Nipagin-Functionalized Porphyrazine and Phthalocyanine—Synthesis,Physicochemical Characterization and Toxicity Study after Deposition on Titanium Dioxide Nanoparticles P25

Aza-porphyrinoids exhibit distinct spectral properties in UV-Vis, and they are studied in applications such as photosensitizers in medicine and catalysts in technology. The use of appropriate peripheral substituents allows the modulation of their physicochemical properties. Phthalocyanine and sulfanyl porphyrazine octa-substituted with 4-(butoxycarbonyl)phenyloxy moieties were synthesized and characterized using UV-Vis and NMR spectroscopy, as well as mass spectrometry. A comparison of porphyrazine with phthalocyanine aza-porphyrinoids revealed that phthalocyanine macrocycle exhibits higher singlet oxygen generation quantum yields, reaching the value of 0.29 in DMF. After both macrocycles had been deposited on titanium dioxide nanoparticles P25, the cytotoxicities and photocytotoxicities of the prepared materials were studied using a Microtox^® acute toxicity test. The highest cytotoxicity occurred after irradiation with a red light for the material composed of phthalocyanine deposited on titania nanoparticles.     

Synthesis of 2-Indolyl-1-nitroalkane Derivatives Using Nanocrystalline Titanium(IV) Oxide

The catalytic Friedel–Crafts alkylation of indoles with nitroalkenes to furnish 2-indolyl-1-nitroalkane derivatives at room temperature with moderate to excellent yields is reported using nanocrystalline titanium(IV) oxide (nano-TiO₂) catalyst. In all cases, a single regioisomer was obtained. After completion of the reaction, the catalyst was recovered by centrifugation and activated under a nitrogen flow for 1 h at 250°C for further reuse. The nano-TiO₂ can be reused for four cycles with a slight decrease of activity under the same reaction conditions.     

Remediation of Wastewater with Ultraviolet Irradiation Using a Novel Titanium (IV) Oxide Photocatalyst

Photocatalysis has become common and nanomaterials having photocatalytic functions have been widely characterized. At present, among the many candidates for photocatalysis, TiO₂ is almost the only material suitable for industrial use. In this paper, we present a TiO₂ synthesis starting from Ti sheets put in contact with a mixture of 0.1 N NaOH and acetone for 72?hours under ambient conditions. The obtained sheets were washed with distilled water and ethanol, and the surface was analyzed for its structural and morphological properties. Thus, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) investigations indicated the formation of TiO₂ on the edges of nanometer circles on the surface of the Ti sheets. For characterizing the photocatalytic capacity for wastewater treatment, Ti sheets with TiO₂ on the surface contacted with methylene blue solutions at room temperature under ultraviolet light. The degradation of the methylene blue concentration was measured by ultraviolet–visible spectroscopy, demonstrating 99.94% efficiency for wastewater treatment using the obtained material.     

可移动金核的二氧化钛空心球合成及光催化性质

Uniform hollow Au@TiO₂ core shell spheres with moveable Au nanoparticles were synthesized based on templating against Au@carbon spheres. The diameter of the shell of the Au@TiO₂ spheres could be controlled by adjusting the Ti(OC₄H₉)₄ hydrolyzing reaction time or the ratio of Ti(OC₄H₉)₄ to Au@carbon spheres, and the shell thickness of the core-shell spheres can be varied from 25 nm to 40 nm. As prepared hollow Au@TiO₂ core-shell spheres display enhanced photocatalytic activity in the initial stage of photocatalytic degradation of methylene blue compared with pure hollow TiO₂ spheres and the commercial photocatalyst TiO₂(P-25).     

Electrochemical Determination of Hydrogen Peroxide and Glucose by Titanium(IV) Oxide Nanotube Arrays

Titanium(IV) oxide nanotube arrays (TiO₂) prepared by electrochemical oxidation were used as a sensor for the catalytic reduction of hydrogen peroxide. The effects of pH, applied voltage, interferences, and linear dynamic range were characterized. The electrode showed rapid response and a linear dynamic range from 5.0 micromolar to 12.0 millimolar in phosphate buffer at pH 6.5 at a working voltage of ?0.8 volt. The maximum sensitivity was 474 milliamperes per molar per square centimeter with good reproducibility and reusability. The electrode was also employed for the electrochemical determination of glucose without a mediator by the immobilization of glucose oxidase on the electroactive surface. The resulting biosensor exhibited good activity and rapid response toward glucose and allowed the determination of glucose from 20 micromolar to 1 millimolar and 1–10 millimolar.     

Atomic Layer Deposition of Hafnium(IV) Oxide on Graphene Oxide: Probing Interfacial Chemistry and Nucleation by using X‐ray Absorption and Photoelectron Spectroscopies

Interfacing graphene with metal oxides is of considerable technological importance for modulating carrier density through electrostatic gating as well as for the design of earth‐abundant electrocatalysts. Herein, we probe the early stages of the atomic layer deposition (ALD) of HfO₂ on graphene oxide using a combination of C and O K‐edge near‐edge X‐ray absorption fine structure spectroscopies and X‐ray photoelectron spectroscopy. Dosing with water is observed to promote defunctionalization of graphene oxide as a result of the reaction between water and hydroxyl/epoxide species, which yields carbonyl groups that further react with migratory epoxide species to release CO₂. The carboxylates formed by the reaction of carbonyl and epoxide species facilitate binding of Hf precursors to graphene oxide surfaces. The ALD process is accompanied by recovery of the π‐conjugated framework of graphene. The delineation of binding modes provides a means to rationally assemble 2D heterostructures.     

Synthesis,Structural and Physicochemical Characterization of a Titanium(IV) Compound with the Hydroxamate Ligand N,2-Dihydroxybenzamide

The siderophore organic ligand N,2-dihydroxybenzamide (H₂dihybe) incorporates the hydroxamate group, in addition to the phenoxy group in the ortho-position and reveals a very rich coordination chemistry with potential applications in medicine, materials, and physical sciences. The reaction of H₂dihybe with TiCl₄ in methyl alcohol and KOH yielded the tetranuclear titanium oxo-cluster (TOC) [Ti^IV₄(μ-O)₂(HOCH₃)₄(μ-Hdihybe)₄(Hdihybe)₄]Cl₄∙10H₂O∙12CH₃OH (1). The titanium compound was characterized by single-crystal X-ray structure analysis, ESI-MS, ¹³C, and ¹H NMR spectroscopy, solid-state and solution UV–Vis, IR vibrational, and luminescence spectroscopies and molecular orbital calculations. The inorganic core Ti₄(μ-O)₂ of 1 constitutes a rare structural motif for discrete Ti^IV₄ oxo-clusters. High-resolution ESI-MS studies of 1 in methyl alcohol revealed the presence of isotopic distribution patterns which can be attributed to the tetranuclear clusters containing the inorganic core {Ti₄(μ-O)₂}. Solid-state IR spectroscopy of 1 showed the presence of an intense band at ~800 cm⁻¹ which is absent in the spectrum of the H₂dihybe and was attributed to the high-energy ν(Ti₂–μ-O) stretching mode. The ν(C=O) in 1 is red-shifted by ~10 cm⁻¹, while the ν(N-O) is blue-shifted by ~20 cm⁻¹ in comparison to H₂dihybe. Density Functional Theory (DFT) calculations reveal that in the experimental and theoretically predicted IR absorbance spectra of the ligand and Ti-complex, the main bands observed in the experimental spectra are also present in the calculated spectra supporting the proposed structural model. ¹H and ¹³C NMR solution (CD₃OD) studies of 1 reveal that it retains its integrity in CD₃OD. The observed NMR changes upon addition of base to a CD₃OD solution of 1, are due to an acid–base equilibrium and not a change in the Ti^IV coordination environment while the decrease in the complex’s lability is due to the improved electron-donating properties which arise from the ligand deprotonation. Luminescence spectroscopic studies of 1 in solution reveal a dual narrow luminescence at different excitation wavelengths. The TOC 1 exhibits a band-gap of 1.98 eV which renders it a promising candidate for photocatalytic investigations.     

Electrochemical Evaluation of Titanium (IV) Oxide/Polyacrylonitrile Electrospun Discharged Battery Coals as Supercapacitor Electrodes

The TiO₂ nanoparticles are electrospun with polyacrylonitrile (PAN) polymer solution onto the discharged battery coal (DBC) electrode and the results are evaluated as a supercapacitor. The morphology and chemical composition of the synthesized TiO₂ nanoparticles and PAN+TiO₂ nanocomposite fibers were characterized by Scanning electron microscopy, thermogravimetry and FTIR analysis. Supercapacitor measurements and electrochemical characterizations of the electrodes examined by cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical measurements showed that the best current value was obtained from PAN and TiO₂ coated DBC. The performances of both PAN and PAN+TiO₂ coated DBC electrodes were investigated as supercapacitors. PAN+TiO₂/DBC showed the best specific capacitance value of 156.00 F g⁻¹ and PAN/DBC showed 74.93 F g⁻¹. In addition, PAN+TiO₂/DBC exhibited reliable stability performance over 2000.00 cycles.     

Titanium (IV) chloride complexes with salen ligands supported on magnesium carrier: Synthesis and use in ethylene polymerization

The magnesium support with the formula MgCl₂(THF)_0.32(Et₂AlCl)_0.36 was used for immobilization of salen complexes of titanium [Ti(salen)Cl₂, Ti(salen(OMe)₂)Cl₂]. The effects of the catalyst composition (i.e. type of titanium complex and type of activator), polymerization temperature, polymerization time, and the effect of comonomer (1‐octene) on the activity of the obtained supported catalysts, on the polymer characteristics (molecular weight, molecular weight distribution, melting point), and on the polymer morphology were studied. The findings were compared to those obtained for corresponding unsupported systems. Catalysts immobilization results in considerable changes in catalysts activity and in properties of resultant polymers. The studied supported catalysts are highly active in ethylene polymerization, their activity increases with increasing temperature and lasts at least 2 hours. Their copolymerizing ability towards 1‐octene is rather low. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6693–6703, 2009     

Photocatalytic Properties of Materials Based on Titanium(IV) Oxide and Silver Nanoparticles

Russian Journal of Applied Chemistry - The effect of the phase composition, the presence of silver nanoparticles, and the pH of the medium on the catalytic activity of heterophasic materials based...     

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.     

Boron（Ⅲ） Tribromide or Tianium （Ⅳ） Bromide and Lewis Base Promoted Baylis—Hillman Reaction

It was found that,when the Baylis-Hillman reaction of arylaldehydes with methyl vinyl ketone was carried out at below -20℃ in the presence of boron (Ⅲ） tribromide or titanium (Ⅳ） bromide using a catalytic amount of Lewis base such as amine,the brominated compounds and the Baylis-Hillman adducts could be obtained as the major products in good yields for various aryl aldehydes.But at room temperature,the elimination products were the major products.In addition,the palladium catalyzed allylic substitution reactions of the elimination products were also examined.     

水相法合成双(环戊二烯基)钛氨基酸配合物的研究

以N-(取代苯基)氨基乙酸及盐与双(环戊二烯基)二氯化钛在水相及有机相反应,得到了五个双(环戊二烯基)钛氨基酸配合物,对配合物进行了熔点、元素分析、IR及^1HNMR的表征,确定了它们的结构。这些配合物在空气中稳定。经比较,水相中的合成反应速度快,操作简便,产物较易分离,产率高。     

Boron(III) Tribromide or Titanium(IV) Bromide and Lewis Base Promoted Baylis-Hillman Reaction

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钛(Ⅳ)离子掺杂的氧化锌多壁纳米纤维结构材料的制备及光催化性能

借助棉花纤维模板、利用两步法制备了Ti⁴⁺/ZnO多壁纳米纤维结构材料,利用热重分析(TG)、X射线衍射(XRD)和扫描电子显微镜(SEM)等技术手段对其进行了表征;以亚甲基蓝(MB)的降解脱色为模型反应,考察了Ti⁴⁺掺杂量对ZnO多壁纳米纤维结构材料光催化性能的影响。 结果表明,利用模板辅助的两步法成功制备了Ti⁴⁺掺杂的ZnO多壁纳米纤维结构材料(Ti⁴⁺/ZnO);Ti⁴⁺的掺入影响ZnO材料的纳米结构,从而使Ti⁴⁺/ZnO的光催化性能明显高于ZnO;Ti⁴⁺/ZnO多壁纳米纤维结构材料良好的光催化性能可主要归于Ti⁴⁺/ZnO材料中活性中心-O^2--Ti⁴⁺-O^2--Zn²⁺-的形成和光生电荷e^--h⁺沿着颗粒间的有效传递。     

Bioanalysis by Immobilization of Antibodies on Hafnium(IV) Oxide with 3-Aminopropyltriethoxysilane

Self-assembled monolayers of 3-aminopropyltriethoxysilane (APTES) are commonly used to promote adhesion between substrates and organic or metallic materials with applications ranging from advanced composites to biomolecular lab-on-a-chip devices. In this work, the silanization on hafnium oxide (HfO₂) films is reported. The layers of HfO₂ were deposited on Si (001) substrates by atomic layer deposition. The grown HfO₂ films were modified in accordance with three main steps: oxidation, silanization, and cross-linking of the APTES monolayer using glutaraldehyde as cross-linking agent. Microscopic features were characterized by atomic force microscopy. Further, both bovine serum albumin and antibovine serum albumin agents were deposited on the samples to test their potential use as the immunosensor.     

电化学方法研究I3^—和Ti^3＋在铂上的异相催化

用电化学方法研究了Ｉ－３和Ｔｉ３＋在还原铂表面上的电极反应，由此计算出Ｉ－３与Ｔｉ３＋在还原铂表面上的混合催化反应速率（νｍｉｘ）．当混合催化电位（Ｅｍｉｘ）位于极限电流区时，νｍｉｘ对［Ｔｉ３＋］为零级反应，对［Ｉ－３］为一级反应，且正比于电极旋转速率的平方根，Ｈ＋浓度影响不大．由动力学方法研究的结果证实了电化学研究结果的正确性，致使可用电化学方法解释溶液中的异相催化问题     

Synthesis, characterization and analytical application of a new inorganic cation exchanger—Titanium(IV) molybdophosphate

A novel polyoxometalate-cation exchanger, titanium(IV) molybdophosphate (TMP) has been synthesized under varying conditions. The material was characterized by X-ray diffraction, infrared spectroscopy, inductively coupled plasma and thermogravimetry techniques. Its stability was investigated in water, dilute acids, alkaline solutions, and high temperature up to 750 °C. Ion-exchange capacity and distribution coefficients (K_d) for twenty-nine radionuclides and metal ions have been determined. It was found that the TMP has high affinity for Cs⁺, Sr²⁺, UO₂²⁺, Ba²⁺, Pb²⁺, Tl⁺, Zn²⁺, Rb²⁺ and Zr⁴⁺ ions. The results of binary separation of metal ions showed that TMP can be potentially useful for analytical applications.     

二丁基锡(IV)磺酸酯催化合成缩醛(酮)

用二丁基氧化锡与苯磺酸、甲磺酸反应制备了两种新的有机锡化合物——二丁基锡(IV)磺酸酯. 以二丁基锡(IV)磺酸酯作催化剂, 合成了一系列缩醛(酮), 并通过正交实验, 优化了有机锡催化缩醛(酮)合成反应的反应条件. 实验表明该催化反应产率高, 反应时间短, 催化剂用量少且能回收再利用.