatase TiO₂ pigments demonstrated excellent performance: the achromic ability of tinctorial strength (TCS) and blue phase index (SCX) were 1,429 and 4.07, respectively. As hydrolysis was a significant step in the process, the structure was simplified to a periodic structure of Ti[OH](H₂O)₃Cl(SO₄) to simulate the cluster structures. Based on experimental results and density functional theory (DFT) calculation, the hydrolysis mechanism was presumed to be a process of anionic (OH⁻, Cl⁻ and SO₄²⁻) competition reaction to explain the formation of anatase-type H₂TiO₃, and the crystal growth direction of H₂TiO₃ was also confirmed to be a (OA) and b (OB).     

An oxo‐bridged centrosymmetric tetranuclear titanium compound

The title compound, octa‐tert‐butoxybis­[μ₃‐2,2′‐(N‐methyl­imino)­diethanolato]­di‐μ‐oxo‐tetratitanium(IV), [Ti₂O{(OCH₂CH₂)₂(NCH₃)}{(CH₃)₃CO}₄]₂ or [Ti₄(C₅H₁₁NO₂)₂(C₄H₉O)₈O₂], lies about an inversion centre, and displays the less usual zigzag configuration. One O atom of the N‐methyl­diethoxo­amine ligand bridges the symmetry‐related Ti atoms, while the other bridges the two independent Ti atoms, with the N atom binding to give a facial configuration. Four ^tBuO⁻ ligands and a bridging oxide complete the respective five‐ and sixfold coordination of the two Ti atoms. The Ti—O bond lengths range in a self‐consistent fashion from 1.7624 (17) to 2.0878 (18) Å, while the Ti—N bond length is 2.374 (2) Å.     

The influence of the molar ratio [H<Subscript>2</Subscript>O]/[Ti(OR)<Subscript>4</Subscript>] on the kinetics of the titanium-oxo-alkoxy clusters nucleation

The influence of the molar ratio h = [H₂O]/[Ti(OR)₄] (R = Pr ⁱ ) on the kinetics of the titanium-oxo-alkoxy clusters (TOAC) nucleation was studied. Clusters were formed by the titanium tetraisopropoxide Ti(OPr ⁱ )₄ chemical reaction with H₂O in n-propanol solution, with the fixed concentration of Ti(OPr ⁱ )₄ (c = 0.04 M), molar ratio h ∈ {11, 14, 17, 20} and temperature T ∈ {298, 308, 318} K. It was determined that the isothermal rate of clusters nucleation is a power law function of the molar ratio h. The kinetic parameter β value changes complexly as h and T change. The value of apparent activation energy of the nucleation process (E _a) decreases with the increase of value h. It was found that nucleation is a reaction with complex kinetics whose elementary stages are hydrolysis Ti(OR)₄ to Ti(OR)₃OH and formation of titanium-oxo-alkoxy clusters [Ti _{n + β}O_β](OR)_{4n + 2β} through the alcoxolation reaction.