Titanium complexes with imidazolin-2-iminato ligands

The reaction of 1,3-di-tert-butylimidazolin-2-ylidene with trimethylsilyl azide furnishes the corresponding N-silylated 2-iminoimidazoline which reacts with titanium(IV) chlorides to yield imidazolin-2-iminato titanium complexes.     

Titanium silicalite-1 zeolite microparticles for enzymeless H2O2 detection

In this communication, we demonstrate for the first time that titanium silicalite-1 zeolite microparticles (TSZMs) can effectively catalyze the reduction of H(2)O(2), leading to an enzymeless H(2)O(2) sensor with a linear detection range from 100 μM to 40 mM (r = 0.994) and a detection limit of 0.5 μM at a signal-to-noise ratio of 3.     

DBD Plasma Treatment of Titanium in O2, N2 and Air

Dielectric Barrier Discharge plasma treatment of a titanium metal foil in oxygen, nitrogen and air under atmospheric conditions is investigated employing X-Ray Photoelectron Spectroscopy (XPS). We investigated three different reference samples and compare the results with a large number of studies on the XPS analysis of titanium compounds containing oxygen and nitrogen. The plasma treatment in all three different process gases leads to the formation of titanium dioxide films, while rather small nitrogen fractions are found after nitrogen and air plasma treatments. This finding is explained basing on plasma chemistry insight from the literature.     

Titanium(IV) complexes as direct TiO2 photosensitizers

Titanium dioxide photosensitization may be achieved in various ways, involving surface modification with appropriate species. The photosensitization process requires a visible light-induced electron or hole injection into conduction or valence band, respectively. Efficiency of this process depends on electronic interaction between the photosensitizer moiety (surface complex) and TiO₂ particle. At least two types of the charge injection mechanisms may be distinguished—in the first, charge is transferred from the excited state of the sensitizer molecule to the conduction or valence band while the second mechanism involves a direct molecule-to-band charge transfer (MBCT). The MBCT process can be realized by surface titanium(IV) complexes with various organic and sometimes inorganic ligands. Catechol, phthalic acid or salicylic acid derivatives, as well as cyanometallate anions, upon chemisorption at TiO₂ surface constitute an especially interesting group of ligands to yield various titanium(IV) surface complexes. Geometry of these complexes, electronic structures and possibility of their use as photosensitizers of TiO₂ are discussed on the basis of experimental data and quantum-chemical modeling. Also prospective applications of photoinduced electron transfer and photocatalytic activity of such systems are presented.     

用氧化氩氮-乙炔火焰原子吸收光谱法测定高温钛合金中硅

在航天空间卫星发动机研制过程中 ,已成功地选用了一种新型的 7715D高温钛合金材料 ,由于 7715D高温钛合金材料中含有元素成分对其质量十分重要 ,特别该材料中含硅量对空间卫星发动机的研制的性能尤为特出。因而提出一种精度、准确度高 ,灵敏度好又能达到要求的硅含量分析方法 ,已成为当前的迫切需要。近几年 ,对含有较多共同被测离子的 7715D高温钛合金中含硅量的分析 ,还未见报道。本文用氧化氩氮 乙炔火焰原子吸收光谱法测定 7715D高温钛合金中含硅量 ,取得了一定的进展。本法能消除钛合金中硅在低温火焰时出现的化学干扰和物理干扰 ,…     

钛及其合金在牙科方面的应用

简述了牙科材料的特性与要求, 以及钛及其合金作为牙科材料的优点, 综述了钛及其合金在牙科方面的应用研究现状和国内外的动态, 介绍了目前钛制品生产主流的熔模铸造技术的工艺关键及其研究进展,指出包埋材料和涂料的发展对于钛及其合金作为牙科材料研究的重要性.     

Silsesquioxane Chemistry, 4.: Silsesquioxane Complexes of Titanium(III) and Titanium(IV)

Reaction of the incompletely condensed silsesquioxane derivative Cy₇Si₇O₉(OH)₃ (1) with Ti(OEt)₄ affords the dimeric titanasilsesquioxane [(Cy₇Si₇O₁₂)Ti(μ-OEt)(EtOH)]₂ (13) in 81% yield. The known titanasilsesquioxane [Cy₇Si₇O₁₁(OSiMe₃)]₂Ti (18) has been prepared through a modified procedure starting from titanium tetraalkoxides. Novel oxotitanium silsesquioxane derivatives are obtained from reactions of titanocene dihalides with Cy₇Si₇O₉(OH)₂(OSiMe₃) (14). Cp₂TiCl₂ yields dinuclear (μ-O)[{Cy₇Si₇O₁₁(OSiMe₃)}TiCp]₂ (19), while with Cp^*₂TiCl₂ the trinuclear titanacycle Cp^*₂Ti₃O₃[Cy₇Si₇O₁₁(OSiMe₃)]₂ (20) is obtained. In addition, a new synthetic route to model compounds for titanium catalysts immobilized on silica has been developed. Disilylated Cy₇Si₇O₉(OH)(OSiMe₃)₂ (15) cleanly reacts with the ‘tucked-in’ fulvene complex Cp*Ti(C₅Me₄CH₂) to give the titanium(III) silsesquioxane Cp*₂Ti[Cy₇Si₇O₁₀(OSiMe₃)₂] (21). In a similar manner treatment of Cp*Ti(C₅Me₄CH₂) with Cy₇Si₇O₉(OH)₂(OSiMe₃) (14) affords the mono(pentamethylcyclopentadienyl) complex Cp*Ti[Cy₇Si₇O₁₁(OSiMe₃)][Cy₇Si₇O₁₀-(OH)(OSiMe₃)] (22) which is an advanced model compound for a catalytically active titanium center on a silica surface. The molecular structures of these titanium silsesquioxane derivatives have been determined by X-ray diffraction analyses.     

ChemInform Abstract: Synthesis of Titanium Silicon Carbide.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

超声波作用下的钛醇盐水解法制备纳米TiO2

近十几年来, 有关二氧化钛光催化性能的研究已引起人们的浓厚兴趣, 在此方面进行了大量研究. 目前, 纳米二氧化钛的制备方法主要有化学沉淀法、溶胶-凝胶法、气相法和水热法等[1,2]. 超声化学是近年来新兴的一门边缘交叉学科, 已被应用于制备具有特殊结构和性能的纳米材料, 如金属[3]、碳化物[4]、氮化物[5]、氧化物[6]、合金[7]以及生物材料[8]等, 但对于超声作用在纳米粒子晶型转变方面的研究报道较少.     

稀土氧化物在Fe1-xO基氨合成催化剂中的作用规律

 系统考察了稀土氧化物La2O3,Nd2O3,Sm2O3,Dy2O3,Sc2O3和CeO2作为助催化剂对Fe1－xO基催化剂性能的影响．结果表明,稀土氧化物与Fe1－xO作用生成了一种作为隔离体的复合氧化物REFeO3,从而促进了催化剂的还原,这种促进作用随稀土离子半径不同呈规律性变化．添加不同稀土氧化物的Fe1－xO催化剂的还原都存在补偿效应,各系列催化剂还原反应的转效温度与所添加稀土元素的离子半径呈正比关系（CeO2除外）．稀土氧化物可以有效地提高催化剂的低温活性,其添加量的变化对催化剂活性的促进作用规律与对催化剂还原性能的促进作用规律一致．     

Thin and Thick RuO2-TiO2 Coatings on Titanium Substrates by the Sol-Gel Process

Thin and thick 20 mol% RuO₂–80 mol% TiO₂ coatings have been obtained through a combination of different preparation parameters, including catalyst and oxide concentrations, using ruthenium trichloride trihydrate and titanium n-butoxide. Acid catalysed solutions produced uniform, crack-free coatings that were too thin for use on electrocatalysis electrodes. On the other hand, base catalysed solutions produced thicker, cracked coatings. Electrodes prepared with base catalysed solutions performed well in electrocatalysis lifetime testing for corrosion stability.     

Titanium (IV) complexes based on substituted 2-[(2-hydroxyethyl)]aminophenols

Novel substituted 2-[(2-hydroxyethyl)]aminophenols, MeN(CHR¹CR²R³OH)(C₆H₄-o-OH) (2-5), were synthesized by the reaction of 2-methylaminophenol with corresponding oxiranes. Titano-spiro-bis(ocanes) [MeN(CHR¹CR²R³O)(C₆H₄-o-O)]₂Ti 6-9 (2, 6, R¹ = H, R² = R³ = Me; 3, 7, R¹ = R² = Ph (treo-), R³ = H; 4, 8, R¹ = Ph, R² = R³ = H; 5, 9, R¹ = R² = H, R³ = Ph) based on [ONO]-ligands have been synthesized. The obtained compounds were characterized by ¹H and ¹³C NMR spectroscopy and elemental analysis data. The complex [Ti(μ²-O){O-o-C₆H₄}{μ²-CMe₂CH₂}NMe]₆ (10) was obtained by controlled hydrolysis of 6. Molecular structure of 10 was determined by X-ray structure analysis.     

戊二酸钛（Ⅲ）与氮化钛的制备

戊二酸钛（Ⅲ）与氮化钛的制备陈吉书，吕真国，徐其亨（曲靖师专化学系曲靖）（曲靖地区环境监测站曲靖）（云南大学化学系昆明６５００９１）关键词戊二酸钛，氮化钛，热分解氮化钛具有硬度大、熔点高、耐磨、耐腐蚀、导电性好、美观（金黄色）等优点，具有重要的工业用...     

Titanium(IV) imido complexes of imine imidazol-2-imine ligands

Free imine imidazol-2-imine ligands with two different substitution patterns have been isolated for the first time and they were found to exist as an equilibrium mixture of geometric and mesomeric isomers. The relative ratios of these isomers are dependent on both the nature of the substituents and of the solvent. The synthesis of the titanium(IV) alkyl and arylimido complexes of these ligands was unexpectedly found to be very selective and was successfully achieved only with the lesser sterically-demanding 2,4,6-trimethylphenyl derivative IMesN^Imine 2a. The solid-state structure of the alkylimido complex further confirms the zwitterionic character of the ligand. The isolated titanium imido complexes were found to be active catalysts for the polymerisation of ethylene.